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ANN ARBOR, Ml 48106 18 BEDFORD ROW. LONDON WC1R 4EJ, ENGLAND 8101168 Sn ider , R enate M a ch an THE BIOECOLOGY OF POLYDESMUS INCONSTANS LATZEL (DIPLOPODA) IN MICHIGAN Michigan State University University Microfilms International Ph.D . 300 N. Zeeb Road, Ann Arbor, MI 48106 1980 PLEASE NOTE: In all cases th is material has been filmed 1n the best possible way from the available copy. Problems encountered with th is document have been Identified here with a check mark . \ / \ / 1. Glossy photographs 2. Colored illu s tr a tio n s 3. Photographs with dark background ________ ‘4. Illu s tra tio n s are poor copy _ _ _ _ _ 5. ° r in t shows through as there is tex t on both sides of page _ _ _ _ _ 6. In d is tin c t, broken or small p rin t on several p ages_________ throughout 7. Tightly bound copy with p rin t lo s t in spine ________ 8. Computer printout pages with in d is tin c t p rin t _ _ _ _ _ 9. 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ANN A R 3 0 S Ml .18106 '3131 761*4700 THE BIOECOLCGY OF POLYDESMUS IHCONSTANS LATZEL (DIPLOPODA) IN MICHIGAN by R enate Machan S n id e r A THESIS S u b m itte d to M ich igan S t a t e U n i v e r s i t y i n p a r t i a l f u l f i l l m e n t o f th e r e q u i r e m e n t s f o r th e degree of DOCTOR OF PHILOSOPHY D epartm ent o f Zoology 1980 ABSTRACT THE BIOECOLOGY OF POLYDESMUS INCONSTANS LATZEL (DIPLOPODA) IN MICHIGAN By R enate Machan S n id e r The p r e s e n t s t u d y was d e s ig n e d to c o m p re h e n s iv e ly a s s e s s m a jo r l i f e h i s t o r y p a r a m e t e r s o f Polydesm us i n c o n s t a n s L a t z e l 1884, a p o ly d e sm id m i l l i p e d e common t h r o u g h o u t Europe and most o f N o rth America* L a b o r a to r y work f o c u s e d on e f f e c t s o f te m p e r a t u r e on m o r t a l i t y , i n s t a r d u r a t i o n and r e p r o d u c t i o n * Companion s t u d i e s , c o n d u c te d i n two d i f f e r e n t s i t e s n e a r M ich ig an S t a t e U n i v e r s i t y , c l a r i f i e d s e a s o n a l d e v e lo p m e n t and b e h a v i o r o f _P. i n c o n s t a n s p o p u la tio n s in th e f i e l d . R ep ro d u cin g l a b o r a t o r y c u l t u r e s p r o v id e d l i v e m a t e r i a l f o r e x p e r i m e n t s a t f o u r c o n s t a n t t e m p e r a t u r e s : 1 0 ° , 1 5 * 5 ° , 21® a n d 26*6°C. I n s t a r d u r a tio n s d ec re a se d w ith in c r e a s in g te m p e ra tu re . D u r a t i o n s d id n o t d i f f e r b etw en s e x e s from s t a g e 1 th r o u g h VI; b u t g r a d u a t i o n from V II t o a d u l t was more r a p i d i n m a les th a n i n f e m a l e s . M o r t a l i t y was l o w e s t a t 1 5 . 5 ° a n d 2 1 8C, s l i g h t l y h i g h e r a t 10°C, and d r a s t i c (up t o 100%) a t 2 6 . 6°C. D u r a tio n o f th e egg s t a g e was a l s o i n f l u e n c e d by t e m p e r a t u r e , 21°C a l l o w i n g t h e most r a p i d d e v e l o p m e n t ; eggs c o u ld n o t s u r v i v e 2 6 .6 °C . As soon as th e y r e a c h e d m a t u r i t y , p a i r e d a d u l t s r e p r o d u c e d re a d ily . I n t e r v a l s betw ee n o v i p o s i t l o n s w ere s h o r t e s t a t 2 1 °C ( a b o u t one week) an d i n c r e a s e d a t lo w e r t e m p e r a t u r e s . a t 21°C. F e c u n d i t y was h i g h e s t At b o th 1 5 .5 ° and 21°C t h e h i g h e s t numbers o f eggs w ere l a i d d u r i n g th e f i r s t e i g h t o v i p o s i t i o n s , th e n s t e a d i l y d e c l i n e d . o f 22 o v i p o s i t i o n s were r e c o r d e d . D uring a l i f e ti m e , a mean A maximum o f a b o u t 500 e g g s were p ro d u c e d p e r f e m a le , w ith a maximum o f 1100. Comparison b etw ee n f i e l d - c o l l e c t e d and l a b o r a t o r y - r e a r e d a d u l t s showed t h a t l a b o r a t o r y - r e a r e d fe m a le s a c c u r a t e l y p o r t r a y e d t h e r e p r o ­ d u c tiv e p o t e n t i a l of th e s p e c ie s . Fem ales o f b o th t y p e s , when p a i r e d w i t h m a l e s , showed c u r t a i l e d l o n g e v i t y . F em ales i s o l a t e d a f t e r s u c c e s s f u l m a tin g l i v e d l o n g e r and o v i p o s i t e d more o f t e n th a n p a i r e d in d iv id u a ls. Egg v i a b i l i t y o f i s o l a t e s , a t f i r s t a s h i g h a s t h a t o f p a i r e d f e m a l e s , d e c r e a s e d s t e a d i l y w ith s u c c e s s i v e o v i p o s i t i o n s . Sperm s t o r a g e c a p a c i t y of t h e s p e c i e s was e f f e c t i v e d u r in g t h e p e r i o d of maximum egg p r o d u c t i o n ( o v i p o s i t i o n s 1 th r o u g h 9 ) . F i e l d d a t a were o b t a i n e d from a home g a r d e n i n 1976 a n d 1978, and from a d e c id u o u s w o o d lo t i n 1979. £ . i n c o n s t a n s b ehaved s i m i l a r l y i n a l l t h r e e y e a r s : o v i p o s i t i o n to o k p l a c e from May t h r o u g h A u g u s t; young h a t c h e d fro m Jun e t h r o u g h A u g u st, and g r a d u a t e d t o i n s t a r s V I, V II a n d V I I I d u r i n g summer and f a l l g r o w th . encom passed one y e a r . The l i f e c y c l e i n t h e f i e l d A d u lts m a tu r in g i n l a t e f a l l and i n t h e f o l l o w i n g s p r i n g r e p r o d u c e d from May t o A u g u s t, t h e n d i e d . S e m e lp a rity was i n d i c a t e d n o t o n ly i n t h e f i e l d , b u t was s u p p o r t e d by r e p r o d u c t i v e p a t t e r n s observed in la b o r a to r y c u l t u r e . S p a t i a l d i s t r i b u t i o n and d e n s i t y w ere s t u d i e d i n a w o o d lo t p o p u la tio n . L o w -ly in g d e p r e s s i o n s , w ith t h i c k l i t t e r l a y e r s and f a v o r a b l e t e m p e r a t u r e and m o istu re c o n d itio n s , harb o red d e n s e s t p o p u l a t i o n s (100 t o 200/m on most d a t e s ) . In u p p e r s l o p e a r e a s , d e n s it ie s in l i t t e r never e x c e e d e d 38/m . n o t be e x t r a p o l a t e d t o l a r g e u n i t s D e n s i t i e s i n s o i l c o u ld b e c a u s e o f t h e l a r g e number o f n i l - c a p t u r e s , b u t were l i k e l y t o be lo w er th a n th o s e i n l i t t e r . M ating b e h a v i o r , c o n s t r u c t i o n o f egg and m o l tin g c h a m b e r s , and a g g r e g a t i o n s w ere docum ented i n l a b o r a t o r y and f i e l d . o b s e r v a t i o n s on Q u a lita tiv e i n c o n s t a n s a s p re y f o r b e e t l e s , c e n t i p e d e s and m i l l i p e d e s showed t h a t p r e d a t i o n and oophagy c o u l d be a s i g n i f i c a n t f a c t o r i n l i m i t i n g _P. i n c o n s t a n s p o p u l a t i o n s . In memory o f my f a t h e r ACKNOWLEDGEMENTS I w ish t o th a n k t h e members o f my g u id a n c e c o m m itte e : Dr. R alph Pax and Dr. Max H e n s le y , D epartm ent o f Z o olo gy , and Dr. James T i e d j e , D epartm ent o f Crop and S o i l S c ie n c e s f o r t h e i r a s s i s t a n c e i n t h e c o u r s e of th is stu d y . To my m a jo r p r o f e s s o r , Dr. T. Wayne P o r t e r , 1 express s in c e re a p p r e c ia ti o n f o r h is i n s p i r i n g en th u siasm in a l l m a tte rs of i n v e r t e b r a t e b i o l o g y , and f o r h i s h e lp d u r in g t h e p r e p a r a t i o n o f t h i s d isse rta tio n . Very s p e c i a l th a n k s a r e due my h u sb an d , R i c h a r d , f o r h i s p a t i e n c e th r o u g h o u t t h e s e y e a r s o f s t u d y , and f o r h i s en co u ra g em en t and v a l u a b l e c o n stru c tiv e c ritic is m . iii TABLE OF CONTENTS Page L i s t o f T a b le s ....................................................................................... L i s t of F ig u re s ..................................... Ix POLYDESHUS INCONSTANS LATZEL1384 PART I BIOLOGY OF POLYDESMUS INCONSTANS AT CONSTANT TEMPERATURE 1. INTRODUCTION 2. MATERIALS AND METHODS 3. RESULTS 1 A. B. C. D. 4. 3 12 ............................................................................................................ 14 .................................... 14 Mating ................................ N e s tin g ....................................... M o ltin g .................................................................................... P r e d a t i o n and oophagy .......................................... 14 17 23 25 ......................................................... 34 Methods .................... Embryonic d e v e lo p m e n t and h a t c h i n g ....................... P o s t- e m b r y o n i c d ev elo p m en t .................. Sex r a t i o I n c u l t u r e ................................................ 34 35 39 46 3. 3. S u r v i v a l A. B. C. 3 ........................................................................... 3 . 2 . Growth and d ev elo p m en t A. B. C. D. ........... .......................................................... 3 . 1 . G e n e ra l B i o l o g i c a l o b s e r v a t i o n s 3 .4 . vl ............ *........................................................................ 47 Methods ............................................................ S u r v i v a l o f im m atures .............................................. S u rv iv al of a d u lts ................................................. 47 48 49 O v i p o s i t i o n and f e c u n d i t y ...... ....................... 53 A. B. C. D. E. 53 58 64 65 Methods ................. F e c u n d i t y ........................ • .............................. Egg v i a b i l i t y ............................................. R e p r o d u c t iv e p e r i o d and l o n g e v i t y ......................... Comparison betw ee n f i e l d - c o l l e c t e d and l a b o r a t o r y - r e a r e d f e m a le s .................................. DISCUSSION .................................................................................................... iv 66 72 PART I I LIFE HISTORY OF PQLYDESMUS INCONSTANS IN THE FIELD 1. INTRODUCTION 2. MATERIALS AND METHODS 2.1 . ............................................................................................. Garden s i c e A. 3. 82 ............................................................... . ................ 82 S ice d e s c r i p t i o n Sampling methods ................ • ........................................... ............. 82 83 ....................................................................... 84 S ite d e s c r i p t i o n ............................... Sampling methods ......... * ................................................. P h y s ic a l p a ra m e te rs .................... 84 87 83 ........................................................................................................ 90 A. 3. C. RESULTS 3*1. H a b ita t c h a r a c t e r i s t i c s A. 3. C. ....................................................... A. 3. C. R eproduction .................... Molting and a g g r e g a t i o n P a r a s i t i s m in th e f i e l d . 3 .3 Seasonal s t a g e d i s t r i b u t i o n 3 .4 . .............................................. 103 103 .............................................. 104 ........... 106 ............................... 109 Garden p o p u la tio n .......................................... 109 Woodlot p o p u l a t i o n ................................ *...................... 112 119 M a rk -re c a p tu re program ............ Sex r a t i o s i n f i e l d p o p u la tio n s ....................................... 121 3 .3 A g gregation , d i s t r i b u t i o n and d e n s i t y A. B. 90 Temperature ............................. 90 L i t t e r c o v e r ....................................................................... 96 M oisture .................................... 100 3*2 General b io lo g y i n th e f i e l d A. 3. C. 78 ......................................................................... 2. 2 Woodlot s i t e 3. 78 ......................... 123 A ggregation i n sam ples ................................................ 125 D i s t r i b u t i o n and d e n s i t y ................................ 125 4. CONCLUSION 5. SUMMARY ........................................................................................................ 132 3I3L10GRAPHY .................................................................................................. 129 ...................................................................................................... 137 v LIST OF TABLES Table 1. Page Summary o f a v a i l a b l e i n f o r m a t i o n on th e r e p r o d u c t i v e p o t e n t i a l o f p o ly d e s m o id s .............................................................................. 10 Mean d u r a t i o n o f m o l ts o f P. i n c o n s t a n s a t two te m p e ra ­ tu re s . Time r e f e r s to d ays e l a p s e d betw een c o m p l e t i o n o f a m o l tin g chamber and em ergence o f t h e n e x t i n s t a r 24 Summary o f a c c e p t a n c e o f v a r i o u s p r e y by l a r v a l and ad u lt p re d a to rs . .............. 26 Mean number (+ S .D . ) o f f i r s t i n s t a r _P. i n c o n s t a n s co n ­ sumed by a d u l t T i d a b i u s t l v l u s ( C h ilo p o d a ) i n e a c h o f t h r e e c o n s e c u t i v e 2 4 -h o u r p e r i o d s ................................................. 31 T i d a b i u s t i v i u s g iv e n a c h o i c e o f p r e y s p e c i e s : number o f p r e y e a t e n i n e a c h o f t h r e e c o n s e c u t i v e 2 4 -h o u r p e r i o d s (means + S. D. ) ....................................... 32 Number of days betw een d e p o s i t i o n o f eggs and r u p t u r i n g o f t h e c h o r i o n . . . . .................... 38 Mean t o t a l d u r a t i o n o f em b ryon ic d e v e lo p m e n t, from egg d e p o s i t i o n t o t h e tim e when t h e m a j o r i t y o f e a c h b a t c h have h a tc h e d .................................................................................. 38 8. Mean d u r a t i o n , 45 9. Mean t o t a l d u r a t i o n , i n d a y s , o f th e p o s t- e m b r y o n i c d e v e ­ lo p m en t o f i n c o n s t a n s r e a r e d i n i s o l a t i o n from h a t c h i n g to a d u l t h o o d . ........... 46 10. P e r c e n t f e m a le s i n l a b o r a t o r y - r e a r e d c l o n e s ..................................... 47 11. S u r v i v a l o f im m atures a t f o u r t e m p e r a t u r e s , c a l c u l a t e d from t h e number o f a g iv e n s t a g e t h a t s u c c e s s f u l l y m o lte d to th e s u b s e q u e n t s t a g e ................................................................................................... 51 2. 3. 4. 5. 6. 7. i n d a y s , o f th e s t a d i a a t f o u r t e m p e r a t u r e s . vi Table 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. Page T o t a l number o f o v i p o s i t i o n s and t o t a l number of eggs l a i d p e r fe m a le ( p a i r e d , l a b o r a t o r y - r e a r e d ) ...................................... 58 I n t e r v a l s , i n d a y s , b etw ee n s u c c e s s i v e o v i p o s i t i o n s ( p a i r e d , l a b o r a t o r y - r e a r e d f e m a l e s ) ........................................ 63 A verage p e r c e n t v i a b i l i t y o f egg s l a i d by p a i r e d , l a b o r a t o r y - r e a r e d f e m a l e s ................................................................................. 65 Mean number o f days from f i r s t t o l a s t o v i p o s i t i o n , and a v e r a g e l o n g e v i t y o f f e m a le s ( p a i r e d , l a b o r a t o r y r e a r e d ) ................... 66 R e p r o d u c t iv e a c t i v i t y o f fe m a le s a t 21°C ( r a n g e s i n p a r e n t h e s e s ; L ** l a b o r a t o r y s t o c k , F * f i e l d - c o l l e c t e d ) 69 B o n f e r r o n i t - t e s t o f t h e mean t o t a l number of o v i p o s i ­ t i o n s , number o f e g g s , and d u r a t i o n o f r e p r o d u c t i v e p e r i o d a t 2 1 ° C (L - l a b o r a t o r y - r e a r e d , F - f i e l d - c o l l e c t e d ) ................. 69 A verage l o n g e v i t y o f fe m a le s a t 21°C: (L ■ l a b o r a t o r y r e a r e d , F « f i e l d - c o l l e c t e d ) . . . . . . . . . . . . . . . . .................................... 70 L o n g e v ity o f f e m a le s a t 21°C: S c h e f f e ' s c o n f i d e n c e i n t e r ­ v a l s on th e d i f f e r e n c e betw een s e l e c t e d means (L ■ l a b o r a t o r y - r e a r e d , F » f i e l d - c o l l e c t e d ) ................................................ 70 V i a b i l i t y o f eggs l a i d by fe m a le s a t 21°C. P e r c e n t v i a b i l i t y i s t h e mean v i a b i l i t y p e r fe m a le ( L ■ l a b o r a t o r y - r e a r e d , F “ f i e l d - c o l l e c t e d ) ..................... 72 The s p e c i e s c o m p o s i t i o n ( im p o r ta n c e v a l u e s ) o f th e t r e e s i n B aker w o o d l o t ................................................................................................ 86 22. S o i l c h a r a c t e r i s t i c s o f th e Baker w o o d lo t s a m p lin g s i t e s . . . . 23. T h i c k n e s s , i n cm, o f l i t t e r and crumb l a y e r s , and number o f s u p e rim p o s e d l e a v e s , i n Baker w o o d lo t: means o f a t l e a s t f i v e m easurem ents p e r d a t e and l o c a t i o n , + S .D ............................... 24. 25. P a r a s i t i s m o f JP. i n c o n s t a n s by e c t o p a r a s i t i c m i t e d e u t o nymphs i n t h e w o o d lo t..................................... T o t a l numbers o f i n c o n s t a n s e x t r a c t e d from g a r d e n s o i l sam p les i n 1976 .......................................... 86 99 108 112 26. T o t a l numbers o f P. i n c o n s t a n s c a p t u r e d from c r y p to z o a n b o a r d s i n t h e g a r d e n s i t e , 1978................................................................... 113 27. T o t a l numbers o f P. i n c o n s t a n s o b t a i n e d from Baker w o o d lo t, a l l s a m p lin g m ethods co m b in ed .............................. vii 113 Table 28. 29. 30. 31. Page F req u en cy o f o c c u r r e n c e o f r e c e n t m o l t s , i n p e r c e n t o f t h e t o t a l number e x am in ed ................................................................................ R e s u l t s o f m a r k - r e c a p t u r e p rogram f o r a d u l t in c o n sta n s i n t h e g a r d e n s i t e ...................................................................................... R e s u l t s o f m a r k - r e c a p t u r e p rogram i n th e g a r d e n s i t e , f o r s u b - a d u l t I*, i n c o n s t a n s . .......................... ............................................ 117 118 LOW l i t t e r s a m p le s from Baker w o o d lo t: e v a lu a tio n of d i s ­ p e r s i o n ( a g g r e g a t i o n i n s a m p le s ) o f _P. i n c o n s t a n s by t e s t . . * . . ............................................................................................................. 32. E s t i m a t e d d e n s i t i e s o f P. i n c o n s t a n s p e r m^ o f l i t t e r ........... 33. Number o f a n i m a ls e x t r a c t e d from s o i l c o r e su b sa m p le s LOW a r e a s ..................................................................................................... 34. 116 126 127 in Number o f a n i m a ls e x t r a c t e d from s o i l c o r e s u b sa m p le s i n HIGH a r e a s .................................................................................................................... 129 viii 128 LIST OF FIGURES Figure 1. 2. Page M ating p a i r o f j?. i n c o n s t a n s ; m ale on t h e r i g h t , fe m a le c o v e r e d and h e l d byt h e m a l e 's l e g s ................................................................. 16 C o n s t r u c t i o n o f an egg chamber by a P. i n c o n s t a n s f e m a l e ; from a low c i r c u l a r w a l l (A) to egg d e p o s i t i o n (B ,C ), c l o s u r e o f th e dome (D ), and cam o u fla g e o f th e n e s t w ith d e b r i s ( E , F ) .................................................................................................................... 19 3* Egg cham bers b u i l t on wood and l e a f d e b r i s 4. D e b ris o f p a r t l y chewed m i l l i p e d e segm en ts l e f t by a p r e d a t o r y c a r a b i d ................................................................. 5. 6. 7. . ............................. Egg d ev elo p m en t and h a t c h in g * A: f r e s h l y l a i d e g g s ; B: c h o r i o n r u p t u r e d , t r a n s l u c e n t embryos v i s i b l e ; C,D: l a r v a f r e e i n g i t s e l f from c h o r i o n ; E: f i r s t i n s t a r s a f t e r f e e d i n g h a s b egu n* ............................. 22 2 37 Escape h o l e s made i n cham ber w a l l s by f i r s t i n s t a r P. in c o n sta n s. ......................................................................... 4 S tadium d u r a t i o n s a t f o u r t e m p e r a t u r e s (2 6 .6 °C i n c l u d e d i f an y a n i m a ls s u r v i v e d ; f o r S. D. o f t h e means s e e T a b le 8 ) ........................................................................................................................... 43 8. P e r c e n t s u r v i v a l o f im m atures a t f o u r t e m p e r a t u r e s ......................... 50 9. L o n g e v ity o f a d u l t s a t f o u r t e m p e r a t u r e s (means + S. D .) . Numbers i n t h e f i g u r e i n d i c a t e t h e number o f r e p l i c a t e s p e r t e m p e r a t u r e a n d s e x ........................................................................................ 52 S u r v i v a l o f p a i r e d , l a b o r a t o r y - r e a r e d a d u l t f e m a le s a t f o u r t e m p e r a t u r e s .............................................. 54 Flow c h a r t o f th e e x p e r i m e n t a l u se made o f m a les and f e m a le s r e a r e d to m a t u r i t y i n l a b o r a t o r y s t o c k s a t 1 5 .5 ° C ........................... 56 10. 11. ix Figure 12. Page Flow c h a r t o f th e u se made o f f i e l d - c o l l e c t e d f e m a le s (B aker w o o d lo t, M a r c h - A p r il 1 9 7 9 ) . . ....................................................... 57 Mean number o f eggs p e r fe m a le and o v i p o s i t i o n a t t h r e e te m p eratu res. .................. 60 Mean number o f e g g s / o v i p o s i t i o n / f e r a a l e , c u m u la te d th ro u g h s u c c e s s i v e o v i p o s i t i o n s , and p l o t t e d a g a i n s t tim e e l a p s e d s i n c e t h e b e g i n n in g o f e g g - l a y i n g ........................................................... 62 15. P e r c e n t v i a b i l i t y o f eggs l a i d a t s e l e c t e d o v i p o s i t i o n s . . . . 71 16. D i f f e r e n c e s betw een t e m p e r a t u r e s u n d e r b o a rd s and te m p e r a ­ t u r e s i n n o n - c o v e r e d a r e a s , g a r d e n , 1978........................................... 91 T e m p e ra tu re p r o f i l e s u n d er sunny and sh ad y b o a rd s on s e l e c t e d d a t e s ................................. 92 S o i l t e m p e r a t u r e s a t 5 cm d e p t h : a f t e r n o o n r e c o r d s ( g a r d e n ) and 8:am r e c o r d s (M ic h ig a n S t a t e U n i v e r s i t y M e t e o r o l o g i c a l S t a t i o n , E a s t L a n s i n g ) .................................................................... 94 13. 14. 17. 18. 19. Depth p r o f i l e o f t e m p e r a t u r e s i n HIGH and LOW l o c a t i o n s . LS =» l i t t e r s u r f a c e ; SS = s o i l s u r f a c e ; v e r t i c a l l i n e s ■ max-min te m p e r a t u r e s day b e f o r e and day o f s a m p l in g .................................... 95 20. Loose a g g r e g a t i o n s o f ? * i n c o n s t a n s on t h e s i d e s o f l o g s i n O c to b e r .............................. 98 21. S o i l m o i s t u r e i n HIGH an d LOW a r e a s , 1979, and t o t a l p r e c i p i t a t i o n d u r i n g t h e s e v e n days p r i o r to e a c h s am p lin g d a t e ................................................................................................................................ 101 22. Weekly p r e c i p i t a t i o n t o t a l s (M ic h ig a n S t a t e U n i v e r s i t y M e t e o r o l o g i c a l S t a t i o n , E a s t L a n s in g ) f o r 1978 and 1 9 7 9 . . . . 102 23. S ta g e d i s t r i b u t i o n , i n p e r c e n t o f t o t a l number p e r d a t e , i n t h e 1976 g a r d e n p o p u l a t i o n . Numbers above e a c h d a t e * t o t a l number e x t r a c t e d ; e i g h t s u b d i v i s i o n s p e r d a t e = s ta g e s 1 to V I I I . ........... 110 D i s t r i b u t i o n o f s t a g e s i n th e 1978 g a r d e n p o p u l a t i o n , i n p e r c e n t o f t o t a l number c a u g h t . Number above eac h d a t e * t o t a l number o f a n i m a l s ; e i g h t s u b d i v i s i o n s p e r d a t e ■ s t a g e s 1 t h r o u g h V I I I ..................................................................................... Ill D i s t r i b u t i o n o f s t a g e s , i n p e r c e n t o f t o t a l number p e r d a t e , i n t h e w o o d lo t p o p u l a t i o n . Numbers above h i s t o g r a m s “ t o t a l number of a n i m a l s ; e i g h t s u b d i v i s i o n s p e r d a t e ■ s t a g e s I t o V I I I ............................................................................................ 114 24. 25. x Figure 26. 2 7. 28. Page P e r c e n t f e m a l e s , o f a l l s t a g e s IV th r o u g h V I I I , i n t h e g a r d e n (1 9 7 6 , 1978) an d t h e w o o d lo t (1979) p o p u l a t i o n s ; w here p o s s i b l e , d a t a w ere sum m arized a t 1 0 -d a y i n t e r v a l s . . . P e r c e n t fe m a le s among a d u l t s i n t h e 1 978 -7 9 g a r d e n p o p u la tio n . Numbers a r e t o t a l numbers c a p t u r e d / m o n t h P e r c e n t f e m a le s i n t h e a d u l t w o o d lo t p o p u l a t i o n , sum m arized p e r m onth..................................................................................... .. xi 122 123 124 POLYDESMUS INCONSTANS LATZEL 1884 The D ip lo p o d a h ave b een n e g l e c t e d by A merican z o o l o g i s t s when m e a su re d a g a i n s t im p r e s s i v e ta x o n o m ic , m o r p h o l o g i c a l and b i o l o g i c a l com pendia am assed by European i n v e s t i g a t o r s . A m erican tax o n o m ic l i t e r a t u r e , s p e c i f i c a l l y p r i o r to 1940, i s o f l i m i t e d v a l u e b e c a u s e i t c o n s i d e r s o n ly one o r a few s p e c i e s . F a u n i s t i c s t u d i e s h av e been p u b l i s h e d f o r o n ly t h r e e s t a t e s : Ohio (W illia m s and H e f n e r , 1 9 2 8 ) , New York ( B a i l e y , 1928) and M ich ig an (Jo h n so n , 19 5 3 ). R e c e n t l y , S h e l l e y ( 1 9 7 8 ) added a c o m p re h e n s iv e i n v e s t i g a t i o n f o r p a r t s o f N o rth C a r o l i n a . The f i r s t c a t a l o g u e o f N o rth American m i l l i p e d e s was c o m p ile d by Bolliuan ( 1 8 9 3 ) . C h am berlin th e n p u b l i s h e d a seco n d i n 194 7, and C h am b erlin and H offm an, i n 1958, c o o p e r a t e d to p u b l i s h th e m ost r e c e n t c h e c k l i s t f o r N orth A m erica. Polydesm us i n c o n s t a n s was d e s c r i b e d by L a t z e l i n 1884, b u t was th e n m isp la c e d . I t was r e d e s c r i b e d a s ]?. d i s t r a c t u s L a t z e l i n 1888, _P. c o r i a c e u s b o r e a l i s P o r a t 1889, and P. rh e n a n u s V e r h o e f f 1891. A cco rd in g to Hoffman ( p e r s . comm.) a number o f taxo nom ic d i f f i c u l t i e s a r e a s s o c i a t e d w i t h P. i n c o n s t a n s . been d e sig n a te d a s c o r i a c e u s P o r a t 1870. For many y e a r s i t had T h is d e s c r i p t i o n was b a s e d on m a t e r i a l from t h e A z o r e s , w here i t had p r o b a b ly been i n t r o d u c e d from s o u th w e s t E urope. A p p a r e n tl y t h e d e s c r i p t i o n d i d n o t a c c u r a t e l y f i t t h e E uropean s y n a n t h r o p i c s p e c i e s d i s c u s s e d by S c h u b a r t (1934b) u n d e r t h e name o f c o r i a c e u s . C ham b erlin and Hoffman (1 9 5 8 ) t h e r e f o r e f e l t j u s t i f i e d t o i n c l u d e t h e s p e c i e s a s P. i n c o n s t a n s i n t h e i r N o rth A merican c h e c k l i s t , 1 2 sy n o n y m iz in g i t w i t h P. c o r i a c e u s ( n o t P o r a t ) S c h u b a r t , 1934. Demange (19 7 0 ) gave a f u l l y docum ented a c c o u n t o f t h e s i t u a t i o n b a s e d on am ple A zo res m a t e r i a l . Known synonyms o f _P. i n c o n s t a n s a r e l i s t e d b elo w . P olydesm us I n c o n s t a n s L a t z e l . 1884. 2, a n n . 1 9 :2 6 9 B u l l . Soc. S c i . N at. Rouen, s e r . Polydesm us d i s t r a c t u s L a t z e l , 188 8. P r o c . V e r b .: l x x x v B u l l . Soc. H i s t . N at. T o u l o u s e , Polydesm us c o r i a c e u s v a r . b o r e a l i s P o r a t , 1889. 1 0 :7 1 Polydesm us rh e n a n u s V e r h o e f f , 1891. 36:121 B e r l i n e r E n t. Z e i t s c h r . v o l . Polydesm us c o r i a c e u s ( n o t P o r a t ) S c h u b a r t , 1934. T i e r w e l t D e u t s c h l a n d s , T e i l 28:165 Polydesm us t e s t i B o lim an , 1 8 8 8 . E n t. T i d s k r . v o l I n : D ah l, Die P ro c . U. S. N at. Mus. v o l 1 0:6 17 Polydesm us s o c a m i u s C h a m b e rlin , 1910. 3:252 Ann. E n t. Soc. Arner. v o l . P olydesm us p i l l d e n s H um bert, 1894. Mem. Soc. Geneve v o l 3 2 :1 4 Polydesm us h o r t u s W illia m s a n d H e f n e r , 1928. no. 1 8 :1 1 3 Polydesm us pro nom eutes C h a m b e r lin , 1942. v o l . 6, n o . 8 :9 Polydesm us w h e e l e r i C a u se y , 1950. B u l l . Ohio B i o l . S u rv ey B u l l . U niv. Utah b i o l . s e r . E n t. News v o l . 6 1 :1 9 7 . The s p e c i e s was fo u n d i n M ichigan f o r t h e f i r s t tim e by J o h n so n ( 1 9 5 2 ) . A lth o u g h u n d er d i f f e r e n t nam es, i t was a l r e a d y known to o c c u r i n New York ( B a i l e y , 1 9 2 8 ) , Ohio ( W illia m s an d H e f n e r , 1 9 2 8 ), I n d ia n a (B o llraan , 1 8 8 8 ) , U tah ( C h a m b e r lin , 1 9 1 0 ) , C o lo ra d o ( C h a m b e r lin , 1942) an d N o rth D akota (C a u s e y , 1 9 5 0 ) . C h am b erlin (1 947 ) l i s t e d M a s s a c h u s e t t s and D elaw are as d i s t r i b u t i o n r e c o r d s o f EH c o r i a c e u s (■ i n c o n s t a n s ) , a d d in g t h a t i t was w id e s p r e a d i n th e e a s t e r n and m id w e s te r n s t a t e s , and had p r o b a b ly b een I n t r o d u c e d from E u ro p e . I n d e e d , S c h u b a r t (19 34b ) and A ttems (1 5 4 0 ) c i t e m ost o f t h e c o u n t r i e s o f E urope i n t h e i r g e o g r a p h i c d i s t r i b u t i o n r e c o r d s o f t h e s p e c i e s . A ll o f J o h n s o n 's s p e c im e n s ( J o h n s o n , 1952) were c o l l e c t e d i n s o u t h c e n t r a l M ic h ig a n , i n c l u d i n g Ingham C o u n ty , w i t h i n w hich t h e p r e s e n t s t u d y was c o n d u c t e d . J o h n so n s u g g e s t e d t h a t w a t e r m ig h t a c t a s a d i s p e r s a l a g e n t o f th e s p e c i e s ; he f r e q u e n t l y fo u n d l a r v a e among d e b r i s on s t r e a m b a n k s , and showed t h a t young i n s t a r s c o u ld s u r v i v e subm erged f o r 36 t o 48 h o u r s . A l l o t h e r c o l l e c t i o n s i t e s were h y g r i c o r m e s i c , w ith a la y e r of p r o t e c t i v e l e a f l i t t e r . J o h n so n a l s o fo u n d t h e s p e c i e s i n g a r d e n s and c e m e t e r i e s , and c o n c lu d e d t h a t man was g e n e r a l l y t h e a g e n t r e s p o n s i b l e f o r i n t r o d u c t i o n and d i s p e r s a l o f c o r i a c e u s (= in c o n sta n s) • J o h n so n (1 9 5 2 , p. 308) d e s c r i b e s P. c o r i a c e u s i n d e t a i l . d e s c r i p t i o n i s c o m p re h e n s iv e , and w i l l n o t be r e p e a t e d h e r e . The In s u b s e q u e n t c h a p t e r s c h a r a c t e r i s t i c s o f th e s p e c i e s , now c o r r e c t l y named J?. i n c o n s t a n s , w i l l be shown i n c o n t e x t w i t h r e s u l t s o f t h i s in v e stig a tio n . PART I THE BIOLOGY OF POLYDESMUS INCONSTANS AT CONSTANT TEMPERATURES 1. INTRODUCTION l u l u s t e r r e s t r i s Koch (now T a c h y p o d o iu lu s n i g e r ( L e a c h ) ) was t h e f i r s t m i l l i p e d e f o r w hich d e v e l o p m e n t a l d a t a were o b t a i n e d (N ew p ort, 1841). L a t e r i n t h e 1 9 th c e n t u r y , a number o f e x t e n s i v e s t u d i e s i n v e s t i g a t e d em b ry o n ic d ev e lo p m e n t b o th o f i u l i d s and p o ly d e s m id s ( M e t s c h n i k o f f , 197 1, 1 9 7 4 ; C h o lo d o v s k y , 1 89 5 ; Rimslcy-Korsakow, 1895; 3 4 H e a t h c o t e , 1 8 8 6 ,1 8 8 8 ) . A l l o f them s t r e s s e d d e t a i l s o f germ l a y e r , o r ­ g a n and ap p e n d a g e d ev elop m en t* Much o f t h i s e a r l y work, was t h e n summa­ r i z e d by At terns ( 1 9 2 6 ) , V e r h o e f f (1 9 2 8 -1 9 3 2 ) and F f l u g f e l d e r ( 1 9 3 2 ) . Not u n t i l C a r l V e r h o e f f s u c c e s s f u l l y began c u l t u r i n g v a r i o u s s p e c i e s d i d d e t a i l s o f an am o rp h lc d ev elo p m en t become a f o c a l p o i n t o f In v e stig a tio n . Among d ip l o p o d d e v e lo p m e n t p a t t e r n s , t h a t o f I u l l f o r m l a p r o v e d m ost d i f f i c u l t to f o l l o w . In t h e s e d i p l o p o d s , in c re m e n t of body r i n g s ad d ed p e r i n s t a r i s v a r i a b l e : a s Blower and G a b b u tt (19 64) i l l u s t r a t e , a fe m a le C y l i n d r o i u l u s l a t e s t r i a t u s p o s s e s s i n g 38 body se g ta e n ts may b elo n g i n any one o f f o u r s t a g e s . d o e s n o t s t o p once m a t u r i t y i s a t t a i n e d . F u r th e r m o r e , m o l t i n g V e rh o e f f (1 9 2 8 ) f i r s t d e s c r i b e d a l t e r n a t i o n o f s e x u a l l y f u n c t i o n a l m a le s w i t h i n t e r c a l a r y m a les ( S c h a l t m a n n c h e n ) : f o l l o w i n g V e r h o e f f , t h i s p r o lo n g e d a n a m o rp h o sis i s te rm ed p e r i o d o m o r p h o s i s , and i s now known to o c c u r i n s e v e r a l i u l i d s a n d b l a n i u l i d s ( R a n t a l a , 19 7 0 , 19 74; S a h l i , 1958, 1961, 1966: H a lk k a , 1 9 5 8 ; Blower and F a i r h u r s t , 1 9 6 8 ). D r i f t (1 9 5 1 ) o b s e r v e d p e r io d o m o r p h o s is i n f e m a le s a s w e l l , b u t c h a r a c t e r i z a t i o n o f l a t e r i n s t a r s , w here seg m en t num bers o v e r l a p , i s so d i f f i c u l t t h a t ev en H a lk a a s (1 9 5 8 ) e x t e n s i v e work does n o t d e t a i l t h e s u c c e s s i o n o f fe m a le in sta rs. The s i t u a t i o n i s q u i t e d i f f e r e n t i n N em atophora, P o ly d esm o id ea a n d th e f i r s t s i x s ta g e s o f F e n ta z o n ia . In s t a r s a r e s e p a r a t e d by a c o n s t a n t i n c r e m e n t o f new s e g m e n t s . T h e re i s a f i x e d t o t a l number of i n s t a r s - e i g h t i n p o ly d e s m id s - o f w hich t h e l a s t ( a d u l t ) does n o t u n d e rg o f u r t h e r e c d y s e s . An e x c e p t i o n to th e r u l e i s p r o v id e d by Brachydesm us s u p e r u s ( L a t z e l ) : t h e s u b a d u l t i n s t a r may m olt i n t o one w i t h th e a d u l t number o f r i n g s , b u t w i th o u t s e c o n d a ry s e x u a l 5 c h a r a c t e r s ; t h e gonopods a r e d e v e lo p e d d u r i n g a s u p e rn u m e ra ry e c d y s l s w i t h o u t a d d i t i o n o f se g m e n ts ( S te p h e n s o n , 1961)* n in e i n s t a r s t o t a l (S ch u b art, 1934a)• Nematophora p o s s e s s I n P e n t a z o n l a , a f i x e d number o f an am o rp h ic i n s t a r s i s f o l l o w e d by f o u r o r more e p lm o rp h ic i n s t a r s ( V e r h o e f f , 19 28; B lo w er, 1958; H e a th e t a l , 1 9 7 4 ) . Segm ental and ap pendage numbers a s g i v e n by S c h u b a r t (1 9 3 4 a ) f o l l o w i n g S e i f e r t (19 3 2 ) h o l d t r u e f o r a l l p o ly d e s r a o id s . By c o n v e n t i o n , i n s t a r s a r e numbered i n roman n u m e r a l s : I t h r o u g h V I I I (a d u lt)• M yriapod eg g s a r e e n c l o s e d by a to u g h membrane, t h e c h o r i o n . As d e s c r i b e d i n d e t a i l by B ohle (1 9 6 4 ) , i t s p l i t s d u r i n g em bryonic d e v e lo p m e n t, b u t one o r more c u t i c u l a r l a y e r s s t i l l e n c l o s e t h e em bryo, which i s now term ed t h e p u p o id s t a g e . V e r h o e ff c o n s i d e r e d t h e p u p o id t o be em bryo nic and t h e hexapod l a r v a w hich h a t c h e s from i t t o be th e f i r s t p o s t- e m b r y o n i c s t a g e . P f l u g f e l d e r ( 1 9 3 2 ) , H alkka (1 95 8) and Dohle (1 9 6 4 ) c o n s i d e r th e p u p o id t o be t h e f i r s t p o s t- e m b r y o n i c s t a g e , and t h e f r e e - l i v i n g l a r v a t h a t em erges to be l n s t a r I I . Most w o r k e r s ,h o w e v e r , c o n s i s t e n t l y a d o p t t h e o l d e r te r m i n o l o g y ; s i n c e i t i s o n l y a m a t t e r o f c o n v e n i e n c e , t h e f r e e - l i v i n g hexapod l a r v a w i l l h e r e be c o n s i d e r e d to be t h e f i r s t p o s t- e m b r y o n i c i n s t a r . Once t h e f i r s t i n s t a r h a s em erg ed , d ev elo p m en t i s a c h i e v e d by a s e r i e s of m o lts. P f l u g f e l d e r ( 1 9 3 2 ) , H alkka (19 5 8 ) and Vachon (19 47) have shown t h a t an a m o rp h ic g ro w th comes a b o u t i n t h r e e s t e p s : a) th e p r o l i f e r a t i o n zone form s new seg m en ts d u r in g a m o l t , b u t th e se g m e n ts re m a in i n em bryo nic c o n d i t i o n i n t h e e n s u in g i n s t a r ; b ) a t t h e n e x t m o l t , t h e s e segm ents become r e c o g n i z a b l e body r i n g s , b u t re m a in a p o d o u s ; and c) d u r in g t h e s e c o n d m o lt f o l l o w i n g t h e i r f o r m a t i o n , t h e s e 6 r i n g s become podous segments* F i e l d s a m p lin g h as e n a b l e d many w o rk e rs to r e c o n s t r u c t t h e l i f e c y c l e s t a g e s o f m i l l i p e d e s a s th e y o c c u r s e a s o n a l l y ( s e e F a r t I I ) . O b v io u s ly , a g e s t r u c t u r e a t a g iv e n tim e o f y e a r i s a p r o d u c t o f g ro w th r a te s of in d iv id u a l i n s t a r s . That g ro w th r a t e s a r e te m p e r a t u r e - d e p e n d e n t i s f r e q u e n t l y i m p l i e d ; th u s Blower (1970) s p e a k s o f t h e d i f f e r e n t s t a g e d i s t r i b u t i o n s o f T a c h y p o d o iu lu s n l g e r i n "good" and " p o o r '* y e a r s . But l i t t l e c o m p re h e n s iv e work h a s been done on t h e I n f l u e n c e o f te m p e r a t u r e on g ro w th r a t e s u n d e r c o n t r o l l e d c o n d i t i o n s . E a r l y w o rk e rs ( V e r h o e f f , 1 9 2 8 ;M il e y , 1927) s u r e l y had no way o f c o n t r o l l i n g e n v i r o n m e n t a l c o n d i t i o n s , and c o n d u c te d t h e i r o b s e r v a t i o n s a t u n s p e c i f i e d room t e m p e r a t u r e s . S in c e th e n , p r o lo n g e d r e a r i n g o f m i l l i p e d e s u n d e r more o r l e s s c o n s t a n t c o n d i t i o n s h a s been r e p o r t e d . R e g a rd in g i u l o i d s , K e i r a l l a h (1 9 6 6 ) r e a r e d l u l u s s c a n d i n a v i u s L a t z e l to a d u l t h o o d . F a i r h u r s t (1 9 7 4 ) p a r t i a l l y r e a r e d Ommatoiulus s a b u l o s u s ( L . ) an d r e c o r d e d s t a d i a l d u r a t i o n s th r o u g h i n s t a r I I I . H alkka (1958) commented on g ro w th r a t e v a r i a t i o n s due to te m p e r a t u r e i n S c h iz o p h y llu m s a b u l o s u s ( L . ) ; f i n a l l y , Blower (1 9 7 4 ) f u l l y documented t h e p o s t- e i a b r y o n ic d e v e lo p m e n t o f O p h y iu lu s p i l o s u s (N ew p ort) in t h e l a b o r a t o r y , u n d e r somewhat f l u c t u a t i n g t e m p e r a t u r e c o n d i t i o n s . D evelop m en tal d a t a f o r poly d esru o id s have been g i v e n f o r a v a r i e t y o f sp e c ie s. F r e q u e n t l y , t h e s e a c c o u n t s c o v e r o n ly a n a rro w segm ent o f th e l i f e c y cle of a s p e c ie s , i . e . t h o s e segm ents o f p a r t i c u l a r i n t e r e s t t o t h e I n v e s t i g a t o r a t th e t i m e . The m ost e x t e n s i v e o b s e r v a t i o n s , m a in ly u n d e r v a r i a b l e c o n d i t i o n s , a r e fou nd i n work by C ausey (1 9 4 3 ) on O rthom orpha g r a c i l i s (K och); by K e i r a l l a h (1 9 7 8 ) who r e a r e d t h a t same s p e c i e s th r o u g h a l l s t a g e s ; by S te p h e n so n (19 6 1 ) on 7 B rachydesm us s u p e r u s ( L a t z e l ) ; an d by B a n e r j e e (1 9 7 0 , 1973) on Polydesm us a n g u s t u s L a t z e l . M i l l i p e d e s g e n e r a l l y do n o t a p p e a r t o be d i f f i c u l t t o m a i n t a i n i n c u l t u r e , a f a c t r e f l e c t e d in th e fr e q u e n t use o f d ip lo p o d s as t e s t a n i m a ls i n l a b o r a t o r y s t u d i e s . B e g in n in g i n th e 1 9 6 0 ' s , d e t a i l e d work on r e s p i r a t o r y r a t e s o f m i l l i p e d e s a s a f f e c t e d by t e m p e r a t u r e was p u b l i s h e d by Byzova ( 1 9 6 7 ) , D w arakanath ( 1 9 7 8 a ,b ) and Gromysz-Kalkowska (1 9 6 7 , 1970a ,b , 1 9 7 3 ). R e c e n t l y , s p e c i f i c o b s e r v a t i o n s on l e a f p a l a t a b i l i t y (N e u h a u s e r and K a r t e n s t e i n , 1978) and co p ro p h a g y (M cB rayer, 1973) h av e a l s o i n c l u d e d p o ly d e sm id s i n t h e i r e x p e r i m e n t a l d e s i g n s . P ro b a b ly t h e most t h o r o u g h l y s t u d i e d p o ly d e sm id i s P olydesm us a n g u s t u s L a t z e l , a common i n h a b i t a n t o f some p a r t s o f c o n t i n e n t a l Europe ( S c h u b a r t , 1 9 3 4 b ; M e i d e l l , 1967) and B r i t i s h w oodlands (B lo w e r, 195 5, 1958, 1 970; B a n e r j e e , 196 7, 1 9 7 3 ). As S c h u b a r t (1 9 3 4 a ) p o i n t s o u t , common s p e c i e s a r e most l i k e l y to be i n v e s t i g a t e d ; s m a l l wonder t h e n t h a t P. a n g u s t u s h a s b een t h e s u b j e c t o f r e s p i r a t i o n s t u d i e s ( P h i l l i p s o n , 1 9 6 7 ) , d e s c r i p t i o n s o f d e v e l o p m e n t a l m orphology ( P e t i t , 1973b, c , 1 9 7 6 ) , r e p r o d u c t i v e b i o l o g y ( S a h l i , 1969) and r e g e n e r a t i o n o f ap p en d a g es ( P e t i t , 1 9 7 3 a ). C o m p a ra tiv e s t u d i e s on g ro w th r a t e s u n d e r s e v e r a l t e m p e r a t u r e r e g im e s h a v e , t o t h i s a u t h o r ' s k n o w led g e, n o t b e e n r e p o r t e d . S i m i l a r l y , r e l a t i o n s h i p s betw een te m p e r a t u r e and s u r v i v a l a r e n o t u su a lly s p e c ifie d . R a t h e r , m o r t a l i t y r a t e s a r e e s t i m a t e d from s e a s o n a l d e n s i t y d a t a i n t h e f i e l d , and a r e s u g g e s t e d to depend on f a c t o r s s u c h a s w a t e r l o g g i n g ( M i l l e r , 197 3, 1974; H eath e t a l . , 1 9 7 4 ) , d e s s i c a t i o n ( O ' N e i l l , 19 6 9 ) o r f o o d l i m i t a t i o n ( M i l l e r , 1 9 7 4 ; Blow er an d M i l l e r , 1 9 7 4 ), a s w e l l a s on u n s p e c i f i e d b i o t i c I n f l u e n c e s . 8 I n d e e d , a l l o f t h e s e p r o b a b ly o u tw e ig h t h e s i n g l e e f f e c t o f te m p e r a t u r e s i n c e m i l l i p e d e s and o t h e r t e r r e s t r i a l i n v e r t e b r a t e s a p p e a r to be c a p a b l e o f a c t i v e s e a r c h f o r p r o p i t i o u s m i c r o c l i m a t i c c o n d i t i o n s ( P e r t t u n e n , 1953, 1955; H a a c k e r, 1 9 7 0 ) . In H a a c k e r 's e x t e n s i v e work on m i l l i p e d e e c o lo g y i n Germany ( 1 9 6 8 ) , h e r e l a t e d d a t a on te m p e r a t u r e p r e f e r e n d a and r e s i s t a n c e t o e x tre m e te m p e r a t u r e s to t h e g e o g r a p h i c a l d is tr i b u tio n reco rds o f fo u rte e n s p e c ie s. From th e p o i n t o f view o f c o m p a r a ti v e p h y s i o l o g y h i s r e s u l t s w ere c o m p re h e n s iv e , b u t by v i r t u e o f h i s e x p e r i m e n t a l d e s i g n d i d n o t i n c l u d e lo n g - t e r m t e m p e r a t u r e e f f e c t s . D ata on d ip l o p o d r e p r o d u c t i v e p o t e n t i a l a r e s c a r c e and i n c i d e n t a l , owing to t h e c r y p t i c h a b i t s o f t h e a n i m a l s , a n d , i n some s p e c i e s , t o th e d i f f i c u l t i e s en co u n tered in t h e i r r e a r i n g . Even i n o t h e r w i s e s u c c e s s f u l c u t l u r e s , a d u l t s t e n d t o be n o n - r e p r o d u c t i v e (B lo w e r, 1 9 7 4 ) . P o ly d e s m o id s , many o f w hich a r e s e m e lp a r o u s (a s i n g l e e g g - l a y i n g p e r i o d a f t e r w hich th e y d i e ) , a r e p r o b a b ly more c o n d u c iv e t o l a b o r a t o r y o b s e r v a t i o n th a n t h e o f t e n l o n g - l i v e d , i t e r o p a r o u s i u l o i d s . T a b le 1 sum m arizes a v a i l a b l e i n f o r m a t i o n on t h e r e p r o d u c t i v e p o t e n t i a l o f p o ly d e s m o id s , and i n c l u d e s comments on where and how t h e i n f o r m a t i o n was o b t a i n e d . As a r u l e , th e p o t e n t i a l number of c o n s e c u t i v e o v i p o s i t i o n s by one fem a le a r e n o t known. R e c u r r in g a c c o u n t s o f s i n g l e o v i p o s i t i o n s by l a b o r a t o r y - r e a r e d f e m a le s p r e s e n t a s i n g u l a r c o n t r a s t to t h e p r o lo n g e d r e p r o d u c t i v e p e r i o d s i n f i e l d p o p u la tio n s (se e P a r t I I ) . In some s p e c i e s , s e a s o n a l o c c u r r e n c e o f m a tu re eggs i n d i s s e c t e d f e m a le s i n d i c a t e s t h a t more t h a n one b ro o d may be t h e r u l e (L e w is , 1 9 7 1 b ). The l a b o r a t o r y i n v e s t i g a t i o n s r e p o r t e d h e r e w ere g e a r e d tow ard a s s e s s i n g th e fo llo w in g a s p e c t s of th e b io lo g y o f £ . in c o n s t a n s ; 9 a) G e n e r a l o b s e r v a t i o n s on t h e b io l o g y o f t h e s p e c i e s In c a p t i v i t y , i n c l u d i n g n e s t i n g and m o l tin g h a b i t s and q u a l i t a t i v e o b s e r v a t i o n s on t h e s p e c i e s ' p r e d a t o r s ; b) T e m p e ra tu re -d e p e n d e n c y o f g ro w th r a t e s , i . e . d u r a t i o n o f t h e s t a g e s when r e a r e d a t c o n s t a n t t e m p e r a t u r e s ; c) T e m p e r a tu re - d e p e n d e n c y o f s u r v i v o r s h i p o f e a c h i n s t a r ; d) F e c u n d i t y , w i t h a c o m p a r is o n b e tw e e n l a b o r a t o r y - r e a r e d and f i e l d - c o l l e c t e d fem a les. Table 1. Summary of available information on the reproductive potential of polydesmoids. SPECIES Oxydesmus s p . AUTHOR Toye 1967 Lewis 1971a In c u l t u r e , a t l e a s t 5 fem a les p e r s p e c i e s 81 (1 6 7 , 56, 49) Counts o f l a r g e o v a , 3 f e m a le s , f i e l d - c o l l e c t e d 172 Tymbodes f a l c a t u s Habrodesmus d u b o sq u i 731 ra n g e 456-1034 COMMENTS 1436 rang e 576-2353 Habrodesmus f a l x Sphenodesmus sh erib o n g en sis NO. EGGS OBSERVED Lewis 1971b Xanthodesmus s p . Xanthode sinus physkon 1213 (7 0 2 ,8 8 7 ,1 2 1 3 ,2 0 5 0 ) Counts o f l a r g e o v a , 4 f i e l d - c o l l e c t e d f e m a le s ; " a t l e a s t 2 b r o o d s /y e a r " 291 (3 3 7 ,2 3 2 ,3 2 3 ,2 7 1 ) Counts o f l a r g e o v a , 4 f i e l d - c o l l e c t e d fe m a le s; "p resum ab ly 2 bro o d s" 1434 (87 1, 1997) Counts o f l a r g e o v a , 2 f i e l d - c o l l e c t e d fem a les u s u a l l y 4-6 ra n g e 1-7 59 n e s t s o b s e rv e d i n c u ltu re Ampylodesmus i y o n i s Murak. Murakami 1965a P la ty rrh ac u s amauros At terns P f l u g f e l d e r 1932 60-80 In c u l t u r e Strongylosom a p a l l i p e s ( O liv ) S e i f e r t 1932 40-60 In c u l t u r e ? ? Table 1 (cont'd) Orthomorpha g r a c i l i s (Koch) Causey 1943 500 ( 1 7 , 4 2 , 5 2 ,6 3 , 1 5 1 ) A p h e lo r ia c o r i a c e a (Koch) Eaton 1943 Luminodesmus se q u ia l Loomis & Dav. D avenport e t a l 1952 Euryurus e r y th r o p y g u s (B r a n d t) M iley 1927 Brachydescius superus (L a tz e l) S tep hen so n 1961 Polydesmus co m p lan atu s ( L . ) V erh o eff 1928 Polydesmus co m planatus ( L . ) Voges 1916 Polydesmus a n g u s tu s L a tz . E f f e n b e r g e r 1909 Polydesmus a n g u s tu s L a tz . B a n e rje e 1973 1076 (7 0 ,1 6 0 ,1 6 5 ) 526 49 r a n g e 42-56 2u0 25-40 100 184 ra n g e 125-246 157 r a n g e 135-251 Cne c l u t c h found i n g reen h o u se In c u l t u r e ; 1 b a tc h l a i d p e r f e m a le ; s t i l l con­ t a i n e d m a tu re eggs upon d issec tio n * In c u l t u r e ; s i n g l e o b serv atio n 3 egg m asses co u n ted 1 nest in c u ltu re 22 n e s t s o b s e r v e d ; u s u a l l y o n ly one brood p o s s i b l y more th a n 1 b ro o d , w ith d e c r e a s i n g no. o f e g g s . n = ? In c u l t u r e In c u l t u r e In f i e l d In c u l t u r e 12 2. MATERIALS AND METHODS A c o n t i n u o u s s u p p ly o f i n c o n s t a n s was a s s u r e d by m a i n t a i n i n g a number o f s t o c k c u l t u r e s a t 15° and 21°C. O rig in a lly f i e l d - c o l l e c t e d i n Baker w o o d l o t , (m ixed d e c id u o u s woods on M ic h ig a n S t a t e U n i v e r s i t y cam p u s), t h e s e s t o c k s u s u a l l y c o n t a i n e d mixed s ta g e s * Once t h e a n i m a ls were a d u l t th e y r e a d i l y r e p r o d u c e d i n c u l t u r e , and t h e i r p ro g en y w ere r a i s e d i n numbers l a r g e enough to p r o v id e m ost of th e ex p e rim e n ta l l i v e m a te r ia l needed. O c c a s i o n a l l y , s t o c k s were r e p l e n i s h e d by f i e l d - c o l l e c t i o n ; t h e s e a n i m a ls were a l lo w e d a p e r i o d of a d j u s t m e n t l a s t i n g no l e s s th a n two w eeks. Where p e r t i n e n t , t h e e x a c t p ro v e n a n c e o f e x p e r i m e n t a l a n im a ls w i l l be m e n tio n e d i n t h e d i s c u s s i o n of re s u lts . A f t e r some t r i a l and e r r o r , c u l t u r e c o n d i t i o n s w ere k e p t c o n s t a n t i n t h e f o l l o w i n g w ays: a) The b a s i c s u b s t r a t e c o n s i s t e d o f p l a s t e r o f P a r i s and c h a r c o a l , mixed w ith w a t e r , p o u red and s e t . L ayered above i t , a m i x t u r e o f m o is t d u f f , d e c a y in g wood and l e a v e s , and d a r k woodland s o i l ; t h e s e m a t e r i a l s p r o v id e d c o v e r , fo o d and n e s t i n g m a t e r i a l s f o r th e an im als. D i s t i l l e d w a t e r was add ed t o th e d u f f when needed to keep i t m o i s t b u t n o t w e t. Whenever t h e amount o f f a e c a l m a t e r i a l ex ce ed ed t h a t o f unconsumed d u f f , t h e o r g a n i c m a t t e r was r e p l a c e d . b) Powdered y e a s t was p r o v id e d a s an a d d i t i o n a l fo o d s o u r c e . It was r e p l a c e d when i t had e i t h e r been e a t e n o r when i t had l e d t o f u n g a l g r o w th . c) Y e a s t was r e a d i l y a c c e p t e d a s fo o d by a l l i n s t a r s . C u l t u r e s w ere k e p t i n c o n t r o l l e d - t e m p e r a t u r e c a b i n e t s ( t e m p e r a t u r e s a v a i l a b l e : 1 0 ° , 1 5 . 5 ° , 21° and 2 6 . 6 ° C ) , in 13 c o n s t a n t d a rk e x c e p t d u r i n g o b s e r v a t i o n p e r i o d s . A ll r e a r i n g c o n t a i n e r s were c y l i n d r i c a l j a r s o f c l e a r p l a s t i c w i t h t i g h t s n a p -o n l i d s . C o n t a i n e r s i z e v a r i e d d e p e n d in g on t h e d e n s i t y o f t h e p o p u l a t i o n s and t h e i r e s t i m a t e d n e e d s f o r s p a c e . Two s i z e s were u s e d most o f t e n : 5 cm d i a m e t e r x 4 cm h i g h ; an d 3 cm d ia m e t e r x 2 . 5 cm h ig h . S p e c i f i c d e t a i l s o f r e a r i n g m ethods a r e d i f f i c u l t t o i n c o r p o r a t e h e r e s i n c e th e y were t h e outcome o f v a r i o u s o b s e r v a t i o n s and e x p erim en ts. Each r e a r i n g c o n t a i n e r h a r b o r e d a p o p u l a t i o n o r an i n d i v i d u a l d i s t i n c t from t h o s e o f o t h e r c o n t a i n e r s ; e a c h c o n t a i n e r a l s o p r o v id e d a s e t o f e n v i r o n m e n t a l c o n d i t i o n s d i f f e r i n g , t o an unknown d e g r e e , from t h o s e o f o t h e r c o n t a i n e r s . T hroug ho ut any r e a r i n g p rogram m inor a d j u s t m e n t s w ere made c o n s t a n t l y , b a s e d on s u b j e c t i v e judgm ent in f a c t , to be most e f f i c i e n t and h o p e f u l l y o p t i m a l , m a n i p u l a t i o n s had t o v ary betw een j a r s . But i n a l l c a s e s , t h e g e n e r a l p r o c e d u r e s o u t l i n e d above were f o l l o w e d , t o a s s u r e u n i f o r m i t y o f o v e r a l l c u l t u r e c o n d itio n s. M i l l i p e d e c u l t u r e s a r e s u b j e c t t o i n f e s t a t i o n by p a r a s i t i c m ite s and n em atod es i n t r o d u c e d w ith t h e o r g a n i c m a t t e r u s e d a s s u b s t r a t e . These i n f e s t a t i o n s can become v e r y h eav y w i t h i n s h o r t p e r i o d s o f tim e . T r a n s f e r r i n g p a r a s i t i z e d I n d i v i d u a l s t o new c o n t a i n e r s may p o s tp o n e t h e b u i l d u p o f p a r a s i t e p o p u l a t i o n s , b u t c a n n o t s o l v e t h e pro b lem . I n f e s t e d s t o c k c u l t u r e s were t h e r e f o r e s im p ly d i s c a r d e d . P a ra sitiz e d e x p e r i m e n t a l c u l t u r e s were a l s o d i s c o n t i n u e d , and th e r e c o r d s p e r t a i n i n g to them w ere n o t u s e d i n t h e c a l c u l a t i o n o f r e s u l t s . 14 3. RESULTS 3 .1 G e n e r a l O b s e r v a t i o n s on th e B io lo g y o f P. i n c o n s t a n s A) M a tin g ; P. i n c o n s t a n s p a i r s assum e t h e same g e n e r a l c o p u l a t o r y a t t i t u d e d e s c r i b e d f o r o t h e r p o ly d e s m id s ( S e i f e r t , 1932; H a rz , 1962) ( F i g u r e 1 ) . The male f i r s t a p p r o a c h e s t h e fe m a le a lo n g h e r d o r s a l m i d l i n e , th e n c u r v e s h i s a n t e r i o r body downward and draws t h e fem a le aro u n d so t h a t th e v e n t r a l s u r f a c e s o f th e p a i r a r e o p p o sed . The fe m a le i s h e l d t i g h t l y by t h e m a l e ’ s l e g s , e s p e c i a l l y i n t h e r e g i o n where gonopods and v u lv a e t o u c h , and t h e gonopods a r e i n s e r t e d i n t o th e v u l v a e . The l a s t f o u r o r f i v e se g m e n ts o f t h e p a r t n e r s a r e o f t e n o n ly l o o s e l y j o i n e d , f r e q u e n t l y ev en s e p a r a t e . M atin g h a s b een r e p o r t e d to l a s t from a p p r o x im a te ly 10 m i n u te s to 30 h o u r s i n o t h e r p o ly d e sm id s p e c i e s ( S c h u b a r t , 1 9 3 4 a ) . One p a i r o f P. i n c o n s t a n s , t h e e x a c t l o c a t i o n and p o s i t i o n of w h ich had been r e c o r d e d , a p p a r e n t l y d i d n o t move f o r 24 h o u r s . F re q u e n tly , d u ra tio n s o f s e v e r a l h o u r s w ere r e c o r d e d . In g e n e r a l , t h e a n i m a ls d id n o t r e a d i l y i n t e r r u p t m a tin g a c t i v i t y , ev en when p ic k e d up w ith f o r c e p s , t r a n s f e r r e d from j a r to j a r , and s u b j e c t e d t o m ild i l l u m i n a t i o n and h eat. The " o u t s t a n d i n g s e x u a l d r i v e o f p o ly d e s m id s " was r e f l e c t e d i n t h e b e h a v i o r o f r e c e n t l y m o lte d a d u l t s i n l a b o r a t o r y c u l t u r e . C o p u l a t i o n f r e q u e n t l y to o k p l a c e w i t h i n a few h o u r s o f em ergence from t h e m o l t i n g cham ber. T w ice, a m ale was o b s e r v e d g r a s p i n g a fe m a le w hich had e a t e n h e r exuvium , b u t was s t i l l c u r l e d i n h e r chamber and had b een a r t i f i c i a l l y e x p o s e d by d e s t r o y i n g th e chamber w a l l . Two o r 15 F i g u r e 1. M a tin g p a i r o f P . i n c o n s t a n s ; m a le on t h e r i g h t , f e m a le c o v e r e d a n d h e l d by m a l e 's le g s. 17 more m a les were som etim es fou nd c l u s t e r e d a r o u n d th e m o l tin g cham bers o f f e m a le s w hich had j u s t begun t o chew t h e i r way o u t o f t h e cham ber. Pheromones c o u l d p o s s i b l y have been I n v o l v e d . Schomann (19 56) f i r s t d i s c o v e r e d c h e m ic a l r e c o g n i t i o n s i g n a l s i n P o ly x e n u s l a g u r u s L. and t h e y have been i m p l i c a t e d i n c o n s p e c i f i c b e h a v i o r o f l u l i d s (H aack er an d F u c h s , 1970; H a a c k e r, 1 9 6 9 b ), s p i r o b o l i d s ( H a a c k e r, 1 9 7 0 ), c h o rd e u m id s ( H a a c k e r , 1971) and g l o m e r i d s ( J u b e r t h l e and T a b a c a r u , 1968; H a a c k e r, 1 9 6 9 a ) . In c u l t u r e , a t c o n s t a n t t e m p e r a t u r e , m a tin g was f r e q u e n t and n o t a t a l l a s e a s o n a l o c c u r e n c e - a s m ig h t be e x p e c t e d . B) N e stin g : F i g u r e 2 i l l u s t r a t e s t h e s e q u e n c e o f e v e n t s i n egg n e s t c o n s t r u c t i o n by a P. i n c o n s t a n s f e m a l e . As a r u l e , t h e p r e l i m i n a r y p r e p a r a t i o n o f a n e s t i n g s i t e e n t a i l s t h e rem o v a l o f d e b r i s ( s a n d and o r g a n i c m a t t e r ) from a r o u g h ly c i r c u l a r a r e a o f t h e s u b s t r a t e . A low w a l l i s b u i l t , and th e fe m a le b e n d s h e r a n t e r i o r segm ents o v e r th e o p e n in g and d e p o s i t s h e r e g g s ( F i g u r e 2A ,B ,C ). Then n e s t c o n s t r u c t i o n p r o c e e d s t o c o m p le ti o n . The dome t h a t f i n a l l y e n c l o s e s t h e eg g s v a r i e s i n c r o s s - s e c t i o n , from a h a l f - c i r c l e v ir t u a l l y s t r a i g h t w a lls. to a p o i n t e d cone w i t h W hile P olyd esm u s c o m p la n a tu s L. i s re p u te d t o s e t a " v e n t i l a t i o n chim ney" on to p o f t h e dome (vom R a th , 1891; V o ges, 1 9 1 6 ) , no s u c h s t r u c t u r e s w ere e v e r o b s e r v e d i n in c o n sta n s. I f u n d i s t u r b e d , th e fe m a le s c o v e r e d t h e cham ber w i t h o r g a n i c d e b r i s , a n a c t i o n r e m i n i s c e n t o f c a m o u fla g e ( F i g u r e 2 E , F ) . Voges (1916) r e c o u n t e d t h e p r o t e c t i v e b e h a v i o r o f j>. co m p la n a tu s f e m a l e s , w hich rem ain ed w ith t h e i r n e s t s f o r s e v e r a l d a y s , and q u i c k l y 18 F ig u re 2. C o n s tr u c tio n o f an egg cham ber by a P. in c o n s ta n s fe m a le ; f r o m a lo w c i r c u l a r w a l l (B , C ) , c l o s u r e o f t h e n e s t dome n e s t w ith d e b ris (E, F ) . (A) t o e g g d e p o s i t i o n (D) a n d c a m o u f l a g e o f t h e F ig u re 2. 20 r e t u r n e d to i t i f f o r c i b l y removed. P. in c o n s t a n s d id n o t show t h i s k in d o f b e h a v i o r . The m a t e r i a l used f o r b u i l d i n g an egg chamber v a r i e d a c c o r d in g to a v a i l a b i l i t y ; most commonly, o r g a n ic m a t t e r . IC was mixed w ith s o i l , i f t h e r e was some i n t h e v i c i n i t y , o r even w ith c h a r c o a l i f th e p l a s t e r - c h a r c o a l s u b s t r a t e happened t o be s o f t enough to be i n g e s t e d . Given n o th i n g b u t m o is t s a n d , fe m a le s s t i l l c o n s t r u c t e d cham bers (by I n g e s t i n g s a n d ? ) - clu m sy, i r r e g u l a r l y shaped s t r u c t u r e s w hich d r i e d o u t and crumbled e a s i l y * Under normal c o n d i t i o n s , t h e n e s t w a l l was t h i n b u t s t r o n g and e l a s t i c . Much d i s p u t e d i n e a r l i e r work ( V e r h o e f f , 1915; vom R a th , 1891; Voges, 1 9 1 6 ), th e m echanics o f po lydesm id n e s t - b u i l d i n g a r e no l o n g e r in q u e stio n . The fe m a le I n g e s t s m a t e r i a l from th e s u r r o u n d in g s and t h e r e s u l t a n t f a e c a l m a t t e r , e x t r u d e d i n m o is t d r o p l e t s and p a t t e d i n t o p l a c e by th e r e c t a l p ad , c o n s t i t u t e s th e a c t u a l w a l l m a t e r i a l . Females o f P. in c o n s t a n s c o u ld o f t e n be o b s e rv e d " f o r a g i n g ” i n th e v i c i n i t y o f a chamber, a l l th e w h ile k eep in g u n i n t e r r u p t e d c o n t a c t w i t h t h e edge o f t h e n e s t by means o f t h e i r p o s t e r i o r l e g p a i r s . N e s tin g s u b s t r a t e s ch o se n by _P. I n c o n s ta n s i n c u l t u r e a p p e a re d t o have one common c h a r a c t e r i s t i c ; they te n d e d t o be r e l a t i v e l y sm oo th , and s o l i d . The p l a s t e r - c h a r c o a l s u b s t r a t e , smooth p i e c e s o f wood and undecomposed p i e c e s o f le a v e s ( F i g u r e 3 ), o r th e c o n t a i n e r w a l l were u t i l i z e d ( i n o r d e r of p r e f e r e n c e , a s c a l c u l a t e d from a t o t a l o f 500 o b s e r v a t i o n s ) . S e i f e r t (1932) s t a t e d t h a t p o ly d e sm id s i n g e n e r a l te n d to n e s t on smooth s u b s t r a t e s . The o n ly egg chambers fo u n d i n f i e l d l o c a l i t i e s d u rin g th e p r e s e n t s tu d y were b u i l t on s m o o th - s u r f a c e d b ra n c h e s and b i t s of wood. 21 F ig u re 3 . Egg c h a m b e r s b u i l t o n w ood a n d l e a f d e b r i s . mam#"* 23 C) M o ltin g : A l l l a r v a l s t a g e s o f P. I n c o n s t a n s c o n s t r u c t e d m o l tin g cham bers much I n t h e way t h a t egg cham bers a r e made, e x c e p t t h a t th e f o r m e r w ere b u i l t from th e i n s i d e * In l a t e r s t a g e s o f c o n s t r u c t i o n , t h e r e c t a l pad and l a s t p a i r o f l e g s c o u l d o f t e n be s e e n a t work a r o u n d t h e s m a l l o p e n in g s t i l l l e f t to be c lo s e d * More o f t e n th a n n o t , a l r e a d y e x i s t i n g s t r u c t u r e s were u s e d o r i n c o r p o r a t e d i n th e cham ber d e s i g n . One i s o l a t e d i n d i v i d u a l m o lte d t h r e e t i m e s (fro m I t o IV) i n s i d e t h e same s e e d c a p s u l e , u n t i l i t f i n a l l y o u tg re w t h e s p a c e a v a i l a b l e . A l l i n s t a r s to o k a d v a n t a g e o f l a r g e p i e c e s o f o r g a n i c m a t t e r ; t h e y c r a w le d u n d e r n e a t h and e n c l o s e d th e m s e lv e s by a c y l i n d r i c a l w a l l w h ich c o n n e c te d d e b r i s and s o l i d s u b s t r a t e b en ea th . E q u a l - a g e d , g ro u p e d i n d i v i d u a l s o f P• i n c o n s t a n s , e . g . c l o n e s from one egg n e s t , te n d e d to u n d e rg o m o l ts a t t h e same tim e and i n t h e same a r e a o f t h e c u l t u r e . R a t h e r th a n a c t i v e a g g r e g a t i o n , t h i s may s im p ly r e p r e s e n t a c h o i c e o f t h e one m o st s u i t a b l e s p o t i n a somewhat h e t e r o g e n e o u s e n v i r o n m e n t. C a s t s k i n s w ere a lw a y s consumed b e f o r e t h e new i n s t a r s em erged from t h e i r c h a m b e rs . To e m e rg e , th e y u s u a l l y a t e an amount o f chamber w a l l j u s t s u f f i c i e n t t o a l l o w p a s s a g e o f t h e body . Blower (197 4) o b s e r v e d a n e x t e n d e d p e r i o d o f f a s t i n g (maximum o f 30 d a y s ) p r i o r to t h e o n s e t o f e c d y s i s i n O p h y iu lu s p i l o s u s ( N e w p o rt). C e s s a t i o n o f f e e d i n g p r i o r t o a m o lt was n o t tim ed i n i n c o n s t a n s , b u t i s p r o b a b ly a g e n e r a l o c c u r r e n c e I n i n v e r t e b r a t e s ; c e n t i p e d e s and i s o p o d s ( p e r s . o b s . ) , an d C o lle m b o la ( P a le v o d y , 1974; J o o s s e , 1 9 7 5 ) , t o name a few . D u r a t i o n o f t h e m o l tin g a c t a s su c h - s p e c i f i c a l l y , from 24 c o m p l e t i o n o f t h e cham ber to em ergence o f t h e n e x t i n s t a r - was tim ed i n i s o l a t e d j?. I n c o n s t a n s a t 15.5® a n d 21 °C. re su lts* T a b le 2 g i v e s th e E c d y s i s from i n s t a r I t o i n s t a r I I was o f s h o r t e r d u r a t i o n th a n l a t e r ecdyses* I n c r e a s e s i n m o lt d u r a t i o n were s l i g h t b u t c o n s t a n t from s t a g e t o s ta g e * The l a s t e c d y s i s , from V II t o a d u l t , was o f t h e l o n g e s t d u r a t i o n a t b o t h t e m p e r a t u r e s . I n g e n e r a l , th e h i g h e r t e m p e r a t u r e d e c r e a s e d th e tim e n e e d e d to c o m p le te a g iv e n e c d y sis. T a b le 2. flean d u r a t i o n o f m o lts o f £ . te m p eratu res. i n c o n s t a n s a t two Time r e f e r s t o d ay s e l a p s e d betw ee n com ple t i o n o f a m o l tin g cham ber and em erg ence o f t h e n e x t i n s t a r . INSTAR T°C 1 5 .5 Days I II III IV V VI V II mean 5 .8 6 .4 6 .9 7 .2 7 .5 8 .7 1 2 .0 + SD 0 .9 1 .1 0 .9 1 .1 1 .1 2 .0 2 .0 30 30 30 27 22 27 28 range 4-8 4-9 5-8 5-9 5-9 5-13 9-16 mean 3 .4 4 .3 5 .0 4. 6 5 .7 7.1 9 .7 + SD 0 .6 0 .9 1 .2 1 .1 1 .2 1 .1 1 .9 14 14 14 14 14 14 10 3-5 3-6 4 -8 4-8 4 -7 5-9 n* 21 n= ran g e 8-13 25 D) Predation and oophagy: P r e d a t i o n on J?. i n e o n s t a n s was d i s c o v e r e d p u r e l y by a c c i d e n t : a p a i r o f a d u l t s i n c u l t u r e d i s a p p e a r e d o v e r n i g h t , a f t e r new and n o t v e r y t h o r o u g h l y exam ined d u f f had b een added to t h e i r c u l t u r e j a r . What re m a in e d were some s i n g l e s e g m e n ta l r i n g s o f P. i n c o n s t a n s and a l a r g e and a c t i v e c a r a b i d l a r v a ( P t e r o s t i c h u s m e l a n a r i u s ) . Time c o n s t r a i n t s p r o h i b i t e d l a r g e - s c a l e q u a n t i t a t i v e o b s e r v a t i o n s , b u t as a p o i n t o f i n t e r e s t s e v e r a l q u a l i t a t i v e s t u d i e s were th e n u n d e rta k e n . D uring f i e l d c o l l e c t i o n s i n l a t e summer and f a l l , any p o t e n t i a l p r e d a t o r s e n c o u n t e r e d were b r o u g h t back to th e l a b o r a t o r y . They were o f f e r e d w h a te v e r s t a g e s o f P. i n c o n s t a n s were a v a i l a b l e a n d , where a p p r o p r i a t e , a c h o i c e o f o t h e r p re y s p e c i e s . A ll p r e d a t o r s were o b t a i n e d from h a b i t a t s known to h a r b o r £ . i n c o n s t a n s : B aker w o o d lo t, l i t t e r and l o g s ; t h e wooded a r e a o f t h e W ater Q u a l i t y Management s i t e n e a r M ich ig an S t a t e U n i v e r s i t y an d an o r c h a r d n e a r Grand R a p i d s , M ic h ig a n . E x p erim en tal c o n d itio n s in c lu d e d t h e u se o f p l a s t e r - c h a r c o a l s u b s t r a t e i n t h e u s u a l c l e a r p l a s t i c c o n t a i n e r s , 5 cm d i a m e t e r ; an d a few s m a l l p i e c e s o f decomposed wood t o g i v e some fo o d to JP. i n c o n s t a n s , b u t n o t enough to c o v e r th e f l o o r of th e c o n ta in e r . days. O b s e r v a t i o n i n t e r v a l s v a r i e d from 24 h o u r s to 3 F eed in g r a t e s c o u l d n o t be c a l c u l a t e d ; f r e q u e n t l y , a l l p r e y had b e e n consumed a t t h e tim e o f o b s e r v a t i o n , w i t h o u t a c c u r a t e c h e c k s on th e tim e s p a n i n v o l v e d . T o t a l o b s e r v a t i o n p e r i o d s a l s o v a r i e d b etw ee n i n d i v i d u a l p r e d a t o r s ( r a n g e from one t o t h r e e w eeks, a f t e r which tim e m o st o f them were s t i l l a l i v e and f e e d i n g ) . i n T a b l e 3. The r e s u l t s a r e sum m arized Table 3* Summary of acceptance of various prey by larval and adult predators. Polydesmus in c o n s t a n s I 11 Amara s p . , ad . — 0 P te ro stic h u s m e l a n a r i u s , ad. + + S t a p h y l i n i d a e , ad.+++ P tero stich u s m e lan ariu s, la r v . + T i d a b iu s t i v i u s , ad. ++ - ++ - not offered 0: n o t a c c e p te d +: o c c a s i o n a l l y a c c e p te d ++: u s u a l l y a c c e p te d 4-H-: alw ays a c c e p te d III IV - -I i TT +++ 4+ i i TT - V VI - IT T - VII _ V III s m a ll med. la rg e C ollem bola F. cand. 0 0 TFT i k t TTT +-H- 0 - - - - - +++ - - + - - I i I. 4+ +++ +++ +++ _ O p hyiu lu s p i l o s u s 0 4 + 0 0 11. arm. — — + + +H- + 27 CARABIDAE, ADULTS: P te r o s ti c h u s m e lan ariu s I l l i g e r : C o l l e c t e d In Baker w oo dlot and Grand R a p id s ( n = 9 ) . O ffered: F o lso m ia C andida (W illem ) and H y p o g a s tr u r a a r m a tu s ( N i c o l e t ) ( C o l l e m b o l a ) ; P. i n c o n s t a n s I t h r o u g h V I I I ; O p h y iu lu s p i l o s u s (N ew port) o f " s m a l l , medium and l a r g e " s i z e s . A l l i n d i v i d u a l s o f t h i s s p e c i e s s h a r e d a common p r e f e r e n c e : th e l a r g e r s t a g e s o f _P. i n c o n s t a n s , p a r t i c u l a r l y a d u l t s and s u b a d u l t s . Depending on p r i o r f e e d i n g h i s t o r y , a maximum o f t e n a d u l t s a n d / o r s u b a d u l t s were consumed by one b e e t l e i n 24 h o u r s . A lso a c c e p t e d w ere s m a l l e r s t a g e s o f J?. i n c o n s t a n s , s m a l l 0 . p i l o s u s , and th e c o l le m b o l a n H. a r m a tu s (a s l u g g i s h s p e c i e s ) . F ig u re 4 i l l u s t r a t e s th e s e g m e n ta l d e b r i s l e f t by a c a r a b i d f e e d i n g on m i l l i p e d e s . S u r p r i s i n g l y , two o f t h e c a r a b i d s l a i d eggs (o n e and t h r e e eggs re sp e c tiv e ly ). Two o f t h e egg s h a t c h e d . m i x tu r e o f JT. C a n d id a , in c o n sta n s. The l a r v a e w ere o f f e r e d a a r m a t u s , and i n s t a r s I , I I an d I I I o f Of t h e s e p r e y , F o lso m ia was n o t e a t e n . H y p o g a s tr u r a was a c c e p t e d , a s were a l l t h r e e s t a g e s o f t h e m i l l i p e d e . The g r e a t e s t number o f p r e y consumed by one l a r v a w i t h i n 24 h o u r s w e re : H y p o g a s tr u r a an d a l l m i l l i p e d e s o f f e r e d four ( f iv e each of s ta g e s I , I I and III). A qara s p . : C o l l e c t e d i n t h e w a te r q u a l i t y management a r e a ( n = l l ) . a c c e p t any s p e c i e s o r s t a g e o f d i p l o p o d s a s f o o d . one week. Did n o t D is c o n ti n u e d a f t e r 28 F ig u re 4. D e b ris o f p a r t l y chew ed m i l l i p e d e s e g m e n ts l e f t by a p r e d a to r y c a r a b id . 29 F ig u re 4. 30 STAPHYLINIDAE, ADULT ( u n i d e n t i f i e d ) : These o b s e r v a t i o n s o f w o o d l o t - c o l l e c t e d b e e t l e s l a s t e d f o r s i x d a y s (number o f b e e t l e s * 3 ) . O f f e r e d P. i n c o n s t a n s s t a g e s I , I I I and V I. I n s t a r s I and I I I were a lw a y s a c c e p t e d , b u t n e v e r i n s t a r VI ( a b o u t tw i c e as l a r g e a s th e p r e d a t o r s ) . CARABID LARVAE P te r o s tic h u s m e lan ariu s I l l i g e r : C o l l e c t e d i n Baker w o o d lo t i n A ugust ( n = 9 ) . O ffered: a ll s t a g e s o f _P. i n c o n s t a n s , and t h e C o lle m b o la F . C an d id a and H. a r m a t a . A ll were a c c e p t e d , e s p e c i a l l y t h e l a r g e r s i z e d m i l l i p e d e s . These l a r v a e w ere a s v o r a c i o u s a s t h e a d u l t s o f t h e s p e c i e s , and e x t r e m e l y a c tiv e . F iv e o r s i x l a r g e m i l l i p e d e s , p l u s a few s m a l l s t a g e s , were commonly e a t e n w i t h i n 24 h o u r s . CHIL0P0DA T ld a b iu s t i v i u s (C h am b erlin ): _T. t i v i u s i s a d i m i n u t i v e l i t h o b i i d ( 7 - 9 nun), c o l l e c t e d i n Grand R a p id s , w hich h a s b een r o u t i n e l y r e a r e d i n t h e l a b o r a t o r y on a d i e t o f F . C a n d id a . A d u lts o f t h i s c e n t i p e d e w ere o b s e r v e d f o r t h r e e c o n s e c u t i v e 2 4 -h o u r p e r i o d s , i n t h e f o l l o w i n g e x p e r i m e n t a l s e t u p : a) Ten m a les and t e n f e m a l e s , s t a r v e d f o r f i v e d a y s , v e r s u s t e n i n d i v i d u a l s o f e a c h s e x w hich had b een w e l l f e d . E very 24 h o u r s , e a c h o f them was o f f e r e d 20 P. i n c o n s t a n s , s t a g e I . b) The same r e p l i c a t i o n a s i n a ) , a l s o fe d and s t a r v e d . Each was o f f e r e d 20 P. i n c o n s t a n s , s t a g e I , a n d 20 F_. C an d id a a s a l t e r n a t i v e p rey. 31 The w e ig h t s o f i n d i v i d u a l p r e d a t o r s w ere n o t r e c o r d e d . P o ssib le e f f e c t s o f h a v in g f e d on F. C a n d i d a , t h e a l t e r n a t i v e p r e y i n b ) , were n o t known. R a t h e r th a n p e r f o r m in g q u e s t i o n a b l e a n a l y s e s , o n ly th e mean number o f p r e y consumed were c a l c u l a t e d * a) In T a b l e 4 , s t a r v e d and f e d T. t i v i u s o f e a c h s e x a r e o p p o s e d . S t a r v e d a n i m a l s consumed more p r e y i n 24 h o u r s , a s m ig h t be e x p e c t e d , b u t s t a n d a r d d e v i a t i o n s o f t h e means w ere g e n e r a l l y l a r g e . L ittle if any d i f f e r e n c e became a p p a r e n t b etw een t h e sex es* T a b le 4. Mean number (+ S . D . ) o f f i r s t i n s t a r P. i n c o n s t a n s consumed by a d u l t T i d a b i u s t i v i u s ( C h il o p o d a ) i n e a c h o f t h r e e c o n s e c u t i v e 2 4 -h o u r p e rio d s. F em ales M ales fe d sta rv e d fe d h ours 7 .4 + 6 .3 5 .8 + 4 .0 8 .4 + 6 . 0 3 .3 + 2 .6 24 - 48 h o u r s 7 .6 + 4 .8 6 .2 + 4 . 9 7 ,9 + 3 .3 4 .7 + 1 . 7 48 - 72 h o u r s 9 . 2 + 7 .8 3 .2 + 2. 2 6 .4 + 4 .2 5. 7 + 4 .1 1 O sta rv e d b) T a b le 5 shows t h a t , g i v e n a c h o i c e o f p r e y , th e c e n t i p e d e s p r e f e r r e d t h e C o llem b o la to t h e m i l l i p e d e s , w i t h s t a r v e d i n d i v i d u a l s consum ing more th a n f e d i n d i v i d u a l s . S in c e n e i t h e r w e ig h ts n o r p h y s i o l o g i c a l c o n d i t i o n o f t h e a n i m a ls w ere known, t h e r e l a t i v e l y h i g h c o n s u m p tio n r a t e of fe d f e m a le s ( v s . f e d m a le s ) c a n n o t w ith c e r t a i n t y be a t t r i b u t e d to s e x . 32 T a b le 5 . T l d a b i u s t i v i u s g iv e n a c h o i c e o f p r e y s p e c i e s : number o f p r e y e a t e n i n e a c h o f t h r e e c o n s e c u t i v e 2 4 - h o u r p e r i o d s (means + S. D .) . S t a r v e d f e m a le s F . C andida 2 3 1 2.6 1 .6 0 .5 1 .0 +2*2 + 1 .9 + 1 .2 + 1 .1 + 0 .8 + 0 .9 1 5 .2 1 3 .4 8 .0 1 1 .4 1 1 .2 6 .9 +3. 7 + 3 .7 + 2 .9 + 5 .1 + 3 .6 + 1 .8 S ta r v e d m a les P. i n c o n s t a n s I F. C andida 2 3 CO F. i n c o n s t a n s I 1 o• DAY Fed fe m a le s 1 .1 Fed m a les 1 .9 1 .6 1 .0 0 .8 0 .3 0 .8 + 2 .5 + 1 .6 + 0 .9 + 0 .9 + 0 .5 + 0 .9 1 3 .6 1 0 .4 8 .1 5 .5 5 .7 4 .8 + 4 .2 + 4 .5 + 2 .0 + 3 .7 + 2 .5 + 1 .6 C iven a c h o i c e o f p r e y , JC. t i v i u s s t i l l o c c a s i o n a l l y f e d on P. in c o n sta n s I. F i r s t i n s t a r s o f th e m i l l i p e d e a r e w h ite an d r e s e m b le _F. C andida i n s i z e * C o lle m b o la : The m i l l i p e d e s were c e r t a i n l y n o t p r e f e r r e d o v e r th e t h e i r c o n t i n u e d , b u t d e c r e a s e d , a c c e p t a n c e by t h e p r e d a t o r may r e p r e s e n t a c c i d e n t a l a t t a c h r a t h e r t h a n p u r p o s e f u l f e e d i n g . F eed in g h a b i t s o f c e n t i p e d e s h a v e most o f t e n been i n v e s t i g a t e d i n l a b o r a t o r y s t u d i e s , w ith a l i m i t e d number o f p re y s p e c i e s o f f e r e d a s fo o d to th e p r e d a t o r s . R o b e rts (1 9 5 6 ) and Lew is ( 1 9 6 5 ) , h o w ever, 33 a n a l y z e d th e g u t c o n t e n t s o f f i e l d - c o l l e c t e d c h i l o p o d s : t o c o n t a i n re m a in s o f d i p l o p o d s . none w ere found A ll e i g h t c e n t i p e d e s p e c i e s i n v e s t i g a t e d had a p p a r e n t l y b een f e e d i n g on m i t e s , o p i l i o n i d s , s p i d e r s , and o t h e r c e n t i p e d e s . DIPLOPODA D i p l o i u l u s c o e r u l e o c i n c t u s (Wood) an d O p h y iu lu s p i l o s u s (N e w p o r t ) : Ten a d u l t i n d i v i d u a l s o f e a c h s p e c i e s were i n t r o d u c e d to c u l t u r e j a r s c o n t a i n i n g eg g s o f P. i n c o n s t a n s . e f f e c t s , y e a s t was a l s o a d d e d . I n o r d e r to a v o i d s t a r v a t i o n Y e a s t was a l r e a d y known to be an a c c e p t a b l e food f o r b o th s p e c i e s . B o th i u l o i d s consumed eggs o f £ . i n c o n s t a n s , w h e th e r th e y were f r e s h l y l a i d o r had d e v e lo p e d t o t h e s t a g e where t h e c h o r i o n had ru p tu re d . G e n e r a l l y , th e l a r g e D i p l o i u l u s consumed more th a n th e s l e n d e r O p h y iu lu s i n 24 h o u r s ( a maximum o f 80 eg g s v e r s u s a maximum o f 28 e g g s ) . B o th s p e c i e s c o n t i n u e d f e e d i n g on t h e e g g s u n t i l none were l e f t , o r , i n t h e c a s e o f d e v e lo p e d e g g s , u n t i l t h e s e began h a t c h i n g . Given i n t a c t egg c h a m b e rs, b o th i u l o i d s a l s o a t t a c k e d t h o s e . 0. p i l o s u s s lo w ly consumed t h e chamber w a l l , and some o f t h e eggs s t i l l re m a in e d u n to u c h e d a f t e r n i n e d a y s . Of e i g h t n e s t s o f f e r e d to e i g h t D. c o e r u l e o c i n c t u s , no t r a c e s o f e i t h e r n e s t s o r eg gs re m a in e d a f t e r f o u r days. T hese r e s u l t s a r e t e n t a t i v e . I t i s p r o b a b l e t h a t ex p o sed eggs w i l l be e a t e n , s i n c e P. i n c o n s t a n s o c c a s i o n a l l y c a n n i b a l i z e s i t s own e g g s . F e e d in g on i n t a c t n e s t s , on t h e o t h e r h a n d , c o u ld i n d i c a t e a need f o r o r g a n i c m a t t e r r a t h e r t h a n an a t t e m p t t o g e t a t th e e g g s . V a r i a t i o n o f e x p e r i m e n t a l c o n d i t i o n s and a c c u r a t e q u a n t i f i c a t i o n 34 a r e c l e a r l y n e e d e d f o r a l l o b s e r v a t i o n s on p r e d a t i o n and oophagy. S p e c i f i c a l l y , p r o o f o f p r e d a t i o n on J?. i n c o n s t a n s i n t h e f i e l d i s o f u tm o s t im p o r ta n c e . Once t h a t p r o o f h a s b een o b t a i n e d f o r a number of p o t e n t i a l p r e d a t o r s ( e . g . th r o u g h g u t c o n t e n t a n a l y s e s ) , l a b o r a t o r y - d e r i v e d f e e d i n g r a t e s and p r e f e r e n c a w i l l g a i n g r e a t e r v a lid ity . 3 . 2 Growth and D evelopm ent A) M e th o d s ; As a r u l e , l i v e a n i m a ls f o r th e s t u d y o f s t a g e d u r a t i o n were o b t a i n e d from l a b o r a t o r y s t o c k s r e a r e d a t t h e same te m p e r a t u r e a s t h a t u s e d f o r a g iv e n e x p e r i m e n t a l s e r i e s . But t h i s c o n s ta n c y o f t e m p e r a t u r e c o u ld n o t a lw a y s be m a i n t a i n e d . For o b s e r v a t i o n s a t 26.6°C a n i m a ls fro m 21°C s t o c k s had to be u s e d , b e c a u s e a t t e m p t s to r e a r s t o c k s a t 2 6 . 6°C were u n s u c c e s s f u l . For e x p e r i m e n t s a t 10°C, i n d i v i d u a l s grown a t 1 5 .5 °C s u p p le m e n te d , when n e e d e d , t h e s lo w -g ro w in g s t o c k s k e p t a t 10°C. 21°C, s t o c k s F re sh ly For e x p e r i m e n t s a t 1 5 .5 ° an d r e a r e d a t t h o s e r e s p e c t i v e t e m p e r a t u r e s were a v a i l a b l e . m o lte d i n d i v i d u a l s o f e a c h s t a g e were o b t a i n e d by c h e c k in g th e s t o c k s once a d a y ; t h u s t h e day o f e n t r y i n t o a s t a g e was known, and was r e c o r d e d a s day n o . 1 i n t h e d ev elo p m en t o f newly emerged i n s t a r s . At e a c h te m p e ra tu re , f o r i n s t a r s I th ro u g h V II, j a r s w ere made up i n t h e u s u a l way ( s e e r e p lic a te c u ltu re S e c t i o n 1 .2 ) and t e n n e w ly - m o lte d i n d i v i d u a l s were I n t r o d u c e d t o e a c h . W ith o n ly f o u r e x c e p t i o n s (due to t h e d e p l e t i o n o f s t o c k s o f t h e r i g h t a g e ) a t o t a l 35 o f a b o u t 100 a n i m a ls of e a c h s t a g e were o b s e r v e d a t e a c h t e m p e r a t u r e . At I n t e r v a l s o f 1 t o 3 d ay s t h e c u l t u r e s were t h e n c h ec k ed f o r m o l t i n g a c t i v i t y , and a l l a n i m a l s t h a t had emerged from t h e i r cham bers (an d now b e lo n g e d to t h e s u b s e q u e n t I n s t a r ) w ere c o u n t e d , s e x e d and rem oved. From i n s t a r IV o n , e a c h o f t h e r e p l i c a t e c o n t a i n e r s was s t o c k e d w ith f i v e m ales and f i v e f e m a l e s . In a few i n s t a n c e s e q u a l numbers o f e a c h se x were n o t a v a i l a b l e , b u t t h e o v e r a l l s e x r a t i o p e r s e r i e s was k e p t a s c l o s e t o u n i t y a s p o s s i b l e . For th e s t u d y o f em b ry on ic d e v e lo p m e n t, some o f th e many egg b a t c h e s l a i d by p a i r e d f e m a le s were s e t a s i d e and o b s e r v e d . These eggs were k e p t a t e ac h o f th e t h r e e , t e m p e r a t u r e s a t w hich th e y had been l a i d : 1 0 ° , 1 5 .5 ° and 2 1 ° C. By rem oving o n ly t h e to p o f t h e n e s t dome, e m b ry o n ic d e v e lo p m e n t c o u ld be o b s e r v e d w i t h o u t c o m p le te ly d e p r i v i n g t h e eggs o f t h e i r p r o t e c t i v e e n c l o s u r e . B) Em bryonic d ev elo p m en t and h a t c h i n g At t h e tim e t h e y a r e l a i d , eggs o f j?. i n c o n s t a n s a r e w h i t e , o p a q u e , an d m e asu re 0 . 4 mm i n d i a m e t e r . They soon become o v o i d a l , and t h e c h o r i o n s p l i t s a f t e r a t e m p e r a t u r e - d e p e n d e n t i n t e r v a l o f em bryo nic g ro w th ( T a b l e 6 ) . The embryo i s w e l l v i s i b l e th r o u g h i t s membranes ( F i g u r e 5 ) . tra n slu c e n t H a tc h in g o c c u r s soon t h e r e a f t e r a t 21°C, b u t i s r e t a r d e d by lo w e r t e m p e r a t u r e s ( T a b l e 7 ) . At 10°C i n p a r t i c u l a r , e m b ry o n ic l i f e may l a s t a p p r o x i m a t e l y 3 m on ths. H a tc h in g b e g i n s w ith slow movements o f t h e em bryo. I t stre tch e s from i t s c u r l e d p o s i t i o n - w i t h l e g s h e l d s t r a i g h t b a c k a lo n g t h e body - u n t i l t h e head and most o f th e rump a r e f r e e d from t h e c h o r i o n c a p s . T h is f i r s t p h a s e may l a s t from 7 rain to h a l f an h o u r (n - 6 36 F i g u r e 5 . E gg d e v e l o p m e n t a n d h a t c h i n g . eggs; B: c h o r i o n r u p t u r e d , C, D: l a r v a f r e e i n g itse lf a f t e r fe e d in g has begun. A: f r e s h l y la id t r a n s l u c e n t em bryos v i s i b l e ; from c h o r i o n ; E: f i r s t in sta rs F ig u re 5. 38 o b s e r v a t i o n s ) , and i s f o l l o w e d by a l t e r n a t i n g p e r i o d s o f im m o b il ity and f u r t h e r s t r e t c h i n g . D uring t h e n e x t 30 to 100 m i n u te s ( n * 8 ) , t h e l e g s a r e b r o u g h t f o r w a r d t o t h e i r norm al p o s i t i o n , and t h e t i p o f t h e abdomen i s f r e e d from t h e g a p in g c h o r i o n s h e l l s * A fter a t o t a l o f 1 to 2 h o u r s (n = 5) t h e l a r v a i s c a p a b l e o f w a lk in g a b o u t . F i g u r e 5 i l l u s t r a t e s some o f t h e s t a g e s d i s c u s s e d a b o v e . T a b le 6. Number o f d ays betw een d e p o s i t i o n of e g g s and r u p t u r i n g of th e c h o rio n . 10°C n (b a tc h e s o bserved) T a b le 7. 1 2 .3 + 0 .7 26 - 33 11 - 13 15 12 • range 2 9 .5 + 2 .1 CO mean days + S . D. 21 °C 1 5 . 5°C + 0 .7 7 - 9 20 1-lean t o t a l d u r a t i o n o f em b ry o n ic d e v e lo p m e n t, from egg d e p o s i t i o n t o t h e tim e when t h e m a j o r i t y o f e a c h b a t c h have h a t c h e d . 10°C mean d a y s + S.D. range 8 2 .6 + 3 .4 76-87 n (b a tc h e s observed) 18 15.5°C 1 8 .6 + 0 .9 21 °C 1 2 .8 + 0 .8 18 - 21 11 - 14 19 17 In n e s t s which had been opened f o r o b s e r v a t i o n o f em bryonic 39 d e v e lo p m e n t, h a t c h e d l a r v a e began l e a v i n g t h e n e s t e n c l o s u r e soon a f t e r f r e e movement had b een a t t a i n e d . sequence of e v e n ts. T h is may n o t be t h e norm al I n ch am bers b u i l t a g a i n s t t h e t r a n s p a r e n t c o n t a i n e r w a l l , h a t c h i n g c o u l d be o b s e r v e d w h ile t h e n e s t s were in ta c t: a maximum of 6 d a y s ( a t 10°C) o f slow m l l l i n g - a b o u t o f th e l a r v a e i n s i d e t h e chamber c o u ld f o l l o w t h e o n s e t o f h a t c h i n g . L arvae emerged from i n t a c t n e s t s by chew ing t h e i r way o u t . F i g u r e 6 i l l u s t r a t e s t h a t s e v e r a l s u c h e s c a p e h o l e s may be made, i n v a rio u s lo c a tio n s - a lth o u g h a o s t f r e q u e n tly a l l la rv a e escaped th r o u g h a s i n g l e h o l e made n e a r t h e b o tto m o f t h e cham ber dome. The l a r v a e began f e e d i n g w i t h i n a day o f h a t c h i n g ; t h e d a r k g u t c o n t e n t s were t h e n v i s i b l e t h r o u g h t h e i r w h ite dorsum ( F i g u r e 5 ) . C) P o s t- e m b r y o n i c dev elo p m en t S in c e i n t e r v a l s betw ee n o b s e r v a t i o n s o f t e n encom passed more th a n 24 h o u r s , t h e d a t a on s t a g e d u r a t i o n were sum m arized a t f i v e - day in te rv a ls. The m ed ian d ays o f t h e s e tim e s p a n s w ere th e n u sed to c a l c u l a t e mean d u r a t i o n s : e . g . , i f f i v e a n i m a ls m o lte d to t h e n e x t i n s t a r b etw een day s 41 and 4 3 , day 43 was u sed a s t h e em ergence day f o r a l l o f them. T a b le 8 d e t a i l s t h e r e s u l t s . I t s h o u ld be n o te d t h a t mean d u r a t i o n o f e a c h s ta d iu m r e p r e s e n t s t h e amount o f tim e s p e n t i n a s t a g e p l u s t h e amount o f tim e n e e d e d t o u n d erg o e c d y s i s (f r o m day 1 of a s ta d i u m t o day 1 o f t h e n e x t s t a d i u m ) . Animals r e a r e d a t 1 0 ° C d e v e l o p e d e x t r e m e l y s l o w l y . W ith t h e e x c e p t i o n o f s ta d i u m 1, d u r a t i o n s v a r i e d g r e a t l y betw een i n d i v i d u a l s . At 1 5 .5 ° an d 21°C d e v i a t i o n s from t h e means w ere q u i t e s m a l l , i n a l l 40 Figure 6. Escape holes made in chamber walls by first instars of P. inconstans. F ig u re 6. 42 s t a d i a e x ce p t V II. I l l u s t r a t e d g r a p h i c a l l y , (F ig u re 7 ) , th e d a ta c l e a r l y show t h a t t h e r e was l i t t l e d i f f e r e n c e b etw ee n t h e d e v e l o p m e n t a l r a t e s a t t h e s e two t e m p e r a t u r e s . At 2 6 . 6°C o n ly a few r e c o r d s o f s ta d i u m d u r a t i o n m o r t a l i t y was so h i g h t h a t c o u ld be o b t a i n e d ( T a b l e 8 ) . The te n a n i m a ls t h a t s u r v i v e d s t a g e IV i n t o s t a g e V showed an I n t e r e s t i n g l e n g t h e n i n g o f s ta d i u m d u r a t i o n by c o m p a ris o n t o lo w e r te m p e ra tu re s. But f o r v a l i d c o n c l u s i o n s , t h e o b s e r v a t i o n s would have to be r e p e a te d under d i f f e r e n t c o n d i tio n s : a l t e r a t i o n o f t y p e s and l a y e r i n g o f s u b s t r a t e s , o r p r i o r a c c l i m a t i o n o f t e s t a n i m a l s , s h o u ld be c o n sid ere d in t h i s re g a rd . S in c e t h e r e a r e i n d i c a t i o n s t h a t m a le p o ly d e s m id s m a tu re f a s t e r t h a n f e m a l e s , p a r t o f t h e r e s u l t s were t e s t e d f o r s e x - s p e c i f i c d i f f e r e n c e s i n s ta d iu m d u r a t i o n . Given t h e v a r i a b i l i t y e n c o u n t e r e d ( T a b le 8 ) , m a jo r d i f f e r e n c e s seemed t o ' o c c u r o n l y i n t h e p e n u l t i m a t e s ta d iu m and o n ly a t 1 5 .5 ° and 21°C. V a r ia n c e s and c o e f f i c i e n t s o f v a r i a t i o n were b o th u n e q u a l , and W e lc h 's (19 38 ) a p p r o x im a te d e g r e e s o f fre e d o m and Behrens (1 9 2 9 ) t - l i k e t e s t s t a t i s t i c were a p p l i e d t o t h e d a t a . At b o th t e m p e r a t u r e s , th e d u r a t i o n o f s ta d i u m V II p ro v e d t o be s i g n i f i c a n t l y g r e a t e r i n f e m a le s t h a t i n m ales (p < 0 . 0 0 0 5 ) . Two o t h e r o b s e r v a t i o n s p r o v i d e d s u p p o r t f o r t h e s e t e s t r e s u l t s : a) A number o f J?. i n c o n s t a n s were r e a r e d i n i s o l a t i o n from th e d ay o f h a t c h i n g to th e day o f a d u l t h o o d . s t a t i s t i c a l t e s t s were p e r f o r m e d . R e p l i c a t i o n was low , and no But a g a i n , mean d u r a t i o n o f t h e e n t i r e l i f e c y c l e was s h o r t e r i n m ales th a n i n f e m a l e s , a t b o th 15.5® an d 21°C (T a b l e 9 ) . b) Some o f th e c l o n e s w hich w ere r o u t i n e l y r e a r e d t o a d u l th o o d a s 140H II FEMALES MALES S3 H 1001 60- 60H io o B H £ Q cn I , III II 20 H 20H ~T 10 1 5 .5 21 26.6 10 I 1 5 .5 I 21 I 26.6 T E M P E R A T U R E ° C Figure 7. Stadium durations at four temperatures (26.6°C included if any animals survived; for S.D. of means see Table 8). 44 140 FEMALES MALES 100 60 IV z 20 0 H e* < 10 01 21 15.5 26.6 10 15.5 21 9 100 CO < Q — • 60 60 VI VII 20 20 10 15.5 21 10 15.5 T E M P E R A T U R E ° C Figure 7 (cont'd). 21 T ab le 8* Mean d u r a t i o n , i n d a y s , o f th e s t a d i a a t f o u r te m p e ra tu re s * DAYS STADIUM n Ill d* I 11 ? 44 81 50 49 Q IV 42 3 2 V II d> 49 47 23 24 3 2 50 49 3 $ 52 v VI mean 4 8 .6 1 2 1 .3 138.5 135.1 9 3 .4 142 .4 6 4 .6 79.1 88 .4 8 2 .9 10 1 .5 96.1 + SD 5 .6 62.5 2 7 .2 2 1 .0 6 3 .8 5 7 .0 2 6 .3 42.5 37.5 2 8 .4 2 9 .9 2 6 .9 95 95 46 53 50 48 50 49 48 50 20 23 15.5°C mean 18.9 2 1 .5 2 5 .6 2 6 .3 2 2 .5 1 9 .7 28.1 23.4 3 2.8 30.2 73.7 4 8 .2 + SD 3 .0 3 .2 5.7 4 .3 2 .9 2 .4 7 .7 8 .0 6 .9 5.4 23.7 20.4 10°C n 99 97 52 46 49 50 49 40 49 47 38 mean 1 3 .3 1 6 .5 23.7 2 3 .0 1 9 .0 1 6 .6 2 8 .0 26 .3 3 5 .8 36.1 6 4 .5 4 3 .3 + SD 1 .4 3 .8 4 .2 6.3 2 .9 2.3 7.1 1 0 .4 7 .8 7.1 1 8 .3 1 5 .6 3 1 26.6°C mean 1 0 .7 (33) = SD 0 .9 n 21°C n 2 40. 5 10 43.1 6 .1 48 46 p a r t o f s t o c k c u l t u r i n g w ere a l s o c h e c k e d f o r th e f i r s t a p p e a r a n c e o f a d u lts* At 21°C (n=5 c l o n e s ) m a les a p p e a r e d f i r s t i n a l l o f them , m a t u r i n g e a r l i e r t h a n f e m a le s by a mean o f 44 d a y s ( r a n g e 15 -8 0 d a y s )* At 15*5°C (n « 17 c l o n e s ) m a les m a tu r e d e a r l i e r i n 15 o f t h e c u l t u r e s , p r e c e d i n g f e m a le s by a mean o f 27 d a y s ( r a n g e 5 - 5 8 d a y s )* Males th u s te n d t o m a tu re e a r l i e r th a n f e m a l e s , m a in ly due to a r e l a t i v e l y s h o r t d u r a t i o n o f s ta d iu m VII* In th e f i e l d (S e c tio n I I . 2 * 4 . ) a s i m i l a r t r e n d was a p p a r e n t i n f a l l s a m p l e s : among i n d i v i d u a l s m a tu r in g i n S e p te m b e r - O c to b e r , t h e r e was a p r e p o n d e r a n c e o f m a les w hich l a s t e d , h o w e v e r, no l o n g e r th a n 5 t o 6 w eeks. T a b le 9. Mean t o t a l d u r a t i o n , i n d a y s , o f th e p o s t- e m b r y o n i c d e v e lo p m e n t o f j?. i n c o n s t a n s r e a r e d i n i s o l a t i o n from h a t c h i n g t o a d u lth o o d . mean ± S. D. 1 5 .5 °C 21°C D) n«* f e m a le 2 4 1 .9 + 4 1 .7 12 male 2 1 3 .6 + 3 1 .6 16 fe m a le 1 9 0 .0 + 3 8 .2 10 m ale 1 6 8 .2 + 2 6 .2 15 Sex r a t i o s i n c u l t u r e : S even egg b a t c h e s , p ro d u ced by p a i r e d , l a b o r a t o r y - r e a r e d f e m a l e s , w ere r e a r e d u n t i l a l l p ro g en y had r e a c h e d i n s t a r IV* t h a t tim e was n o t a s s e s s e d . M o rta lity d u rin g T h u s, o n ly t h e f i n a l number o f i n d i v i d u a l s i n e a c h c l o n e was known ( T a b le 1 0 ) . They were k i l l e d and sex ed 47 ( i n c l u d i n g th o s e e x t r a c t e d from m o l tin g ch am bers)* P e r c e n t fe m a le s p e r c l o n e r a n g e d fro m 3 9 .0 t o 5 9 . 5 , w ith a mean o f 48.5% . Sex r a t i o o f pro g en y p r o d u c e d i n c u l t u r e was t h u s c l o s e to u n ity . D uring th e tim e when s t o c k a n i m a ls were u sed f o r o b s e r v a t i o n s on i n s t a r d u r a t i o n and m o r t a l i t y , t h i s o b s e r v a t i o n was i n d i r e c t l y c o n firm ed . More th a n 2500 l a b o r a t o r y - r e a r e d i n d i v i d u a l s were needed f o r t h e s e o b s e r v a t i o n s ; t h e r e was n e v e r a d e a r t h o f a n i m a ls o f e i t h e r s e x , from i n s t a r IV t o V l l ( a l t h o u g h t h e r e w a s , e v e n t u a l l y , a l a c k o f a n i m a ls o f s p e c i f i c i n s t a r s ) . A ll s t o c k s a p p e a r e d t o c o n t a i n r o u g h ly e q u a l numbers o f e a c h s e x . T a b le 10. P e r c e n t f e m a le s i n l a b o r a t o r y - r e a r e d c l o n e s . C lone no._______ 1________ 2________ 3________ 4________ 5________ 6________ 7 n o ./c lo n e % f e m a le s 3 .3 . 37 71 47 56 39 25 . 39 5 9 .5 5 9 .2 4 4 .7 4 8 .2 4 8 .7 4 0 .0 3 9 .0 S u rv iv a l A) M ethods^ The r e c o r d s o b t a i n e d f o r t h e d u r a t i o n s o f Imm ature s t a d i a o f j?. i n c o n s t a n s were a l s o u s e d t o e s t i m a t e t e m p e r a t u r e - s p e c i f i c su rv iv o rsh ip . b a sis. M o r t a l i t y i n t h e s e c u l t u r e s was n o t a s s e s s e d on a d a i l y Dead P. i n c o n s t a n s were d i f f i c u l t t o l o c a t e w i t h o u t s e v e r e d i s t u r b a n c e o f th e c u l t u r e s and t h e i r I n h a b i t a n t s , e s p e c i a l l y i f d e a t h had o c c u r r e d i n s i d e a m o l tin g cham ber. T h e r e f o r e , 2 t o 4 weeks a f t e r t h e e c d y s e s o f t h e presumed l a s t l i v e i n d i v i d u a l s o f a g iv e n s t a g e , th e 48 c u l t u r e s were t h o r o u g h l y exam ined f o r d e a d a n i m a l s . V irtu a lly a l l of them c o u l d be l o c a t e d . B) S u r v i v a l o f im m atures The d a t a f o r im m atures w ere e x p r e s s e d a s t o t a l p e r c e n t s u r v i v a l p e r s t a g e and t e m p e r a t u r e . R a th e r t h a n t i m e - r e l a t e d m o r t a l i t y r a t e s , t h e y th u s r e f l e c t t h e s u r v i v o r s h i p p o t e n t i a l o f i n d i v i d u a l s from th e tim e t h e y e n t e r e d a s t a g e to t h e i r em ergence a s t h e n e x t h i g h e r i n s t a r . A p p ro x im a te ly 100 i n d i v i d u a l s o f e a c h s t a g e were o b s e r v e d , th e e x c e p t i o n b e in g s t a g e V II o f w hich n o t enough w ere a v a i l a b l e . S u r v i v a l a t 26.6°C was so p o o r t h a t i n s t a r V II was n o t s u b j e c t e d to t h a t t e m p e r a t u r e . S ta g e IV had t h e h i g h e s t s u r v i v a l p e r c e n t a g e (10% ), w h i l e no V and V I, and o n ly v e r y few I , I I and I I I , su rv iv ed ( T a b le 1 1 ) . At 1 5 .5 ° and 21°C s u r v i v a l f r e q u e n t l y r e a c h e d 100%, w ith l i t t l e e v i d e n c e o f d i f f e r e n c e s b etw een t h e two t e m p e r a t u r e s o r betw een in s ta rs. O v e r a l l , b o t h m a les and f e m a le s a p p e a r e d t o s u r v i v e e q u a l l y w e l l ( T a b le 1 1 ) . Only 44% o f th e i n s t a r I r e a r e d a t 10°C s u c c e s s f u l l y m o lte d to i n s t a r 11. P e r c e n t s u r v i v a l t h e n r o s e t o 79% f o r I I , and f i n a l l y r e a c h e d l e v e l s o f 90 t o 98% s i m i l a r t o t h o s e r e c o r d e d a t 1 5 .5 ° and 21°C. High m o r t a l i t y o f s m a l l s t a g e s a t 10°C may be a t l e a s t p a r t i a l l y an a r t i f a c t . Toward t h e v e r y end o f t h e s e o b s e r v a t i o n s t h e s u b s t r a t e used f o r i n s t a r s I a n d I I c u l t u r e s was found t o d i f f e r s l i g h t l y from t h a t u s e d f o r o t h e r i n s t a r s : t h e d u f f was c o a r s e r , c o n t a i n e d l e s s l e a f mold and o r g a n i c d e b r i s and seemed t o have a l e s s e r c a p a c i t y f o r w a t e r 49 re te n tio n * I f f i r s t and s e c o n d i n s t a r s w ere in d e e d f o r c e d to m o lt u n d e r i n a d e q u a t e c o n d i t i o n s , th e n m o r t a l i t y o f s m a l l s t a g e s would h av e been o v e re s tim a te d . S u r v i v a l d a t a a r e g r a p h i c a l l y sum m arized i n F i g u r e 8 , w i t h o u t d i f f e r e n t i a t i o n b etw ee n s ex es* I f one d i s r e g a r d e d t h e d a t a f o r I and I I a t 10°C, s u r v i v o r s h i p was h i g h - v i r t u a l l y e q u a l l y so - a t t e m p e r a t u r e s r a n g i n g from 10° t o 21°C. High m o r t a l i t y a t 2 6 .6 °C may be i n t e r p r e t e d a s a r e s u l t o f th e lo n g p e r i o d s o f e x p o s u re o f a n i m a ls to t h a t t e m p e r a t u r e : fie ld t h e r e i s e v i d e n c e from b o a r d c a p t u r e s i n t h e ( s e e S e c t i o n I I . 3 . 3 . ) t h a t b r i e f p e r i o d s o f h ig h te m p e r a t u r e can be e n d u r e d by P. i n c o n s t a n s . C) 'B* S u rv iv a l of a d u lts i n c o n s t a n s u sed i n s t u d i e s o f t e m p e r a t u r e - d e p e n d e n t r e p r o d u c t i o n ( S e c t i o n 1 . 3 . 4 . ) stemmed from l a b o r a t o r y s t o c k s . They w ere c o l l e c t e d and p a i r e d upon c o m p l e t i o n o f t h e i r f i n a l m o lt ( d a y 1 of a d u lt l i f e ) . S in c e t h e i r day o f d e a t h was known, t h e r e c o r d s were u s e d to a s s e s s t h e e f f e c t s o f t e m p e r a t u r e on a d u l t l o n g e v i t y . At 21°C, o b s e r v a t i o n s w ere c a r r i e d th r o u g h t o t h e d e a t h o f a l l i n d i v i d u a l s . At 10° and 1 5 .5 ° C , t h e s tu d y was d i s c o n t i n u e d on day 330. At t h a t t i m e , 4 f e m a le s and 6 m a les were s t i l l a l i v e a t 10°C ; 2 fe m a le s and 1 male w ere a l i v e a t 1 5 .5 °C . L o n g e v ity was c a l c u l a t e d w i t h o u t r e g a r d to t h e s e s u r v i v o r s , and l o n g e v i t y means a r e t h e r e f o r e a p p r o x im a te r a t h e r th a n e x a c t v a l u e s . F i g u r e 9 shows t h a t betw een 10° a n d 21°C t h e r e l a t i o n b etw een l o n g e v i t y and t e m p e r a t u r e a p p e a r s t o be l i n e a r , f o r b o th m ales and f e m a l e s ; and t h a t 26. fc°C p r o b a b l y comes c l o s e t o t h e u p p e r l e t h a l 50 PERCENT SURVIVAL 100 80 60 40 10 20 I II III IV V VI VII I N S T A R Figure 8. Percent survival of immatures at four temperatures. T ab le 11* S u r v i v a l o f im m atures a t f o u r t e m p e r a t u r e s , c a l c u l a t e d from the number o f a n im a ls o f a g iv e n s t a g e t h a t s u c c e s s f u l l y m o lted to th e s u b se q u e n t s ta g e * INSTAR 1 n 10°C % su rv iv . n 1 5 . 5°C % s u rv iv * n 21°C % su rv iv . n 26.6°C Vo su rv iv . II III IV V 100 100 100 4 4 .0 7 9 .0 9 9 .0 100 100 100 9 5 .0 9 5 .0 9 9 .0 100 99 100 99 .0 9 8 .0 9 8 .0 100 100 100 100 3 .0 1 .0 2 .0 10. 0 VI VII C? £ d* 46 54 51 51 50 50 24 25 9 1 .3 96 .3 9 8 .0 96.1 9 8 .0 9 4 .0 9 5 .8 9 6 .0 51 49 50 50 49 51 29 26 9 8 .0 9 8 .0 9 8 .0 9 8 .0 9 8 .0 100 9 2 .0 50 50 50 40 50 50 40 50 9 8 .0 100 9 8 .0 9 4 .0 9 5 .0 9 5 .0 98 .0 100 100 100 0. 0 100 0 .0 52 300” 14 200 FEMALES “ 13 MEAN LONGEVITY, DAYS MALES .23 23 100 ‘ 15 15 n-------------- 1---------------1---------------r 10 15.5 21 26.6 TEMPERATURE ° C Figure 9. Longevity of adults at four temperatures (means + S.D.). Numbers in the figure indicate the number of rep­ licates per temperature and sex. 53 te m p e ra tu re f o r I n c o n s t a n s * A p o s s i b l e dichoto m y i n l o n g e v i t y b e tw e e n m a le s and f e m a le s a t 10° and 1 5 . 5°C was t e s t e d w ith B e h r e n s ' (1 9 2 9 ) t - s t a t i s t i c . At 10°C m a le s l i v e d s i g n i f i c a n t l y l o n g e r th a n f e m a le s (p < 0 . 0 5 ) , b u t n o t so a t 15*5°C (p < 0 * 1 ) . The p r o g r e s s i v e m o r t a l i t y o f f e m a le s o v e r tim e i s i l l u s t r a t e d i n F ig u r e 10. At t h e two lo w e r t e m p e r a t u r e s t h e l i n e s a r e o p e n -e n d e d b e c a u s e o b s e r v a t i o n s had t o be d i s c o n t i n u e d a f t e r 330 d a y s , b u t s u r v i v a l p e r c e n t a g e s were c a l c u l a t e d from t h e t o t a l o r i g i n a l number o f re p lic a te s. The l i f e sp an o f a d u l t f e m a le s i n c u l t u r e a p p a r e n t l y can e x c e e d 330 d ay s a t 10° and 1 5 .5 °C . F u r t h e r a s p e c t s o f a d u l t l o u g e v i t y w i l l be d i s c u s s e d i n l a t e r s e c t i o n s , p a r t i c u l a r l y t h o s e p e r t a i n i n g to t h e r e p r o d u c t i v e p o t e n t i a l o f J?. i n c o n s t a n s . 3 .4 . O v i p o s i t i o n and f e c u n d i t y A) Methods F r e s h l y - m o l t e d a d u l t s w ere c o l l e c t e d from 1 5.5°C s t o c k c u l t u r e s an d d i s t r i b u t e d , i n p a i r s , o v e r t h r e e t e m p e r a t u r e r e g im e s . At 10°C, 13 p a i r s were e s t a b l i s h e d ; 15 p a i r s were i n c u b a t e d a t 1 5 .5 °C , an d 45 p a i r s a t 2 1 °C. From t h o s e 45 p a i r s , 22 w e re random ly s e l e c t e d f o r a s s e s s m e n t o f sperm s t o r a g e c a p a b i l i t y : a f t e r t h e f e m a le s had o v i p o s i t e d t w i c e , t h e m ales were removed from t h e i r c u l t u r e s . A s im p le c h a r t ( F i g u r e 11) sum m arizes th e e x p e r i m e n t a l d e s i g n . At 21°C a l l a n i m a ls were o b s e r v e d u n t i l d e a t h , b u t a t 10° an d 15.5°C t h e l a s t s u r v i v o r s were d i s c o n t i n u e d a f t e r 330 d a y s . A s e c o n d e x p e r i m e n t a l s e r i e s was e s t a b l i s h e d w ith a n im a ls c o l l e c t e d i n Baker w o o d lo t betw ee n m id-M arch and m i d - A p r i l 1979. Most o f t h e c o l l e c t e d fe m a le s w ere p a i r e d e i t h e r w i t h f i e l d - c o l l e c t e d o r 54 10 PERCENT SURVIVAL 80- 60 " 40- 50 250 150 TIME IN DAYS Figure 10. Survival of paired, laboratory-reared adult females at four temperatures. 350 55 w i t h l a b o r a t o r y - r e a r e d m a le s , w h i l e some w ere i s o l a t e d im m e d ia te ly a f t e r c o lle c tio n * R e p l i c a t i o n and e x p e r i m e n t a l h i s t o r y o f a l l c o l l e c t e d a n i m a ls a r e sum m arized i n F i g u r e 12. R e a rin g methods f o llo w e d t h e g e n e r a l r u l e s o u t l i n e d p r e v i o u s l y * The c u l t u r e s w ere o b s e rv e d a t i n t e r v a l s o f 2 t o 4 d a y s . Those t h a t became i n f e s t e d w i t h m i t e s were d i s c a r d e d an d t h e d a t a p e r t a i n i n g t o them w ere n o t u s e d . The r e p l i c a t i o n s g i v e n i n F i g u r e s 11 and 12 i n c l u d e o n ly t h o s e f e m a le s and p a i r s t h a t d i d n o t become p a r a s i t i z e d . In b o th s e r i e s ( l a b o r a t o r y - r e a r e d and f i e l d - c o l l e c t e d ) r e c o r d s were k e p t o f t h e d a t e s o f o v i p o s i t i o n , t h e c h o i c e o f n e s t i n g s i t e s , t h e number o f eggs l a i d , and o f egg v i a b i l i L y . In g e n e r a l , t h e p a r e n t s w ere t r a n s f e r r e d t o a new c o n t a i n e r e v e r y ti m e an egg chamber was d i s c o v e r e d . Sim ple i n v e r s i o n o f t h e o ld j a r o v e r a new one p ro v e d to be th e f a s t e s t means o f t r a n s f e r , and d i d n o t a p p e a r to c a u s e even s l i g h t d i s t u r b a n c e t o th e p a r e n t s . Whenever an egg n e s t had b een b u i l t on l o o s e d e b r i s , t h e i n t a c t cham ber (on i t s s u b s t r a t e ) Was t r a n s f e r r e d t o a d i f f e r e n t j a r . Egg cham bers l e f t i n a j a r a f t e r re m o v a l o f t h e p a r e n t s were k e p t m o i s t by o c c a s i o n a l l y a d d in g a d ro p o f w a te r t o th e s u b s t r a t e on w hich t h e y had b een b u i l t . The eg gs were a l lo w e d to h a t c h ; t h e l a r v a e w ere t h e n c o u n te d and t h e chamber was o pened and c h ec k ed f o r any u n d e v e lo p e d e g g s . Egg cham bers In v a d e d by f u n g u s were t e a s e d a p a r t , so t h a t t h e eg g s c o u ld be e n u m e r a te d . I f t h e r e were i n d i c a t i o n s t h a t m a n i p u l a t i o n o r u n u s u a l c u l t u r e c o n d i t i o n s had p la y e d a r o l e i n egg d e v e lo p m e n t, t h e e g g s were c o u n te d b u t th e d a t a on v i a b i l i t y w ere n o t I n c l u d e d i n th e summary o f r e s u l t s . 56 118 FEMALES 118MALES ( r e a r e d to m a t u r i t y a t 1 5 .5 °C ) 15 PAIRS 15 PAIRS a t 10°C a t 1 5 . 5°C 4 SURVIVORS 2 SURVIVORS 73 PAIRS PAIRS a t rti O« AFTER 2 OVIPOSITIONS d is c o n tin u e d a f t e r 330 days 10 PAIRS 22 ISOLATED 23 PAIRS 18 PAIRS a t 10°C a t 21°C a t 21°C a t 2 6 . 6°C F ig u r e 11. Flow c h a r t o f th e e x p e r i m e n t a l use o f m ales an d f e m a le s r e a r e d t o m a t u r i t y i n l a b o r a t o r y s t o c k s a t 1 5 .5 °C . 57 150 FEMALES ( F ie ld -c o lle c te d ) 49 PAIRED 23 PAIRED ._ a t 21°C c iC 23 PAIRED i rtOn XU 15.5°C u 55 ISOLATED a t 21°C a f t e r 25 d a y s (o v ip o sitio n s ta rte d ) ALL TRANSFERRED TO 21°C RANDOM DIVISION 23 PAIRS a t 21°C 22 ISOLATES (m ales removed) a t 21°C F i g u r e 12. Flow c h a r t o f t h e u s e made o f f i e l d - c o l l e c t e d f e m a le s (B a k e r W oo d lo t, M a r c h -A p r ll 1 9 7 9 ). 58 B) F e c u n d i t y and egg v i a b i l i t y T a b le 12 shows th e mean number o f o v i p o s i t i o n s o b s e r v e d i n p a i r e d f e m a le s a t t h r e e t e m p e r a t u r e s , a s w e l l a s t h e mean t o t a l number o f eg g s la id . At t h e tim e t h a t o b s e r v a t i o n s on s u r v i v i n g i n d i v i d u a l s a t 10° an d 1 5 . 5°C w ere d i s c o n t i n u e d ( s e e F i g u r e 1 1 ) , e g g - l a y i n g had become s p o r a d i c and few eggs w ere l a i d a t any one o v i p o s i L i u u . T ab le 12. T o t a l number o f o v i p o s i t i o n s and t o t a l number o f eg g s l a i d p e r fe m a le ( p a i r e d , l a b o r a t o r y - r e a r e d ) . 10°C n f e m a le s o b s e r v e d 12 1 5 . 3°C 15 21°C 22 o v i p o s i t • /fe m a le mean + S.D. (range) 4 . 4 + 2. 4 9 . 8 + 3 .5 1 1 . 0 + 3 .7 (1-9) (4-16) (3-18) e g g s/fe m a le mean + S.D. (range) 2 2 3 .9 + 1 2 3 .2 4 6 8 .7 + 1 4 8 .4 ( 5 1 -4 4 2 ) (187 - 687) 5 2 1 .9 + 2 2 1 .0 (54-839) The h i g h e s t f e c u n d i t y was r e c o r d e d a t 21°C, b e in g s l i g h t l y h i g h e r t h a n t h e mean t o t a l s o b s e r v e d f o r f e m a le s a t 1 5 . 5°C. At 10°C m a tin g and o v i p o s i t o n d i d o c c u r i n t h e c u l t u r e s , b u t th e f e m a le s w ere s l u g g i s h ; some d i d n o t b e g i n e g g - l a y i n g u n t i l th e y had b een i n c u l t u r e f o r o v e r two m onths. Low t e m p e r a t u r e s n o t o n ly d e p r e s s e d f e c u n d i t y r a t e s , b u t a l s o 59 d e c re a se d th e freq u en cy of o v ip o s i t io n s . I n t e r v a l s betw een them enco m passed r o u g h ly one week a t 21°C, 11 days to two weeks a t 1 5 .5 ° C , and a month o r more a t 10°C ( T a b l e 1 3 ) , and i n c r e a s e d w ith s u c c e s s i v e o v ip o sitio n s. The r e p r o d u c t i v e p a t t e r n o f p a i r e d f e m a le s i s i l l u s t r a t e d i n F ig u r e 1 3. The mean number o f eg gs l a i d p e r o v i p o s i t i o n i n c r e a s e d so o n a f t e r r e p r o d u c t i o n b e g a n , th e n d e c r e a s e d s t e a d i l y o v e r a r e l a t i v e l y lo n g p e r i o d o f ti m e . o v ip o sitio n . F e c u n d i ty p eaked e a r l y a t 1 5 .5 ° C , a t t h e t h i r d At 21aC t h e h i g h e s t mean number o f eg g s was r e c o r d e d i n t h e 6 t h o v i p o s i t i o n , and means re m a in e d r e l a t i v e l y h i g h t h r o u g h o u t t h e grad u al d e c lin e . The few e g g - l a y i n g s r e c o r d e d f o r f e m a le s i n i t i a l l y i n c u b a t e d a t 10°C may m i s l e a d : had t h e r e b een more r e p l i c a t e s , a p a t t e r n o f i n c r e a s e and d e c l i n e may h av e em erged more c l e a r l y . However, egg l a y i n g d i d a p p e a r to be c u r t a i l e d by low t e m p e r a t u r e s : t h e t e n f e m a le s t r a n s f e r r e d t o I0°C a f t e r th e y had begun r e p r o d u c i n g a t 21°C ( s e e F ig u r e 11) showed a n e q u a l l y low f r e q u e n c y o f o v i p o s i t i o n , and m ost o f them s t o p p e d e g g - l a y i n g a f t e r a t o t a l o f 8 o r 9 o v i p o s i t i o n s (2 o v i p o s i t i o n s a t 21°C, 6 o r 7 a t 1 0°C ). A few c o p u l a s were o b s e r v e d i n p a i r s o r i g i n a l l y in c u b a t e d a t 2 6 .6 ° C , b u t no eg g s were e v e r l a i d . F iv e o f t h e 18 fe m a le s t h a t were t r a n f e r r e d t o 2 6 . 6°C from 21°C ( s e e F i g u r e 1 1 ) , p ro d u ced one egg b a t c h e a c h , b u t none o f t h e s e d e v e l o p e d . The fe m a le s d i e d soon t h e r e a f t e r . How t e m p e r a t u r e a f f e c t s th e r e a l i z a t i o n o f r e p r o d u c t i v e p o t e n t i a l i n _P. i n c o n s t a n s I s f u r t h e r i l l u s t r a t e d i n F ig u r e 14, by c u m u la tin g mean numbers o f egg s l a i d p e r b a t c h . W i th in any g iv e n p e r i o d o f tim e ( e . g . 100 d a y s ) 2 l° C a llo w e d f o r th e p r o d u c t i o n o f a h i g h e r number o f 60 70 50 40 10°C 30 20 MEAN NO. OF EGGS PER FEMALE 60 15.5°C 10 11 9 OVIPOSITION 13 15 NO. Figure 13. Mean number of eggs per female and oviposition at three temperatures. 61 Figure 14. Mean number of eggs per female , cumulated through successive ovipositions, and plotted against time elapsed since the beginning of egg-laying. MEAN CUMULATIVE TOTAL NO. OF EGGS u> o o CT o © *-J © © o © to o U1 DAYS o> CO CO o SINCE FIRST o o co to OVIPOSITION cn M it* © M o O 00 39 co 63 T a b le 13. I n t e r v a l s , I n d a y s , b e tw e e n s u c c e s s i v e o v i p o s i t i o n s ( p a i r e d , la b o ra to ry -re a re d fe m a le s). 15 .5 °C 10 °C n mean (+ S .D .) ( 1 3 .3 ) iJ.V e 1 2 .4 2 8 .4 ( 1 6 .9 ) 15 7 2 5 .6 ( 9 .1 ) 4-5 7 4 6 .6 5-6 4 3 1 .0 6-7 2 2 9 .5 21 °C n mean (3 .9 ) 22 7 .1 (2 .1 ) 1 1 .3 (2 .4 ) 22 7 .3 (2 .3 ) 15 1 2 .5 (4 .0 ) 21 7 .1 (2 .0 ) ( 2 1 .3 ) 15 1 1 .8 (3 .4 ) 20 7 .1 (1 .2 ) ( 7 .0 ) 13 1 2 .6 (3 .2 ) 19 6 .7 (1 .8 ) 13 1 3 .2 (4 .0 ) 19 7 .7 (2 .9 ) 7-8 10 1 3 .3 (5 .6 ) 19 7 .8 (1 .9 ) S-9 8 1 9 .5 (1 2 .5 ) 16 7 .9 (2 .1 ) 9-10 7 1 5 .6 (3 .7 ) 16 8 .0 (1 .5 ) 10-11 7 1 9 .0 (8 .0 ) 13 8 .2 (2 .2 ) 1 1 -1 2 6 1 6 .3 ( 3 .4 ) i^ C.S (4 .3 ) 1 2 -1 3 4 1 8 .8 (2 .5 ) 8 1 0 .6 (5 .3 ) 13-14 5 1 0 .8 (4 .5 ) 14-15 3 1 2 .3 (2 .9 ) O v ip o s . n mean (± S .D .) 1 -2 10 2 8 .2 2 -3 9 3 -4 (±S .D . ) 64 p r o g e n y b o t h th r o u g h more f r e q u e n t e g g - l a y i n g and th r o u g h a s l i g h t l y h ig h e r f e c u n d i ty (F ig u re 13). Of t h e t e m p e r a t u r e s used i n t h i s i n v e s t i g a t i o n , 21°C a p p e a r e d to be o p t i m a l f o r t h e s p e c i e s , a t l e a s t w i t h r e g a r d to r e p r o d u c t i v e r a t e . C) Egg v i a b i l i t y : D ata on egg v i a b i l i t y p ro v ed to be d i f f i c u l t t o sum m arize. R e c o g n i t i o n o f n o n - v i a b l e e g g s , a f t e r t h e r e m a in d e r o f a b a t c h had h a t c h e d , p r e s e n t e d no p r o b le m s . But when f u n g i in v a d e d a chamber and s m o th e re d i t s c o n t e n t s , one c o u l d n o t t e l l w h e th e r n o n - v i a b i l i t y a l lo w e d f u n g a l g ro w th o r w h e th e r c u l t u r e c o n d i t i o n s en h an c ed f u n g a l in v a s io n of o th e rw ise v ia b le eggs. F i n a l l y , i n view o f th e f a c t t h a t f u n g a l a t t a c k was o b s e r v e d i n t h e f i e l d and may in d e e d be a common o c c u r r e n c e ( S e i f e r t , 1 9 3 2 ) , any eg g s t h a t f a i l e d t o h a t c h were i n c l u d e d i n v i a b i l i t y c a l c u l a t i o n s . The o n l y e x c e p t i o n s were e g g s t h a t had b een m a n i p u l a t e d , and t h o s e i n d e b r i s - b a s e d c h a m b e rs : t h e s e n e s t s w ere d i f f i c u l t t o keep m o i s t on ce th e y h ad b een removed from t h e p a r e n t c u l t u r e s . T a b le 14 shows t h e v i a b i l i t y c o u n t s f o r eggs l a i d by p a i r e d fe m a le s. The h i g h e s t v i a b i l i t y p e r c e n t a g e was r e c o r d e d a t 1 5 .5 °C , b u t th e v a l u e d i d n o t d i f f e r s i g n i f i c a n t l y from t h a t o b t a i n e d a t 21°C (p > 0 . 2 5 ) . V i a b i l i t y am ounted t o 85% a t 10°C; a c c o r d i n g to th e s p a r s e e v i d e n c e a v a i l a b l e f o r 2 6 . 6°C, e g g s w ere t o t a l l y u n a b l e t o d e v e l o p a t t h a t t e m p e r a t u r e . F u n g al c o n t a m i n a t i o n , u n d e r t h e c o n d i t i o n s o f t h e s e e x p e r i m e n t s , a c c o u n te d f o r 67% ( a t 1 0 ° C ), 7 3/o ( a t 1 5 . 5°C) a n d 53% ( a t 21°C) of a l l n o n - v i a b l e e g g s . 65 T a b le 14. A verage p e r c e n t v i a b i l i t y o f eg g s l a i d by p a i r e d , la b o r a to r y - r e a r e d fem a les. __________________________ I n c u b a t i o n T e m p e ra tu re s _______________ 1 5 . 5°C 21°C 8 5 .2 9 3 .7 9 1 .7 + 2 0 .4 + 6 .6 + 7 .4 10°C mean V, v ia b . S.D. n o f f e m a le s n o f eg g s L) 11 15 2687 7030 21 11484 R e p r o d u c t iv e p e r i o d and l o n g e v i t y The d u r a t i o n o f th e r e p r o d u c t i v e p e r i o d was m easured a s t h e number o f d ay s e l a p s i n g betw een t h e f i r s t and l a s t o v i p o s i t i o n o f e a c h f e m a le . As m e n tio n e d e a r l i e r , o b s e r v a t i o n s a t 10° and 1 5.5 °C were d i s c o n t i n u e d a f t e r 330 d a y s . But by t h a t t i m e , few egg b a t c h e s were b e in g l a i d , and t h e lo n g i n t e r v a l s b etw ee n them, a s w e l l a s t h e low number o f eg gs i n them , i n d i c a t e d t h a t l i t t l e b i a s was i n t r o d u c e d by d i s c o n t i n u a t i o n : r e p r o d u c t i o n was in d e e d n a t u r a l l y coming t o a c l o s e . In T a b le 15, l o n g e v i t y o f p a i r e d f e m a le s i s op p o sed t o th e d u ra tio n o f rep ro d u c tiv e a c t i v i t y a t th re e te m p eratu res. v a l u e s i n c l u d e a p r e - and p o s t - r e p r o d u c t i v e p e r i o d . L o n g e v ity At 1 5 .5 ° and 21°C p r e - r e p r o d u c t i v e ti m e (from t h e day o f i n c u b a t i o n ) was o f t h e o r d e r o f a few days o n l y ; b u t a t 10°C i t l a s t e d a s lo n g a s 4 0 -9 0 d a y s . Assuming t h a t c u l t u r e c o n d i t i o n s w ere a d e q u a t e f o r in c o n sta n s, a g r a d u a l d e c l i n e i n f e c u n d i t y ( F i g u r e 13) was n a t u r a l l y f o ll o w e d by a v a r ia b le p e rio d o f s e n i l i t y death . ( p o s t - r e p r o d u c t i v e p e r i o d ) , and e v e n t u a l At none o f t h e t e m p e r a t u r e s w ere t h e r e an y i n d i c a t i o n s t h a t e g g - l a y i n g c o u ld be resumed a f t e r a p e r i o d o f r e s t (w hich would have su g g e ste d i t e r o p a r i t y ) . 66 T a b le 15. Mean number o f days from f i r s t to l a s t o v i p o s i t i o n , and a v e r a g e l o n g e v i t y o f f e m a le s ( p a i r e d , l a b o r a t o r y - r e a r e d ) . 10°C 1 5 .5 °C 21 °C mean + S.D. 110 .1 + 7 7 .3 1 2 7 .1 + 6 0 .6 8 0 .5 + 3 5 .5 ( r a n g u) (1-250) ( 5 8 -2 5 1 ) (1 4 -1 8 0 ) n»12 n=l 5 n=22 2 1 2 .2 + 8 9 .7 1 7 6 .4 + 7 7 .7 re p ro d . p e rio d L o n g e v ity mean + S.D. ( 2 9 - 2 9 0 )* (range) n=9 (1 3 - 3 0 8 ) * n -1 3 1 4 0 .3 + 5 1 .1 (4 8 -2 2 7 ) n»23 * on day 3 30, 4 f e m a le s w ere s t i l l a l i v e a t 10°C, an d 2 a t 1 5 . 5°C; th e y ware n o t i n c l u d e d i n l o n g e v i t y c a l c u l a t i o n s . E) C om parison b etw een f i e l d - c o l l e c t e d and l a b o r a t o r y - r e a r e d fe m a le s: The r e s u l t s n a r r a t e d below c o n c e r n a c o m p a ris o n betw een l a b - r e a r e d and f i e l d - c o l l e c t e d f e m a le s ( M a r c h -A p ril c o l l e c t e d i n Baker v o o d l c t ) . By co m p arin g t h e r e p r o d u c t i v e b i o l o g i e s o f t h e two g r o u p s , a n sw e rs to t h e f o l l o w i n g q u e s t i o n s were s o u g h t : a) Under t h e r e a r i n g c o n d i t i o n s s p e c i f i e d i n t h i s s t u d y , do i n d i v i d u a l s r e a r e d i n t h e l a b o r a t o r y from egg s y i e l d v a l i d d a t a w hich r e f l e c t th e tr u e p o t e n t i a l of th e s p a c ie s ? b) Does t h e s p r i n g - p o p u l a t i o n o f f e m a le s i n t h e f i e l d c o n s i s t o f two g e n e r a t i o n s o f a d u l t s ( o n e - y e a r o l d s and tw o - y e a r o l d s ) ? I f so, 67 would they be recognizable by their differential reproductive biology? c) Is t h e r e e v i d e n c e o f i t e r o p a r i t y i n f e m a le s w hich have n o t been s u b je c te d to c o n s ta n t la b o r a to r y te m p e ra tu re s th ro u g h o u t t h e i r d ev e lo p m e n t? d) What I s t h e sperm s t o r a g e c a p a b i l i t y o f f e m a l e s , and how does i t a f f e c t egg v i a b i l i t y ? e) Does t h e c o n t i n u e d p r e s e n c e o f m a le s a f f e c t t h e l i f e sp a n o r r e p r o d u c t i v e c a p a c i t y o f fe m a le s ? The d a t a u sed i n t h i s c o m p a ris o n stem from p a i r s an d i s o l a t e s c o l l e c t e d from th e f i e l d in e a r l y s p r i n g and i n c u b a t e d a t 21 °C (F f e m a l e s ) a n d from p a i r s and i s o l a t e s o b t a i n e d fro m l a b o r a t o r y s t o c k s and r e a r e d a t 21°C (L f e m a l e s ) ( s e e F i g u r e s 11 and 1 2 ) . Three o f t h e main p a r a m e t e r s o f r e p r o d u c t i v e a c t i v i t y a r e sum m arized i n T a b le 16. Both g r o u p s o f i s o l a t e d f e m a le s p ro d u ced a l a r g e r mean number o f n e s t s , l a i d more e g g s , and had a l o n g e r eg g -ia > iu 6 ^ r i o u th a n e i t h e r o f th e g r o u p s o f p a i r e d f e m a l e s . V a r ia n c e s o f e a c h s e t o f d a t a were t e s t e d w ith B a r t l e t t ' s (1 9 3 7 ) s t a t i s t i c and w ere found to be e q u a l . The means o f e a c h s e t o f r e s u l t s w ere t h e n t e s t e d by t h e B o n f e r r o n i t - t e s t ( n o n - o r t h o g o n a l c o n t r a s t s ) ; t h e r e s u l t s a r e summarized i n T a b l e 17. C on cerning t h e number o f o v i p o s i t i o n s ( n e s t s ) , t h e m o st s i g n i f i c a n t d i f f e r e n c e s l a y b e tw e e n p a i r e d and i s o l a t e d f e m a l e s , w i t h i n t h e L a s w e l l a s w i t h i n t h e F g r o u p , b u t F - p a i r s l a i d s l i g h t l y few er egg b a t c h e s t h a n L - p a i r s (P 0 .0 1 ). The two g r o u p s o f i s o l a t e s d id not d iffe r sig n ific a n tly . I s o l a t e d f e m a l e s , b o t h L an d F , a l s o l a i d s i g n i f i c a n t l y more e g g s 68 t h a n t h e i r p a i r e d c o u n t e r p a r t s , " i t h i n p a i r e d (L an d F) and w i t h i n i s o l a t e d (L and F) f e m a l e s , d i f f e r e n c e s i n egg p r o d u c t i o n w ere u u i sig n ific a n t. S i m i l a r r e l a t i o n s h i p s betw een t h e f o u r g ro u p s became a p p a r e n t in t h e d u r a t i o n o f t h e i r mean r e p r o d u c t i v e p e r io d s * L p a i r s b eh av e d much l i k e F p a i r s , b u t b o t h d i f f e r e d s i g n i f i c a n t l y from t h e i r r e s p e c t i v e is o la te d c o u n te rp a rts. L o n g e v ity i n c u l t u r e f o ll o w e d Much th e same t r e n d a s r e p r o d u c t i v e a c t i v i t y : i s o l a t e d f e m a le s l i v e d l o n g e r t h a t p a i r e d f e m a l e s , w h e th e r l a b o r a t o r y - r e a r e d o r f i e l d - c o l l e c t e d ( T a b le 1 8 ) . C a l c u l a t i o n o f 95% c o n f i d e n c e i n t e r v a l s show ed, ho w ev er, t h a t t h e means d i f f e r e d s i g n i f i c a n t l y b o t h w i t h i n and betw een g r o u p s ( S c h c f f c ' o i n t e r v a l , v a r i a n c e s b e in g u n e q u a l ; . g iv e n i n T a b le 19. C o n fid e n c e i n t e r v a l s f o r e a c h c o n t r a s t a r e Knowing th e p a s t h i s t o r y o f e a c h g r o u p , a s im p l e e x p la n a tio n f o r th e se d i f f e r e n t i a l l i f e spans p r e s e n ts i t s e l f : p a ir s d i f f e r e d from i s o l a t e s ( w i t h i n L an d w i t h i n F) a p p a r e n t l y due t o th e p resen ce of m ales. L p a i r s l i v e d l o n g e r t h a n F p a i r s , and L i s o l a t e s l o n g e r th a n F i s o l a t e s , b e c a u s e a n i m a ls from t h e f i e l d had a l r e a d y s p e n t p a r t o f t h e i r l i f e s p a n a t t h e tim e th e y were c o l l e c t e d . The p a r a m e te r t h a t re m a in e d to be t e s t e d was egg v i a b i l i t y . In o r d e r to a v o id b i a s , t h e few f e m a le s w hich n e v e r l a i d v i a b l e e g g s o v e r t h e i r e n t i r e r e p r o d u c t i v e p e r i o d w ere I n c l u d e d ; a s a r e s u l t , v i a b i l i t y o f t e n r a n g e d from 0 t o 100 p e r c e n t . On t h e a v e r a g e , v i a b i l i t y was s l i g h t l y h i g h e r i n p a i r e d fe m a le s th a n i n i s o l a t e s ( T a b l e 2 0 ) ; b u t when th e y w ere s t a t i s t i c a l l y c o n t r a s t e d ( S c h e f f e ' s 95% C . 1 . ) , none o f t h e d i f f e r e n c e s p ro v e d t o be s i g n i f i c a n t ( a l l c o n f i d e n c e i n t e r v a l s i n c l u d e d zero). 69 T a b le 16. R e p r o d u c t i v e a c t i v i t y o f f e m a le s a t 2 1 °C ( r a n g e s I n p a r e n t h e s e s ; L = l a b o r a t o r y s t o c k , F *» f i e l d - c o l l e c t e d ) . d u ra tio n t o t a l n e sts t o t a l eggs eg g -la y in g Groups n» mean ± S.D. mean + S.D . mean + S.D . L p aire d 22 1 1 . 0 + 3 .7 5 2 1 .9 + 2 2 1 .0 8 0 .5 + 3 5 .5 (3-18) (54-839) 22 L iso la te d 1 4 . 1 + 3 .8 6 9 4 .7 + 1 9 3 .0 (4-22) F p aired 48 b' i s o l a t e d T a b le 17. 55 1 1 6 .1 + 4 0 .6 (2 1 7 -1 0 3 6 ) 8 .6 + 3 .6 4 9 0 .5 + 19 3 .6 (1-21) ( 4 8 -1 1 0 6 ) 1 2 .4 + 3 .6 6 1 7 .4 + 1 5 9 .0 (3-22) ( 1 5 5 -9 2 0 ) 6 6 .0 + 3 1 .9 1 0 7 .3 + 3 2 .5 B o n f e r r o n l t - t e s t o f t h e mean t o t a l number o f o v i p o s i t i o n s , number o f e g g s , an d d u r a t i o n o f r e p r o d u c t i v e p e r i o d a t 21°C (L * la b -re a re d , F * fie ld -c o lle c te d ). S ig n if ic a n c e Level C o n tra sts repro. per. no. o f o v ip . n o . eggs L p aire d vs. L is o la te d P < 0 .0 2 P < 0 .02 P 4 0 .0 1 F p aire d v s. F is o la te d P < 0 .1 P <0.01 B 40.01 L p a ire d v s. F p aired P < 0 .0 1 P>0.1 P>0.1 L is o la te d vs. F iso la te d P > 0 .1 P>0.1 P >0.1 70 T a b l e 18. A v erag e l o n g e v i t y o f f e m a le s a t 21°C: (L ■ l a b - r e a r e d ; F ■ fie ld -c o lle c te d ). L o n g e v i t y , days Groups mean ± S.D._________ ra n g e L p aired 1 4 0 .3 + 5 1 .1 48 - 227 L is o la te d 2 0 6 .8 + 5 1 .4 10 7 - 270 9 7 .3 + 3 7 .2 51 - 190 1 4 2 .9 ± 3 6 .0 70 - 209 F p aired F iso la te d T a b le 19. L o n g e v ity o f f e m a le s a t 21°C: S c h e f f e ' s c o n f i d e n c e i n t e r v a l s on t h e d i f f e r e n c e s b etw ee n s e l e c t e d mean. (L ■ l a b - r e a r e d ; F ■ f i e l d - c o lle c te d ). ________ C o n t r a s t s _______________________________ 95% C . I . L p aired v s . L is o la te d -6 6 .5 + 3 9 .0 F p aire d v s. F iso la te d -4 5 .6 + 1 8 .7 L p aire d vs. F p aire d L is o la te d vs F is o la te d 43. 0 + 30. 5 6 3 .9 + 3 0 .7 E f f e c t s o f i s o l a t i o n on egg v i a b i l i t y c o u l d , h o w ev er, be shown by su m m a rizin g egg d e v e lo p m e n t d a t a f o r s u c c e s s i v e o v i p o s i t i o n s ( F i g u r e 15). In F fe m a le s e s p e c i a l l y , i s o l a t i o n d i d n o t s i g n i f i c a n t l y d e c r e a s e v i a b i l i t y d u r i n g t h e f i r s t 9 t o 11 o v i p o s i t i o n s . At t h a t p o i n t , p a i r e d f e m a le s e x p e r i e n c e d r a p i d m o r t a l i t y , b u t i s o l a t e s c o n t i n u e d t o l a y e g g s , o f which few er and few er h a t c h e d ( F i g u r e 15A). In L f e m a l e s , th e d i s c r e p a n c y b etw ee n p a i r s and i s o l a t e s was 71 100- PAIRS 80- 60Em H 40 “ ISOLATES FIELD-COLLECTED FEMALES (-1 H CQ 20- < H > Em 100 T T T 5 7 9 T" 11 ~~r 13 "T “ 15 T " 17 “ 2 W O 80- w & 60- PAIRS at 40ISOLATES LAB-REARED FEMALES 20- i 1 1---------1---------1---------1-------- 1-------- 1-------- r 3 5 7 9 11 13 15 OVIPOSITION NO. Figure 15. Percent viability of eggs laid at selected ovipositions. 72 somewhat g r e a t e r d u r i n g e a r l y o v i p o s i t i o n s ( F i g u r e 15 B ), b u t t h e d e c l i n e i n v i a b i l i t y o f egg s l a i d by i s o l a t e s was e q u a l l y pronounced* I n g e n e r a l , r e p e a t e d m a tin g a p p e a r e d to be u n n e c e s s a r y f o r th e p r o d u c t i o n o f v i a b l e eg g s - a t l e a s t d u r i n g t h e p e r i o d o f h i g h e s t f e c u n d i t y ( g r e a t e s t number o f eg g s p e r o v i p o s i t i o n ) . I n c r e a s e d l o n g e v i t y o f i s o l a t e s a llo w e d them to o v i p o s i t f o r a l o n g e r p e r i o d o f t i m e ; t h e y p ro d u c e d more n e s t s , b u t w i t h fe w e r eg g s i n e a c h , and p r o g r e s s i v e l y f e w e r o f t h e s e eg g s h a t c h e d . T a b le 20. V i a b i l i t y o f eggs l a i d by l a b and f i e l d fe m a le s a t 21°C. P e r c e n t v i a b i l i t y i s t h e mean v i a b i l i t y p e r f e m a le . (L « l a b - r e a r e d ; F = fie ld -c o lle c te d ). n Female group (fe m a le s) n % v ia b ility (eggs) mean + S.D . range % L - p aire d 22 1 1 ,4 8 1 8 7 .5 + 2 0 .4 0 - 100 L - iso la te d 22 1 5 ,2 8 4 8 3 .4 + 1 2 . 6 54 - 100 F - p aired 48 2 3 ,5 4 5 9 0 .7 + 1 7 .0 0 - 100 F - iso la te d 55 33 ,957 8 3 .9 + 2 1 .9 0 ~ 100 4. DISCUSSION C om prehensive d i p l o p o d r e a r i n g program s h a v e r a r e l y been c o a d u c te d in th e p a s t. B lo w e r 's (19 7 4 ) work i s an o u t s t a n d i n g e x c e p t i o n : r e a r e d O p h y iu lu s p i l o s u s fro m egg to a d u l t . he The d a t a w ere l a t e r used t o c l a r i f y d e t a i l s o f t h e s p e c i e s ' l i f e c y c l e i n t h e f i e l d (B low er and M ille r , 1974). R a n t a l a (1 9 7 0 , 1974) f o l l o w e d th e d ev elo p m en t of 73 in d i v i d u a l s of P r o te r o i u lu s fu sc u s f o r a p e rio d o f s e v e r a l y e a r s , p r o v i d i n g an u n u s u a l d e m o n s t r a t i o n o f r e a r i n g s u c c e s s * A number o f o t h e r s p e c i e s have been r e a r e d th r o u g h p a r t s o f t h e i r l i f e c y c le * A lth o u g h ev en p a r t i a l r e a r i n g i n d i c a t e s a d e q u a t e c u l t u r e c o n d i t i o n s , i n d i s c r i m i n a t e u se o f t h e te rm " s u c c e s s f u l r e a r i n g " does n o t alw ay s appear ju s tif ie d . Three m a jo r c r i t e r i a may be u s e d f o r " s u c c e s s ” : a ) p ro d u c tio n of v i a b l e o f f s p r i n g i n l o n g - t e r m c u l t u r e , th r o u g h more t h a n one g e n e r a t i o n ; b) low m o r t a l i t y o f a l l s t a g e s a t t h e m ost f a v o r a b l e t e m p e r a t u r e s ; and c) c o m p a t i b i l i t y o f l a b o r a t o r y d a t a w ith co rresp o n d in g f i e l d o b s e r v a tio n s . a l l t h e ti m e . Not a l l o f t h e s e c r i t e r i a a r e met Blower (1974) c o n s i d e r s t h e r e a r i n g o f p il o s u s to 0* a d u l t h o o d , on sycam ore l e a v e s a l o n e , a r e s u l t o f n o t e . But th e s p e c i e s would n o t r e p r o d u c e i n c u l t u r e , and t h e a u t h o r s u g g e s t s t h a t r e a r i n g c o n d i t i o n s were n o t a d e q u a t e . In g e n e r a l , th e c r i t e r i o n o f s u c c e s s f u l r e p r o d u c t i o n a p p e a r s t o be t h e m ost d i f f i c u l t to m eet i n t h e la b o ra to ry . At l e a s t i n p o l y d e s m i d s , s i n g l e o v i p o s i t i o n s f o ll o w e d by d e a t h o f t h e f e m a le s p r o b a b l y do n o t r e f l e c t t h e i r t r u e p o t e n t i a l . In th e p r e s e n t s t u d y , r e c o r d s o f up to 22 o v i p o s i t i o n s p e r f e m a le g i v e th e im p re ssio n o f a f u l l y r e a l i z e d r e p r o d u c tiv e p o t e n t i a l . C u l t u r e m ethods w ere a d e q u a t e , s i n c e P. i n c o n s t a n s c o u ld be r e a r e d th r o u g h two g e n e r a tio n s w ith o u t s ig n s o f d e t e r i o r a t i o n . s u c c e s s were w e l l m e t: In f a c t , a l l c r i t e r i a f o r M o r t a l i t y o f a l l s t a g e s was low . C o n tin u o u s p r o d u c t i o n o f v i a b l e eggs was m a i n t a i n e d th r o u g h more t h a n one g e n e ra tio n . And r e p r o d u c t i v e b e h a v i o r and l o n g e v i t y were s i m i l a r i n l a b o r a t o r y s t o c k and f i e l d - c o l l e c t e d i n d i v i d u a l s . 74 L i f e c y c l e d a t a o b t a i n e d i n t h e l a b o r a t o r y c a r r y th e s tig m a o f p a r t i a l i n v a l i d i t y due to t h e c o n s t a n c y and a r t i f i c i a l i t y o f co n d itio n s* U s u a lly t h i s c a n n o t be p r e v e n te d * But i t was shown h e r e t h a t p a s t d ev elo p m en t h i s t o r y o f _P. i n c o n s t a n s d i d n o t a f f e c t th e v a l i d i t y of r e s u l t s co n ce rn in g re p ro d u c tio n . F em ales r e a r e d fro m eg gs u n d e r c o n s t a n t c o n d i t i o n s b ehaved i n a manner v e r y s i m i l a r to t h o s e th a t reached m a tu rity under f l u c t u a t i n g f i e l d co n d itio n s* S t u d i e s on t h e e f f e c t o f fo o d t y p e on m i l l i p e d e d e v e lo p m e n t s u g g e s t t h a t c h o i c e o f fo o d m a t e r i a l s can p l a y an i m p o r t a n t r o l e in r e a r i n g s u c c e s s ( G e r e , 1955; McBrayer, 1973; K e i r a l l a h , 1973; K e i r a l l a h , 1978). In t h e l a b o r a t o r y , d e c id u o u s l i t t e r i s p r o b a b ly t h e m o st commonly u s e d foo d so u rce* O th e rs i n c l u d e s o i l and p o t a t o s l i c e s ( B a k e r , 1 9 7 8 a ) , s o i l , moss and p o t a t o ( P e r t t u n e n , 1955) and f i l a m e n t o u s a l g a e ( K e i r a l l a h , 1 9 7 3 ). Blower (1 9 7 4 ) s u g g e s t t h a t p r e - d r i e d fo o d l a c k s m i c r o f l o r a , a n e c e s s a r y fo o d it e m f o r m i l l i p e d e s . McBrayer (1 973 ) shows t h a t r e - i n g e s t i o n o f f e c e s a l lo w s t h e a n i m a ls a c c e s s to m ic ro b e s and t h e i r c e l l u l a s e s , and e n h a n c e s w e ig h t g a i n o v e r ti m e . In t h e p r e s e n t s t u d y , d e ca y ed l i t t e r and wood were alw ays u s e d f r e s h , an d t h e added y e a s t may have p r o v id e d a s e m i - n a t u r a l , r e a d i l y a v a i l a b l e s o u r c e o f e n e r g y f o r P. i n c o n s t a n s * In c u l t u r e s t h a t had b een n e g l e c t e d f o r some t i m e , a d d i t i o n s o f y e a s t p ro d u ced a n im m ediate resp o n se: t h e a n i m a ls l i n e d up a ro u n d th e y e a s t and f e d much l i k e c a t t l e aro u n d a t r o u g h . Under t h e c o n d i t i o n s o f t h i s s t u d y , P. i n c o n s t a n s d e v e lo p e d f a s t e s t a t 21°C, w hich in d u c e d t h e s h o r t e s t d u r a t i o n s o f egg and im m ature s t a g e s a s w e l l as t h e h i g h e s t f e c u n d i t y and o v i p o s i t i o n frequency. M o r t a l i t y was low a t b o t h 15*5° and 21°C, and a l s o a t 75 10°C - w i t h th e p o s s i b l e e x c e p t i o n o f v e r y young i n s t a r s , a s d i s c u s s e d e a rlie r. The h i g h e s t t e m p e r a t u r e u s e d , 2 6 .6 °C , a p p r o x im a te d t h e u p p e r l e t h a l l i m i t f o r th e s p e c i e s . N e i t h e r e g g s n o r im m atures c o u ld s u r v i v e p r o lo n g e d e x p o s u r e t o i t . S u r v i v a l o f a d u l t f e m a le s was i n f l u e n c e d n o t o n ly by t e m p e r a t u r e , b u t a l s o by t h e p r e s e n c e o f m a le s . th o se k ep t i n i s o l a t i o n . P a i r e d fe m a le s d i e d s o o n e r th a n P a irin g in sm all c o n ta in e rs i s a fo rc e d s i t u a t i o n , i n w hich th e " s e x u a l d r i v e " ( S a h l i , 1969) o f m ales r e s u l t s i n f r e q u e n t c o p u l a t i o n , ev e n i n t e r r u p t i n g e g g - l a y i n g a c t i v i t y . S ah li (1 969 ) a l s o o b s e r v e d , i n P. a n g u s t u s , t h a t many m a tin g s d i m i n i s h e d t h e l i f e span o f f e m a le s . I t i s p r o b a b l e t h a t r e p e a t e d m a tin g s ta k e p l a c e i n th e f i e l d as w e ll, c o n t r i b u ti n g to th e n a t u r a l m o r t a l i t y r a t e s o f fem a les. T his i s n o t n e c e s s a r i l y a n e g a t i v e e f f e c t . P a i r e d fe m a le s i n c u l t u r e g e n e r a l l y showed r a p i d d i e - o f f o n ly a f t e r t h e i r m a jo r c o n t r i b u t i o n to r e c r u i t m e n t had b een made, e . g . a t a tim e when t h e number o f eg g s p e r o v i p o s i t i o n c l e a r l y b egan t o d e c r e a s e . In t h e f i e l d , fo o d a v a i l a b i l i t y can b e a l i m i t i n g f a c t o r d u r i n g th e summer months ( M i l l e r , 1974; S t a c h u r s k i , 196 8, 1 9 7 2 ). Removal o f a d u l t f e m a le s from th e p o p u l a t i o n would r e d u c e i n t r a s p e c i f i c c o m p e t i t i o n f o r food a t a tim e when th e new r e c r u i t s o f t h e s e a s o n a r e p r e s e n t i n l a r g e num bers. Of a l l s t a d i a , th e p e n u l t i m a t e was o f th e l o n g e s t d u r a t i o n i n bo th m ales and f e m a l e s ; t h i s seems t o be g e n e r a l l y t r u e f o r p o ly d e sm id s ( M ile y , 1927; C au sey , 19 43; K e i r a l l a h , 1 9 7 8 ). Males w ere a b l e to m a tu re e a r l i e r th a n fe m a le s by s h o r t e n i n g t h e d u r a t i o n o f t h e i r p e n u l t i m a t e s ta d i u m . In £ . p i l o s u s , a l t h o u g h most m ales m a tu re s l i g h t l y e a r l i e r th a n f e m a l e s , m a les te n d t o d e f e r m a t u r i t y . Blower 76 (19 74) r e c o r d e d i n a c t i v i t y p e r i o d s o f raore th a n two months f o r s u b a d u l t m a l e s , and i n t e r p r e t s them a s a d a p t i v e i n a c t i v i t y d e s i g n e d to s y n c h r o n i z e m a t u r a t i o n o f m a les and f e m a l e s . d if f e r e n t stra te g y of d e fe rra l. Ji. s u p e r u s a d o p t s a S te p h e n so n (1 9 6 1 ) fo un d t h a t t h e m a j o r i t y o f _B. s u p e r u s f e m a le s m a tu re i n th e s p r i n g , and t h a t m ales o v e rw in te r in an i n t e r c a l a r y s ta g e : gonopods a r e d e v e lo p e d d u r i n g a s u p e rn u m e ra ry s p r i n g m o lt i n t h e s e o t h e r w i s e m a tu re m a le s . E a r l y m a t u r a t i o n o f m a les i s a d a p t i v e I n s o f a r a s i t a s s u r e s i n s e m i n a t i o n o f f e m a le s as soon a s th e l a t t e r a r e m a tu r e . In i n c o n s t a n s , sperm s t o r a g e a l lo w s m ated b u t i s o l a t e d fe m a le s t o p ro d u c e a p p r o x i m a t e l y t e n b a t c h e s o f eggs w i t h n e a r - n o r m a l v i a b i l i t y , w hich d e c r e a s e s r a p i d l y i n s u b s e q u e n t egg b a t c h e s . Blower (1 96 9b) s u g g e s t s t h a t t h e f r e q u e n t d e p o s i t i o n o f eg gs by s e m e lp a r o u s Polydesm us s p p . i s a means o f " s e e d i n g " n o t y e t c o l o n i z e d a r e a s w i t h new i n d i v i d u a l s . Even s i n g l e f e m a l e s , once m a te d , can s u c c e s s f u l l y in v a d e new h a b i t a t a r e a s b e c a u s e o f t h e i r sperm s t o r a g e c a p a b i l i t y . P'• i n c o n s t a n s a p p e a r s to be w e l l s u i t e d f o r th e t y p e o f p o p u l a t i o n e x p a n s io n d e s c r i b e d by Blower ( 1 9 6 9 b ). I t has th e p o t e n t i a l o f d e p o s i t i n g l a r g e numbers o f s m a l l b ro o d s i n many d i f f e r e n t p l a c e s . A d i f f e r e n t s t r a t e g y i s h y p o t h e s i z e d by Lewis (1 9 7 1 a ) f o r p o ly d e sm o id s i n w hich a d u l t s a r e d i s t i n c t l y s u r f a c e - a c t i v e . In creased p r e d a t i o n on t h e s e s p e c i e s i s a p p a r e n t l y o f f s e t by th e p r o d u c t i o n o f l a r g e numbers o f e g g s ( a b o u t 1000) p e r b r o o d , w hich would te n d to reduce th e e f f e c t of p re d a tio n as a l i m i t i n g f a c t o r . Even i n s p e c i e s w hich a r e n o t c l e a r l y s u r f a c e - a c t i v e , p r e d a t i o n c o n c e iv a b l y r e p r e s e n t s a m a jo r l i m i t i n g f a c t o r . S e i f e r t (1 93 2) m e n tio n s t h a t eg gs and j u v e n i l e s o f S tro n g y lo s o m a p a l l i p e s f r e q u e n t l y 77 f a l l p r e y to th e c e n t i p e d e L i t h o b i u s s p . and t o c a r a b i d b e e t l e s , an d t h a t egg ch am bers may be p lu n d e r e d by o t h e r m i l l i p e d e s . Cole ( 1 9 4 6 ) s u g g e s t s , b a s e d on c i r c u m s t a n t i a l e v i d e n c e , t h a t some s p i d e r s may f e e d on S c y t o n o t u s g r a n u l a t u s . Baker (19 7 4 ) comments on th e p o s s i b i l i t y t h a t s o i l m i t e s may p r e y on f i r s t i n s t a r s o f B. s u p e r u s , a m i l l i p e d e i m p l i c a t e d a s p e s t o f s u g a r b e e t s ( B a k e r , 1974j P i e r r a r d and B ie r n a u x , 1 9 7 4 ) . And M iley ( 1 9 2 7 ) o b s e r v e d a b e e t l e l a r v a e a t i n g t h r e e m o l t i n g i n d i v i d u a l s o f E u ry u ru s e r y t h r o p y g u s . A p p a r e n tl y t h e d e f e n s i v e s e c r e t i o n s o f m i l l i p e d e s (Bano and K r is h n a m o o r th y , 19 78; D uffey and Tow ers, 1978; R o p e r, 1978) a r e i n e f f e c t i v e a g a i n s t c e r t a i n p r e d a t o r s . S m all p o ly d e s m id s s u c h a s P. i n c o n s t a n s may be prim e c a n d i d a t e s f o r p o p u l a t i o n c o n t r o l by p r e d a t i o n . The sm o o th , r o u n d , s t r o n g l y s c l e r o t i z e d i u l i d s a r e more d i f f i c u l t t o g r a s p . Medium and l a r g e - s i z e d 0 . p i l o s u s f o r i n s t a n c e c a n n o t be h e l d and c r u s h e d by c a r a b i d m an d ib les. U sing t h e t y p i c a l w in d in g m o tio n so a p t l y d e s c r i b e d by H aack er ( 1 9 7 4 ) , £ . p i l o s u s s im p ly w inds i t s way o u t o f t h e m o u t h p a r ts o f th e b e e t l e . However, t h e r e i s no good f i e l d e v i d e n c e r e g a r d i n g t h e e x t e n t to w hich m i l l i p e d e p o p u l a t i o n s a r e l i m i t e d by p r e d a t o r s . J u d g in g by t h e d a t a p r e s e n t e d h e r e , t h e r e a r e i n d i c a t i o n s t h a t c a r a b i d s may be a b l e to consume l a r g e num bers o f m i l l i p e d e s , and a l s o t h a t th e a r r a y o f I n v e r t e b r a t e p r e d a t o r s immune t o d e f e n s i v e s e c r e t i o n s may be l a r g e . t h a t were t r u e i n t h e f i e l d , t h e h i g h r e p r o d u c t i v e c a p a c i t y o f JP. i n c o n s t a n s c o u ld e f f e c t i v e l y be c o u n t e r a c t e d by p r e d a t o r a c t i v i t y . If PART II THE LIFE HISTORY OF POLYDESMUS INCONSTANS IN THE FIELD 1. INTRODUCTION The h u m i f i c a t i v e f u n c t i o n o f D ip lo p o d a , w h ich a r e among th e m a jo r s a p r o p h a g e s i n f o r e s t s and g r a s s l a n d , h a s b e e n r e c o g n i z e d f o r many years. Q u a l i t a t i v e l y , t h e i r im p o r ta n c e i s e n v i s i o n e d a s l y i n g i n th e m e c h a n ic a l breakdown o f o r g a n i c m a t t e r and i n t h e m ix in g o f d e t r i t u s w i t h t h e s o i l i t s e l f ; by t h e p r o c e s s o f co m m in u tio n , m i c r o b i a l a c t i v i t y i s en h an c ed a n d , w i t h i t , t h e c h e m ic a l p r o c e s s o f humus f o r m a t i o n . Even th o u g h l i t t e r breakdown i s a x i o m a t i c , t h e s p e c i f i c im p o r ta n c e o f d i p l o p o d f e e d i n g c a n be shown c o n c l u s i v e l y o n ly where th e y a r e t h e d o m inant l a r g e d e t r i t i v o r e , e . g . i n t h e a b s e n c e o f earthw orm s ( G h i l a r o v , 1 9 4 7 ). Q u a n t i f i c a t i o n o f t h e i r e f f e c t s i n te rm s o f l i t t e r d i s a p p e a r a n c e h a s b een a t t e m p t e d a s e a r l y a s t h e 1 9 2 0 's and 3 0 ' s (S o u d ek , 1 928; B o rn e b u s c h , 193C; U l r i c h , 1933; Fourman, 1 9 3 8 ). S in c e t h e n , m a jo r s t u d i e s h a v e shown t h a t t h e m a g n itu d e o f t h e d i p l o p o d c o n t r i b u t i o n to d e c o m p o s i ti o n v a r i e s w i t h t h e c l i m a t i c and v e g e t a t i o n a l c h a ra c te ris tic s of sp e c ific lo c a litie s ( D r i f t , 1 9 5 1 ; D unger, 1956, 1958 , 1960; G e re , 1956, 1962; K u rcev a, 19 60; V o lz , 1 9 5 4 ). Much l a b o r a t o r y work h as a t t e m p t e d to e l u c i d a t e t h e p r e c i s e n a t u r e and e f f e c t o f d i p l o p o d f e e d i n g a c t i v i t y . Sakwa (1 9 7 4 ) foun d t h a t th e a t t r a c t i v e p r o p e r t i e s o f r o t t i n g s u b s t a n c e s seem to i n v o l v e a c o m b in a tio n o f s u g a r - p r e s e n c e and p o l y p h e n o l - a b s e n c e ; on t h e o t h e r h a n d , N eu hauser and H a r t e n s t e i n (1 9 7 8 ) w ere u n a b l e t o r e l a t e food p r e f e r e n c e s to t h e p h e n o l i c c o n t e n t o f l e a v e s . D e s p ite su ch 78 79 d i s c r e p a n c i e s , many a u t h o r s ( S c h m i d t, 19 5 2 ; N i e l s e n , 1 962; K e i r a l l a h , 19 66; Sakwa, 1 97 4 ; and o t h e r s ) have s u g g e s t e d t h a t m i l l i p e d e s can g e n e r a l l y a s s e s s th e n u t r i t i v e v a l u e o f t h e i r fo od and t h a t e n v i r o n m e n ta l c o n d i t i o n s , th r o u g h t h e i r e f f e c t s on m i c r o b i a l a c t i v i t y , s h o u ld c o r r e l a t e w ith p a l a t a b i l i t y . Many o f t h e f i e l d s t u d i e s c o n c e r n e d w ith t u r n o v e r r a t e s o f o r g a n i c m a t t e r i n c l u d e a n a l y s e s o f t h e e c o s y s t e m 's f a u n a l co m p o n en ts. These p u b l i c a t i o n s a r e to o numerous t o m e n tio n h e r e ; one may r e f e r t o s o i l z o o l o g i c a l com pendia su c h a s t h o s e o f Doeksen and D r i f t ( 1 9 6 3 ) , B urges and Raw (1 9 6 7 ) o r W allwork ( 1 9 7 6 ) . W ith few e x c e p t i o n s , t h e o r g a n i c m a t t e r c y c l e h as n o t been c o r r e l a t e d w ith p o p u l a t i o n d e n s i t i e s and ag e s tr u c tu r e s o f s p e c if ic m illip e d e p o p u la tio n s. P u rely p h e n o lo g ic a l d a t a , on t h e o t h e r h a n d , a r e q u i t e n um ero us. The m a j o r i t y o f t h e s e p h e n o l o g i c a l i n v e s t i g a t i o n s c o n c e r n s i u l o i d s p e c i e s i n England and o t h e r p a r t s o f Europe (H a lk k a , 1958; Blower and G a b b u tt , 1 964 ; Blow er and F a i r h u r s t , 1 9 6 8 ; Blower 1969 a , b , 1970; B ro o k es, 19 7 4 ; F a i r h u r s t , 1 974; C o tto n and M i l l e r , 1 9 7 4 ) ; i n A u s t r a l i a ( B a k e r , 1978 a , b ) , and t h e W estern I n d i a n Ocean ( S p a u l l , 1 9 7 6 ) . G lo m e rid s , e s p e c i a l l y G lo m e ris m a r g i n a t a ( V i l l e r s ) have been o f i n t e r e s t t o z o o l o g i s t s f o r o v e r 100 y e a r s ; Bocock and H e a th ( 1 9 6 7 ) , Bocock e t a l (1 9 6 7 ) and H eath e t a l (1 9 7 4 ) have d e a l t most e x t e n s i v e l y w i t h t h e l i f e h i s t o r y and e c o lo g y o f th e s p e c i e s i n E n g lan d . The p o ly d e s m o id s whose l i f e h i s t o r y h as been s t u d i e d i n t h e f i e l d s h a r e some common c h a r a c t e r i s t i c s . T h eir l i f e cy cle i s r e l a t i v e l y s h o r t when com pared to m ost l u l o i d s : i t i s f r e q u e n t l y c o m p le te d i n a b o u t one y e a r ( S e i f e r t , 1 9 3 2 ;3 t e p h e n s o n , 1961; M urakami, 1962, 1966a; L ew is, 1971 a , b ) . Polydesm us c o m p la n a tu s ( L i n n e ) p r o b a b ly t a k e s two 80 y e a r s i n E n gland (B lo w er, 1 9 7 0 ), and Murakami (1965 b ) r e p o r t s t h a t Ampelodesmus i y o n i s Murakami i n J a p a n may have a t h r e e - y e a r l i f e cy cle. In t e m p e r a t e c l i m a t e s , peak s e a s o n a l a c t i v i t y c o i n c i d e s w ith r e p r o d u c t i v e a c t i v i t y , and i s u s u a l l y m easured by t h e r e l a t i v e number o f in d iv id u a ls caught in p i t f a l l t r a p s . A s p rin g -su m m e r p eak i s u s u a l l y t h e o n ly one o c c u r r i n g , o r i s t h e more p ro n o u n ced one i n p o p u l a t i o n s where a s e c o n d p e a k i s a p p a r e n t i n th e f a l l ( S te p h e n s o n , 1961; B lo w er, 19 70; H a a c k e r, 19 68; B arlow , 1 9 5 7 ). E g g - l a y in g t a k e s p l a c e o v e r a p e r i o d o f two to s e v e r a l m o n t h s , and most s p e c i e s c o n s t r u c t p r o t e c t i v e cham bers aro u n d t h e i r e g g s (E v a n s , 1910; S e i f e r t , 1 93 2 ; Voges, 19 16; M urakam i, 1965 a , b ; S te p h e n s o n , 1 9 6 1 ). I t o l t i n g a l s o t a k e s p l a c e i n c h am b ers. In N ig e r ia n p a r a d o x o s o m a tid s and gom phodesm ids, t h e s e cham bers e n a b l e d i a p a u s i n g l a r v a e t o s u r v i v e t h e d r y s e a s o n ( L e w is , 1971 a , b ) . In te m p e r a t e z o n e s , p o ly d e s m id s u s u a l l y o v e r w i n t e r a s a d u l t s and l a r v a e ( S te p h e n s o n , 1961; V e r h o e f f , 19 29; B low er, 1955; B a n e r j e e , 1 9 6 7 ). Of s e v e r a l p o ly d e s m id s i n v e s t i g a t e d by V e r h o e f f ( 1 9 2 9 ) , one o v e r w i n t e r e d a s l a r v a e o n l y - a s d o es O xidus g r a c i l u s (Koch) i n J a p a n (M urakami, 1962, 1 9 6 6 ). The e a r l i e s t b i o l o g i c a l and e c o l o g i c a l s t u d i e s on N o rth A m erican p o ly d e sm o id s were t h o s e by M ile y (1927) on E u ry u ru s ery th ro p y g u s (B ra n d t) . Causey (1 9 4 3 ) s t u d i e d th e b i o l o g y o f th e h o th o u s e m i l l i p e d e , w hich c a n n o t s u r v i v e w i n t e r s o u t d o o r s i n o u r c lim a te s. E ato n (19 4 3 ) i n v e s t i g a t e d A p h e l o r l a c o r i a c e a (K o c h ), b u t h i s f i e l d d a t a were b ased on o n l y two c o l l e c t i o n s . As p a r t o f a l a r g e - s c a l e s t u d y on c r y p t o z o a , C ole (1 9 4 6 ) n o te d some a s p e c t s o f t h e b i o l o g y o f S c y to n o t u s g r a n u l a t u s ( S a y ) , s p e c i f i c a l l y t h o s e d e a l i n g w i t h 81 a g g r e g a t i o n In th e f i e l d . Jo h n so n ( 1 9 5 2 ) , I n h i s s u r v e y o f M ich igan p o ly d e s m o id s , I n c l u d e d b r i e f a u t e c o l o g i c a l n o t e s on m ost o f them , _P. c o r l a c e u s (now J?. I n c o n s t a n s ) among them. In many s t u d i e s , d e n s i t y e s t i m a t e s a r e p r e c l u d e d by t h e m etho ds u s e d t o sam ple a p o p u l a t i o n . P i t f a l l t r a p p i n g g i v e s a m easure o f a c t i v i t y o n l y , s i n c e c a t c h e s depend on a c t i v e movement o f a n i m a l s . H a n d - s o r t i n g o f a r e a u n i t s o f s u b s t r a t e and h a n d - c o l l e c t i n g a lo n g t r a n s e c t l i n e s a r e a l s o commonly u s e d , b u t y i e l d d e n s i t y e s t i m a t e s o n l y i f a l l c o lo n lz e a b le s u b s t r a t e la y e r s a re in c lu d e d . F u n n e l- t y p e e x t r a c t i o n i s one o f t h e l e s s tim e -c o n s u m in g m ethods o f s a m p lin g , and y i e l d s b o th q u a l i t a t i v e and q u a n t i t a t i v e d a t a . E x t r a c t i o n e f f i c i e n c i e s may v a r y w ith t h e t y p e o f f u n n e l , th e s p e c i e s i n q u e s t i o n , and p o s s i b l y th e d e v e lo p m e n ta l s t a g e (B lo w e r, 1 9 7 0 ). In most c a s e s e x t r a c t i o n e f f i c i e n c i e s a r e n o t a s s e s s e d ; i t i s d e b a t a b l e w h e th e r th e y would in d e e d by u s e f u l . M o ltin g i n d i v i d u a l s a r e im mobile f o r lo n g p e r i o d s o f t i m e , and t h e p r o p o r t i o n o f t h e p o p u l a t i o n i n t h a t s t a t e v a r i e s w i t h th e s e a s o n . S h o r t o f l a b o r i o u s l y c h e c k in g e f f i c i e n c e s a t e v e r y s a m p lin g d a t e , i t e x tra c tio n m ig h t be p r e f e r r a b l e to d i s r e g a r d them - know ing, h o w ev er, t h a t t h e d e n s i t y e s t i m a t e s o b t a i n e d a r e l i k e l y t o be s l i g h t l y u n d e r e s t i m a t e d . D e te r m in a t io n o f a g e s t r u c t u r e r e q u i r e s r e p e a t e d s a m p lin g . A g a in , a l l h a b i t a t s u b d i v i s i o n s m ust be i n c l u d e d , s i n c e some s p e c i e s show s t a g e - s p e c i f i c s u b s t r a t e p r e f e r e n d a (C ausey and 1970; L ew is, 1971 a ) . F u r th e r m o r e , i t r e c o g n i z e a g iv e n s t a g e . Tiem ann, 1969; B low er, r e q u i r e s t h e a b i l i t y to In i u l o i d s , segm ent numbers v a r y w i t h i n one i n s t a r : r a t h e r t h a n s e g m e n ta l c o u n t s , Vachon (1 9 4 7 ) and S a u d ra y (1 9 5 2 ) have u sed o c e l l a r p a t t e r n s f o r s t a g e a s s i g n m e n t , H alkka (1 9 5 8 ) n o te d \ 82 t h e s i z e and c o l o r o f d e f e n s e g l a n d s , and Blower and G a b b u tt (1 964 ) used a r ith m e tic p r o b a b ility paper a n a l y s i s . In p o ly d e sm id s a s w e l l a s n e m a to p h o ra n s a f i x e d number o f seg m en ts c h a r a c t e r i z e s e a c h i n s t a r , so t h a t s i m p l e s e g m e n ta l c o u n t s s u f f i c e . In p o ly d e s m id s , h o w ev er, th e im m atu res o f d i f f e r e n t s p e c i e s c l o s e l y re s e m b le e a c h o t h e r ; i f t h e s e s p e c i e s c o h a b i t , s t a g e d i s t r i b u t i o n d a t a som etim es have t o be t e n t a t i v e (B lo w e r, 1 9 7 0 ) . In t h e p r e s e n t i n v e s t i g a t i o n , f i e l d work was c o n d u c te d i n 1976, 1978 and 1979. Two s i t e s were s t u d i e d : a b a c k y a rd g a r d e n and a d e c id u o u s w o o d lo t, b o t h i n t h e v i c i n i t y o f M ichig an S t a t e U n i v e r s i t y campus. Polydesm us i n c o n s t a n s was t h e o n ly p o ly d e sm id e v e r e n c o u n t e r e d in e ith e r s i t e . The g o a l s o f t h e f i e l d s tu d y i n c l u d e d a s s e s s m e n t o f : a) t h e b i o l o g y o f th e s p e c i e s i n th e f i e l d , i n c l u d i n g s e x u a l a c t i v i t y , m o l t i n g , and p a r a s i t i s m ; b) th e l i f e c y c le o f th e s p e c ie s , i . e . seasonal s ta g e d istrib u tio n ; c) t h e s p a t i a l d i s t r i b u t i o n o f th e p o p u l a t i o n : i n v e r t i c a l s u b d i v i s i o n s o f t h e h a b i t a t ( l i t t e r , s o i l ) and i n two h o r i z o n t a l l y op po sed a r e a s ( u p h i l l , low d e p r e s s i o n s ) ; d) 2. 2 .1 th e sex r a t i o s in f i e l d p o p u la tio n s . MATERIALS AND METHODS The g a r d e n s i t e A) S ite d e s c rip tio n : In 1976 and 1978, an e f f o r t was made to m o n ito r a p o p u l a t i o n of 83 Pm i n c o n s t a n s i n t h e im m e d ia te s u r r o u n d i n g s o f a home l o c a t e d n e a r M ich ig an S t a t e U n i v e r s i t y cam pus. The s i t e i n c l u d e d a v a r i e t y o f s m a l l , more o r l e s s w e l l d e f i n e d h a b i t a t s : g r a s s y a r e a s a lo n g t h e n o r t h e r n f o u n d a t i o n w a l l o f t h e home; b a re s o i l , d e n s e l y s h a d e d by s h r u b b e r y , on i t s e a s t and w est s i d e s ; a n d a number o f l o c a t i o n s d i s p e r s e d th r o u g h o u t a b a c k y a rd g a r d e n p l a n t e d w ith v a r i o u s p e r e n n i a l s and a n n u a l v e g e t a b l e s . The g a r d e n was r a r e l y i r r i g a t e d , and no p e s t i c i d e s w ere a p p l i e d . The s o i l s , g e n e r a l l y s a n d y , v a r i e d i n o r g a n i c m a t t e r c o n t e n t fro m 3.3% i n t h e g a r d e n t o b.6% u n d e r s h r u b b e r y on t h e w e s t s i d e . G arden s o i l had a pH o f 7 .7 t o 7 .9 (mean 7 . 8 ) , and s o i l u n d e r s h r u b b e r y was o n l y s l i g h t l y more a c i d ( 7 . 2 t o 7 . 6 , mean 7 . 3 ) . B) Sam pling m e th o d s : In 1976 , s q u a r e s o i l sa m p le s (10 x 10 cm) w ere t a k e n t o a d e p t h o f 8 cm w ith a n arrow s p a d e . T hese s a m p le s i n c l u d e d th e v a r i a b l e , b u t s m a l l , amount o f o r g a n i c d e b r i s on t o p o f th e s o i l . The a n i m a l s were r e c o v e r e d by h e a t e x t r a c t i o n ( m o d i f i e d T u l l g r e n f u n n e l s ) . E ig h t s am p les were t a k e n on e a c h d a t e . I n 19 7 8 , two d i f f e r e n t t e c h n i q u e s were em ployed to a s s e s s th e P. in co n sta n s p o p u la tio n . One was t h e " c r y p t o z o a n b o a r d " t e c h n i q u e , s i m i l a r to t h a t u s e d bv C ole ( 1 9 4 6 ) : b o a r d s o f w e a th e r e d wood, 25 x 12 cm and 2 cm t h i c k , w ere s e t down on t h e s o i l i n p erm a n en t l o c a t i o n s . A t o t a l o f 20 b o a r d s w ere t h u s p o s i t i o n e d , 7 i n sh a d y a r e a s a ro u n d th e f o u n d a t i o n o f t h e home, and 13 i n sunny a r e a s i n th e g a r d e n . betw ee n any two b o a r d s m easured n o t l e s s th a n 1 m. D ista n c e s P e r i o d i c a l l y , th e b o a r d s were l i f t e d and P. i n c o n s t a n s were c o l l e c t e d from t h e i r 84 u n d e r s i d e a s w e l l a s from th e s o i l and c r u m b - l a y e r b e n e a t h them* The a n i m a ls were s t a g e d and s e x e d i n t h e l a b o r a t o r y , and r e t u r n e d to t h e b o a r d s th e y came from . S i m u l t a n e o u s l y , a m a r k - r e c a p t u r e program was c o n d u c te d w i t h th e b o a r d - c o lle c te d a n im a ls. S u b a d u lt s and a d u l t s w ere marked w ith a c r y l i c p a i n t , i n a p a t t e r n t h a t a llo w e d d i s t i n c t i o n b etw ee n s e x e s , s t a g e s , and p ro v e n a n c e from s p e c i f i c b o a r d s . E very 20 t o 30 day s t h e c o l o r scheme was chan ged t o a l l o w d i s t i n c t i o n b etw ee n c o l l e c t i o n d a t e s , a t l e a s t on a m onthly b a s i s . B e g in n in g on A p r i l 1 6 , 1978 and e n d in g on A p r i l 1 8 , 1979, a t o t a l o f 30 c o l l e c t i o n s w ere made. C o n d it io n s u n d e r th e b o a r d s (amount o f l e a f y d e b r i s , m o i s t u r e , s o i l t e x t u r e ) v a r i e d g r e a t l y betw een b o a r d s and were n o t m o n i t o r e d . But s o i l t e m p e r a t u r e was m o n i to r e d from bJay to November 1978 , a t th e tim e o f c o l l e c t i o n . T hese t e m p e r a t u r e m e a s u re m e n ts , made w ith a YS1 p o r t a b l e t e l e t h e r m o m e t e r , w ere meant t o o p p o se t h e shady and sunny a r e a s , and to a s s e s s t h e m e d i a t i n g e f f e c t o f t h e b o a r d s when com pared t o n e a r b y , n o n - c o v e r e d l o c a t i o n s . Thus t e m p e r a t u r e m e asu re m en ts were made: a) on t h e s o i l s u r f a c e and a t d e p t h s o f 1 , 3 and 5 cm; b) u n d e r b o a r d s as w e l l as i n c l o s e v i c i n i t y to them , on an d in u n p ro te c te d s o i l ; c) i n s h a d e d a r e a s ( t h r e e b o a r d s a l o n g th e n o r t h e r n f o u n d a t i o n ) and i n sunny l o c a t i o n s ( t h r e e b o a r d s i n t h e g a r d e n ) . 2 .2 . The w o o d lo t s i t e A) S ite d e s c r ip tio n : In th e f a l l o f 197 8, a d en se p o p u l a t i o n o f P. i n c o n s t a n s was 85 d i s c o v e r e d i n th e NW c o r n e r o f B aker w o o d lo t (M ich ig an S t a t e U n i v e r s i t y campus)* The w o o d lo t i s a 73 - a c r e b e e c h -m a p le woods d o m in a te d by m a p les ( T a b l e 2 1 ) . I t i s c r i s s - c r o s s e d by p a t h s and f r e q u e n t e d by s t u d e n t s t o th e e x t e n t t h a t t h e h e r b a c e o u s v e g e t a t i o n i s p a r t i a l l y decim ated in c e r t a i n a r e a s . The h e r b l a y e r i s v a r i e d and c o n s i s t s o f f e r n s , may a p p l e , common b a r b e r r y , and o t h e r s p e c i e s c h a r a c t e r i s t i c o f mixed w o o d lo ts i n t h i s a r e a . W e l l - t r a v e l l e d l o c a t i o n s , w here s o i l c o m p a c tio n and d e s t r u c t i o n o f l i t t e r and v e g e t a t i o n w ere o b v i o u s , w ere a v o id e d d u r in g t h i s s t u d y . I n t h e p a r t o f t h e w o o d lo t c h o s e n f o r s a m p lin g , s o i l t y p e s v a r y c o n sid e ra b ly . H i l l s d a l e san d y loam ( c o a r s e , w e l l - d r a i n e d ) and Colwood loams ( f i n e , somewhat p o o r l y d r a i n e d ) p r e d o m i n a te . In th e two t y p e s o f s a m p lin g l o c a t i o n s d e s c r i b e d below ( u p h i l l , d e p r e s s i o n s ) a number o f s o i l sam p les w ere t a k e n i n March o f 1980 and a n a l y z e d f o r pH and o rg a n ic m a tte r c o n te n t. The s o i l t y p e s w ere a s s e s s e d m a n u a lly (D r. Mokma, Crop and S o i l S c i e n c e , M ichigan S t a t e U n i v e r s i t y ) . T a b le 22 g iv e s th e r e s u l t s . F o llo w in g s e v e r a l h a n d - c o l l e c t i o n s i n l a t e 1978, a sa m p lin g prog ram was c o n d u c te d t h r o u g h 1979, i n two t y p e s o f l o c a t i o n : a) d e p r e s s i o n s a t th e b o tto m o f s l o p e s (te r m e d LOW): t h e i r s i z e v a r i e d from a b o u t 1 m^ t o o v e r 3 m^. The s m a l l e r d e p r e s s i o n s were sam p led q u a n t i t a t i v e l y o n ly o n c e , b u t were som etim es r e v i s i t e d l a t e r t o be h a n d - c o l l e c t e d . The l a r g e r o n e s were sam pled up t o t h r e e tim e s q u a n t i t a t i v e l y , on d i f f e r e n t d a t e s . b) Upper s l o p e a r e a s (HIGH), s l i g h t l y below t h e c r e s t of e le v a tio n s. These a r e a s l a y above t h e LOW d e p r e s s i o n s , t h e s l o p e s b e i n g i n c l i n e d to w ard t h e l a t t e r . D i s t a n c e s betw een HIGH and LOW 86 T a b le 21. The s p e c i e s c o m p o s i tio n ( I m p o r ta n c e v a l u e s ) o f th e t r e e s i n Baker w o o d l o t . * ) Im p o r t. E el. Z % R el. He 1. % v alue f req. domin. dens. 104.9 3 0 .4 3 2 .0 4 2 .5 A c e r rubrum 4 1 .1 1 6 .5 9 .2 1 5 .3 Fagus g r a n d i f o l i a 2 8 .4 1 1 .2 7.1 1 0 .0 Q uercus r u b e r 2 5 .2 6 .0 1 4 .9 4 .3 F r a x in u s a m e r ic a n a 2 4 .9 7 .7 1 1 .5 5 .8 T i l i a a m e r ic a n a 2 2 .2 1 0 .0 1 0 .0 6 .0 P runus s e r o t i n a 1 6 .6 1 4 .9 7 .5 4 .3 A cer sacch a ru m *) From an u n p u b l i s h e d m a n u s c r i p t by Y. R. Beach an d W. D. S t e v e n s , D ept, o f B o ta n y , M ich ig an S t a t e U n v i e r s i t y : w o o d lo t. T ab le 22. II. " A s tu d y o f Baker V e g e t a t i o n and e c o l o g y ”. S o i l c h a r a c t e r i s t i c s o f t h e Baker w o o d lo t s a m p lin g s i t e s . LOW AREAS SOIL TYPE *) C olw ood-B rookston lo an s HIGH AREAS k i d d l e s Loam and H i l l s d a l e sandy loatn MEAN pH + SD 6.1 + 0 .4 6 .4 + 0 .2 MEAN % O .il. ± SD 8 .6 ± 1 . 2 5 .9 + 1 . 1 * ) A cco rd in g t o : S o i l Survey o f Ingham C ounty, M ic h ig a n ; U.S. D epartm ent o f A g r i c u l t u r e , S o i l C o n s e r v a t i o n S e r v i c e ( 1 9 7 9 ) . 87 l o c a l i t i e s were on t h e o r d e r o f a t l e a s t 10 u , and u s u a l l y much more* I n b o t h l o c a l i t i e s , one c r i t e r i o n f o r c h o o s in g a c t u a l sa m p lin g s p o t s was s t r i c l y a d h e r e d t o ; l a r g e b ra n c h e s* no s am p les were ta k e n c l o s e t o l o g s o r That i s , s t r u c t u r e s t h a t m ig h t s e r v e a s r e f u g i a f o r J?. i n c o n s t a n s were a v o i d e d . The d i f f e r e n t i a t i o n o f n i c h e s on th e f o r e s t f l o o r i s so com plex t h a t , h ad s u c h p o t e n t i a l r e t r e a t s b e e n i n c l u d e d , t h e s a m p lin g program would h av e s u r p a s s e d a v a i l a b l e tim e and s p a c e resources. B) Sam pling m e th o d s ; L i t t e r sam p les: on t h e l i t t e r . a s q u a r e m e ta l f r a m e , 25 x 25 cm, was s e t down A s h a r p k n i f e was t h e n r u n a l o n g i t s c u t t i n g th r o u g h t h e l i t t e r and th e s m a l l e r t w i g s . in s id e p e rip h e ry , W hile l e a v i n g th e fram e i n p l a c e , l i t t e r and d e b r i s from t h e i n s i d e o f th e s q u a r e w ere t r a n s f e r r e d to p l a s t i c b a g s . L a r g e r t w i g s , i f s h o r t and l y i n g w i t h i n t h e f r a m e , w ere i n c l u d e d ; i f l o n g , th e y w ere exam ined on t h e s p o t f o r £ . i n c o n s t a n s and moved a s i d e . I n LOW a r e a s e s p e c i a l l y , m in g le d w ith s o i l . t h e l e a f l i t t e r was c h a r a c t e r i s t i c a l l y The d i s t i n c t i o n betw een l i t t e r and s o i l ( t h e s o i l - l i t t e r i n t e r f a c e ) was t h e r e f o r e made a r b i t r a r i l y : t h o s e o r g a n i c a g g r e g a t e s t h a t w ere e a s i l y g a t h e r e d by a g e n t l e b r u s h i n g m o tio n o f t h e f i n g e r s w ere i n c l u d e d w i t h t h e l i t t e r s a m p le s . The s o i l s u r f a c e was t h e n exam ined f o r £ . i n c o n s t a n s and any a n i m a ls moving o v e r i t w ere a l s o In c lu d e d . S o il sam p les: on s e l e c t e d d a t e s , a f t e r th e l i t t e r sam p les had b e e n rem oved, two s o i l c o r e s were t a k e n from e a c h 25 x 25 cm s q u a r e . The c o r e s r e a c h e d a t o t a l d e p t h o f 15 cm, and e a c h was s u b d i v i d e d i n t o 88 a 0 -8 cm and a 8 -1 5 cm s u b sa m p le . The I n s i d e w id th o f t h e c o r e s a m p le r was 5 . 5 cm. E x t r a c t i o n o f a n i m a ls fro m t h e s o i l and l i t t e r s a m p l e s : u n til l a t e Ju n e 1 9 7 9 , b o th t y p e s o f sam p les were h a n d s o r t e d In th e l a b o r a t o r y , I n hopes o f f i n d i n g egg n e s t s and m o l tin g i n d i v i d u a l s . S in c e n e i t h e r was e v e r d e t e c t e d , t h e l a b o r i o u s h a n d s o r t i n g was th e n r e p l a c e d by T u l l g r e n f u n n e l e x t r a c t i o n from 5 t o 7 d a y s (d e p e n d in g on t h e m o i s t u r e c o n t e n t o f t h e s a m p l e s ) . H an d -co llectin g t i n t e r s p e r s e d betw een a r e a - s p e c i f i c l i t t e r and s o i l s a m p lin g , _P. i n c o n s t a n s were c o l l e c t e d by hand from t h e same g e n e r a l a r e a o f Baker w o o d lo t. W h ile h a n d - c o l l e c t i n g c a n be u sed as a q u a n t i t a t i v e t o o l , i n th e p r e s e n t s t u d y th e t e c h n i q u e was s im p ly meant t o p r o v i d e s u p p le m e n ta r y m a t e r i a l f o r e v a l u a t i n g th e s t a g e d i s t r i b u t i o n w i t h i n t h e P. i n c o n s t a n s p o p u l a t i o n . N e ith e r s p e c i f i c a re a u n i t s nor c o l l e c t i o n - t i m e l i m i t s were a d h e r e d t o ; r a t h e r , an a t t e m p t was made t o th o r o u g h l y i n s p e c t a l l h a b i t a t s a v a i l a b l e to t h e s p e c i e s : litte r, d u f f , s o i l a g g r e g a t e s ; a l l b r a n c h s i z e s ; l o o s e b a r k a ro u n d th e e n t i r e p e r i p h e r y o f a g i v e n l o g ; t h e o u t s i d e s u r f a c e o f lo g s a s w e l l a s any a c c e s s i b l e c h a n n e l s w i t h i n them. C) P h y s ic a l p aram eters o f th e s i t e : L i t t e r t h i c k n e s s : u s u a l l y , l i t t e r i s c h a r a c t e r i z e d a s d r y w eig h t o f l i t t e r p e r u n i t a r e a ( M i l l e r , 1 9 7 4 ). L ebrun (1 9 7 1 ) f o ll o w e d t h e te m p o r a l p r o g r e s s i o n o f l e a f f a l l and d e t e r m in e d th e t o t a l number o f l e a v e s p e r m^ o f f o r e s t f l o o r , a s w e l l a s t h e gram p e r c e n t o f e a c h s p e c ie s of tr e e in f r e s h w e ig h ts. Dunger (1 9 5 8 ) sum m arily d e s c r i b e d t h e l i t t e r c o v e r i n a f l o o d p l a i n a s c o n s i s t i n g o f two to f o u r l a y e r e d 89 l e a v e s i n l a t e f a l l , w hich d i s a p p e a r e d r a p i d l y d u r i n g s p r i n g so t h a t v i r t u a l l y no l i t t e r was l e f t by l a t e summer* In t h i s s t u d y , n e i t h e r q u e s t i o n s o f o r g a n ic m a t t e r breakdow n n o r o f fo o d a v a i l a b i l i t y w ere a d d r e s s e d * Thus, o c c a s i o n a l m e asu re m en ts o f l i t t e r t h i c k n e s s were made o n ly a s a g r o s s c h e c k on g e n e r a l c o n d i t i o n s on t h e w oodland f l o o r . F i r s t , a s h a r p k n i f e was u s e d t o make a v e r t i c a l c u t t h r o u g h t h e l i t t e r f o r a d i s t a n c e o f a b o u t 15 cm. Any d r y to p l e a v e s were com pacted u n t i l t h e y to u c h e d t h e m o i s t l a y e r u n d e r n e a t h by s l i g h t downward p r e s s u r e w i t h th e palm o f a hand. T o tal l i t t e r t h i c k n e s s was t h e n m e asu re d w i t h a r u l e r h e l d a g a i n s t t h e c u t s u r f a c e . In a d d i t i o n , t h e number o f d r y and m o i s t l e a v e s were c o u n te d a l o n g a random ly c h o s e n v e r t i c a l l i n e on t h e t r a n s e c t . "Crumbs and d e b r i s " t h i c k n e s s (decom posed s k e l e t a l l e a v e s mixed w ith s o i l ) was m easured se p a ra te ly . In b o th HIGH a n d LOW l o c a t i o n s , from f i v e to s e v e n r e p l i c a t e m e asu re m en ts o f t h i s k i n d w ere made p e r d a t e , on f i v e d a t e s from l a t e A p r i l to l a t e A u g u st. S o i l t e m p e r a t u r e and m o i s t u r e ; On most sa m p lin g d a t e s , t e m p e r a t u r e was m easured w ith a YSI t e l e t h e r m o m e t e r on t h e l i t t e r s u r f a c e , t h e s o i l - l i t t e r i n t e r f a c e , and a t d e p th s o f 1 , 3, 5 and 10 cm i n t h e s o i l . W ater c o n t e n t o f t h e s o i l was a s s e s s e d by w e ig h i n g , d r y i n g a n d r e - w e i g h i n g a number o f s o i l s a m p le s . At t h e tim e o f w e ig h in g th e y w ere b r i e f l y c h ec k ed f o r s t o n e s and r o o t s , w hich were rem oved. They w ere t h e n d r i e d i n a 60°C oven u n t i l no f u r t h e r w e ig h t l o s s o c c u r r e d , and w eighed a g a i n . In b o t h LOW a n d HIGH a r e a s f o u r c o r e s w ere ta k e n p e r d a t e , e a c h o f them s u b d i v i d e d i n t o a 0 - 8 cm and a 8 -1 5 cm 90 in c re m e n t* J. RESULTS 3.1* H ab itat c h a r a c t e r i s t i c s A) T em p eratu re; The g a r d e n s i t e ; T e m p e r a tu re r e c o r d s fro m u n d e r b o a r d s when com pared to t h o s e o f open a r e a s n e a r b o a r d s showed c l e a r l y t h e m e d i a t i n g e f f e c t o f b o a rd c o v e r . F i g u r e 16 i l l u s t r a t e s t h e d i f f e r e n c e s betw ee n mean t e m p e r a t u r e s i n t h e two c o n t r a s t e d l c o a t i o n s . In sunny l o c a t i o n s , th e e x p o s e d s o i l s u r f a c e was a l m o s t i n v a r i a b l y warmer th a n t h a t u n d e r b o a r d s , ev en i n O c to b e r an d November. D i s c r e p a n c i e s b etw een s u r f a c e and d e p t h m easurem ents (5 cm) w ere o f t e n l a r g e . Not so i n shad y l o c a t i o n s , where s u r f a c e and d e p t h d a t a w ere c l o s e l y r e l a t e d , and where open a r e a t e m p e r a t u r e s f r e q u e n t l y e x c e e d e d b o a rd t e m p e r a t u r e s by o n ly 1°C o r le ss. As an exam ple o f te m p e r a t u r e p r o f i l e s u n d e r t h e b o a r d s , F i g u r e 17 shows t h e d a t a o b t a i n e d on s i x s e l e c t e d d a t e s , and c o n t r a s t s sunny and sh ad y b o a r d s . On c l o u d l e s s days ( h a y 7 , May 1 9, J u l y 6 ) t h e d i f f e r e n c e s i n t e m p e r a t u r e p e r s i s t e d t o a d e p th o f 5 cm a t l e a s t . At tim e s w i t h no s u n s h i n e , b u t a f t e r s e v e r a l days w i t h h i g h maximum a i r t e m p e r a t u r e (J u n e 1 7 , J u l y 1 8 ) t e m p e r a t u r e s w ere h i g h i n b o t h l o c a t i o n s an d a t a l l d e p t h l e v e l s . M ild d a y s , w i t h t e m p e r a t u r e s p r o p i t i o u s f o r m i l l i p e d e a c t i v i t y , s t i l l o c c u r r e d l a t e i n th e f a l l (November 1 1 ) . I n g e n e r a l , s o i l s u r f a c e t e m p e r a t u r e s u n d er th e b o a r d s s t a y e d w i t h i n a r a n g e o f 16° t o 24°C, b u t o c c a s i o n a l l y r o s e t o 2 6 °C and 91 SUNNY BOARDS + 1.0 MINUS BOARD-TEMP +4.0 J A J S O N OPEN-AREA TEMP. °C M SOIL SURFACE 5 cm DEPTH SHADY BOARDS + 3.0 + 1 . 01 M A J DATE OF S 0 N RECORDING Figure 16. Differences between temperatures under boards and temperatures in non-covered areas, garden, 1978. 30 June 17 S S 1 3 5 S S 1 3 5 S S 1 3 5 SUNNY BOARDS SHADY BOARDS SS SOIL SURFACE 20 10 Nov 11 July 18 July 6 - SS 1 3 5 SS 1 P R O F I L E 3 5 SS 1 3 5 D E P T H, CM Figure 17. Temperature profiles under sunny and shady boards on selected dates. 93 beyond. O f f i c i a l s o i l and a i r te m p e r a t u r e r e c o r d s f o r E a s t L a n s in g ( r e c o r d e d by M ic h ig a n S t a t e U n i v e r s i t y M e t e o r o l o g i c a l S t a t i o n ) i n 1978 showed t h a t t h e d a t a o b t a i n e d i n t h e g a r d e n p r o b a b ly r e p r e s e n t maximum d a ily s o i l te m p era tu re s. As i l l u s t r a t e d i n F ig u r e 1 8, r e c o r d s t a k e n i n E a s t L a n s in g a t 8:am w ere c o n s i s t e n t l y much lo w e r th a n t h e g a r d e n r e c o r d s t a k e n betw ee n l:p m an d 4 : pm on t h e same days and a t t h e same dep th . F i g u r e 18 shows a g a i n t h a t t h e b o a r d s had a m e d i a t i n g e f f e c t on s o i l t e m p e r a t u r e , and i l u s t r a t e s t h e r e l a t i o n s i p betw een maximum a i r te m p e r a t u r e and s o i l t e m p e r a t u r e . The w o o d lo t s i t e : S in c e no c o n t in u o u s r e c o r d c o u l d be made, t h e p o i n t m e asu re m en ts made on e i g h t d a t e s had to s u f f i c e f o r a c h a r a c t e r i z a t i o n o f th e t e m p e r a t u r e p r o f i l e i n HIGH and LOW a r e a s o f t h e w o o d lo t. F i g u r e 19 g i v e s mean t e m p e r a t u r e s i n e a c h o f th e h a b i t a t s u b d i v i s i o n s and a t e a c h o f t h e d e p t h l e v e l s m o n i t o r e d . L arg e d i f f e r e n c e s betw ee n HIGH an d LOW w ere a p p a r e n t o n ly on J u l y 1 4 , b u t d e p r e s s i o n s g e n e r a l l y a l lo w e d t e m p e r a t u r e s t o re m a in c o o l e r d u r i n g s p r i n g and summer. The d a t a f o r O c to b e r 9 p r o v i d e an exam ple o f th e i n v e r s i o n o f t h i s re la tio n sh ip : i n s p i t e o f l e a f f a l l b e in g w e l l u n d e r way, HIGH a r e a s a p p a r e n t l y c o o l e d down more r a p i d l y , o r r e s p o n d e d more r a p i d l y to f a l l i n g a i r t e m p e r a t u r e s , th a n t h e w e l l - p r o t e c t e d LOW a r e a s . At t h e same t i m e , t h e u s u a l t e m p e r a t u r e g r a d i e n t ( lo w e r te m p e r a t u r e w ith i n c r e a s i n g d e p t h ) was a l s o r e v e r s e d . From May t o S e p te m b e r, t e m p e r a t u r e s a t t h e s o i l - l i t t e r i n t e r f a c e and a t 1 cm d e p t h n e v e r r o s e above a f a v o r a b l e l e v e l f o r temperature °c ^ M a x air temperature East Lansing (8:am) Garden, under boards — Garden, near boards 7\ /X 20- 10- M J J A S 0 N RECORDING DATE (1978) Figure 18. Soil temperatures at 5 cm depth: afternoon records (garden) and 8:am records (Michigan State University Meteorological Station, East Lansing). 95 HIGH LOW 20 10 - April 29 LS SS 1 May 31 3 5 10 LS SS 1 3 5 10 30 U 20 U 04 » 10 June 24 July 14 < 05 u cu £ H x 20 10 August 9 September 12 15 5 October 9 LS SS 1 3 November 17 5 10 LS SS 1 3 PROFILE DEPTH, CM 5 10 Figure 19. Depth profile of mean temperature in HIGH andLOW locations. LS=litter surface; SS=soil surface; vertical lines: max-min temperatures day before and day of sampling. 96 2L* i n c o n s t a n s . As shown i n th e l a b o r a t o r y ( S e c ti o n 1 . 3 . 3 ) , 15° to 21°C seem to be o p tim a l te m p e r a tu r e re g im e s f o r th e s p e c i e s . At l e a s t in LOW a r e a s ( F ig u r e 19) t h i s ra n g e was p r o b a b ly m a in ta in e d th r o u g h o u t th e summer, u n d e r th e p r o t e c t i v e l i t t e r c o v e r , a llo w in g u n i n t e r r u p t e d f e e d in g and r e p r o d u c t i v e a c t i v i t y o f I*, i n c o n s t a n s . D u rin g A p r i l , O c to b e r an d November, j?. in c o n s t a n s was c o n s p ic u o u s on th e s i d e s o f l o g s , on m o is t b r a n c h e s , and in th e u p p erm o st l i t t e r l a y e r s ( F ig u r e 2 0 ) . J u d g in g by th e te m p e r a tu r e d a ta f o r A p r il 29 and November 1 7 , te m p e r a tu r e s ab o v e th e s o i l w ere h ig h e r a t th o s e tim e s th e n w ith i n th e s o i l a n d , more p e r t i n e n t , th e l i t t e r and l i t t e r - s u r f a c e te m p e r a tu r e l e v e l s a p p ro a c h e d th o s e l e v e l s a t w h ich j?. in c o n s t a n s was d e f i n i t i v e l y a c t i v e i n th e l a b o r a t o r y (1 5 °C ). B) L itte r c o v e r: T a b le 23 su m m arizes th e d a t a on l i t t e r t h i c k n e s s , and g iv e s e x a c t s a m p lin g d a t e s . On u p p e r s l o p e s , th e crumb l a y e r was v i r t u a l l y n o n - e x i s t e n t a t a l l tim e s . In f a c t , a s c o r in g s y ste m o f " t h i n - p a t c h y - none" w ould hav e been e q u a l l y a c c u r a t e . The l a y e r s o f m o is t and d ry le a v e s v a r i e d w ith p r i o r w e a th e r c o n d i t i o n . In LOW a r e a s , th e r e was alw ay s some h a b i t a t p r o p i t i o u s f o r m i l l i p e d e s b e c a u se th e com plex crumb l a y e r was r e l a t i v e l y t h i c k a n d , a s th e s e a s o n p r o g r e s s e d , was k e p t r e p le n is h e d and ev en in c r e a s e d by in p u t o f s k e l e t o n i z e d le a v e s fro m a b o v e. In a d d i t i o n t o th e m easu rem en ts o f l i t t e r t h i c k n e s s , q u a l i t a t i v e o b s e r v a ti o n s w ere made a t tim e s o f h a n d - c o l l e c t i n g and q u a d r a t s a m p lin g . E x c e p t f o r s m a l l, i s o l a t e d p a tc h e s ( 4* 0 .2 5 m ) HIGH a r e a s w ere a c t u a l l y n e v e r t o t a l l y den u d ed o f l e a v e s . But i n m id - and l a t e 97 Figure 20. Loose aggregations of P. inconstans on the sides of logs in October. Figure 20 99 T a b le 23. T h ic k n e s s , i n cm, o f l i t t e r and crumb l a y e r s , an d number o f su p e rim p o se d le a v e s i n B aker w o o d lo t. Means o f a t l e a s t f i v e m easu rem en ts p e r d a te and l o c a t i o n s , + S . D. A pr. 29 May 31 Ju n e 24 Aug. 9 Aug. 25 L itte r Crumbs no. o f le a v e s d ry no. o f le a v e s m o is t HIGH 0 .6 + 0 .3 0 .3 + 0 .1 3 .0 + 0 .7 2 .3 + 0 .8 LOW 4 .0 + 1 .3 1 .1 + 0 .5 7 .9 + 2 .5 1 0 .7 + 1 .8 HIGH 0 .7 + 0 .2 0 .3 + 0 .1 4 ,6 + 1 .2 0 .8 + 0 .7 LOW 3 .4 + 0 .6 0 .8 + 0 .3 9 .4 + 1 .0 5 .0 +1. 7 HIGH 0 .7 + 0 .2 0 .2 + 0 .2 5 .8 + 1 .3 0 .5 + 0 .8 LOW 2 .3 + 0 .5 0 .5 + 0 .2 1 5 .3 + 3 .6 2 .3 + 1 .5 HIGH 0 .3 + 0 .1 0 .2 + 0 .1 3 .6 + 1 .4 1 .0 + 0 .6 LOW 1 .0 + 0 .3 1 .8 + 0 .7 6 .8 +1. 7 3 .0 +1. 3 HIGH 0 .2 + 0 .1 0 .1 + 0 .1 2 .9 + 1 .0 0 .6 + 1 .0 LOW 1 .3 + 0 .3 1 .3 + 0 .4 1 2 .0 + 3 .! 1 .6 + !-° summer, l i t t e r c o v e r c o n s i s t e d o f o n ly one to t h r e e d ry l e a v e s . In c o n t r a s t to t h a t , th e c o n tin u e d r i c h n e s s o f l i t t e r i n LOW a r e a s was v e ry much e v i d e n t . In b o th l o c a t i o n s th e o n ly i n t a c t le a v e s l e f t by th e end o f summer w ere th o s e o f b e e c h and o ak . 100 C) M o is tu r e : S o i l m o is tu r e l e v e l s i n HIGH a r e a s w ere g e n e r a l l y lo w e r th a n th o s e i n d e p r e s s io n s ( F ig u r e 2 1 ) . F r e q u e n tly th e u p p e r 8 cm o f th e p r o f i l e c o n ta in e d more w a te r th a n th e 8 -1 5 cm l e v e l . R a i n f a l l i n 1979, com pared to 1978 ( F ig u r e 2 2 ) was u n e v e n ly d i s t r i b u t e d . U ith th e e x c e p tio n o f th e S ep te m b er d r o u g h t, th e d i s t r i b u t i o n was n o t r e f l e c t e d i n s o i l m o is tu r e l e v e l s . The d ro u g h t was e v i d e n t i n b o th HIGH an d LOU a r e a s , m o is tu r e l e v e l s re m a in in g low w e ll i n t o O c to b e r. The am ount o f p r e c i p i t a t i o n a c t u a l l y r e c e iv e d by th e s o i l d ep en d s on l i t t e r th ic k n e s s a s w e ll a s on th e s t a t e o f can o p y d e v e lo m e n t. N o i r f a l i s e (1 9 6 2 ) c a l c u l a t e d a s e a s o n a l " i n t e r c e p t i o n c o e f f i c i e n t " c o n c e r n in g canopy d e v e lo p m e n t. B are c a n o p ie s ( w in te r ) a llo w e d 85% o f th e r a i n w a te r to r e a c h th e s o i l ; d u r in g l e a f d ev elo p m en t and l e a f fa ll, 75% o f th e p r e c i p i t a t i o n re a c h e d th e s o i l ; and d u r in g summer, 65% a c t u a l l y p e n e t r a t e d to th e g ro u n d . These d a t a a r e i n t r i g u i n g , b u t t h e i r a p p l i c a t i o n to th e p r e s e n t s tu d y i s c o m p lic a te d by o t h e r p a r a m e te r s . In LGU a r e a s th e c o n tin u e d p re s e n c e o f a t h i c k l i t t e r c o v e r m ust r e d u c e e v a p o r a tio n from th e s o i l . T hat same l i t t e r c o v e r m ust have an i n t e r c e p t i o n p o t e n t i a l o f i t s own, e s p e c i a l l y when r a i n s a r e o f s h o r t d u r a t i o n a n d /o r low i n t e n s i t y . In HIGH a r e a s , l i t t e r c o v e r i s g e n e r a l l y t h i n and o f te n c o n s i s t s o f d ry le a v e s n o t a d h e r in g t i g h t l y to th e s o i l - t h e r e f o r e a llo w in g a i r movement an d e v a p o r a tio n . These r e l a t i o n s h i p s a p p e a r to be q u i t e i n t r i c a t e , an d a r e p ro b a b ly a l s o d e p e n d e n t on a i r te m p e r a t u r e , a s L eb ru n (1 9 7 1 ) h a s shown. s tu d y , th e y w ere n o t f u r t h e r q u a n t i f i e d . In t h i s B u t, a s F ig u r e 21 sh o w s, th e d i f f e r e n t i a l m o is tu r e c o n te n t o f th e s o i l i n HIGH a n d LOW a r e a s was 101 E PERCENT HoO 30 - o co l o HIGH LOCATIONS in i— i I CO 20 - 10 - MM PRECIP. 5/31 6/24 10 9/12 10/10 11/17 - “ 1 20 PRIOR TO t— T" SAMPLING r DATES LOW LOCATIONS 30 H90 8/25 30 - WEEKS PERCENT 7/14___ 8/9 - 10 - i 5/31 i 6/24 7/14 i i i 8/9 8/25 9/12 10/10 SAMPLING i i 11/17 DATE Figure 21. Soil moisture in HIGH and LOW areas, 1979, and total precipitation during the seven days prior to each sampling date. 102 1978 40 - 20 - z o H Eh Eh w cu N M M < £ 11 -P 80 - H u w « cu 60 - 1979 40 - 20 * a . M A M J J A S Figure 22. Weekly precipitation totals for 1978 and 1979 (Michigan State University Meteorological station, East Lansing). 103 c l e a r on a l l sa m p lin g d a t e s , and s e r v e d to en h an c e i n t e r p r e t a t i o n o f th e s p a t i a l d i s t r i b u t i o n o f _P. in c o n s t a n s . 3 .2 G e n e ra l o b s e r v a t i o n s on th e b io lo g y o f _P. in c o n s t a n s A) R e p r o d u c tio n ; M atin g p o ly d e sm ld s w ere e a s i l y fo u n d i n th e f i e l d b e c a u se th e p a r t n e r s d id n o t r e a d i l y s e p a r a t e . They o f t e n re m a in e d i n c o p u la th r o u g h o u t c o l l e c t i o n , t r a n s p o r t to th e l a b o r a t o r y , and t r a n s f e r to c u ltu re ja r s . I n f o u r s u c c e s s iv e y e a r s , th e f i r s t m a tin g s w ere alw ay s o b s e rv e d i n e a r l y to m id - A p r il. fre q u e n c y . D u rin g May, c o p u la s o c c u r r e d w ith i n c r e a s i n g None w ere s e e n i n l a t e J u ly and A u g u st. A gain i n O c to b e r , and a s l a t e a s November 1 7 , m a tin g o c c u r r e d b o th i n th e w o o d lo t and th e g a rd e n p o p u la tio n . Egg cham bers w ere l o c a t e d o n ly i n B aker w o o d lo t, in 1979 - th e f i r s t one on Ju n e 7. Two o t h e r s w ere d is c o v e r e d on Ju n e 2 8 , se v e n more on J u l y 1 2 , and th e l a s t one on A ugust 9 . on p i e c e s o f wood w ith sm ooth s u r f a c e s . s u b s tr a te s as n e s t-b u ild in g s i t e s , A ll o f them had b een b u i l t The p r e f e r e n c e f o r sm ooth r e c o rd e d i n l a b o r a t o r y c u l t u r e s , a p p e a re d to be t r u e in th e f i e l d a s w e l l . Of t h e s e n e s t s , f o u r c o n ta in e d e g g s : Ju n e 2 8 : 89 e g g s , on w h ich th e c h o r io n had j u s t r e c e n t l y ru p tu re d ; J u ly 12: A u g u st 9: 62 e g g s , f r e s h l y l a i d ; and 68 e g g s , c h o r io n r u p t u r e d ; 70 eg g s w hich had b een in v a d e d by fu n g u s and w ere n o t 104 v ia b le . T h re e n e s t s ( J u l y 12) w ere em p ty , b u t th e s p l i t and d is c a r d e d c h o r io n s w ere s t i l l i n th em : th e eg g s had h a tc h e d . em p ty , b u t c o n ta in e d no c h o r io n s : Four n e s t s w ere p o s s i b l y th e y had b een p lu n d e r e d , s i n c e two o f th e cham bers had i r r e g u l a r h o le s i n th e to p an d s i d e s , l a r g e r th a n th o s e u s u a l l y made by e s c a p in g young. The r e m a in in g th r e e e a c h c o n ta in e d a b e e t l e l a r v a , w hich may o r may n o t have been r e s p o n s i b l e f o r th e a b s e n c e o f e g g s . O v e r a l l , th e e v id e n c e on e g g - la y in g i n th e f i e l d i s m eag re. But t h e r e a r e i n d i c a t i o n s t h a t d e s t r u c t i o n o f eg g s i s a f a c t o r t h a t l i m i t s th e p o t e n t i a l o f th e s p e c i e s . F u n g al m ycelium , t i g h t l y p ack e d i n s i d e th e ch am b er, h as a l s o b een o b s e rv e d by S e i f e r t (1 9 3 2 ) in th e f i e l d . T h at a u th o r f u r th e r m o r e I m p l ic a t e s m i l l i p e d e s , c e n tip e d e s and c a r a b i d s a s n e s t p lu n d e r e r s and p r e d a t o r s on f i r s t i n s t a r s o f S tro n g y lo so m a p a l l i p e s 01 i v . B) M o ltin g and a g g r e g a t i o n : S e i f e r t (1 9 3 2 ) n o te d t h a t th e f i r s t t h r e e i n s t a r s o f S tro n g y lo so m a p a l l i p e s rem a in ed c l o s e l y a g g r e g a te d . H aving s e p a r a t e d them and d i s t r i b u t e d them o v e r a l a r g e r a r e a , he o b s e rv e d th e r e - f o r m a t io n o f th e o r ig i n a l a g g re g a tio n s . H ard in g (1 9 6 9 ) u se d " f e e d in g f l o c k s " a s a d e s c r i p t i v e te rm f o r f i r s t i n s t a r l a r v a e o f £ . c o r i a c e u s , and Blow er (1 9 6 7 ) m e n tio n e d t h a t a g g r e g a tio n s o f P olydesm us s p p . may be f a m ily g ro u p s . The " f e e d in g f l o c k s " o f H ard in g w ere o b s e rv e d o n ly tw ic e in th e w o o d lo t s i t e . The two g ro u p s c o n ta in e d 24 and 17 I n s t a r I re s p e c tiv e ly . They w ere o b v io u s ly t i g h t g r o u p s , th o u g h th e i n d i v i d u a l s 105 r a r e l y to u c h e d e a c h o t h e r . In c u l t u r e , th e o f f s p r i n g from one n e s t a l s o t r a v e l t o g e t h e r , i n lo o s e f o r m a t io n s , b u t w ith a l l i n d i v i d u a l s m oving i n th e same d i r e c t i o n . L a t e r s t a d i a o f te n a g g r e g a te i n one s m a ll a r e a o f a c u l t u r e j a r ; t h a t c o u ld , h o w ev er, sim p ly i n d i c a t e l o c a l i z e d o p tim a l c o n d i t i o n s . A g g re g a tio n s o b s e rv e d in th e f i e l d , p a r t i c u l a r l y i n th e f a l l o f th e y e a r , c o n s i s t e d o f a m ix tu re o f s t a g e s from th e f o u r t h up to a d u l t s . M o ltin g i n d i v i d u a l s w ere e x tre m e ly d i f f i c u l t to l o c a t e in f i e l d s itu a tio n s . A t o t a l o f 18 m o ltin g cham bers w ere fo u n d d u r in g h a n d - c o l l e c t i o n i n A u g u st, S ep tem b er and O c to b e r o f 1979. Two g e n e r a l ty p e s o f l o c a t i o n had been ch o se n by th e a n im a ls : 1) The u n d e r s id e o f l o g s , i . e . t h a t p a r t o f lo g s t h a t i s t i g h t l y a p p o sed to th e s o i l u n d e r n e a th ; th e cham bers w ere b u i l t on th e lo g i t s e l f , b u t p r o tr u d e d i n t o th e s o i l b e n e a th i t . 2) (n ■ 5 ch am b ers) The f r a s s c h a n n e ls i n s i d e l o g s , n e a r th e l o g 's s u r f a c e . E ig h t a n im a ls , a l l l o c a t e d c l o s e t o g e t h e r , had ch o se n s m a ll ro u n d h o le s (s u c h a s x y lo p h a g o u s b e e t l e l a r v a e would m ake) i n th e l i g h t - c o l o r e d wood o f a r e l a t i v e l y u n d ecay ed lo g ; th e cham ber w a lls w ere o f th e same l i g h t c o lo r and c o n s is te n c y a s th e f r a s s aro u n d th e h o l e s . F iv e o th e r i n d i v i d u a l s w ere l o c a t e d i n a c h a n n e l o f a d a r k - c o l o r e d , w e ll d eca y ed lo g . A g a in , th e cham ber w a lls a p p e a re d to be made o f d eca y ed wood. S e i f e r t (1 9 3 2 ) m e n tio n s t h a t j) . p a l l i p e s i s one o f th e l a s t l i t t e r - i n h a b i t a n t s to d is a p p e a r f o r h i b e r n a t i o n , and one o f th e f i r s t t o r e a p p e a r i n th e s p r i n g . P eaks o f a c t i v i t y in m ost te m p e r a te - z o n e s p e c ie s seem to o c c u r m o s tly i n s p r in g an d to a l e s s e r d e g re e i n th e f a l l ( B a n e r je e , 1 9 6 7 ; 1 9 7 3 ; B arlow , 1 9 5 7 ). shows a s i m i l a r b e h a v io r p a t t e r n . £ . in c o n s ta n s , in our re g io n s , In e a r l y M arch, w h ile snow c o v e rs th e 106 g ro u n d In p a tc h e s (a n d lo g s c a n n o t be moved b e c a u se th e y a r e f r o z e n to th e g r o u n d ) , ev en s h o r t p e r io d s o f warm ing w e a th e r t r i g g e r m i l l i p e d e a c tiv ity * W herever th e su n p e n e t r a t e s to th e l i t t e r , and aro u n d thaw ed dead b r a n c h e s , P. i n c o n s t a n s c a n be fou n d b etw een w et le a v e s and on th e s i d e s o f ex p o sed woody d e b r is * No a g g r e g a tio n s a r e o b v io u s a t t h a t tim e ; in s m a l l - s c a l e f a v o r a b l e a r e a s , th e i n d i v i d u a l s a p p e a r q u i t e w e ll d is p e r s e d * T h ro u g h o u t s p r in g and summer, P* in c o n s t a n s shows no d i s t i n c t a g g r e g a t i o n s , w ith th e p o s s i b l e e x c e p tio n o f i n s t a r I , a s m e n tio n e d e a rlie r. But in th e f a l l , e s p e c i a l l y in e a r l y to m id -O c to b e r, l a r g e a g g r e g a tio n s c a n be fo u n d on th e s i d e s o f lo g s ( F ig u r e 2 0 ) . Most o f th e s e a r e q u i t e l o o s e , and c o n t a in up to a b o u t 20 i n d i v i d u a l s o f a l l s t a g e s p r e s e n t i n th e p o p u la tio n a t t h a t tim e (IV to a d u l t ) . The a n im a ls f r e q u e n t l y c o n g r e g a te r i g h t a t th e w e t- d r y l i n e w h ich c a n be found on th e s i d e s o f lo g s a t v a r i o u s h e ig h ts * b e h a v io r can be o b s e r v e d . In November, on m ild d a y s , th e same Not u n t i l l a t e November does th e s p e c ie s f i n a l l y r e t i r e f o r th e w i n t e r . C) P a r a s i t i s m i n th e f i e l d : G r e g a r in e s have been fo u n d to be e n d o p a r a s i te s o f v a r io u s m i l l i p e d e s p e c i e s ( S e i f e r t , 1 9 32; J o h n s o n , 1 9 5 2 ). N em atodes, a l s o m e n tio n e d by B aker (1978 a ) , o c c u r a s e c t o p a r a s i t e s o f j?. i n c o n s t a n s . They p e n e t r a t e th e s o f t p l e u r a l t i s s u e b etw een s e g m e n ts , and a r e m ost e a s i l y s e e n on l i v e sp e c im e n s : th e y a p p e a r a s t i n y t r a n s p a r e n t c u r l s . But o f th e many h u n d re d i n d i v i d u a l s c o l l e c t e d i n B aker w o o d lo t, o n ly a few w ere p a r a s i t i z e d by n e m a to d e s. At l e a s t in 1 9 7 8 -7 9 , th e d e g re e o f nem atode I n f e s t a t i o n a p p e a re d to b e n e g l i g i b l e . 107 The e c t o p a r a s i t l c deutonym phs o f a m i t e , h o w ev er, w ere fo u n d w ith g re a te r re g u la rity . The s p e c i e s was n o t d e te rm in e d w ith c e r t a i n t y , b u t behav ed much l i k e H is tlo s to m a s p « , w h ich h a s been i m p lic a te d by B aker (1978 a ) a s a m a jo r c a u s e f o r th e d e t e r i o r a t i o n o f i u l i d c u l t u r e s . T hese p a r a s i t e s a r e a g a in m ost e a s i l y c o u n te d on l i v e a n im a ls . Once im m ersed i n a l c o h o l , th e y te n d to r e l e a s e t h e i r h o ld on th e h o s t s . From November 1978 to O c to b e r 1979, tw e lv e c a tc h e s o f l i v e a n im a ls ( r a n g e of to ta l P, p a ra s itis m . in c o n s t a n s p e r c a t c h : 6 7 -3 3 4 ) w ere exam ined f o r m ite The p e r c e n ta g e o f a n im a ls p a r a s i t i z e d (T a b le 24) r a n from a low o f 0.36% ( A p r i l 2 9 , 1 979) to a h ig h o f 7.76% (O c to b e r 1 0 , 1 9 7 9 ). Over th e e n t i r e s e a s o n , 2.67% o f a l l exam ined a n im a ls c a r r i e d m i te s . T w e n ty -th re e o f th e s e m i l l i p e d e s ( o r 37.1% ) w ere a d u l t s ; 19 ( o r 30.6%) w ere s u b a d u l t s ; 13 (21.0% ) w ere i n s t a r V I; 5 w e re s ta d iu m V an d o n e , th e s m a l l e s t s ta g e fo u n d t o be p a r a s i t i z e d , was a IV . S m all s t a g e s a p p e a r to be p a r a s i t i z e d o n ly r a r e l y by m ite s - a l th o u g h i n c u l t u r e s c o n ta in in g s t a d i a I and I I , m ite i n f e s t a t i o n c a n be a s e v e r e d e t r i m e n t . O v e r a ll , m ite i n f e s t a t i o n o f th e w o o d lo t p o p u la tio n c o u ld n o t be c a lle d e x te n s iv e . Most m i l l i p e d e s c a r r i e d a t o t a l o f o n ly 1 to 4 m i te s (mean num ber o f m ite s p e r a n im a l: 2 .7 7 ) . N in e ty -s e v e n p e r c e n t o f th e tim e , th e m ite s w ere a t t a c h e d to a p p e n d a g e s ; o n ly two s t a d i a VI had p a r a s i t e s on t h e i r v e n t r a l p l e u r a e . None c a r r i e d m ite s on t h e i r h ead s - a s o f t e n h ap p en s in h e a v i l y I n f e s t e d l a b o r a t o r y c u l t u r e s . Table 24. Parasitism of P* inconstans by ectoparasitic mite deutonymphs in the woodlot. 1978 / / 1979 1 1 /3 1 1 /8 No. exam ined 148 No. p a r a s i t . % p a ra s itiz . b a te 1 1 /1 0 3/1 8 3 /2 3 4/1 4 4 /1 6 4 /2 9 5/3 1 6 /6 9 /1 5 10/10 T o ta ls 101 334 67 318 186 189 276 247 134 202 116 2318 1 4 4 3 5 3 11 1 14 5 2 9 62 0 .7 4 .0 1 .2 4 .5 1 .6 1 .6 5 .8 0 .4 5 .7 3.7 1 .0 7.8 2.67 109 3 .3 S easo n al s ta g e d i s t r i b u t i o n A) G arden p o p u la tio n The y i e l d i n t o t a l num bers o f P . in c o n s t a n s from th e 1976 f u n n e l e x t r a c t i o n s was g e n e r a l l y p o o r, in March and A p r il f o r i n s t a n c e (T a b le 25) v i r t u a l l y no s p e c im e n s w ere o b t a i n e d , a lth o u g h hand c o l l e c t i n g a t t h a t tim e r e c o v e re d a num ber o f a d u l t s f o r l a b o r a t o r y r e a r i n g . i n th e s e a s o n , t o t a l num bers in c r e a s e d s u d d e n ly . L a te r As i l l u s t r a t e d i n F ig u re 2 3 , a d u l t s and s u b a d u l t s rem a in ed e l u s i v e , w h ile th e b u lk o f th e p o p u la tio n c o n s i s t e d o f th e new r e c r u i t s o f th e s e a s o n . se c o n d i n s t a r s o c c u r r e d i n l a r g e num bers i n J u n e . g r a d u a te d to I I , I I I an d IV. F i r s t an d By J u l y , m ost had P r o g r e s s i v e l y , th e p o p u la tio n a d v an c ed to i n s t a r s VI and V II i n S e p te m b e r. The l a s t e x t r a c t i o n , on O c to b e r 1 , a g a i n b ro u g h t v e ry p o o r r e s u l t s . D u rin g 1 9 7 8 , f r e q u e n t sa m p lin g from c r y p to z o a n b o a rd s gave somewhat b e t t e r r e s u l t s ( T a b le 2 6 ) . For r e a s o n s o f c l a r i t y , up to th r e e c o l l e c t i o n d a t e s w ere com bined i n one g iv e n d a t a p o i n t . Any com bined c o l l e c t i o n s s p a n no more th a n 10 d ay s t o t a l , and th e d a t e s g iv e n in T a b le 26 a r e m edian d a t e s b etw ee n th e f i r s t and l a s t day o f com bined c o l l e c t i o n d a t e s . In A p r il and May th e m a j o r i t y o f th e p o p u la tio n c o n s i s t e d of a d u l t s , w ith some V II and a n o c c a s i o n a l VI ( F ig u r e 2 4 ) . From m id -Ju n e to m id -A u g u st, th e a d u l t s t a g e was no lo n g e r r e p r e s e n t e d : im m atu res now d o m in ated th e p o p u l a t i o n . Not u n t i l S ep tem b er an d O c to b e r d id a d u l t s and p e n u ltim a te s t a g e s r e a p p e a r . At t h a t tim e , s t a d i a IV t o a d u l t were a l l p r e s e n t w ith a s l i g h t p re p o n d e ra n c e o f VI an d V II ( F ig u r e 2 4 ) . W hile p o p u la tio n r e c r u i tm e n t was o b v io u s in Ju n e o f 19 7 6 , no NO 60 H TOTAL 100- 20 21 (1-V) (1-VIII) I I I T*l' TT 1 I iiR r r i Apr 15 TTT May 6 n r>Tl June 8 169 =*• i n July 2 110 PERCENT OF Mar 26 191 60i 43 59 (4-VII) (1-VIII) 20 TTT Aug 13 ft Sept 16 I I I I I I I 11 Oct 1 Figure 23. Stage distribution, in percent of total number per date, in the 1976 garden population. Numbers above each date = total number extracted; eight subdi visions per date = stages I through VIII. 100 - • o 60 H z 30 35 84 58 15 20 - Ii i i l I fl < Apr 19 ti i'l l l i i i If f l May 1 May 11 II il T i l I11I I n May 21 June 1 O fe O 38 26 51 10 Ill z 60 - 20 ~ 11 i t I i l l w i June 17 o H D-m , r t■rrrr July 11 =H t Aug 4 TTT a Aug 18 TT TTT Sept 10 Pi w Pi 60- 47 20 72 52 - Sept 30 Oct 20 Nov 11 Figure 24. Distribution of stages in the 1978 garden population, in percent of total number caught. Total animals = number above each date; eight subdivisions per date = stages X through VIII. 112 l n s t a r s 1 w ere c o l l e c t e d I n 19 7 8 . In f a c t , th e c o l l e c t i o n s i n m id -Ju n e o f 1978 y i e l d e d a s i n g l e sp e c im e n , an a d u l t fem ale* I t i s m ost l i k e l y t h a t th e a b s e n c e o f f i r s t i n s t a r s can be a t t r i b u t e d to d i f f e r e n t i a l b e h a v io r: f i r s t i n s t a r s may p r e f e r d e e p e r s o i l s t r a t a , and w ould t h e r e f o r e be o b ta in e d from s o i l sam p les to a d e p th o f 8 cm (1976 d a t a ) , b u t n o t from th e u p p e r 1 t o 2 cm exam ined in th e b o a rd c o l l e c t i o n s . F u r th e r m o re , f i r s t and seco n d s ta g e s have a s h o r t d u r a t i o n a t h ig h e r te m p e r a tu r e s and a l a r g e p r o p o r ti o n o f them m ig h t be u n d e rg o in g e c d y s is a t t h a t tim e and so be i n a c c e s s i b l e to th e c o l l e c t o r . T a b le 25. T o ta l num bers o f P . in c o n s t a n s e x t r a c t e d from g a rd e n s o i l sam p les in 1976. Number e x t r a c t e d D ate t o t a l no. B) 3 /2 6 4 /1 5 5 /6 6 /8 7 /2 8 /1 3 9 /1 6 1 0 /1 4 21 6 191 169 43 59 5 The W oodlot P o p u l a t i o n : F o r a c l e a r p r e s e n t a t i o n o f s t a g e d i s t r i b u t i o n o f th e in c o n s ta n s p o p u l a t i o n , t h e r e s u l t s from a l l s a m p lin g te c h n iq u e s w ere com bined ( q u a l i t a t i v e h a n d - c o l l e c t i n g , and q u a n t i t a t i v e h a n d - s o r tin g and f u n n e l e x tra c tio n ). (T a b le 2 7 ) . The t o t a l num bers th u s o b ta in e d w ere r e s p e c t a b l y h ig h D a te s w ere co m b in ed , b u t o n ly i f th e y w ere n o t m ore th a n 4 days a p a r t. S t a r t i n g w ith O c to b e r 1978, F ig u re 25 i l l u s t r a t e s th e s t r u c t u r e o f T a b le 2b. T o ta l numbers o f D ate A/19 to t a l no. 5 /1 30 T ab le 27. 35 P. I n c o n s ta n s c a p tu r e d from c ry p to z o a n b o a rd s i n th e g a rd e n s i t e , 1978. 5 /1 1 5/2 1 84 58 6 /1 15 6 /1 7 7/1 1 1 37 8 /4 26 8 /1 8 9 /1 0 9 /3 0 10 51 47 1 0 /2 0 72 11/11 52 T o ta l num bers o f P . in c o n s ta n s o b ta in e d from Baker w o o d lo t, a l l sam p lin g m ethods com bined. 1978 D ate 1 0 /1 0 1 0 /2 4 1 1 /3 1 1 /1 0 232 142 178 436 t o t a l no. 1979 D ate 3 /8 3 /1 8 3 /2 3 4 /1 6 4 /2 9 t o t a l n o . 41 152 358 587 296 5 /1 5 5 /3 1 6 /6 6 /2 6 7 /1 4 8 /9 8 /2 5 68 272 152 215 224 164 304 9 /1 3 1 0 /1 0 350 326 1 1 /5 1 1 /1 7 447 418 1978 // 19 79 60 232 142 178 436 _ 41 d 20 b -n - r f T 11 n TTT Oct 8-11 Oct 24 152 358 NOV 3 TTTT Nov 8-10 Mar 6-10 < Eh ° 60 Eh 587 296 ■r f f T - 1 n -rF 68 & 20 -I i . 1 1~T Eh 3 w u Mar 18 m rrf Mar 23 -n -rfl Apr 16 Apr 29 215 n 224 w May 15 60 272r Pi 152 164 w 20 n i rlT 04 May 31 l li rflT June 6 n n FI n June 24-28 l~H r n J July 14 Aug 9 60 350 304 20 326^ O 418 447 “ T * fli Aug 25 r r ff Sept 12-15 =0 TTT Oct 9-10 M-rf =r Nov 5 s i t i TTT f t Nov 17 Figure 25. Distribution of stages in the woodlot population. Numbers above histo­ grams = total number of animals; eight subdivisions per date = stages I through VIII, 115 th e w o o d lo t p o p u l a t i o n . little From O c to b e r to November o f t h a t y e a r , t h e r e was e v id e n c e o f ad v an cem en t in th e p o p u la tio n * O c c a s io n a l t h i r d i n s t a r s w ere p r e s e n t ; IV an d a d u l t s o c c u r r e d i n low n u m b ers; th e b u lk o f th e p o p u l a t i o n c o n s i s t e d o f VI an d V II. No i n d i v i d u a l s s m a l le r th a n I I I w ere fo u n d . In e a r l y s p r i n g o f 19 7 9 , th e s t a g e d i s t r i b u t i o n was r e m i n is c e n t o f t h a t r e c o r d e d th e p r e v io u s f a l l , w ith p o s s i b l y a h ig h e r f r e q u e n c y o f V II (75% o f th e p o p u la tio n on M arch 1 8 ) . I n l a t e M arch to m i d - A p r i l, th e p r o p o r t i o n o f a d u l t s r o s e t o 24%, o n ly to f a l l a g a in to 3% on A p r i l 2 9 : th e su d d en a p p e a ra n c e o f an i n s t a r V p e a k on t h a t d a t e (60%) i s n o t e n t ir e ly e x p la in a b le , b u t th e re i s a p o s s i b i l i t y th a t fo u rth in s ta r s c o m p le te d a s p r in g m o lt to i n s t a r V a t t h a t tim e . At t h i s p o i n t one m ig h t c o n s id e r th e p ro b lem o f m o l tin g - an d t h e r e f o r e i n a c c e s s i b l e - i n d i v i d u a l s i n th e p o p u la tio n . The d i s t i n c t i o n b etw een f r e s h l y m o lte d and o l d e r i n d i v i d u a l s can n o t be c l e a r l y made in young i n s t a r s . The f i r s t t h r e e a r e w h ite ; IV i s o n ly f a i n t l y p ig m e n te d ; p ig m e n ta tio n , th o u g h v a r i a b l e , becom es more and m ore p ro n o u n ced from th e n o n . S u b a d u lts and a d u l t s h av e a b o u t th e same c o l o r a t i o n , b u t f r e s h l y m o lte d i n d i v i d u a l s do show l i g h t e r p ig m e n ta tio n f o r a few d ay s f o llo w in g e c d y s i s , p a r t i c u l a r l y i n th e p e n u ltim a te segm ent o f a d u l t s . B ecau se d a rk e n in g o f th e in te g u m e n t f o llo w in g a m o lt i s g r a d u a l b u t r e l a t i v e l y r a p i d , r e c o g n i t i o n o f v e r y r e c e n t m o lts i s s u b j e c t to some e r r o r . H ow ever, t h i s k in d o f c i r c u m s t a n t i a l e v id e n c e was r e c o rd e d f o r h a n d - c o l l e c t e d P. in c o n s t a n s in th e s p r in g o f 1979 ( T a b le 28) and was fo u n d to en h an ce i n t e r p r e t a t i o n o f th e d a ta i l l u s t r a t e d 25: in F ig u re 116 On M arch 23 ( F ig u r e 23) t h e p r o p o r ti o n o f a d u l t s I n th e p o p u la tio n b eg an t o I n c r e a s e ; a t t h a t tim e , 17% o f th e m a les an d 23% o f th e fe m a le s a p p e a re d to have m o lte d v e r y r e c e n t l y ( T a b le 2 8 ). On May 31 ( F ig u r e 2 5) th e p e r c e n ta g e o f a d u l t s had a g a in d o u b le d , and th e p e r c e n ta g e o f r e c e n t l y m o lte d i n d i v i d u a l s was ev en h ig h e r th a n i n M arch (T a b le 2 8 ) . On Ju n e 6 , th e a d u l t p o p u la tio n r e a c h e d a h ig h o f 64%, and c o n t a in e d 23-28% f r e s h l y m o lte d a n im a ls . As m ig h t be e x p e c te d , d a t a f o r s u b a d u lt s w ere s i m i l a r to th o s e f o r a d u lts . S p rin g and e a r l y summer a r e a p p a r e n tly th e tim e s o f a m a jo r m a tu r a ti o n p u sh th r o u g h s u b a d u lt s to a d u l t s . To r e t u r n now to F ig u re 2 5 : by e a r l y J u n e , f o u r t h i n s t a r s w ere s p a r s e , and a d u l t s c o n s t i t u t e d 64% o f th e p o p u la tio n . By l a t e J u n e , th e new g e n e r a t i o n had a p p e a r e d , c l e a r l y o f f s e t from th e g e n e r a t i o n o f th e p r e v io u s y e a r : 11, 111 a n d IV w ere l a c k i n g , V w ere v i r t u a l l y n o n - e x i s t e n t , and a d u l t s w ere s t i l l p ro m in e n t. T a b le 28. F req u en cy o f o c c u r r e n c e o f r e c e n t m o l ts , i n p e r c e n t o f th e t o t a l num ber ex am in ed . T o ta l n o . and (% r e c e n t m o lts ) I n s t a r s exam. M arch 23 May 31 June 6 V I1 fe m a le s 45 ( 2 2 .2 ) 46 ( 3 0 .4 ) 19 ( 2 1 .1 ) V II m a les 55 ( 2 5 .5 ) 22 ( 1 3 .6 ) V I I I fe m a le s 47 ( 2 3 .0 ) 53 ( 3 7 .7 ) 57 ( 2 8 .1 ) V I I I m ales 24 ( 1 6 .7 ) 24 ( 3 3 .3 ) 39 ( 2 3 .1 ) 117 T a b le 29. R e s u lt s o f m a rk - r e c a p tu r e program f o r a d u l t P. in c o n s t a n s i n th e g a rd e n s i t e . C ate m arked A pr. 16 19 23 29 30 May 3 7 10 14 18 23 29 Ju n e 4 17 J u ly 7 18 31 Aug. 10 16 20 Sep. 3 15 25 O ct. 8 16 26 Nov. 11 TOTALS no. m arked no. re c a p t. 10 6 8 17 8 8 25 19 15 9 13 9 1 1 0 2 3 3 2 5 4 1 0 1 1 d a te s re c a p t. d ay s m a rk - r e c a p . A pr. 30 A pr. 29 May 3 , 10 May 3 , 10 May 7 , 10 May 7 , 18 May 1 0 , 1 8 , 19 May 1 4 , 19 May 29 14 10 10-1 7 4 -1 1 7-1 0 4 -1 5 3-1 2 4 -9 15 May 29 Ju n e 6 6 0 - 0 - - M0 ADULTS FOUND - 3 1 2 5 13 22 194 0 1 0 1 3 0 O c t. 16 21 O c t. 26 Nov. 1 1 , 20 10 1 6 -2 5 28 (14.4% ) S p rin g 1 9 79: 0 r e c a p t u r e d ( o f 31 c o l l e c t e d ) A d u lt l i f e a p p e a re d to be b r i e f , ho w ev er. i n J u l y , n o t to r e a p p e a r u n t i l S ep te m b er. T h e ir num bers d w in d led At t h a t tim e i n s t a r s 1 and I I had d is a p p e a r e d , and th e num bers o f IV, V an d VI w ere r e p le n is h e d d u r in g th e f a l l g ro w th p e r io d . o f th e p o p u la tio n . In November, VI a n d V II form ed th e b u lk The p r o p o r t i o n o f a d u l t s was q u i t e h ig h th e n - 118 T a b le 30* R e s u l t s o f m a r k - r e c a p tu r e p ro g ram In th e g a rd e n s i t e f o r s u b a d u lt P* In c o n s ta n s * D ate m arked no. m arked A pr. 16 19 23 29 30 Hay 3 7 10 14 18 19 23 29 Ju n e 4 17 J u ly 7 18 31 Aug. 10 16 20 S ep . 5 15 25 O c t. 8 16 26 Nov. 11 17 4 8 5 5 16 TOTALS 73 no. re c a p t. d a te s re c a p t. days m a r k - r e c a p t. mm 2 4 - 0 1+1 tw ic e May 7 , 1 0 , 14 1 4 -2 1 May 1 0 , 18 3-11 - - - - - 4 1 3 0 - - 2 0 - - 5 0 - NO SUBADULTS FOUND - 0 0 1+1 tw ic e 1 0 1 O ct. 16, 26 O ct. 26 Nov. 20 8 -1 8 10 9 11 (15.1% ) S p rin g 1 9 7 9 : 0 r e c a p t u r e d ( o f 9 c o l l e c t e d ) w h e th e r th e r e l a t i v e l y low num bers e n c o u n te r e d I n e a r l y s p r in g w ere a r e s u l t o f o v e r w in te r m o r t a l i t y m ust be l e f t to s p e c u la tio n * 119 C) M a r k - r e c a p tu r e p ro g ra m ; M a r k - r e c a p tu r e p ro g ram s a r e n o rm a lly u se d to o b t a i n p o p u la tio n p a ra m e te r s su c h a s s u r v i v a l , r e c r u i tm e n t and l i f e s t a g e d i s t r i b u t i o n . In t h e g a rd e n s i t e , su c h a program was p erfo rm e d in o r d e r to an sw er two more s p e c i f i c q u e s t i o n s : a ) d o es th e a d u l t p o p u la tio n p r e s e n t i n th e s p r in g s u r v iv e th ro u g h th e summer? O r, a l t e r n a t i v e l y , i s t h e r e an o v e r la p betw een p o s t - r e p r o d u c t i v e a d u l t s and th e n e w ly -m o lte d au tu m n al p o p u la tio n o f a d u lts ? b) Can ad v an cem en t o f s u b a d u lt s to a d u l t s te docum ented s e a s o n a l l y by th e d is a p p e a r a n c e o f m arked i n d i v i d u a l s ? The d e t a i l e d r e s u l t s a r e g iv e n i n T a b le s 29 an d 30. As w itn e s s e d by s e v e r a l n i l - r e c a p t u r e s , and by th e r e l a t i v e l y low o v e r - a l l r e c a p t u r e r a t e (1 4 t o 15 %), th e program was n o t t o t a l l y s u c c e s s f u l . I n t e r v a l s b etw een m ark in g and r e c a p t u r i n g d a t e s a r e o f p a r t i c u l a r in te re s t. F irs t: F o r a d u l t s ( T a b le 29) th e y may be i n t e r p r e t e d i n two w ays. i n s p r i n g an d e a r l y sum m er, m arked i n d i v i d u a l s w ere r e c a p tu r e d a f t e r a maximum o f 17 d a y s . In d e p e n d e n t o f tim e o f m a rk in g , a d u l t s th u s w ould n o t be fo u n d a g a in a f t e r a p p r o x im a te ly two weeks had p a s s e d . T h is makes i t h ig h ly u n l i k e l y t h a t th e l a s t s p rin g -m a rk e d i n d i v i d u a l s ( i n May) w ould be fo u n d a g a in i n S ep tem b er - a b o u t e i g h t weeks l a t e r . An a l t e r n a t i v e i n t e r p r e t a t i o n ( s u p p o r te d by l o n g e v i t y o b s e r v a ti o n s i n th e l a b o r a t o r y ) w ould be t h a t th e s e s h o r t tim e i n t e r v a l s i n d i c a t e a c o n t in u o u s , g r a d u a l d i e - o f f o f a d u l t s th r o u g h o u t s p r in g and e a r l y sim m er; t h a t th e summer g ap i n th e a d u l t p o p u la tio n in d e e d r e p r e s e n t s t o t a l m o r t a l i t y ; an d t h a t in th e f a l l r e p le n is h m e n t o f th e a d u l t c o n t in g e n t ta k e s p la c e th ro u g h m a tu rin g i n d i v i d u a l s b e lo n g in g to th e 120 y e a r 's new r e c r u i t s • T h e re i s e v id e n c e to s u p p o r t th e l a t t e r I n t e r p r e t a t i o n * Of a l l r e c a p tu r e d i n d i v i d u a l s ( a d u l t s and s u b a d u l t s ) 79% w ere fo u n d u n d e r th e same b o a rd s th e y had o r i g i n a t e d fro m , and o n ly 21% w ere fo u n d u n d er n e ig h b o rin g b o a r d s ( a t m ost two b o a rd s aw a y ). s p e c ie s seem ed to e x h i b i t l i t t l e th u s would add l i t t l e In th e g a r d e n s i t e , th e h o r i z o n t a l m o b i l i t y , and e m ig r a tio n b i a s ; a d u l t d is a p p e a r a n c e c o u ld in d e e d be b e s t e x p l a in e d by m o r t a l i t y . F u r th e r c o r r o b o r a t i o n i s f u r n is h e d by th e s i m i l a r s e a s o n a l o c c u r r e n c e p a t t e r n s o f s u b a d u lt s and a d u l t s i n th e g a rd e n p o p u la tio n i n 1976 and in th e w o o d lo t p o p u la tio n i n 1979. Few s u b a d u lt s w ere fo u n d , and ev en fe w e r w ere r e c a p tu r e d (T a b le 3 0 ). I t i s l i k e l y t h a t n i l - r e c a p t u r e s i n th e c a s e o f s u b a d u lt s i n d i c a t e e x u v i a t i o n , b o th i n s p r in g and f a l l . E v id e n c e o f g r a d u a t io n a t th e s e tim e s was a l s o found i n th e w o o d lo t p o p u la tio n ( s e e S e c tio n 3 . 3 . ) a s w e ll a s i n th e g a rd e n p o p u l a t i o n , a s d is c u s s e d e a r l i e r . S e v e r a l a u t h o r s h av e a d d r e s s e d th e m s e lv e s to th e v a l i d i t y of m a rk - r e c a p tu r e te c h n iq u e s (M cLeod, 1 9 5 8 ; T u r n e r , 1 9 60; G r e e n s la d e , 1964; E r ic s o n , 1 9 7 7 ) , b u t t h e i r s e a r c h f o r b ia s c o n c e rn e d q u a n t i t a t i v e p o p u la tio n p a r a m e te r s n o t in c lu d e d in th e g o a l s o f t h e p r e s e n t s tu d y . In g e n e r a l i t may be s a i d t h a t th e m a r k - r e c a p tu r e program w a s , in i t s e l f , n o t c o n c l u s i v e . But th e p h e n o lo g ic a l d a t a o b ta in e d f o r P. in c o n s ta n s in th e f i e l d s u p p o r t th e t e n t a t i v e c o n c lu s io n s draw n from th e p ro g ra m , j u s t a s th e r e c a p t u r e r e s u l t s le n d c re d e n c e to th e i n t e r p r e t a t i o n o f sa m p lin g r e s u l t s . 121 3 .4 . Sex r a t i o s in f i e l d p o p u la tio n s F ig u r e 26 su m m arizes th e sex r a t i o s o b s e rv e d i n th e g a rd e n (1976 and 197 8 ) and i n th e w o o d lo t p o p u la tio n s ( 1 9 7 8 - 7 9 ) ; a l l s t a g e s fro m IV upw ard w ere I n c lu d e d in th e d a ta * R eco rd s fro m th e g a rd e n p o p u la tio n w ere n o t e n t i r e l y r e l i a b l e b e c a u s e o f r e l a t i v e l y s m a ll sam p le s i z e s : s e a s o n a l v a r i a b i l i t y i n s e x r a t i o s ra n g e d fro m 50 t o 85% f e m a le s in 1 9 7 6 , an d 32 t o 80% i n 1978. In th e w o o d lo t p o p u l a t i o n , th e p e r c e n t fe m a le s was r e l a t i v e l y m ore c o n s t a n t (ra n g e o v e r a l l d a t e s : 37-66% ), f r e q u e n t l y a ro u n d 50%. T h is w ould s u p p o r t th e c o n j e c t u r e s d is c u s s e d i n S e c t i o n 1 . 3 : t h a t th e young p o s s e s s a s e x r a t i o o f a b o u t 1 : 1 , and t h a t any s e x - s p e c i f i c d i f f e r e n c e s i n m o r t a l i t y a r e n o t d r a s t i c , i f in d e e d th e y e x i s t . C o n s id e rin g o n ly th e a d u l t g a r d e n p o p u la tio n ( F ig u r e 27) i n 1 9 7 8 , t h e r e was some e v id e n c e o f a s e a s o n a l d i f f e r e n c e i n se x r a t i o s : fe m a le s a p p e a re d to p r e v a i l i n th e s p r i n g , m ales in th e f a l l . U sing th e much more am ple a d u l t m a t e r i a l c o l l e c t e d i n B aker w o o d lo t ( F ig u r e 2 8 ) , a t r e n d s i m i l a r to t h a t i n F ig u re 27 c o u ld be seen . The p e r c e n t fe m a le s rem a in ed h ig h th r o u g h s p r i n g and summer (60 to 75%). In S ep tem b er an d O cto b er th e p r o p o r t i o n o f fe m a le s d ro p p e d to a b o u t 25% - p o s s i b l y b e c a u s e m ales te n d to m a tu re s l i g h t l y f a s t e r th a n f e m a le s . B ut e a r l y m a t u r a t i o n o f m ales became a p p a r e n t o n ly f o r a s h o r t tim e ; by m id-N ovem ber th e s e x r a t i o was a g a i n c l o s e to u n i t y . A s h o r t e r d u r a t i o n o f th e p e n u l tim a te s ta d iu m i n m ales w ould e n s u r e i n s e m in a tio n o f fe m a le s a s soon a s th e y m a tu re d . The sp erm s t o r a g e c a p a c i t y o f th e s p e c ie s would th e n e n a b le th o s e fe m a le s to p ro d u c e 1976 1978 co w 60" E 40- W 20- § 10 - 1979 Figure 26. Percent females, of all stages IV through VIII, in the garden (1976, 1978) and the woodlot (1979) populations; where possible, data were summarized at 10-day intervals. 123 140 51 (4 ) 21 23 FEMALES / (FEMALES + MALES) x 100 30 1978 1979 F i g u r e 2 7 . P e r c e n t f e m a l e s among a d u l t s i n t h e 1 9 7 8 -7 9 g a r d e n p o p u l a t i o n . N um bers a r e t o t a l n u m b e rs c a p t u r e d p e r m o n th . + MALES) x 100 80 36 148 78 70 41 60 215 157 149 NO. FEMALES (2 ) 40 22 124 / (FEMALES 50 30 16 20 26 10 1978 N 1979 Figure 28. Percent females in the adult woodlot population, summarized per month. 125 v i a b l e eg g s a s so o n a s s p r i n g te m p e r a tu r e s w ere c o n d u c iv e to i t , w ith o u t need f o r f u r t h e r m a tin g . 3 .5 . A g g re g a tio n , d i s t r i b u t i o n and d e n s i t y A) A g g r e g a tio n i n s a m p le s : B low er (1 9 7 0 ) fo u n d t h a t P olydesm us s p p . i n a B r i t i s h w o o d lo t w ere much more c o m p a c tly a g g r e g a te d th a n i u l i d s i n th e same h a b i t a t a t v a r io u s tim e s o f th e s e a s o n . In th e p r e s e n t s tu d y , num bers o f P. I n c o n s ta n s e x t r a c t e d from l i t t e r sam p les w ere h ig h enough to m e r i t c a l c u l a t i o n o f v a r ia n c e /m e a n r a t i o s as i n d i c e s o f sam p le a g g r e g a tio n . A X2 t e s t f o r s m a ll sam p les ( E l l i o t t , 1973) was u sed to e v a l u a te p o p u la tio n d i s p e r s i o n i n c o m p a riso n w ith a P o is s o n s e r i e s , w here X2 * s 2 ( n - l ) / x . T ab le 31 d e t a i l s th e r e s u l t s . Compared to a c h a r t o f 5% s i g n i f i c a n c e l e v e l s ( E l l i o t t , 1 9 7 3 ), a l l v a lu e s i n T a b le 31 la y f a r beyon d 5% c r i t i c a l v a l u e s . C o n c lu sio n s draw n f o r £ . in c o n s t a n s p o p u la tio n s th u s a g r e e d w ith th o s e drawn by B low er (1 9 7 0 ) f o r o t h e r p o ly d e s m id s . o f y e a r. D is p e r s io n was h ig h l y a g g r e g a te d , i r r e s p e c t i v e o f tim e And a g g r e g a tio n was in d e p e n d e n t o f p o p u la tio n s ta g e s tru c tu re , i . e . i t was no more p ro n o u n ced a t th e tim e o f y e a r l y r e c r u i tm e n t th a n a t an y o t h e r tim e . Even when th e m a jo r it y o f i n d i v i d u a l s in th e p o p u la tio n had r e a c h e d i n s t a r s IV t o V II (O c to b e r 9 , November 1 7 ) , th e y w ere d i s t i n c t l y a g g r e g a te d . B) D i s t r i b u t i o n and d e n s i t y : C o n s id e rin g o n ly th e l i t t e r - i n h a b i t i n g segm ent o f th e w o o d lo t T a b le 31* LOW l i t t e r sam p les fro m B ak er w o o d lo t: e v a lu a tio n of d i s p e r s i o n ( a g g r e g a t io n i n sa m p le s ) o f J?. in c o n s t a n s by X2 t e s t . no. o f D ate sam p les 3t/sam. S2 X2 Apr 29 10 2 8 .1 4 7 0 .7 1 5 0 .8 May 31 10 9 .4 4 7 .6 4 5 .6 June 24 10 1 3 .0 2 1 4 .2 1 4 8 .3 J u ly 12 15 9 .3 7 5 .7 1 1 4 .3 Aug 9 15 7 .7 7 9 .9 1 4 4 .7 Aug 25 15 6 .7 4 0 .9 8 5 .8 S ep t 12 15 9 .8 3 2 6 .0 4 6 5 .2 O ct 9 15 1 1 .9 2 3 9 .1 2 8 2 .0 Nov 17 15 6 .1 4 2 .5 9 7 .1 p o p u la tio n (T a b le 3 2 ) , d i f f e r e n c e s b etw ee n LOW an d HIGH a r e a s became c le a r. P. in c o n s t a n s re a c h e d re m a rk a b ly h ig h d e n s i t i e s i n th e r i c h l i t t e r s t r a t a o f d e p re s s io n s : A p r il 29. th e maximum e s t i m a t e was 450/m 2 , on HIGH sa m p le s c o n ta in e d c o n t r a s t i n g l y few a n i m a ls ; e s ti m a t e d d e n s i t i e s ra n g e d from 4 .8 /m 2 i n May to 3 8 . 4/w 2 i n J u l y . C l e a r l y , a c c u m u la te d l i t t e r ( s e e T a b le 23 f o r l i t t e r d e p t h s ) w ith i t s p r o p e r t i e s o f m o is tu r e r e t e n t i o n an d fo o d a v a i l a b i l i t y , s u p p o r te d l a r g e r p o p u la tio n s o f _P. i n c o n s t a n s . The s ta n d a r d e r r o r s o f e s tim a te d d e n s i t i e s w ere f r e q u e n t l y l a r g e ( e . g . A p r il 2 9 , Ju n e 24, S eptem ber 1 2 ) , 127 Table 32. Estimated densities of P. Inconstans per of litter. E s tim a te d n o ./ra ^ + S. E. LOW Apr 29 4 4 9 .6 + 1 0 9 .8 May 31 1 5 0 .4 + 3 4 .9 4 .8 + 4 .8 Ju n e 24 2 0 8 .0 + 7 4 .1 8 .0 + 4 .7 J u ly 12 1 4 8 .3 + 3 5 .9 3 8 .4 + 2 1 .2 Aug 9 1 2 3 .7 + 3 6 .9 30. 9 + 1 2 . 9 Aug 25 1 0 6 .7 + 2 6 .4 2 8 .8 + 9 .5 Sep 12 1 5 7 .0 + 7 4 .6 (no s a m p le s ) O ct 9 1 8 9 .9 + 3 .9 3 4 .1 + 0 .6 9 8 .1 + 1 - 7 1 1 .7 + 0 .4 Nov 17 in d ic a tin g HIGH (no s a m p le s ) t h a t th e s p e c ie s was n o t e v e n ly d i s t r i b u t e d th r o u g h th e sam ple u n i t s . H ow ever, s ta n d a r d e r r o r s w ere s m a ll i n O c to b e r and N ovem ber, s u g g e s tin g t h a t a g g r e g a tio n te n d e n c ie s may v a r y s e a s o n a l l y . S o il c o r e d a t a r e i n f o r c e d th e h o r i z o n t a l d i s t r i b u t i o n p a t t e r n n o te d i n l i t t e r s a m p le s . T a b le 33 shows LOW sam p le t o t a l s and m e a n s/s a m p le u n i t o f 20 cm^. HIGH a r e a s (T a b le 3 4 ) y i e l d e d few a n i m a l s ; o v e r th e e n t i r e s e a s o n , o n ly se v e n sam p les c o n ta in e d JP. in c o n s t a n s ( o f 200 sa m p le s t o t a l ) . D e n s ity v a l u e s f o r th e s o i l - i n h a b i t i n g p o p u la tio n w ere p u r p o s e ly r e s t r i c t e d to th e s u r f a c e a r e a o f one sam p le u n i t . The l a r g e num ber o f 128 s a m p le s c o n t a in in g z e r o I n d i v i d u a l s made an y e s t i m a t e s p e r m2 h ig h l y u n re lia b le * Thus th e 0 -8 cm su b sa m p le s o n J u l y 1 2 , w ith a mean o f 2 .2 5 i n d i v l d u a l s / 2 0 cm2, w ould y i e l d an e s ti m a t e d d e n s i t y o f 1125 i n d i v i d u a l s / m2 - a f i g u r e made t o t a l l y u n b e l ie v a b l e by t h r e e y e a r s o f h a n d - c o l l e c t i n g and s o r t i n g e x p e r i e n c e . a ro le : H ere a g a i n , a g g r e g a tio n p la y e d o f th e 45 i n d i v i d u a l s i n th e J u l y 12 s a m p le s , 19 ( a l l i n s t a r 1 ) wer e x t r a c t e d from one s i n g l e s o i l c o r e . D i f f e r e n t i a l d i s t r i b u t i o n o f _P. in c o n s t a n s w ith d e p th c o u ld th u s n o t be a s s e s s e d w ith a c c u r a c y . The o n ly m e a n in g fu l c o m p a riso n w ould h av e in v o lv e d d e n s i t i e s / m ^ i n e a c h v e r t i c a l h a b i t a t s u b d i v i s i o n - an e s t i m a t e p o s s i b l e f o r l i t t e r , b u t p r e c lu d e d f o r s o i l s a m p le s by th e m ethod em ployed. T a b le 33. Number o f a n im a ls e x t r a c t e d from s o i l c o r e su b sa m p le s in LOW a r e a s . 0 - 8 cm to ta l m ean/ 8 - 15 cm to t a l m ean/ no. 20 cm^ no. 20 cm2 Way 31 11 0 .5 5 6 0 .3 Ju n e 24 20 1 .0 J u ly 12 45 A ugust 9 November 17 11 0 .5 5 2 .2 5 9 0 .4 5 7 0 .3 5 1 0 .0 5 3 0 .1 5 2 0 .1 129 T a b le 34. Number o f a n im a ls e x t r a c t e d fro m s o i l c o re su b sa m p le s i n HIGH a r e a s . 0 - 8 cm to ta l no. 4. m ean/ 20 cm^ 8 - 15 cm to ta l no. m ean/ 20 cm^ May 31 2 0 .1 0 0 J u n e 24 0 0 1 J u l y 12 3 0 .0 5 0 0 A u g u st 9 2 0 .1 0 0 November 17 0 0 1 0. 05 0 .0 5 CONCLUSION The s ta g e d i s t r i b u t i o n o f P. in c o n s t a n s p o p u la tio n s was re m a rk a b ly s i m i l a r i n d i f f e r e n t y e a r s and d i f f e r e n t s i t e s . In c o n t r a s t to l o n g e r - l i v e d p o ly d e sm id s (B lo w er and G a b b u tt, 1 9 64; 3 1ow er, 1969) o r to th o s e i u l i d s p o s s e s s in g a l i f e s p a n o f more th a n t h r e e y e a r s (B lo w er and G a b b u tt, 1 9 6 4 ; B low er and F a i r h u r s t , 1 9 6 8 ), t h e r e was l i t t l e i f an y o v e r la p b etw ee n s u c c e s s iv e g e n e r a t i o n s . By d e s i g n a t i n g th e 1978 p o p u la tio n o f B aker w o o d lo t a s g e n e r a t i o n 0 , p o p u la tio n d e v e lo p m e n t c o u ld e a s i l y be d e s c r ib e d . G e n e r a tio n 0 r e a c h e d m a t u r i t y i n f a l l o f 1978 an d s p r in g o f 1979. T hese a d u l t s 130 re p ro d u c e d from May to l a t e J u l y , th e n d ied * T h e ir o f f s p r i n g , g e n e r a t i o n I , r a p i d l y grew to i n s t a r s VI an d V II, and some re a c h e d V II I l a t e i n 1979* In th e s p r in g o f 1980 th e r e m a in d e r of g e n e r a tio n I w ould r e a c h m a t u r i t y a n d , come May, w ould b e g in to p ro d u c e g e n e r a t i o n I I eggs. O n se t o f e g g - la y in g was n o t d i r e c t l y o b s e r v e d . The f i r s t eggs w ere p r o b a b ly l a i d i n e a r l y May, when d a y tim e s o i l and l i t t e r te m p e r a tu r e s f r e q u e n t l y e x c e e d e d 10°C. In th e l a b o r a t o r y , 10°C a llo w e d m a tin g a s w e ll a s th e p r o d u c tio n o f v i a b l e e g g s , and o v i p o s i t i o n f r e q u e n c y i n c r e a s e d r a p i d l y a t te m p e r a tu r e s ab o v e 10°C , i n d i c a t i n g t h a t fie ld te m p e r a tu r e s i n May w ere in d e e d c o n d u c iv e to r e p r o d u c t io n . G iven a r e p r o d u c t i v e p e r io d l a s t i n g from May to l a t e J u l y , an e s t i m a t e d 6 t o 8 b ro o d s c o u ld be p ro d u ced p e r fe m a le (b a s e d on te m p e r a tu r e - d e p e n d e n t o v i p o s i t i o n f r e q u e n c i e s o f 8 to 14 d a y s ) . Fem ales s u r v iv in g th r o u g h th e b r e e d in g p e r io d w ould t h e r e f o r e l a y a t o t a l o f 300 t o 500 eg g s e a c h , b u t some o f th e s e eg g s w ere a lm o s t c e r t a i n l y d e s tr o y e d by f u n g a l a t t a c k and o o p h ag y . F i r s t i n s t a r s a p p e a r e d i n e a r l y Ju n e i n th e g a r d e n , and I n m id -Ju n e i n th e w o o d lo t. Given d i u r n a l l y f l u c t u a t i n g te m p e r a tu r e s , a n em bry o n ic d ev e lo p m e n t tim e o f 4 t o 6 w eeks i n th e f i e l d com pared w e ll w ith d e v e lo p m e n ta l r a t e s o b s e rv e d i n th e l a b o r a t o r y : 4 to 6 w eeks c o rr e s p o n d to a tim e sp a n in t e r m e d i a t e b etw ee n th o s e r e c o r d e d a t 10° and 1 5 .5 * 0 c o n s ta n t te m p e r a tu r e . G row th was r a p id a t 1 5 .5 ° a n d 21°C i n th e l a b o r a t o r y , s u p p o r tin g f i e l d e v id e n c e o f f a s t m a tu r a ti o n o f th e new g e n e r a t i o n fro m Ju n e to O c to b e r. A d u lts c o l l e c t e d i n th e f a l l c o n c e iv a b ly may have been g e n e ra tio n 0 (p o s t-re p ro d u c tiv e ) In d iv id u a ls . But th e i n a b i l i t y to 131 l o c a t e an y a d u l t s fro m l a t e J u l y th r o u g h A ugust I n t h r e e d i f f e r e n t y e a r s f u r n i s h e d e v id e n c e to th e c o n tr a r y * A d u lts do n o t m o lt* A ll t h e m ore r e a s o n why t h e i r d is a p p e a r a n c e may b e s t be a s c r i b e d to m o r t a l i t y r a t h e r th a n to deep v e r t i c a l m i g r a ti o n ( th e o n ly o t h e r a l t e r n a t i v e ) . S te p h e n so n (1 9 6 1 ) a l s o fou n d no a d u l t s o f B rachydesm us s u p e r u s from A ugust to O c to b e r ; he s u g g e s te d t h a t m a les d ie d a f t e r m a tin g , fe m a le s a f t e r o v ip o s itio n . F a ll - m a t u r i n g a d u l t s th u s c o n s i s t e d o f i n d i v i d u a l s h a tc h e d th e same y ear. They re p ro d u c e d th e f o llo w in g s p r in g and c o m p le te d t h e i r l i f e c y c l e i n a p p r o x im a te ly 12 m o n th s. T h ere was no i n d i c a t i o n o f i t e r o p a r i t y w h ic h , i n i u l i d s , i s e v id e n c e d by c o n tin u e d m o ltin g and s u r v i v a l o f a d u l t s th ro u g h more th a n one b r e e d in g s e a s o n (B lo w e r, 1969; Blow er and F a i r h u r s t , 1 9 6 8 ; B a k e r, 1 9 7 8 b ). S im ila r i n t e r o p a r o u s b e h a v io r h as b een docum ented f o r o th e r l i t t e r i n v e r t e b r a t e s a s w e ll . The is o p o d T r a c h e o n is c u s r a t h k e i ( B r a n d t) h as a maximum l i f e sp an o f 2 t o 3 y e a r s i n th e f i e l d (McQueen, 1 9 76; S n id e r , i n p r e s s ) . B ro u g h t i n t o th e l a b o r a t o r y , a t te m p e r a tu r e s r a n g in g from 1 5 .5 ° t o 2 6 .6 °C , th e s p e c i e s m a in ta in s i t e r o p a r i t y : up t o f o u r b r e e d in g p e r io d s a r e d i s t i n c t l y s e p a r a t e d by n o n - b r e e d in g g ro w th p e r i o d s , an d th e num ber o f young p ro d u ced i n c r e a s e s w ith a g e ( S n id e r , i n p r e s s ) . d id n o t b eh av e t h i s way. _P. in c o n s t a n s F e c u n d ity d e c r e a s e d w ith a g e , and a l l fe m a le s d ie d a t th e end o f o n e , u n i n t e r r u p t e d , r e p r o d u c t iv e p e r io d . B oth o b s e r v a ti o n s i n d i c a t e d s e m e l p a r lt y . P o p u la tio n d e n s i t i e s w ere r e l a t i v e l y h ig h i n th e w o o d lo t. In p in e f o r e s t s , Rubeova (1 9 6 7 ) fo u n d more th a n 1 5 .6 /m ^ ( a l l d ip lo p o d s in c lu d e d ). F o r G lo m e ris m a r g i n a ta , 50/m^ r e p r e s e n t s a h ig h d e n s it y (B ocock e t a l , 1 9 6 7 ). G is t and C r o s s le y (1 9 7 5 ) g av e a summer d e n s i t y 132 o f 14 d ip lo p o d s /m ^ i n a L ir io d e n d r o n f o r e s t . O nly B o rn eb u sch ( 1 9 3 0 ) , w orking i n o ak w oods, a r r i v e d a t a h ig h e s t i m a t e o f 433 d ip lo p o d s /m ^ . _P. in c o n s t a n s was d i s t r i b u t e d u n ev e n ly i n th e w o o d lo t. T h at p o p u la tio n s i z e v a r i e s g r e a t l y b etw ee n l o c a l i t i e s h as a l s o been n o te d by S p a u ll (1 9 7 6 ) , by Dunger (1 9 7 8 ) f o r d ip lo p o d s i n g r a s s l a n d s , and by B o rn eb u sch (1 9 3 0 ) f o r t o t a l m i l l i p e d e s i n t h r e e d i f f e r e n t f o r e s t s i t e s . In P. i n c o n s t a n s , d i f f e r e n t i a l h o r i z o n t a l d i s t r i b u t i o n c o u ld be q u a l i t a t i v e l y c o r r e l a t e d to l i t t e r th i c k n e s s and m o i s tu r e . fu lfille d th e d u a l f u n c t i o n o f fo o d an d c o v e r. L itte r The q u a n t i t y o f l i t t e r a v a i l a b l e i n p a l a t a b l e , m o is t c o n d i t i o n a l s o d e te rm in e d th e c h a r a c t e r i s t i c s o f th e a n i m a ls ' m i c r o - h a b i t a t . U p h ill l o c a t i o n s w ere d r i e r , w arm er, and p o o re r i n fo o d r e s o u r c e s (ju d g in g by th e q u a n t i t y and s t a t e o f th e l i t t e r p r e s e n t ) . A cco rd ing to Manton (1 9 5 6 ) p o ly d e sm id s a r e I n e f f i c i e n t b u rro w e rs and depend on e x i s t i n g c r e v i c e s f o r movement. In lo w - ly in g a r e a s , c r e v i c e s a llo w in g v e r t i c a l movement away from u n f a v o r a b le c l i m a t i c c o n d i t i o n s would have been p ro v id e d by th e t h i c k , lo o s e l i t t e r and crumb l a y e r . In u p h i l l a r e a s , P. in c o n s t a n s w ould have had to e s c a p e u n f a v o r a b le s u r f a c e c o n d i t i o n s by ta k in g r e c o u r s e to th e s o i l w ith i t s fo o d , r e l a t i v e la c k o f i t i s c o n c e iv e a b le t h a t th e p e r s i s t e n c e o f s p a r s e u p h i l l p o p u la tio n s was a id e d by th e p r e s e n c e o f r e f u g i a su c h a s h a l f - b u r i e d b r a n c h e s , s h e a v e s o f d ead b a r k , and lo g s . 5. SUMMARY 1) P olydesm us in c o n s t a n s L a t z e l 1884 w as r e a r e d i n th e l a b o r a t o r y 133 a t c o n s t a n t te m p e r a tu r e s o f 1 0 ° , 1 5 .3 ° , 21° an d 2 6 . 6°C. C u ltu r e cham bers c o n s i s t e d o f c l e a r p l a s t i c j a r s w ith s n a p -o n l i d s . A p i a s t e r - c h a r c o a l s u b s t r a t e , o v e r l a i n by p e r i o d i c a l l y r e p l e n i s h e d d u f f , r o t t e n wood and s o i l , was u se d a s medium. 2) Y e a st was ad d ed a s f o o d . M atin g and c o n s t r u c t i o n o f egg and m o ltin g ch am b ers w ere d e s c rib e d . 3) Q u a l i t a t i v e a c c o u n ts o f oophagy by o t h e r m i l l i p e d e s p e c i e s , and o f p r e d a t i o n by b e e t l e s and c e n t i p e d e s , w ere g iv e n .. C a ra b id s and t h e i r l a r v a e w ere shown to be o f p o t e n t i a l Im p o rta n c e in th e c o n t r o l o f m illip e d e p o p u la tio n s . The c e n t ip e d e T id a b iu s t i v i u s consum ed f i r s t l n s t a r s o f _P. i n c o n s t a n s , b u t p r e f e r r e d C o lle m b o la a s f o o d . 4) D u r a tio n o f th e s t a d i a i n c r e a s e d w ith s u c c e s s i v e s t a d i a a s w e ll a s w ith d e c r e a s e d te m p e r a tu r e . v i r t u a l l y e q u a l to th o s e a t 21°C. S t a d i a l d u r a t i o n s a t 1 5 .5 °C w ere D if f e r e n c e s b etw ee n th e s e x e s d id n o t become a p p a r e n t u n t i l s ta d iu m V I I , w h ich l a s t e d s i g n i f i c a n t l y lo n g e r i n f e m a le s . 5) Sex r a t i o s o f p ro g en y p ro d u ced i n c u l t u r e a p p ro x im a te d 1 :1 . 6) Iram atures s u r v iv e d e q u a l l y w e ll a t 1 5 .3 ° an d 2 1 °C, b o th m a le s an d fe m a le s show ing s u r v i v a l p e r c e n ta g e s b etw een 90 and 100%. was lo w e r f o r th e f i r s t two l n s t a r s a t 10°C . to 100% m o r t a l i t y o f a l l i n s t a r s t e s t e d S u r v iv a l 2 6 . 6°C r e s u l t e d i n c l o s e ( I th r o u g h V I ) . 134 7) The r e l a t i o n s h i p b etw een a d u l t l o n g e v i t y and te m p e r a tu r e a p p e a re d to b e l i n e a r b etw ee n 10° an d 21°C. 2 6 . 6°C d e c r e a s e d a v e r a g e lo n g e v ity to a p p r o x im a te ly 60 d a y s . M ales s u r v iv e d lo n g e r th a n a t 10°C <285 v s . 212 d ay s m ean) and a t 1 5 .5 °C (218 v s . 176 d ay s m ean). 8) fe m a le s A maximum o f 22 o v i p o s i t i o n s p e r fe m a le w ere r e c o r d e d . I n t e r v a l s b etw ee n o v i p o s i t i o n s in c r e a s e d w ith s u c c e s s iv e egg l a y i n g s . At 21°C, 7 -1 0 d a y s e la p s e d b etw een o v i p o s i t i o n s , com pared to 11-1 6 d ay s a t 1 5 .5 °C an d 2 5 -3 0 d ay s a t 10°C. The num ber o f eg g s l a i d in c r e a s e d th ro u g h th e f i r s t few o v i p o s i t i o n s a t a l l te m p e r a t u r e s , th e n u n d erw en t a s te a d y d e c l i n e . F e c u n d ity was lo w e s t a t 10°C and h i g h e s t a t 21°C, a te m p e r a tu r e s u g g e s te d to be n e a r - o p t i m a l : h ig h o v ip o s it o n fre q u e n c y c o u p le d w ith a l a r g e num ber o f eg g s p e r o v ip o s ti o n a llo w e d f o r th e h ig h e s t o f a l l re p ro d u c tiv e r a t e s o b se rv e d . 9) The r e p r o d u c t iv e b io lo g y o f f i e l d - c o l l e c t e d fe m a le s was com pared to t h a t o f fe m a le s r e a r e d from egg to a d u lth o o d a t c o n s ta n t te m p e r a tu r e . Both ty p e s o f fe m a le s w ere k e p t u n d e r i d e n t i c a l c o n d i t i o n s , a t 2 1 °C. The r e s u l t s showed t h a t l a b o r a t o r y s to c k c o u ld be u s e d to o b t a i n v a l i d d a t a on th e p o t e n t i a l o f A maximum t o t a l th e s p e c i e s . num ber o f 1106 eg g s w ere r e c o r d e d f o r one fe m a le . On a v e r a g e , fe m a le s p ro d u c e d 500 to 700 eg g s i n a l i f e tim e . L a b o r a t o r y - r e a r e d , i s o l a t e d fe m a le s show ed th e h ig h e s t mean number o f o v i p o s i t i o n s ( 1 4 ) , th e l a r g e s t mean t o t a l number o f eg g s (9 6 9 5 ) and th e l o n g e s t d u r a t i o n o f th e r e p r o d u c t iv e p e r io d (116 d a y s ) . P ro v en an ce an d p a s t h i s t o r y ( l a b o r a t o r y v s . f i e l d ) had fe w e r s i g n i f i c a n t e f f e c t s on r e p r o d u c t iv e b io lo g y th a n s p e c i f i c r e a r i n g 135 c o n d i t i o n s ( f e m a le s i n i s o l a t i o n v s . fe m a le s p a i r e d w ith m a le s ) . As a r u l e , b o th ty p e s o f i s o l a t e s l a i d more eg g s and l i v e d lo n g e r th a n t h e i r p a ire d c o u n te rp a rts . 10) V i a b i l i t y o f eg g s d id n o t d i f f e r s i g n i f i c a n t l y b etw een 1 5 .5 ° an d 21°C (94% an d 92% r e s p e c t i v e l y ) , b u t was re d u c e d t o 85% a t 10°C . F em ales k e p t i n i s o l a t i o n showed g r e a t l y d e c r e a s e d egg v i a b i l i t y o n ly a f t e r th e f i r s t 8 to 10 o v i p o s i t i o n s . Sperm s t o r a g e c a p a c i t y was th u s e f f e c t i v e d u r in g th e tim e o f h i g h e s t f e c u n d i t y . 11) P o p u la tio n s o f i n c o n s t a n s w ere s t u d i e d i n two f i e l d s i t e s : a home g a rd e n (1976 and 1978) an d a d e c id u o u s w o o d lo t ( 1 9 7 8 - 7 9 ) , b o th in th e v i c i n i t y o f M ich ig an S t a t e U n iv e r s it y cam pus. Q u a l i t a t i v e d a ta on s e a s o n a l s t a g e s t r u c t u r e w ere o b ta in e d i n b o th s i t e s . The w o o d lo t p o p u la tio n was a l s o sam pled q u a n t i t a t i v e l y f o r p o p u la tio n d e n s i t y and s p a t i a l d i s t r i b u t i o n . 12) S ta g e s t r u c t u r e s o f th e p o p u la tio n s w ere s i m i l a r in th e th r e e y e a r s o f s tu d y . Eggs w ere l a i d fro m May th r o u g h J u ly by g e n e r a t i o n 0, w hich d ie d o u t a f t e r r e p r o d u c in g . June and c e a s e d i n l a t e A u g u st. H a tc h in g o f g e n e r a t i o n 1 began in By O c to b e r, th e b u lk o f th e p o p u la tio n h a d re a c h e d i n s t a r s V, VI an d V I I , and a s m a ll p r o p o r ti o n o f t h i s g e n e r a t i o n I had g r a d u a te d to a d u l t s by November. The m a jo r it y d id n o t r e a c h m a t u r i t y u n t i l th e f o llo w in g s p r i n g , t o g iv e r i s e to g e n e r a tio n I I , an d th e n to d i e . The l i f e c y c le i n th e f i e l d encom passed one y e a r . L a b o r a to r y o b s e r v a ti o n s on th e s p e c i e s ' r e p r o d u c t i v e p a t t e r n s u p p o r te d th e 136 conclusion that P. inconstans was semelparous. 13) dense* The i n c o n s t a n s p o p u la tio n i n th e w o o d lo t was r e l a t i v e l y E s tim a te s v a r i e d w ith th e s e a s o n . F or low a r e a s ( d e p r e s s io n s a t th e b o tto m o f s l o p e s ) d e n s i t i e s o f a b o u t 100 t o 200 in d i v id u a l s / m ^ w ere o b ta in e d . In u p h i l l a r e a s , d e n s i t i e s re a c h e d a b o u t 30/m ^. T hese v a l u e s c o n c e rn o n ly th e seg m en t o f t h e p o p u la tio n i n h a b i t i n g l i t t e r and d u f f . Due to in a d e q u a te s a m p lin g p r o c e d u r e s , e s t i m a t e s f o r d e n s i t i e s i n th e s o i l c o u ld n o t b e o b ta in e d . D i f f e r e n t i a l d e n s i t i e s w ere q u a l i t a t i v e l y c o r r e l a t e d w ith l i t t e r t h i c k n e s s , m o is tu r e and te m p e r a tu r e m easu rem en ts in th e two l o c a l i t y ty p e s (lo w d e p r e s s io n s and u p h i l l a r e a s ) . 14) Nem atodes and m ite s w ere fo u n d to be e c t o p a r a s i t e s on P . in c o n s ta n s i n th e w o o d lo t. n e g lig ib le . Nematode i n f e s t a t i o n a p p e a re d to be M ite s w ere e n c o u n te r e d more f r e q u e n t l y , and t h e i r o c c u r r e n c e on 2318 l i v e m i l l i p e d e s was r e c o r d e d . p a r a s i t i z a t i o n v a r i e d th r o u g h th e s e a s o n . D egree o f O v e r a ll , 2.7% o f th e p o p u la tio n w ere p a r a s i t i z e d ( r a n g e 0.4% t o 7.8% on g iv e n d a t e s o f e x a m in a tio n ) . Most a f f e c t e d a n im a ls c a r r i e d a t o t a l o f 1 t o 4 m i t e s , and i n s t a r s V II an d V I I I w ere fo u n d to be th e m ost f r e q u e n t h o s t s . BIBLIOGRAPHY BIBLIOGRAPHY A tte s ts , C. 1926* D ip lo p o d a . Handb. Z o o l. 4 :2 3 9 -4 0 2 . At te rn s, C. 577 pp. 1940. P o ly d e ssto ld e a I I I * In : Das T l e r r e i c h v o l . 70: B a i l e y , J . W. 1928. The C h llo p o d a o f New York S t a t e w ith n o te s th e D ip lo p o d a . N.Y. S t a t e Mus. B u l l . 2 7 6 :5 -5 0 . B a k e r, A. N. m illip e d e s . on 1974. Some a s p e c t s o f th e econom ic Im p o rta n c e o f Syrnp.Z o o l. S oc. Lond. 3 2 :6 2 1 -6 2 8 . B a k e r, G. H. 1 9 7 8 a. The p o s t-e m b ry o n ic d ev elo p m en t and l i f e h i s t o r y o f th e m i l l i p e d e , O m m atoiulus m o r e l e t i i (D ip lo p o d a , l u l i d a e ) , in t r o d u c e d i n s o u t h - e a s t e r n A u s t r a l i a . J . Z o o l. Lond. 1 8 6 :2 0 9 -2 2 8 . B a k e r, G. H. 19 7 8 b . The p o p u la tio n dynam ics o f th e m i lli p e d e O m m atoiulus m o r e l e t i i (D ip lo p o d a : l u l i d a e ) . J . Z o o l. Lond. 1 8 6 :2 2 9 -2 4 2 . B a n e r je e , B. 1967. D iu r n a l and s e a s o n a l v a r i a t i o n s i n th e a c t i v i t y o f th e m i l l i p e d e s C y ll n d r o iu lu s p u n c t a tu s ( L e a c h ), T ach y p o d o iu lu B n i g e r (L e a c h ) an d P o ly d esm u s a n g u s tu s L a t z e l . O ikos 1 8 :1 4 1 -1 4 4 . B a n e r je e , B. 1970. E f f e c t s o f unmixed and m ixed l e a f l i t t e r o f th r e e s p e c i e s o f p l a n t s on th e d ev e lo p m e n t and g ro w th o f P olydesm us a n g u s tu s L a t z e l . E x p e r i e n t i a 2 6 :1 4 0 3 . B a n e r je e , B. 19 7 3 . The b r e e d in g b io lo g y o f P olydesm us a n g u s tu s L a t z e l ( D ip lo p o d a , P o ly d e s m id a e ). N o rsk , e n t . T i d s s k r . 2 0 :2 9 1 -2 9 4 . Bano, K. an d K rls h n a m o o rth y , R. V. 1978. D e fe n s iv e s e c r e t i o n from th e r e p u g n a t o r i a l g la n d s o f a p o ly d e sm id m i l l i p e d e . C u rr. S c i. 47 (1 1 ) :3 8 7 - 3 8 9 . B a rlo w , C. A. 1 9 5 7 . D i s t r i b u t i o n and s e a s o n a l a c t i v i t y in t h r e e s p e c ie s o f d ip lo p o d s . T i j d s c h r . Entom. 1 0 0 :1 0 8 -1 3 3 . B a r t l e t t , M. S . 19 3 7 . Some ex am p les o f s t a t i s t i c a l m ethods o f r e s e a r c h i n a g r i c u l t u r e and a p p l i e d b io lo g y . J . R oyal S t a t . S o c. ( s u p p l . ) 4 :1 3 7 -1 4 7 . B lo w er, J . G. 1955. M ill ip e d e s and c e n t ip e d e s a s s o i l a n im a ls . S o i l Z o o lo g y , McE. Kevan e d . , p p . 1 3 8 -1 5 1 . B lo w er, J . G. 1958. B r i t i s h m i l l i p e d e s (D ip lo p o d a ) . Fauna No.1 1 :1 -7 4 . 137 S y n o p ses B r. In : 138 B lo w er, J . G. 1969. Age s t r u c t u r e s o f m i l l i p e d e p o p u la tio n s in r e l a t i o n to a c t i v i t y and d i s p e r s i o n . F u b ls . S ystem . A sso c. 8 :2 0 9 -2 1 6 . B lo w er, J . G. 1970. Lond. 1 6 0 :4 5 5 -4 9 6 . The m i l l i p e d e s o f a C h e s h ire wood. J . Z o o l. B lo w er, J . G. 1974. Food c o n su m p tio n and g ro w th i n a l a b o r a t o r y p o p u la tio n o f O p h y iu lu s p i l o s u s (N e w p o rt). Symp. Z o o l. Soc. Lond. 3 2 :5 2 7 -5 5 1 . B lo w er, J . G. and P. a Devon oak wood. D. G a b b u tt. 19 6 4 . S tu d ie s on th e m i l l i p e d e s P ro c . Z o o l. Soc. Lond. 1 4 3 :1 4 3 -1 7 6 . of B low er, J . G. and C. P. F a i r h u r s t . 1968. N o tes on th e l i f e - h i s t o r y and e c o lo g y o f T a c h y p o d o iu lu s n i g e r ( D ip lo p o d a , l u l i d a e ) in B r i t a i n . J . Z o o l. Lond. 1 5 6 :2 5 7 -2 7 1 . B low er, J . G. an d P. F . M i l l e r . 1974. The l i f e c y c le and O p h y iu lu s p i l o s u s (N ew p o rt) i n B r i t a i n . Symp. Z o o l. S oc. 3 2 :5 0 3 -5 2 5 . e c o lo g y o f Lond. B ocock, K. L . , M. D. M o u n tfo rd and J . H e a th . 1967. E s tim a tio n o f a n n u a l p r o d u c tio n o f a m i l l i p e d e p o p u la tio n . I n : S eco n d ary p r o d u c t i v i t y o f t e r r e s t r i a l e c o s y te m s . K. P e tr u s e w ic z e d . , K rakow :7 2 7 -7 3 9 . B o llm an , C. H. 1893. The M y riap o d a o f N o rth A m erica. S t a t e s N at. Mus. n o . 4 6 , 210 p p . B o rn e b u sc h , C. H. 19 3 0 . F o rs o g . Dan. 1 1 :1 - 2 2 4 . The fa u n a o f th e f o r e s t s o i l . B u ll . U n ite d F o rs tl. B ro o k e s , C. H. 1974. The l i f e c y c le o f P r o t e r o i u l u s f u s c u s (am S te i n ) an d I s o b a te s v a r i c o r n i s (K och) w ith n o te s on th e an a m o rp h o sis o f B l a n i u l i d a e . Symp. Z o o l. Soc. Lond. 3 2 :4 8 5 -5 0 1 . B u rg e s , A. and F. Raw ( e d s ) . London, New Y ork. B yzova, J . B. 1967. (D ip lo p o d a ) . Rev. 19 6 7 . S o i l B io lo g y . Academic P r e s s , R e s p ir a t o r y m e ta b o lism i n some m i l l i p e d e s E c o l. B io l. S o l 4 :6 1 1 -6 3 4 . C au sey , N. B. 1943. S tu d ie s on th e l i f e h i s t o r y and th e e c o lo g y o f th e h o t-h o u s e m i l l i p e d e O rthom orpha g r a c i l i s (C . L. K och) Arner. M id i. N at. v o l . 2 9 ( 3 ) :6 7 0 - 6 8 2 . C ausey, N. B. and D. L. Tiem ann. 1969. A r e v i s i o n o f th e b io lu m in e s c e n t m i l l i p e d e s o f th e g enus M o ty x la (X y sto d e s m id a e , P o ly d e s m id a ). P ro c . Am. P h i l . S oc. 1 1 3 :1 4 -3 3 . C h a m b e rlin , R. V. 1947. Some r e c o r d s and d e s c r i p t i o n s o f d ip lo p o d s c h i e f l y in th e c o l l e c t i o n o f th e Academy. P ro c . Acad. N a t. S c i. P h i l a d . 9 9 :2 1 -5 8 . 139 C h a m b e rlin , R. V* and H offm an, R. L. 1958. C h e c k l is t o f th e m i l l i p e d e s o f N o rth Am erica* U .S. Nat* Mus* Wash. 2 1 2 :1 -2 1 1 . C h o lo d k o v sk y , N. A. 18 9 5 . Zur E m b ry o lo g ie d e r D ip lo p o d e n . S e a n c e s. Soc. Imp. N a t. S t . - P e t e r s b o u r g , B d .2 . C. R. C o le , L. C. 1 9 4 6 . A s tu d y o f th e c r y p to z o a o f an I l l i n o i s w o o d lan d. E c o l. Monogr. 1 6 :4 9 -8 6 . C o tto n , M. J . and P. F. M i l l e r . 1974. l a t e s t r i a t u s ( C u r t i s ) on sa n d d u n e s . 3 2 :5 8 9 -6 0 2 . A p o p u la tio n o f C y l i n d r o i u l u s Symp. Z o o l. Soc. Lond. D a v e n p o rt, D ., D. M. W otton and J . E. C u sh in g . 1952* The b io lo g y o f t h e s i e r r e lu m in o u s m i l l i p e d e Lum inodesmus s e q u l a l Loomis and D a v e n p o rt. B io l . B u ll . 1 0 2 :1 0 0 -1 1 0 . D oeksen, J . an d D r i f t , v an d e r J . ( e d s .) . N o rth -H o lla n d P u b lis h i n g C o l. A m sterdam . 19 6 3 . S o i l O rg an ism s. D o h le, W. 1964. D ie E m b ry o n a le n tw ic k lu n g v o n G lo m eris m a r g in a ta ( V i l l e r s ) im V e r g le ic h z u r E n tw ic k lu n g a n d e r e r D ip lo p o d e n . Z o o l. J a h r b . A n a t. 8 1 :2 4 1 -3 1 0 . D r i f t , J . v an d e r . 1951. A n a ly s is o f th e a n im a l com m unity i n a beech f o r e s t f lo o r . Meded. I n s t . T oegep. B io l. O n d erz. N a t. 9 :1 - 1 6 8 . D u ffe y , S. S. and T o w ers, G. H. N. 1978. On th e b io c h e m ic a l b a s i s o f HCN p r o d u c tio n i n th e m i l l i p e d e H arp ap h e h a y d e n ia n a (X y s to d e s m id a e : P o ly d e s m id a ). Can. J . Z o o l. 5 6 ( 1 ) :7 - 1 6 . D unger, W. 1958. U eber d ie Z e r s e tz u n g d e r L a u b s tre u d u rc h d i e B oden-M akrofauna im A uenw ald. Z o o l. J a h r b . A b t. G eogr. 8 6 :1 3 9 -1 8 0 . D unger, W. 1 9 6 0 . Zu e ir tig e n F ra g e n d e r L e is tu n g d e r B o d e n tle r e b e i d e r U m setzung o r g a n l s c h e r S u b s ta n z . Z e n t r a l b l . B a k te r . 5 2 :3 4 8 -3 5 5 . D u n g er, W. 1978. P a ra m e te r d e r B o d en fau n a i n e i n e r C a te n a von R asen -O ek o sy stem en . P e d o b io l. 1 8 : 3 1 0 -3 4 0 . D w a ra k an ath , S. K. 1 9 7 1 a. E f f e c t o f te m p e r a tu r e on th e oxygen co n su m p tio n on a t r o p i c a l m i l l i p e d e , H a r p u r o s t r e p tu s s p . P ro c. in d . A cad. S c i . 7 3 :4 - 7 . D w a ra k a n a th , S. K. 1 9 7 1 b . The i n f l u e n c e o f body s i z e and te m p e r a tu r e on th e oxygen c o n su m p tio n i n th e m i lli p e d e S p l r o s t r e p t u s a s th e n e s (P o c o c k ) . Comp, b iochem . p h y s i o l . 38A: 2 5 1 -2 5 8 . E a to n , T. J . 1 9 4 3 . B io lo g y o f a m u ll-fo rm in g m i l l i p e d e , A p h e lo r ia c o r i a c e a (K o ch ). Amer. M id i. N a t. 2 9 :7 1 3 -7 2 3 . 140 E f f e n b e r g e r , W. 1909* B e i t r a g e z u r K e n n tn is d e r G a ttu n g P o ly d e sm u s. J e n a is c h e Z. N a tu r w is s . 4 4 :5 2 7 -5 8 6 * E l l i o t t , J . M. 1 9 7 3 . Some m ethods f o r th e s t a t i s t i c a l a n a l y s i s o f s a m p le s o f b e n t h ic i n v e r t e b r a t e s . F re s h w a te r B io lo g y A s s n ., S c i e n t i f i c P u b l i c . No. 25: 148 p p . E r i c s o n , D. 19 7 7 . E s tim a tin g p o p u la tio n p a r a m e te r s o f P t e r o s t i c h u s c u p re u s and P. m e la n a r iu s ( C a r a b id a e ) i n a r a b l e f i e l d s by m eans o f c a p tu re -re c a p tu re . O ikos 2 9 :4 0 7 -4 1 7 . E v a n s , J . T. m illip e d s . 1 9 1 0 . B io n o m ic a l o b s e r v a t i o n s on some B r i t i s h Ann. Mag. N a t. H i s t . (8 ) 6 :2 8 4 -2 9 1 . F a l r h u r s t , C. 1 9 7 4 . The a d a p t i v e s i g n i f i c a n c e o f v a r i a t i o n s i n th e l i f e c y c le s o f s c h iz o p h y llin e m illip e d e s . Symp. Z o o l. S oc. Lond. 32: 5 7 5 -5 8 7 . Fourraan, K. L. 1 9 3 8 . U n te rsu c h u n g e n u b e r d ie B edeutung d e r F auna b e i d e r b i o l o g i s c h e n Umwandlung d e s B e s ta n d e s a b f a ll e s f o r s t l i c h e r S ta n d o r t e . M i t t e i l . a u s F o r s t w i r t s c h . - und W iss. 9 :1 4 4 -1 6 9 . G e re , G. 1956. The e x a m in a tio n o f th e f e e d in g b io lo g y and h u m i f i c a t i v e f u n c t i o n o f D ip lo p o d a and Is o p o d a . A cta b i o l . Hung. 6 :2 5 7 -2 7 1 . G e re , G. 1962. E r n & h ru n g s b io lo g is c h e U n te rsu o h u n g e n a n D ip lo p o d e n . A cta B io l. h u n g . 8 :2 5 -3 8 . G h ila r o v , M. S. 19 4 7 . P o c v e n n a ja fa u n a t e r r a r o s s a ju z n o g o b e re g a Kryraa. V e s tn . M oskovsk. u n i v e r s . 2 :1 0 6 -1 1 4 . ( r u s s . ) G i s t , C. S. and D. A. C r o s s l e y , J r . 19 7 5 . The l i t t e r a r th r o p o d com m unity i n a s o u th e r n A p p a la c h ia n hardw ood f o r e s t : n u m b e rs, biom ass and m in e r a l e le m e n t c o n t e n t . Amer. M id i. N a tu r. 9 3 : 1 0 7 -1 2 2 . G re e n s la d e , P. J . M. 19 6 4 . The d i s t r i b u t i o n , d i s p e r s a l and s i z e o f a p o p u la tio n o f N e b ria b r e v i c o l l i s ( F . ) w ith c o m p a ra tiv e s t u d i e s on t h r e e o t h e r C a r a b id a e . J . Anim. E c o l. 3 3 :3 1 1 -3 3 3 . G rom ysz-K alkow ska, K. 1967. Minimum, maximum and p r e f e r e n t i a l te m p e r a tu r e i n O rthom orpha g r a c i l i s (C. L. Koch) (D ip lo p o d a ) . F o lia b i o l . Krakow 1 5 :1 0 1 -1 1 5 . G rom ysz-K alkow ska, K. 1 9 7 0 a. T h erm al b e h a v io r o f v a r i o u s l y a c c li m a t i z e d i n d i v i d u a l s o f P o ly d esm u s c o m p la n a tu s ( L . ) (D ip lo p o d a ) i n a te m p e r a tu r e g r a d i e n t . F o l i a b i o l . Krakow 1 8 :2 0 5 -2 1 9 . G rom ysz-K alkow ska, K. 1970b. The i n f l u e n c e o f body w e ig h t, e x t e r n a l te m p e r a t u r e , s e a s o n s o f th e y e a r and f a s t i n g on th e r e s p i r a t o r y m e ta b o lism i n P o ly d esm u s c o m p la n a tu s ( L . ) ( D ip lo p o d a ) . F o l i a b i o l . Krakow 1 8 :3 1 1 -3 2 6 . 141 G rom ysz-K alkow ska, K. 1973. Some ex o g en o u s and en d o g en o u s e f f e c t s on r a t e o f r e s p i r a t i o n i n S tro n g y lo so m a p a l l i p e s ( O l i v i e r ) (D ip lo p o d a ) an d b e h a v io r i n te m p e r a tu r e g r a d i e n t . F o l i a b i o l . Krakow 2 1 :2 5 1 -2 6 9 . H a a c k e r, U. 1968. D e s c r i p t i v e , e x p e r i m e n t e lle und v e r g le ic h e n d e U n te rsu c h u n g e n z u r A u tttk o lo g ie r h e i n - m a i n i s c h e r D ip lo p o d e n . O e c o lo g ia 1 :2 5 7 -3 1 6 . H a a c k e r, U. 1 9 6 9 a. Das S e x u a l v e r h a lt e r n von S p h a e ro th e rlu m d o r s a l e (M y ria p o d a , D ip lo p o d a ). V erh . d t . Z o o l. G es. 3 2 :4 5 4 -4 6 3 . H a a c k e r, U. 1969b. An a t t r a c t i v e s e c r e t i o n i n th e m a tin g b e h a v io r o f a m illip e d e . Z. T ie r p s y c h . 2 6 :9 8 8 -9 9 0 . H a a c k e r, U. 1970. Das P a a r u n g s v e r h a lte n von R h in o c r in u s p a d b e r g l V erh . (D ip lo p o d a : S p i r o b o l i d a ) . Rev. Com port. Anim. 4 :3 5 - 3 9 . H a a c k e r, U. 1971. T ro m m e lsig n a le b e i T a u s e n d f u s s le m . N a tu r w is s e n s c h a f te n 5 8 :5 9 -6 0 . H a a c k e r, U. 19 7 4 . Z u r E v o lu tio n e i n e r d e f e n s iv e n V e r h a lte n s w e is e b e i T a u s e n d f iis s le r n (D ip lo p o d a : I u l i d a : S p i r o s t r e p t i d a ) . Abh. V erh . n a t u r w i s s . V e r. Hamburg 1 7 :1 1 7 -1 2 4 . H a a c k e r, U. an d S . F u c h s. 1 9 7 0 . Das P a a r u n g s v e r h a lte n v o n C y ll n d r o iu lu s p u n c ta tu s L e a c h . Z. f . T ie r p s y c h . 2 7 :6 4 1 -6 4 8 . H a lk k a , R. 1958. L if e h i s t o r y o f S c h iz o p h y llu in sa b u lo su m ( L .) (D ip lo p o d a , l u l i d a e ) . Suom al. e l a i n - j a k a s v i t . s e u r . v a n . e l a l n . J u l k 19 ( 4 ) : l - 7 2 . H a rd in g , D. J . L. 1 9 6 9 . D is c u s s io n . A sso c. P u b l. No. 8 :2 1 5 . I n : The S o i l E c o sy ste m . S y s t. H a rz , K. 1962. U eber d ie P a a ru n g von T a u s e n d f iis s le r n ( D ip lo p o d a ) . N a tu r und Museum 9 2 :2 9 4 -2 9 5 . H e a th , J . , K. L. Bocock and M. D. M o u n tfo rd . 1974. The l i f e h i s t o r y o f th e m i l l i p e d e G lo m e ris m a rg in a ta ( V i l l e r s ) i n N o rth -W est E n g la n d . Symp. z o o l. S oc. Lond. 3 2 :4 3 3 -4 6 2 . H e a th c o te , F. G. 1 8 8 6 . The e a r l y d ev elo p m en t o f l u l u s t e r r e s t r l s . Q u a rt. J . m ic r . Soc. 26. H e a th c o te , F. G. 18 8 8 . The p o s t-e m b ry o n ic d ev elo p m en t o f l u l u s t e r r e s t r i s . P h i l T ra n s . R oyal Soc. Lond. 179 B. J o h n s o n , B. M. 19 5 2 . The m i l l i p e d s o f M ic h ig a n . U n iv e r s it y o f M ic h ig a n . Ph.D . T h e s i s , J o h n s o n , B. M. 1953. S c i. 3 9 :2 4 1 -2 5 2 . P a p e rs M ich. A cad. The m i l l i p e d s o f M ic h ig a n . 142 J u b e r t h i e - J u p e a u , L. an d I* T a b a c a ru . 1968* G lan d es p o s tg o n o p o d ia le s d e s O n lscotoorphes (D ip lo p o d e s , m y r ia p o d e s ) . E c o l. B io l. S o l 5 :6 0 5 - 6 1 8 . Rev* k e i r a l l a h , A. M. 1 9 6 6 . S tu d ie s on th e f e e d in g b e h a v io r o f th e m i l l i p e d e l u l u s s c a n d in a v iu s . P h.D . T h e s i s , U niv. o f M a n c h e s te r. K h e i r a l l a h , A. M. 1 9 7 3 . E f f e c t o f d i f f e r e n t fo o d s on th e d ev elo p m en t o f th e g re e n h o u s e m i l l i p e d e O rthom orpha g r a c i l i s * B u ll . S oc. E n t. E gypt 5 7 :4 1 9 -4 2 3 . K h e i r a l l a h , A. M. 1978. The c o n su m p tio n and u t i l i z a t i o n o f two d i f f e r e n t s p e c ie s o f l e a f l i t t e r by a l a b o r a t o r y p o p u la tio n o f O rthom orpha g r a c i l i s (D ip lo p o d a : P o ly d e s m o id e a ). E n t. e x p . e t a p p l. 2 3 :1 4 -1 9 . K u rc e v a , G. F. I9 6 0 . The r o l e o f i n v e r t e b r a t e s i n th e d e c o m p o slto n o f th e o ak l e a f f a l l . P o c v o v e d e n ie 4 4 :1 6 -2 3 . L e w is, J . G. E. 1 9 6 4 . The fo o d and r e p r o d u c t iv e c y c l e s o f th e c e n t ip e d e s L i th o b iu s f o r f l c a t u s an d L i th o b iu s v a r i e g a t u s i n a Y o r k s h ir e w o o d lan d . P ro c . Z o o l. S oc. Lond. 1 4 0 :2 6 9 -2 8 3 . L e w is, J . G. E. 1 9 7 1 a. The l i f e h i s t o r y and e c o lo g y o f th e m i l l i p e d e Tymbodesmus f a l c a t u s (P o ly d e s m ld a : Gomphodesraidae) i n n o r t h e r n N ig e r ia w ith n o te s on Sphenodesm us s h e r i b o n g e n s i s . J . Z o o l. Lond. 1 6 4 :5 5 1 -5 6 3 . L e w is , J . G. E. 1 9 7 1 b . The l i f e h i s t o r y and e c o lo g y o f t h r e e p a ra d o x o s o m a tid m i l l i p e d e s (D ip lo p o d a : P o ly d e sm id a ) i n n o r th e r n N ig e r ia . J . Z o o l. Lond. 1 6 5 :4 3 1 -4 5 2 . H a n to n , S. M. 19 5 6 . The e v o l u t i o n o f A rth ro p o d a n lo c o m o to ry m ech an ism s. 4. The s t r u c t u r e , h a b i t s and e v o l u t i o n o f th e D ip lo p o d a . J o u r n . L in n . S oc. London, Z o o l. 42 ( 2 8 6 ) : 2 9 9 -3 6 8 . M cB rayer, J . F . 1973. E x p l o i t a t i o n o f d e c id u o u s l e a f l i t t e r by A p h e lo r ia m ontana (D ip lo p o d a : E u ry d e s m id a e ). P e d o b io l. 1 3 :9 0 - 9 8 . McLeod, J . 1958. The e s t i m a t i o n o f num bers o f m o b ile i n s e c t s from lo w - in c id e n c e r e c a p t u r e d a t a . T ra n s . Roy. E n t. Soc. London 1 1 0 :3 6 3 -3 9 2 . McQueen, D. J . 1976. The i n f l u e n c e o f c l i m a t i c f a c t o r s on th e dem ography o f th e t e r r e s t r i a l is o p o d T r a c h e o n ls c u s r a t h k e i B ra n d t. Can. J . Z o o l. 54: 2185 -2 1 9 9 . M e id e l l, B. A. 1967. P olydesm us a n g u s tu s L a t z e l 1884 (D ip lo p o d a ) new to Norway. N o rsk , e n t . T i d s s k r . 1 4 :1 0 3 -1 0 5 . t i e t s c h n i k o f f , E. 1 8 7 1 . w is s . Z o o l. Bd 21. E n tw ic k lu n s g e s c h ic h te d es C h e l i f e r . Z tsc h r. 143 M e ts c h n ik o f f , E. 1 8 7 4 . E m b ry o lo g ie d e r d o p p e l t f d s s i g e n M y rlap o d en ( C h il o g n a th a ) . Z s c h r . w is s . Z o o l. Bd 24. M ile y , Hugh H. 19 2 7 . D evelopm ent o f th e m ale gonopods an d l i f e h i s t o r y o f a p o ly d e sm id m i l l i p e d e . Ohio J o u r n . S c l. 2 7 :2 5 -4 1 . M i l l e r , P. F . 1973. The c o n su m p tio n and u t l l l z a t o n o f fo o d by m i lli p e d e p o p u l a t i o n s . Ph.D . T h e s i s , U n iv e r s it y o f M a n c h e s te r. M i l l e r , P. F . 19 7 4 . C o m p e titio n betw een O p h y iu lu s p i l o s u s (N ew p o rt) and l u l u s s c a n d in a v iu s L a t z e l . Symp. Z o o l. S oc. lo n d . 3 2 :5 5 3 -5 7 4 . M urakam i, Y. 1962. P o ste m b ry o n ic d ev elo p m en t o f th e common M yriapoda o f J a p a n X. L if e h i s t o r y o f O xidus g r a c i l i s (K och) (D ip lo p o d a , S tr o n g y lo s o m id a e ) . Z o o l. Mag. Tokyo 7 1 :2 4 5 -2 4 9 . M urakam i, Y. 1 9 6 5 a. P o ste m b ry o n ic d ev elo p m en t o f th e common M yriap o d a o f Ja p a n X VII. L i f e h i s t o r y o f Ampelodesmus iy o n l s Murakami (D ip lo p o d a : C ry p to d e s m id a e ). 1. Z o o l. Mag. 7 4 :1 - 5 . M urakam i, Y. 1965b. P o s te m b ry o n ic d ev elo p m en t o f th e common M yriapoda o f Ja p a n X V III. L if e h i s t o r y o f Ampelodesmus i y o n l s M urakami (D ip lo p o d a , C ry p to d e sm id a e ) 2. Z o o l. Mag. 7 4 :3 1 -3 7 . M urakam i, Y. 1966. A c o r r e c t i o n r e g a r d in g th e a r t i c l e o f th e l i f e h i s t o r y o f O xidus g r a c i l i s . Z o o l. Mag. Tokyo 7 5 :5 1 . N e u h a u se r, E. F. an d R. H a r t e n s t e i n . 1978. P h e n o lic c o n t e n t and p a l a t a b i l i t y o f le a v e s and wood to s o i l is o p o d s and d ip lo p o d s . P e d o b io l. 1 8 :9 9 -1 0 9 . N ew port, G. 1841. On th e o r g a n s o f r e p r o d u c t io n and th e M y riap o d a. P h i l T ra n s . R. S o c. 1 8 4 1 : 9 9 -1 3 0 . d ev elo p m en t in N ie l s e n , C. O v e rg a a rd . 1962. C a rb o h y d ra s e s i n s o i l and l i t t e r in v e rte b ra te s . O ikos 1 3 : 2 0 0 -2 1 5 . N o irfa lis e , A. 1962. I n f lu e n c e de q u e lq u e s ty p e s de fo re ts su rle b i l a n d e s eau x d ' i n f i l t r a t i o n . La te c h n iq u e de l 'e a u , L ie g e , 10 pp. O 'N e i l l , R. V. 1969. A d a p tiv e r e s p o n s e s to d e s s i c a t i o n in th e m ille p e d e N arceu s a m e ric a n u s ( B e a u v o is ) . Amer. M id i. N a tu r. 8 1 :5 7 8 -5 8 3 . P a llv o d y , C. 19 7 4 . R e l a ti o n s c h r o n o lo g iq u e s e n t r e c y c l e s de mue e t c y c le s de p o n te ch ez F o lso m ia C an d id a ( C o lle m b o la , I s o to m id a e ) . P e d o b io l. 1 4 :1 9 6 -1 9 8 . P e r t t u n e n , V. o f th e a i r . 1953. R e a c tio n s o f d ip lo p o d s to th e r e l a t i v e h u m id ity Suom al. e l a i n - j a k a s v i t . S e u r . v a n . J u lk 1 6 :1 - 6 4 . 144 P e r t t u n e n , V. 1955* The e f f e c t o f a n te n n e c to ra y on th e h u m id ity r e a c t i o n s o f n o rm al an d d e s s i c a t e d s p e c im e n s o f S c h iz o p h y llu m sab u lo su m L. ( D ip lo p o d a , l u l i d a e ) . Suomen H y o n t. A ik ak . 2 1 :1 5 7 -1 0 2 . P e t i t , G. 1 9 7 3 a. E tu d e m o rp h o lo g iq u e de l a r ^ g ^ n ^ r a tio n d e s a p p e n d ic e s a m b u la to ir e s ch ez l e d ip lo p o d e P olydesm us a n g u s tu s L a tz e l. B u ll. S oc. Z o o l. F r . 9 8 :4 3 -5 3 . P e t i t , G. 1973b. E tude m o rp h o lo g iq u e e t e x p e r ir a e n ta le de l a m etam orphose d 'u n a p p e n d ic e a m b u la to ir e en gonopode ch ez l e d ip lo p o d e P o ly d esm u s a n g u s tu s L a t z e l . Ann. d 'E m b ry o l. e t de M orphogen. 6 ( 2 ) :1 3 7 -1 4 9 . P e t i t , G. 1 9 7 4 . Sur l e s m o d a lite s de l a c r o i s s a n c e e t l a r e g e n e r a t i o n d es a n te n n e s de l a r v e s d e P o ly d esm u s a n g u s tu s L a t z e l . Symp. Z o o l. Soc. Lond. 3 2 :3 0 1 -3 1 5 . P e t i t , G. 1976. D eveloppem ents co m p ares d e s a p p e n d ic e s c o p u l a t e u r s (g o n o p o d es) c h e z Polydesm us a n g u s tu s L a t z e l e t B rachydesm us s u p e ru s L a t z e l (D ip lo p o d e s : P o ly d e s m id a e ). I n t . J . I n s e c t M orphoi. and E m bryol. 5 :2 6 1 -2 7 2 . P f l u g f e l d e r , 0 . 1932. Uber den M echanism us d e r S eg m e n tb ild u n g b e i d e r E m b ry o n a le n tw ic k lu n g und A nam orphose v o n P l a t y r r h a c u s am auros At te rn s. Z t s c h r . w is s . Z o o l. 1 4 0 :6 5 0 -7 2 3 . P h illip s o n , J . 1967. S tu d ie s on th e b i o e n e r g e t i c s o f w oodland D ip lo p o d a . I n : S e c o n d a ry p r o d u c t i v i t y o f t e r r e s t r i a l e c o s y s te m s , K. P e tr u s e w ic z , e d . , Krakow: 6 7 9 -6 8 3 . P i e r r a r d , G. an d J . B ie rn a u x . 1974. N ote a p ro p o s des d ip lo p o d e s n u i s i b l e s au x c u l t u r e s du S e n e g a l. Symp. z o o l . S oc. Lond. 32: 6 2 9 -6 4 3 . R a n t a la , M. 1 9 7 0 . A n am orphosis and p e rio d o m o rp h o s is o f P r o t e r o l u l u s f u s c u s (am S t e i n ) . B u l l . mus. n a t n . h i s t . N a t ., P a r i s (2 ) 4 1 , s u p p l. 2 :1 2 2 -1 2 8 . R a n t a l a , M. 19 7 4 . Sex r a t i o and p e rio d o m o rp h o s is o f P r o t e r o i u l u s f u s c u s (am S t e i n ) (D ip lo p o d a , B l a n i u l i d a e ) . Symp. Z o o l. S oc. Lond. 3 2 :4 6 3 -4 6 9 . R a th , 0 . Vom. 1 8 9 1 . Zur B io lo g ie d e r D ip lo p o d e n . G es. F r e ib u r g i . B re is g a u 5 :1 6 1 -1 9 9 . B e r. n a t u r f o r s c h . Rim sky-ICorsakow , N. 18 9 5 . U ber P o ly zo n iu m germ anicum B r a n d t. S oc. Imp. N at. S t . - P e t e r s b o u r g , Bd 25. T ra v . R o b e r ts , H. 1956. An e c o l o g i c a l s tu d y o f th e a r th r o p o d s o f a m ixed b e e c h -o a k w o o d lan d , w ith p a r t i c u l a r r e f e r e n c e t o L i t h o b i i d a e . Ph. D. T h e s i s , U niv. o f S outham pton. 145 R o p e r, H. 1978* E r g e b n is s e c h e m is c h - a n a l y tis c h e r U n te rs u c h u n g e n d e r W e h rs e k re te von S p lr o b o li d e n , S p i r o s t r e p t i d e n und J u l i d e n ( D ip lo p o d a ) , v o n P e r i p a t o p s i s (O n y ch o p h o ra) und von P o ly zo n iu m (D ip lo p o d a , C o lo b o g n a th a ). Abh. Verh* n a tu rw is s * Ver* Hamb. (N F ), 2 1 -2 2 : 3 5 3 -3 6 3 . R ubcova, Z. I* 1967. U eber M y riap o d en i n v e r s c h ie d e n e n Typen von k ie fe r n w itld e r n im w e s tli c h e n T e i l d e r B e lo r u s s is c h e n S o w je tr e p u b lik . P e d o b io l. 7: 4 2 -5 4 . S a h l i , F . 1958. D onnies s u r l e d ^ v elo p p erae n t p o s t- e m b ry o n n a ir e du d ip lo p o d e T a c h y p o d o iu lu s a l b i p e s C. L. Koch. C. R. h eb d . s c e a n c e s A cad. S c i. P a r i s 246: 2 0 3 7 -2 0 3 9 . S a h l i , F. 1961. La s u c c e s s io n d e s d i f f ^ r e n t e s fo rm es m a les au c o u rs de l a p £ rio d o m o rp h o se ch ez l e d ip lo p o d e T a c h y p o d o iu lu s a lb ip e s C. L. Koch. C. R. h eb d . S cean c es Acad. S c i. P a r i s 253: 3 0 9 4 -3 0 9 5 . S a h l i , F . 1966. C o n tr ib u tio n s & l '^ t u d e de l a p e rio d o m o rp h o se e t du syst&me n e u r o s d c r ^ te u r d es d ip lo p o d e s l u l i d e s . T h e s i s , F a c u l te d es S c ie n c e s , D ijo n . S a h l i , F. 19 6 9 . S u r l a b i o l o g i e s e x u e l l e (a c c o u p le m e n t, p o n te , i n s t i n c t s s e x u e l s ) du D ip lo p o d e P olydesm us a n g u s tu s L a t z e l . Rev. E c o l. B io l. S c i 6 ( 4 ) :4 3 7 -4 4 5 . Sakw a, W. N. 19 7 4 . A c o n s i d e r a t i o n o f th e c h e m ic a l b a s i s o f fo o d p re fe re n c e in m illip e d e s . Symp. Z o o l. S oc. Lond. 3 2 :3 2 9 -3 4 6 . S a u d ra y , Y. 1952. D e v e lo p p u e n t p o s t- e m b ry o n n a ir e d 'u n l u l i d e in d ig e n e C y li n d r o iu lu s ( A n e u lo b o iu lu s ) s ilv a r u m M e in e r t. A rch . Z o o l. e x p . Gen. 8 9 :1 - 1 4 . S c b m id t, H. 1 9 5 2 . N ahrungsw ahl und N a h ru n g s v e r a r b e itu n g b e i D ip lo p o d e n ( T a u s e n d f d s s le r n ) . M i t t , n a t u r w i s s . V er. S te ie r m a r k 8 1 /8 2 :4 2 - 6 6 . S c h u b a r t, 0. 7 :7 7 -1 3 4 . 1 9 3 4 a. M y riap o d a. T a b u la e B io lo g ic a e P e r io d i c a e IV, S c h u b a r t, O tto . 1934b. T a u s e n d f u s s ie r o d e r M yriapoda I : D ip lo p o d a . I n : D ah l, Die T ie r w e lt D e u ts c h la n d s , T e i l 28. 318 p p . S e i f e r t , B. 1 9 3 2 . A natom ie und B io lo g ie d e s D ip lo p o d e n S tro n g y lo so m a p a l l i p e s O liv . Z e i t s . M orph. O ek o l. T le r e 2 5 :3 6 2 -5 0 7 . S h e l l e y , R. M. 1978. M ill ip e d s o f th e e a s t e r n P iedm ont r e g io n o f N o rth C a r o l in a , U. S. A. ( D ip lo p o d a ) . J . N at. H i s t . 1 2 :3 7 -7 9 . S n id e r , R. M. and J . H. S haddy. 1980. The e c o b io lo g y o f T r a c h e lip u s r a t g j e u ( B r a n d t) . P e d o b io l. ( i n p r e s s ) . 146 S oudek, S. 1928* Brno 8 :1 - 2 4 . Fauna o f th e f o r e s t s o i l * B ull* Gcol* s u p p . a g r . S p a u l l , V. W. 1976. The l i f e h i s t o r y an d p o s t-e m b ry o n ic d e v e lo p m e n t o f " S p ir o b o lu s " b i v i r g a t u s (D ip lo p o d a : S p ir o b o li d a ) on A ld a b ra , W e ste rn I n d ia n O cean . J . Z o o l. Lond. 1 8 0 :3 9 1 -4 0 5 . S t a c h u r s k i , A. 1968* E m ig ra tio n and m o r t a l i t y r a t e s and f o o d - s h e l t e r c o n d i t i o n s o f L ig id iu m hypnorum L* ( I s o p o d a ) . p o l. S e r. A 16 ( 2 1 ) :4 4 5 -4 5 9 . E c o l. S t a c h u r s k i , A. 1972. P o p u la tio n d e n s i t y , b io m ass and maximum n a t a l i t y r a t e and fo o d c o n d i t i o n s i n L ig id iu m hypnorum L. ( I s o p o d a ) . E c o l. P o l. 20 ( 1 9 ) :1 8 5 -1 9 7 . S te p h e n so n , J . W. 1961. B io lo g y o f B rachydesm us s u p e ru s ( L a t z . ) . Ann. mag. n a t . h i s t . ( 1 3 ) 3: 3 1 1 -3 1 9 . Toye, S. A. 1967. O b s e r v a tio n s on th e b io lo g y o f t h r e e s p e c i e s o f N ig e r ia n m i l l i p e d e s . J . Z o o l. Lond. 1 5 2 :6 7 -7 8 . T u rn e r, F. B. 1960. S iz e and d i s p e r s i o n o f a L o u is ia n a p o p u la tio n o f th e c r i c k e t f r o g , A c r ls g r y l l u s . E c o l. 4 1 : 2 5 8 -2 6 8 . U l r i c h , A. 1933. D ie M akrofauna d e r F o r s t w l r t s c h .- u n d w is s . 4 :2 8 3 -3 2 3 . W a ld s tr e u . M itte il. V achon, M. 1947. C o n tr i b u tio n a 1*e tu d e du d ev e lo p p e ra e n t p o s te m b ry o n n a ire de P a c h y b o lu s l i g u l a t u s Voges (M y ria p o d e s , D ip lo p o d e s , S p i r o b i l i d e s ) . Les 6 ta p e s de l a c r o i s s a n c e . Ann. d e s Sc. N a t ., Z o o l ., l i e . s e r i e : 1 0 9 - 1 2 1 . V e rh o e f f , K. W. 1915. Bau d e r l a r v a l e n S c h u tz g lo c k e n von P oly d esm u s. Z o o l. Anz. 4 5 :7 3 . V e r h o e f f ,• K. W. 1 9 2 8 -1 9 3 2 . D ip lo p o d a . I n : B ro n n 's K la s s e n and O rdnungen d e s T i e r r e i c h s , Band 5, L e ip z ig . V e r h o e f f , C. 1929. S tu d ie n u b e r O e k o lo g ie und G e o g ra p h ie d e r D ip lo p o d en h a u p t s S c h l ic h d e r O s ta lp e n . 11 2 . D ip lo p o d e n A u f s a tz . Z. M o rphol. 1 5 :3 5 - 8 9 . V oges, E. 1916. 3 6 :5 1 5 -5 3 7 . Der N e s tb a u d e r P o ly d e sm id e n . B io l . Z e n t r a l b l a t t V o lz , P. 1964. Uber d ie R o lle d e r T i e r w e lt in W aldboden, b e s o n d e rs beim Abbau d e r F a l l s t r e u . Z t s c h r . f . P f . e r n a h r . , D u n g ., Bodenk. 6 4 :2 3 0 -2 3 7 . U a llw o rk , J . A. 1976. The d i s t r i b u t i o n and d i v e r s i t y o f s o i l f a u n a . Academ ic P r e s s , London, New Y ork. W elch, B. L. 1 9 3 8 . The s i g n i f i c a n c e o f th e d i f f e r e n c e b etw ee n two means when th e v a r i a n c e s a r e u n e q u a l. B io m e trik a 2 9 :3 5 0 -3 6 2 . 147 W illia m s , S. R. and R. A. H e fn e r. 1 9 2 8 . The m i l l i p e d e s and c e n t ip e d e s o f O hio. B u ll. Ohio B io l. S u rv ey 4 :9 3 -1 4 6 .