WEE BIGN’QMICS 0F SEYCQE‘QRUS ‘JUSE‘I PORTER! N. 35?. {GHYCRWEIMER CGLLEMBQLA) “195:3 its? fiém Beg?“ cg {33; D. 3523353“ SHE“? LV’ZESH? Richard 3021:: Snider $9372 ‘-J-m AMA- fl LIBRARY Michigan State University This is to certify that the thesis entitled The Bionomics of Onlchiurue luau gorteri r1412: (Onychiuridae: Collembola) \c presented by Richard J. Snider has been accepted towards fulfillment of the requirements for Ph . D. degree in Entomology ajor professor Date W 0-7639 - 1 V. ABSTRACT THE BIONOMICS 0F ONYCfliURUS JUSTi PORTERi N.SSP. (ONYCHIURIDAET‘COLLEMBOLA) BY Richard J. Snider A new subSpecies of Onychjurus iusti (Denis) was described from Michigan and its taxonomic position defined. The male ventral organ was illustrated and analyzed as a taxonomic character. Culture techniques for mass and individual rearing procedures were developed for observation of over 2000 specimens. A method for assessing the effect of relative humidity on survival using various concentrations of glycerol and water was employed at 50°, 60°, 70° and 80°F. As temperature increased and RH decreased, survival decreased accordingly. The egg laying process and subsequent embryonic deveIOpment of Q: lgsti porteri was described for the first time. Egg cannibalism was found to occur in the case of non-deveIOping eggs. Fecundity of mass, low-number reared, and paired cultures was observed. in general, an increase in temperature lowers the number of eggs produced. instar duration was shown to be related to temperature. And, in addition, the presence or absence of individuals of the Opposite sex may govern instar duration. It was found that Dyar's Rule was supported by head capsule width masurener alarger 1 by the l2 The was descr segment, describec inve no food 1 growth, Sur In mass vivai ti M in re measurements. Females developed more rapidly than males and attained a larger size. Maximum length of both males and females was reached by the 12th and lhth instar and decreased thereafter. The development of the chaetotaxy of the fifth abdominal segment was described. in addition, the dorsal setal pattern of the first thoracic. segment, the male and female genital plates,and the male ventral organ was described. investigation of the effect of yeast, high protein, low protein and no food was undertaken. lndications were that food quality can influence growth, fecundity and morphology. Survival at the four temperatures was found to be highest at 60°F. ln mass culture, juveniles appeared to have a higher percentage of sur- vival than in low number reared cultures. Whereas the adults in the same cultures exhibited prolonged survival. THE BIONOMICS OF ONYCHIURUS JUSTI PORTERI N. SSP. (ONYCHIURIDAE: COLLEMBOLA) BY Richard John Snider A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Entomology 1972 KS,“ Iwish t Department of Porter, of th Department of Department of the Preparati Special Preparation - help With mi 44M) 6\ ACKNOWLEDGMENTS i wish to thank the members of my committee: Dr. Paul Rieke, Department of CrOp and Soil Sciences; Dr. Ralph Fax and Dr. T. Wayne Porter, of the Department of Zoology; Dr. Gordon Guyer, Chairman, Department of Entomology; and my major professor, Dr. James w. Butcher, Department of Entomology, for their help and guidance in the course of the preparation of this dissertation. Special thanks go to Mr. Ernest Bernard for helping with the preparation of the graphs. To Mr. Erhard Wawra i am indebted for his help with microphotography. To my wife, Renate, i dedicate this thesis for her constant help with typing, library research, criticism and enthusiasm. Without her aid this work would never have been completed. TABLE OF CONTENTS LIST OF TABLES . . LIST OF FIGURES LIST OF GRAPHS . THE GENUS ONYCHIURUS GERVAIS SENSU LATU . . ONYCHIURUS GERVAIS, I8hl, SENSU SALMON, IN NORTH AMERICA . . Onychiurus Iusti Denis . . . Onychiurus usti porteri n. ssp. Discussion . . . . . . . . . Distribution . . . . . . . . I964, THE BIONOMICS OF ONYCHIURUS JUSTI PORTERI N. SSP. Introduction . . . . . Culture Method Review . . . . . Culture and Manipulation Techniques with Stock Cultures. Transfer Technique RESPONSE TO VARIABLE RELATIVE HUMIDITY . Introduction . . . . Materials and Methods . . Results and Discussion OVIPOSITION EGG CANNIBALISM . . EGG DEVELOPMENT . . EGG PRODUCTION Introduction . Methods . . . . . . . Fecundity in Mass Reared Cultures . . Fecundity in Low Number Reared Cultures . . Fecundity in Isolated Females . . Discussion . . . . . . . . POSTEMBRYONIC DEVELOPMENT . . Introduction . . . . Methods . . INSTAR DURATION Mass Cultures . . . . Low Number Cultures . . Cultures of Pairs . . Page . vii xi U'IU'IUJ Instar Duration of Single Males and Females . . Instar Duration of Pairs of Males and Pairs of Females Discussion . GROWTH Introduction Methods . Head Length and Width of the First Six Instars Growth: Over-all Length . Discussion . . . DEVELOPMENT OF INSTAR CHAETOTAXY . . . Dorsal Setae of the Fifth Abdominal Segment . . Dorsal Setae of the First Thoracic Segment . . . Chaetotaxy of the Male and Female Genital Plates . . Chaetotaxy of the Male Ventral Organ of Abdominal Segment II DIETARY INFLUENCE ON GROWTH AND FECUNDITY . Introduction . . . . . . . . . . . Materials and Methods . . Results . . Discussion SURVIVAL AT 60°, 70° and 80°F Introduction . . . . . . . . . . . . Survival in Mass Culture . . . . . . . . . Survival in Low Number Reared Cultures . . Survival in Cultures Containing Single Individuals and Pairs. Discussion . . . . . . . . . . . . . . SUMMARY LITERATURE CITED . . . APPENDIX 73 77 79 79 79 80 81 86 9O 90 91 9h 99 . . 100 . 100 . 103 . 105 112 . . l15 . 115 . 115 . 118 . 118 . 121 . l22 . 125 - 137 labia VI. VII, VIII. XI, XII. XI”. XIV. Xv. XVI. XVII. LIST OF TABLES Table Page I. Distribution of North American species of Onychiurus . . . . A II. Comparison of the pseudocellar arrangement in Onychiurus justi Denis and 9, iusti Eorte:l_ . . . . . . . . 6 III. Glycerol-water solutions used to obtain various re'ative humidities O O O O O O O O O O O O O O O 0 O O O O 29 IV. 70°F: Time-table for various stages in the development of the embryo . . . . . . . . . . . . . . . . . . . . . . . A1 V. Number of days required for the deveIOpment of the eggs from the time of laying to eclosion . . . . . . . . . . #6 VI. 60°F: Egg production and percent hatching per oviposition, for pairs of male and female reared in isolation..;. . . . . 53 VII. 70°F: Egg production and percent hatching per oviposition, for pairs of male and female reared in isolation . . . . . . 5A VIII. Over-all survival of eggs produced in mass and low number reared cultures . . . . . . . . . . . . . . . . . . . . . . 55 IX. Egg production of a single female in a low number reared culture for 366 days . . . . . . . . . . . . . . . . . . . . 61 X. Estimated fecundity for A species of Protaphorura cultured by Hale (1965) at 15°C (60°F) . . . . . . . . . . . 62 XI. Number of individuals observed at three constant tempe- ratures in each experimental run . . . . . . . . . . . . . . 6h XII. Summary of instar duration averages at 60°, 70° and 80°F, for mass reared cultures . . . . . . . . . . . . . . . . . . 67 XIII. Summary of instar duration averages at 60°, 700 and 80°F, for cultures containing five or less individuals . . . . . . 68 XIV. Average instar duration, in days, for pairs of male and female . . . . . . . . . . . . . . . . . . . . . . . . 7O XV. Average instar duration, in days, for isolated males and females . . . . . . . . . . . . . . . . . . . . . . . . 7h XVI. Average instar duration, in days, for pairs of males (2) and pairs of females (2) . . . . . . . . . . . . . . . . . . 77 XVII. Mean head length and head width, in microns, for the first six instars of mass reared individuals . . . . . . . . . . . 80 TatIe XXIII. Nunbe XIX. Cons‘ ther XX. Numb XXI. Inst var'I XXII. Inf' XXIII. Mea: var var XXIV, Per SII' XXV~ PeI Sir XXII. pe. si Table XVIII. XIX. XX. XXI. XXII. XXIII. XXIV. XXV. XXVI. Number of setae per instar on the genital plate Constituents of diets “A“ and “B” as provided by the manufacturer . . . . . . . . Number of individuals used per diet Instar duration in days under the influence of various diets . . . . . . . . . . . Influence of various diets on the percent survival Mean over-all lengths (in microns), at the end of various time periods,of individuals reared on various diets . . . . . . . . . . . . . Percent mortality at 60°F in cultures containing single and paired individuals . . . . . . . . . Percent mortality at 70°F in cultures containing single and paired individuals . . . . Percent mortality at 80°F in cultures containing single and paired individuals . . . . . APPENDICES I.- XLVII vi Page 99 . 10h . 105 . 105 . 106 . 112 . 120 . 120 . 121 . 137 Figure 12. I3. lip LIST OF FIGURES Figure Page 1. Onychiurus justi porteri n. ssp., culture containing adults, juveniles and eggs . . . . . . . . . . . . . . . . 8 2. Position of the postantennal organ and associated pseudocelli . . . . . . . . . . . . . . . . . . . . . . . 10 3. Postantennal organ, detail . . . . . . . . . . . . . . . . 10 A. Postantennal organ, single tubercle . . . . . . . . . . . 10 5. Antennal organ, third antennal segment of a seventh instar juvenile . . . . . . . . . . . . . . . . . . . . . . lO 6. Hindclaw of first instar juvenile (oil) . . . . . . . . . . 10 7. Foreclaw of first instar juvenile (oil) . . . . . . . . . . 10 8. Foreclaw of seventh instar adult showing inner tooth on unguis . . . . . . . . . . . . . . . . . . . . . . . . 10 9. Firstinstar juvenile showing dorsal pseudocellar pattern. . 10 10. Split seta on the posterior part of abdominal segment V, third instar juvenile . . . . . . . . . . . . . . . . . . . 10 11. Double pseudocellus on the fourth abdominal segment of a fifth instar individual . . . . . . . . . . . . . . . IO 12. Photograph, phase-contrast oil, of the eleventh instar male abdominal organ . . . . . . . . . . . . . . . . . . . 12 13. Photograph, phase-contrast oil, of the twenty-fifth instar male abdominal organ. Note the splitting of the seta typical of senile adults . . . . . . . . . . . . . . . . . 12 1h. Male ventral organ seta, fourth instar (oil) . . . . . . . 1h 14. Male ventral organ seta, fifth instar (oil) . . . . . . . 1h 16. - 18. Male ventral organ setae, thirty-fourth instar, of a 339 day old individual raised at 70°F (oil) . . . . . 1h 19. Male ventral organ seta, thirty-fourth instar, of a 339 day old individual raised at 70°F (oil) . . . . . . . . 1h 20. - Zh. Diagrams showing position of areas lacking major tubercles on the dorsum of the head . . . . . . . . . 1h vii u. fifth tenth 26. Sane I II-IaI! sr there. used charc 23. Dessi conta dessi 29. The I 3'3. Hath; Inje cont H. ReIa 33- Free 34. 35. 36. 37. 38. 39. In. Figure 25. 26. Fifth abdominal segment pseudocellar pattern of a tenth instar female, left side of body Same female, right side of body 27. (a): small rearing container (25 x 3h mm) with plaster- 28. 29. 30. 31. 32. 33. 3h. 35. 36. 37. 38. 39. A0. A1. #2. #3. Ah. #5. charcoal substrate. (b): large rearing container used for stock cultures (50 x 37,5 mm) with plaster- charcoal substrate Dessication chamber constructed from two 25 x 3h mm containers welded together, with silica-gel as a dessicant . The Honeywell humidity and temperature meter Method of checking RH of a specific gravity solution Injection of specific gravity solution into a test container . Relative humidity test container Freshly laid egg (70°F) . . . Egg, 1h hours old, eight cell stage (70°F) Egg, three days old (70°F) Egg, between three and four days of age, showing the ruptured chorion (70°F) . . . Egg, fifth day (70°F) Egg, sixth day (70°F) Egg, eighth day (70°F) Egg, eleventh day (70°F) Fifth abdominal segment dorsal setal pattern: First instar First instar about to moult Second instar . . . . Second instar about to moult Third instar viii Page 19 19 32 32 32 32 32 32 Ah AA AA AA Ah Ah Ah AA 93 93 93 93 93 ‘hwe 56. Third i7. Fourt IS. Fourt I9. Fiftr w: SixtI 3L Sever 52. Atyp Uheq :I- Seve cell 68. In, F. n, 72, 73. 7S. (/7 7s, Figure Page A6. Third instar about to moult . . . . . . . . . . . . . . . . . . 93 A7. Fourth instar . . . . . . . . . . . . . . . . . . . . . . . . . 93 48. Fourth instar about to moult . . . . . . . . . . . . . . . . . . 93 49. Fifth instar . . . . . . . . . . . . . . . . . . . . . . . . . 93 50. Sixth instar . . . . . . . . . . . . . . . . . . . . . . . . . 93 51. Seventh instar . . . . . . . . . . . . . . . . . . . . . . . . 93 52. Atypical fifth abdominal segment setal pattern showing unequal number of setae on the same individual . . . . . . . . . 93 53. Atypical third abdominal segment setal pattern . . . . . . . . . 93 SA. Seventh instar individual illustrating the pseudo- cellar pattern typical of the species . . . . . . . . . . . . . 93 First dorsal thoracic segment setae: 55. First instar . . . . . . . . . . . . . . . . . . . . . . . . . . 96 56. - 61. Third instar . . . . . . . . . . . . . . . . . . . . . . . 96 62. - 63. Fourth instar . . . . . . . . . . . . . . . . . . . . . . . 96 6h. - 66. Fifth instar . . . . . . . . . . . . . . . . . . . . . . . 96 67. Atypical fifth instar showing unequal number of setae from one side of the body to the other . . . . . . . . . . . . 96 68. - 69. Sixth instar . . . . . . . . . . . . . . . . . . . . . . . 96 Female genital plate setal pattern: 70. Fourth instar . . . . . . . . . . . . . . . . . . . . . . . . . 98 71. Fourth instar about to moult . . . . . . . . . . . . . . . . . . 98 72. Fifth instar . . . . . . . . . . . . . . . . . . . . . . . . . 98 73. Sixth instar . . . . . . . . . . . . . . . . . . . . . . . . . 98 7h. Sixth instar about to moult . . . . . . . . . . . . . . . . . . 98 75. Seventh instar . . . . . . . . . . . . . . . . . . . . . . . . . 98 Male genital plate setal pattern: 76. Third instar (oil) . . . . . . . . . . . . . . . . . . . . . . . 98 iTgure 77. Thil 75. Fou 79. Fif 5. Fit 51. Six 52. FOL ":3. HI 35'. Fit ES. FI' Si; 57. Si 88- El ‘.'9 T“ 90. Se 91 E'- SI 92. - . Figure Male ventral setae of the second abdominal segment: Third instar about to moult (oil) . . Fourth instar, lanceolate setae . spatulate setae . spatulate setae . lanceolate setae lanceolate setae spatulate split seta Eleventh instar, spatulate seta . Twelfth instar, lanceolate Split seta . Seventeenth instar, lanceolate setae . . . . . . . . Eighteenth instar about to moult; note (arrow) spatulate seta formed under lanceolate seta . 77. 78. Fourth instar (oil) 79. Fifth instar 80. Fifth instar about to moult 81. Sixth instar 82. 83. Fifth instar, 84. Fifth instar, 85. Fifth instar, 86. Sixth instar, 87. Sixth instar, 88. 89. 90. 91. 92 . - 96. Twenty-fifth instar, split setae typical of senile adults . . . Page 98 98 98 98 . 98 . 102 . 102 . 102 . 102 102 . 102 . 102 . 102 . 102 . 102 . 102 ‘ ‘- ‘Lwnruh Graph 39. Io, In. ‘42.- LIST OF GRAPHS Graph Page 1. Onychiurus justi porteri n. ssp., percent mortality at_80°F and five relative humidities . . . . . . . . . . . . 35 2. Percent mortality at 70°F and five relative humidities. . . . 36 3. Percent mortality at 60°F and five relative humidities. . . . 37 A. Percent mortality at 50°F and five relative humidities. . . . 38 5. Relationship of temperature to the duration (in days) of the egg stage . . . . . . . . . . . . . . . . . . . . . . A7 6., 7.0and 8. Average number of eggs per individual at 60°, 70 and 80°F laid in mass culture . . . . . . . . . . . . . . 50 9. and 10. Average number of eggs per individual at 600 and 70°F laid in low number reared cultures . . . . . . . . . 52 11. and 12. Average number of eggs laid at 60° and 70°F by isolated females . . . . . . . . . . . . . . . . . . . . . 56 13. Average number of eggs laid per female at 600 and 70°F, plotted against instar . . . . . . . . . . . . . . . . . . . 57 1A.- 23. 0Egg production per instar of 10 females reared at 60 F . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 2A.- 38. Egg production per instar of 15 females reared at 70°F . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 39. Instar duration (in days) of mass reared individuals at 60°, 70 and 80°F . . . . . . . . . . . . . . . . . . . . 69 A0. lnstag duration (indays) of low number reared individuals at 60 , 70° and 80°F . . . . . . . . . . . . . . . . . . . . 71 A1. Instar duration (6° days) of pairs of males and females reared at 60°, 70 and 80°F . . . . . . . . . . . . . . . . . 72 A2.- AA. Instar duratign of single males and females reared at 60°, 70° and 80 F . . . . . . . . . . . . . . . . . . . . 75 A5. Instar duration of pairs of males reared at 600 and 70°F. . . 76 A6. Instar duration of pairs of females reared at 60° and 70°F . 76 A7. Log‘ON of the head length for the first six instars reared at 60°, 70° and 80°F . . . . . . . . . . . . . . . . . 82 58. Log rea I9. Ove rea 50. Ove rea 51. CW re. 52. UV fe 53. CV fe 55- OI. it 55. T YI 56. p I 57.- 5 I 60. 61, Graph A8. A9. 50. 51. 52. 53. SA. 55. 56. 57.- 60. 61. Log N of the head width for the first six instars reaigd at 60°, 70° and 80°F Over-all length (in microns) per instar of individuals reared in mass culture at 60°F . Over-all length (in microns) per instar of individuals reared in mass culture at 70°F . Over-all length (in microns) per instar of individuals reared in mass culture at 80°F . . . . Over- all length (in microns) per instar of males and females reared in mass culture at 60° F . . . . Over- all length (in microns) per instar of males and females reared in mass culture at 70° F . Over- all length (in microns) per instar of males and females reared in mass culture at 80° F . . Time required for each instar in cultureso reared on yeast, diet A, diet 8, and control, at 70° F Percent survival of individuals reared at 70°F for 100 days and fed yeast, diet A, diet 8 and control . 59. Average number of eggs laid per week by individuals reared on diet A, diet 8, and yeast, at 70°F . Pegcent survival of mass reared cultures at 60°, 70° and 80 F O . C . C C C C C O C . O C . C C C O C . Percent survival of low number reared cultures at 60°, 70° and 80°F xii Page 82 83 8A 85 87 88 . 89 107 108 110 117 119 The ge‘ CoHenboIa Cutain Spe hrge numbe result, mar Comur Mntieth c many taxonc This led tc early worke criPtions, foy aImOSt Anothe by Salmon . I "The ; stati< I906 3 and fig eithel SYSter I SaImo. wntributir ml of onYChiu atIVes ' S 3533' In “”98. A! “Md Spec I. THE GENUS ONYCHIURUS GERVAIS SENSU LATU The genus Onychiurus is one of the largest taxa in the order Collembola and has been studied since the time of Linneaus (I758). Certain species are herbivorous and because they inhabit the soil in large numbers, are easily collected with the Berlese funnel. As a result, many additions to the list of known Species are being made. Communication between researchers prior to the beginning of the twentieth century was not as easy or common as today. Consequently many taxonomists worked independently of others in the same area. This led to duplication of generic and specific designations. Moreover, early workers often did not use illustrations in their species des- criptions, causing compilation of long and complicated lists of synonyms for almost any individual species of Onychiurus. Another factor contributing to taxonomic difficulties was stated by Salmon (196A): "The classification of Collembola has remained almost static since Borner‘s 'Das System der Collembolen' in 1906 and his 'Die Familien der Collembolen' in 1913 and no attempt has been made since the latter date either to evaluate or to revise the currently accepted system for classification of these insects.” Salmon's viewpoint notwithstanding, there have been some major contributions to the systematics of the Onychiuridae and more specifically' Onychiurus. In I917, Folsom attempted to bring together the known species of Onychiurus in a small monograph listing eleven North American representa- atives. Stach (I93A) produced a major paper discussing the genus 92153: 13525, In it he lists thirty-eight species and varieties known from Europe. Again in 195A, Stach monographed the family Onychiuridae, inte- grating the European species with the known world fauna. The list of ' world species of Onychiurus came to one hundred and thirty six. Twenty- j I M species Since 5 bem produce: 1963b, 196% characters a . I Iisin (I960) II’rotaEhorur one hundred An evol “9 Proposed twenty-six E deSIsnated a he redefine: Characters; ranked as 9, Salmon Icy to the I the ta XOOOm‘ lead' In tI Sumo" (1961 saIIIIOn ('95, Before I0 epraIn Prevent Unng Investigdtf adescn'pti m'SIMErpre two species for which he lacked sufficient data were not included. Since Stach's (195A) monograph, the major work on Onychiuridae has been produced by two taxonomists. The careful and detailed analysis of Onychiurus Species by Hermann Gisin (1956, 1957, 1960, 1961, I962, l963a, l963b, l96Aa, l96Ab, 1968) led to a better understanding of Specific characters and variation. In his monograph on the European Collembola, Gisin (1960) recognized two subgenera, Onychiurus 5. str. and Onychiurus (Pgotaghorura) Absolon (I901). The total number of species listed was one hundred and thirty-five of which twenty-one were questionable Species. An evolutionary approach to Onychiuridae was taken by Salmon (1959). He proposed a new and revised scheme of classification which recognized twenty-six genera under the family, many of which had previously been designated as subspecific in rank. Most important to note here is that he redefined Onychiurus Gervais, I8Al, on the basis of morphological characters; separating it from a complex of subgenera which he subsequently ranked as genera. Salmon (l96A) used the scheme developed in 1959 as a basis for his key to the known genera of Onychiuridae. Because his approach clears the taxonomic difficulties of subgeneric ranking, I have followed his lead. In the present paper the taxonomic status of Onychiurus follows Salmon (l96A). For a taxonomic history of the genus Onychiurus see Salmon (1959). Before any discussion of blonomics can proceed, I feel it necessary to explain the Specific status of Onychiurus justi Denis (1938). To prevent unnecessary confusion about the new subspecies considered in this investigation, an explanation of the current status of 9: iusti Denis and a description of the new subspecies are offered. In the event of possible misinterpretation concerning the species determination and subsequent erection o The I senSu Salrr four speci Guthrie (I TuIIberg) “9’ Specie as a synor cOrl'ectly Later, Der “OPOSed 1 FOISOm foI Classificl who l’ecor. Species w DO" and 5 Hi 1] Under Sal the genus North Ca I‘ HIS taXOn erection of a subspecies, a description of the animal will be provided. II. ONYCHIURUS GERVAIS, I8AI, SENSU SALMON, l96A, IN NORTH AMERICA The list of North American representatives of Onychiurus Gervais sensu Salmon is not impressively long. Salmon (196A) records seventy- four species for the world, seven of which are found in the United States. Guthrie (I903) incorrectly identified a new Species as (Aphorura inermis Tullberg) = Onychiurus fimetarius (Linneaus). Folsom (I917) erected a new species, Onychiurus pseudofimetarius, and placed Guthrie's inermis as a synonym of pseudofimetarius. In the same paper, Folsom (1917) in- correctly recorded Onychiurus fimetarius (Linneaus) from North America. Later, Denis (1938) showed that Folsom's specimens were a new species and proposed the name Onychiurus Justi. The additional species listed by Folsom for North America are included in other genera under Salmon's (l96A) classification. Folsom somehow missed the collection data of Packard (1873) who recorded Onychiurus_ambulans (Linneaus) from the United States. This species was subsequently reported by MacGillivray (1891), Guthrie (1903), Dow and Smith (1909) and Mills (1930) from Nbrth America. Mills (193A) recorded seven species of Onychiurus from Iowa. However, under Salmon's systematics only 9: pseudofimetarius is representative of the genus. Wray (1950) described a new species, Onychiurus wilchl, from North Carolina, and Maynard (1951) recorded 9: fimetarius from New York. His taxonomic description is almost a direct parallel to Folsom's (1917). Therefore, his record would seem to be of Onychiurus justi rather than fimetarius. Christiansen (1961) described a new species, Onychiurus reluctus, from iowa, while Scott (1961) records Onychiurus fimetarius (Lhneaus one subsp The for the k' MAL sen: TASLE I. SPEC CD . anbular \ [c2 'ambUIar \ Oreoc N; [o (Linneaus) from North America for the first time. iustl, Q, pseudofimetarius, and Q, wilchi. He also lists 9, There remains to be mentioned one subSpecies with the somewhat dubious designation Onychiurus ambulans- inermis oregonensis described by Denis (I929). The following table lists the species, distribution, and authority for the known North American members of the genus Onychiurus Gervais, 18Al, sensu Salmon, l96A. TABLE I. Distribution of North American Species of Onychiurus. SPECIES 0. ambulans (L.) 9, ambulans-inermis oregonensls Denis Q: fimetarius (L.) DISTRIBUTION Wash., Mass. Wash.D.C. , N.Y. , Ohio N. America Minn. N. J. Agriculture pest Agriculture pest Oregon U.S.A. U.S.A.* Mass.* N.Y.* Mass.,Wash.,0hio.,N.Y.* Calif.* North America* Florida, California* Florida* Minn.* N.J.* Agriculture pest* N. American caves* Agriculture pest* Calif.* N. Carolina* Western U.S.* U.S.A.* N.Y.* Conn.* Utah* Calif.* N. Mex. N. Carolina* AUTHORITY Packard, 1873 MacGilIivray, I891 MacGilIivray, 1893 Guthrie, 1903 DOW 5 Smith, 1909 Mills, 1930 Folsom, I933 Denis, I929 Bonet, I931 Packard, 1871 Packard, 1873 Lintner, 1885 MacGilIivray, 1891 SchUtt, 1891 MacGilIivray, I893 Lonnberg, 189A SchUtt, 189A Guthrie, 1903 Dow 5 Smith, 1909 Mills, 1930 Bonet, 1931 Folsom, 1933 Scott, 1937 Brimley, 1938 Scott, l9A2 Chamberlain, 19A3 Maynard, 1951 Bellinger, 195A Wray 8 Knowlton, I956 Wilkey, 1959 Scott, 1961 Wray, I967 [Table I CC SPECIE 0.]5ti DI 'u .pseudof U .reluctu (L.) .chhi The I IStaken - he thOth ”th EIOn ShOr with and CUrV atte abse Iitt abdC on t whit (Table I continued) SPECIES DISTRIBUTION AUTHORITY 9, lusti Denis Mass., Penn., Fla. Calif. Folsom, 1917 N. Mex. Scott, 1961 Q, pseudofimetarius Folsom Minn. Guthrie, I903 111. Folsom, 1917 Iowa Mills, 193A Utah Wray 6 Knowlton, I956 Calif. Wilkey, 1959 N. Mex. Scott, 1961 Q, reluctus Christiansen lowa Christiansen, 1961 0. wilchi Wray N. Carolina Wray, 1950 N. Mex. Scott, 1961 */ These citations must be considered in question because they are probably based on Folsom's (I917) designation. ouvcntunus JUSTI DENIS The following description, exclusive of the pseudocellar pattern, is taken from Folsom (1917). It consists of his observations on what he thought to be 93 fimetarius: "White. Abdomen broad, rounded behind. Postantennal organs elongate, each with 8 to 17 branched tubercles. Antennae Shorter than the head. Sense organ of third antennal segment with four slender papillae, five guard setae, two sense rods, and two ovate erect smooth sense clubs. Unguis slender, curving, untoothed. Unguiculus gradually tapering, distally attenuate, three-fourths as long as unguis. Anal spines absent. Anus ventral. Clothing of sparse short setae, a little longer and stiffe? on the posterior part of the abdomen. Cuticular tubercles relatively coarse; coarser on the head than on the body. Length, often 1.8 mm; maximum 2.1 mm.” ouychiuhus JUSTI gonrehi_n. SSP. White. Abdomen broad, rounded behind (fig. 1). Postantennal organs elongate (I antennae 51 with four 1 ovate, snoI toothed in instar on, the apical as long as Anal Spine abdominal Simetimes “VET whic 3'32 (figs, genital p I is A6./2 The Ant. Ben. P051 HEAD Pro Pro HESI Pro: Ante Met,- I‘o: ”ts THOR/1 X elongate (fig. 2), each with 8 to 17 branched tubercles (figs. 3 and A); antennae shorter than the head; sense organ of the third antennal segment with four slender papillae, five guard setae, two sense rods, and two ovate, smooth, erect sense clubs (fig. 5). Unguis slender, curving, un- toothed in the first three instars, (figs. 6 and 7), but from the fourth instar on, with a single tooth inserted at one quarter the length from the apical end (fig. 8); unguiculus gradually tapering, distally attenuate, as long as the unguis; pretarsus with an anterior and posterior setula. Anal spines absent; anus ventral; ventral organ of the male (on second abdominal segment) consists of four to five setae (figs. 12 and 13), sometimes six, having a seta-like thick median shaft wrapped by a broad cover which is slit longitudinally on one side, variable with increased Page (figs. 1A to 19); male genital plate with A2 to 57 setae; female genital plate with 28 to 37 setae; ratio of M/s setae of abdominal segment V is A6/26, seta M' somewhat longer than M. The following table (II) compares the new subspecies pseudocellar arrangement with that of [usti: TABLE 11. LOCATION FOLSOM.(1917) SNIDER Ant. base 2+2 2+2 9: Beh. ant. base 1+1 1+1 3:4 Post. bord. head l+l,2+2 2+2 Ventral head 1+1 l+l(ant.), l+l(post.) Pro.th. dorsal 1+1 l+l,0;I-0 fl Prox. precoxal 2+2 2+2 x Meso. dorsal 2+2 2+2 3:: Prox. precoxal 2+2 2+2 g Antero-ventral 1+1 l-I-l F- Meta.th. dorsal 2+2 2+2 Prox. precoxal 2+2 2+2 Antero-ventral 1+1 y_l+l \ rf (Table I Abd Lat AntI Abd Ante Pos: Abd. Vent Post ABDOHEN Abd. Post Abd. Vent Abd. Clot DOSter-ior CUtICUIar my; dor (“95. 2C great We l’or Dr, T (Table 11 continued) LOCATION FOLSOM (I917) SNIDER Abd.I. dorsal 3+3 3+3 Lat. (base V.T.) 1+1 l+l Anteroelateral 1+1 1+1 Abd.Il. dorsal 3+3 3+3 Anteroeventral 1+1 l+l Posteroeventral 1+1 l+l E Abd.III. dorsal 3+3 3+3 8 Ventral-lateral l-I-l 1+1 g Postero-ventral 1+1 1+1 Abd.IV. dorsal 5+5 (d=3+3, lat=2+2) 3+3 (d=2+2, lat=l+II Postero-ventral 1+1 I+I Abd.V. dorsal 3+3 3+3,2+2 Ventral 1+1 1+1 Abd.VI. 0 0 Clothing of sparse short setae, a little longer and stiffer on the posterior part of the abdomen; occasionally a seta will be Split (fig. 10). Cuticular tubercles relatively coarse, coarser on the head than on the body; dorsum of the head with six distinct areas lacking major tubercles (figs. 20-2A). Length, average 1.9 mm, maximum of 2.2 mm. It is with great pleasure that I name this new subspecies Onychiurus justi porteri for Dr. T. Wayne Porter. Figure l. Onychiurus ‘usti porteri n.ssp., culture containing adults, juveni es, and eggs. JPW \DCDNO‘U‘I 10. ll. Onychiurus jgstl porteri n. ssp. - list of figure captions Position of the post antennal organ and associated pseudocelli. Post antennal organ, detail. Post antennal organ, single tubercle (oil). Antennal organ, third antennal segment of a seventh instar individual. Hindclaw of first instar juvenile (oil). Foreclaw of first instar juvenile (oil). Foreclaw of seventh instar adult showing inner tooth on unguis. First instar juvenile showing dorsal pseudocellar pattern. Split seta on the posterior part of abdominal segment V, third instar juvenile. Double pseudocellus on the fourth abdominal segment of a fifth instar individual. lO 12. 13. ll Onychiurus justi porteri n. ssp. - list of figure captions Photograph, phase—contrast oil, of the eleventh instar male abdominal organ. Photograph, phase—contrast oil, of the twenty-fifth instar male abdominal organ. Note the splitting of the seta typical of senile adults. 12 3.0.0.0... c Ode-00‘ ...... IA. 15. 16. I9. 20. I3 Onychiurus justi porteri n. ssp. - list of figure captions Male ventral organ seta, fourth instar (oil). Male ventral organ seta, fifth instar (oil). — 18. Male ventral organ setae, thirty-fourth instar, of a 339 day old individual raised at 70°F (oil). Male ventral organ seta, thirty-fourth instar, of a 339 day old individual raised at 70°F (oil). - 2A. Diagrams showing position of areas lacking major tubercles on the dorsum of the head. 1A IS Discussion Folsom's I917 description of Q, fimetarius (Linneaus) was adequate enough for Denis (1938) to recognize it as a new species. He was quick to point out that the two ovate, erect, smooth sense clubs of the third antennal segment separated Folsom's species from fimetarius. 0n the strength of that morphological character he designated Onychiurus fimetarius (Linneaus) Folsom, 1917 as Onychiurus justi. It must be mentioned that while Folsom states the pronotum has dorsal pseudocelli (1+1), Denis missed this in translation and writes, "lacking the pseudocelli of the pronotum." Folsom makes no mention of a male ventral organ and Denis later writes "no ventral organ." Denis does, however, recognize that the unguiculus may be more elongate than the one drawn by Folsom. In the course of a discussion of known morphological characters used in the identification of Onychiurus, Hale (1969) states that it is possible to recognize two general types of antennal organs. In one of these the organ usually consists of four or five papillae, each with a guard seta protecting a pit with tuberculate sensory clubs. The other possesses smooth sensory clubs, which may be either curved or straight. In pointing out species with curved or straight sensory clubs within the antenr sensory c I I novae-zeal species fr'l 0.5ubanta sinensis S novae-zeal; on the pror However, on Pionotal p5 Care r segnents. IIWIIEI' of ; ”The I: used 1 reliar myself I have materi tergit SPECIm Of the 16 the antennal organ, Stach (195A), p. 173, states that straight, smooth sensory clubs appear in ...”Qnychiurus justi Denis 1938, and Onychiurus ..,_,______ novae-zealandia Salmon, 19A2.” In order to differentiate these two species from other members of the group which includes 9: gridelli Denis, Q: subantarctlcus Salmon, 9: stachianus Bagnall, Q: nervosus Stach, Q, sinensls Stach, and Q: subcadaverinus Denis, he suggests that lusti and novae-zealandia can be recognized through the presence of pseudocelli on the pronotum. He also makes this point on page 166 of the same paper. However, on page 177, he recognizes that there can be variation of the pronotal pseudocelli in the case of Q: fimetarius. Care must be exercised in reading the pseudocellar pattern on body segments. The onychiurid Collembola are notorious for variation in the number of pseudocelli. Salmon (1959) states: “The pseudocelli of the Onychiurlnae have been extensively used in the past by many authors as specific characters. Much reliance has been placed by some authors, and, indeed, by myself, on the number of pseudocelli on each body tergite. I have noticed repeatedly, in working through Onychiurid material, that the number of pseudocelli on individual body tergites can vary, sometimes quite considerably, between specimens of the same species and even between the two Sides of the same individual." Hale (1968) comments that when one side of the animal has an aberrant number, the corresponding side has the normal number, "generally speaking.” He found the average variation in five species of Onyghiurus to be two percent. In the same paper, Hale found the incidence of a tooth on the claw too variable for use. Of four reliable and consistent characters which he described, the following three are used in the present investigaticnwz The pseudocellar formula, the chaetotaxy of abdominal segment V, and the ratio of the lengths of setae M and s. The differences between 9: ZEEEI.°"° the population from Michigan are enough to justify erection of a new subspecies. Folsom's (1917) analysis agrees WI‘ 0968) me? dnractert does not a adult spec variation population- The Hichi; Exami ation beta Table II 5 Hention is M while posterior. I 5+5 in I22. COnsistent thousand M dominant cI OCeIIi wil Varia‘ th0ught tha But after c found to be ‘15 heavy Ia spatulate. “nIoIIed Sp 59* Instar The Do. I7 agrees with resPect to the antennal and postantennal organs. As Hale (I968) mentions, the tooth on the unguis can not be used as a serious character. In the present subspecies, the inner tooth of the unguis does not appear until the fourth instar. Even then, there are a few adult specimens in which it is lacking. Denis (1938) observed that variation may occur in the length of the unguiculus. Folsom, in his population, found the unguiculus to be 3/A the length of the unguis. The Michigan Specimens all exhibited an unguiculus as long as the unguis. Examination of the pseudocellar formula (fig. 9) shows enough vari- ation between [usti sensu stricto and justi porteri to warrant discussion. Table [1 summarizes the differences between justi and justi porteri. Mention is made of the ventral pseudocelli of the head. in justi it is 1+1 while in justi porteri it is 2+2, one set anterior and the other posterior. The dorsal pseudocellar pattern of abdominal segment IV is 5+5 in jg§£j_as described by Folsom, while in justi porteri it is 3+3 consistently. Abdominal segment V In 13351 has 3+3, but out of over two thousand Michigan specimens examined, only three had the 3+3 formula, the dominant condition being 2+2 (figs. 25 and 26). Occasionally two pseud- ocelli will converge and form one locus (fig. 11). Variation in the male ventral organ is confusing. At first it was thought that the shape of the setae could be correlated with the instar. But after careful examination, the setae of the male ventral organ were found to be extremely variable. They first appear in the fourth instar as heavy lanceolate setae. In the later instars they unroll and become spatulate. From instar to instars this change from rolled lanceolate to unrolled spatulate occurs (figs. IA to 19). Sometimes members of the same instar exhibit this variation. The position of distinct areas on the head lacking major tubercles 25. 26. I8 Onychiurus justi porteri n. ssp. - list of figure captions Fifth abdominal segment pseudocellar pattern of a tenth instar female, left side of body. Same female, right side of body. 19 20 is used as a key characteristic, consistent from the fourth instar on. Hale (1969) lists these patterns or ”new characters“ in his stereoscan studies of the genus Onychiurus. Taking into consideration the antennal organ structure and the pseudocellar pattern, I find It difficult to erect a new species. The variation in the pseudocelli of abdominal segment V, the consistency of segment IV, the presence of a tooth on the unguis, and the length of the unguiculus Indicate a pOpulatlon which differs consistently from the type in respect to significant minor characters. DIStribution Specimens of 9: justi porteri first came to my attention in the spring of 1967 when a sample was sent from a mushroom grower in Wayne County, Michigan, for identification. It seems they were a pest in the mushroom culture medium, where they ate fungal hyphae. From this sample cultures were raised for experimental life cycle Studies and have been maintained ever since. Many of my collection records in the past which were listed as Q: fimetarius Linneaus are probably 9: justi. However, it will take careful examination of all museum specimens to determine its true distribution in North America. The only reliable records we can use are those of Folsom (1917) and Scott (1961). That would lead to the following distribution: Massachusetts, Pennsylvania, Florida, California, and New Mexico. In EurOpe, Denis (1938) records 9: justi from Italy. Tarsia in Curia (19A3) found it in Italian caves. Stach (195A) describes jg§£i_ from New Zealand, based on Salmon's (I9Al) determination of Q: fimetarius. Salmon‘s drawings Show clearly the erect position of the antennal organ 21 papillae and the similarity to Folsom's (1917) description of the pseudocellar pattern; leading to the conclusion that what Salmon really saw and reported was jgstj: Onychiurus justi porteri n. ssp. is so far known only from one mushroom house in Michigan. Onychiurus justi Denis has been taken from under bark, leaf mould, around root systems, and caves. III. THE BIONOMICS OF ONYCHIURUS JUSTI PORTERI N. SSP. Introduction wifi T—v Collembolan bionomics studies have in recent years undergone many changes in methodology and direction. The ”curious naturalist" approach of the last century has given way to laboratory and field techniques based on both qualitative and quantitative data. Observations on the physiology, behaviour, and population dynamics of Collembola in natural systems have magnified the apparent role of these animals in organic breakdown and chemical translocation. The study of life cycles and composition of diets has been recognized as an important factor in the understanding of the dynamics of soil communities (Christiansen, I970a, b). Recent symposia such as the "International Symposium on Pesticides in the $011” at Michigan State University (1970), the "IV Colloquium Pedoe biologiae" in Dijon (1970), the ”Colloque International sur les Collemboles'l in Paris (1970), and the ”Symposium on Soil Microcommunities“ at Syracuse (1971) have been largely concerned with biology, population dynamics and biomass, energy flow, and edaphic factors. This shift in emphasis from taxonomy to biological investigations points out the need for critical data on individual species. Fortunately reviews of literature dealing with collembolan bionomics 5 22 have received much attention in the last decade (Christiansen, l96A; Schaller, 1970; Butcher, Snider and Snider, 1971). Hale (in: Burges and Raw, 1967) compiled a paper similar to Christiansen's (196A) review, which included predominantely European literature. More specific compendia are offered by Vannier (1970) in his “Reaction des Microarthropodes aux Variations de l'Etat Hydrique du Sol” and by Thibaud (1970) in “Biologie et Ecologie des Collemboles Hypogastruridae Edaphiques et Cavernicoles.” Publications by North American workers on collembolan bionomics in the past have been few, with some notable exceptions (Davis and Harris, 1936; Britt, 1951). Perhaps this could be attributed to insufficient knowledge of the North American collembolan fauna. In recent years, in- vestigation of nearctic Collembola has increased. Life cycle studies by Marshall and Kevan (I962), Sharma and Kevan (1963 a,b) and Sharma (1967 a,b) have dealt with food, embryonic deveIOpment, postembryonic development and temperature effects. Specific studies contributing to our knowledge of collembolan biology have been made in the following areas: ingested food and dietary require- ments (Knight and Angel, 1967); colonization (Vail, I965); experimental studies on aggregation and disPersion (Christiansen, 1970a); competition between species (Christiansen, 1967); survival (Christiansen, l970b); factors affecting predation on Collembola by various Arthropods (Christhansen, 1970a); reproductive biology, oviposition inhibition, and egg cannibalism (Waldorf 1971 a,b,c); and the effect of light and temperature on phenotypes (Willson, I960). The present study was undertaken to ascertain what some of the ecological factors impinging on a soil collembolan are and how the animal responds to them under laboratory conditions. In addition, data were collected on egg laying, hatching and dietary requirements as collateral 23 information. it is my conviction that basic laboratory observation of these animals will reveal patterns in deve10pment that might be taken for granted or overlooked in field studies. The following investigations are presented in the belief that Collembola are important contributors to the fertility of soil and that knowledge of their bionomics will lead to a better understanding of their role in soil communities. Culture fiethodffleyiew The culture methods used for rearing members of the family Onychiuridae all bear close resemblance to each other. Basically the technique was started by Wharton (l9h6) in an effort to raise mites. Goto (1960) des- cribed a rearing method consisting of a mixture of charcoal and plaster poured into a container with a close fitting lid or stOpper; the food material most frequently used was yeast. One of the first papers dealing with onychiurid life histories was written by Milne (1960) who used the method of Edwards (1955) for his observations. it consisted of plaster blocks with cells inserted for culturing individual Specimens. Milne reared Qnychiurus furcifer Bdrner, l ' V ‘ ' Q, latus Gisin, Q, procampatus Gisin and four other species at 5°, 12°, and 2h°C, using bracken Spores as food source. Choudhuri (1961), while studying the influence of temperature on Q: furcifer, used small glass containers with a charcoal-plaster substrate and yeast as food. A similar technique, employing tubes covered with coverslips and a constant temperature of 15°C, was used by Hale (1964) for experimental studies on members of the pnychiurus armatu§_species grOUp. W‘Tfi ffi‘ firw—VY Hale (1965 a) applied the same method for observations on the breeding biology of Collembola, among them Q: furcifer, Q: pggcampatus, 9: latus and Q, trlCanp- 29 patus Gisin. The cultures were maintained at 8°C. In later work, the same Species were observed during postembryonic development (Hale 1965 b) at a temperature of 15°C. Among the Species studied by TUrne (1967), Onychiurus cf. cebennarius Gisin was reared on various soil materials and on pure sand to determine whether food substance or microbial flora affected the reproduction rate; temperature was held at 21°C. Ashraf (1969) tried to use wide mouth glass Jars fitted with wire gauze screw caps. One of the three species he observed was 9: bhattii Yosii. A mixture of three parts ground and sterilized soil with one part leaf manure constituted the substrate; food consisted of freshly fallen leaves of Trjfoiium and Sesbania aegyptica. The cultures were kept at room temperature (13.6°-27OC). in a recent paper, Petersen (1970, in press) reports using plastic canisters (32 x 36 mm) as culture containers, filled to half their depth with plaster—charcoal mixture. Before the substrate sets, a glass tube (8 mm x ‘12 mm) is pushed into the soft mixture, and a rubber bung is inserted in the tap of the tube. According to the author the advantage over other types of rearing chambers is that water can be administered to the sur- rounding piasterrcharcoal instead of directly to the culture surface. He used this type of chamber to rear 9: furcifer at 15°C and provided yeast as food (Candida s23). Culture and Manipulation T9°h939”°§-withc§FEEk Cultures Stock cultures of ngchiurus Justi porteri were set up in the lab- oratory as a source of eggs, Juveniles and adults. The rearing technique employed was basically that reported by Snider et al (1969). The only modifications are described as follows. .7 Plas used inst dition of charcoal r containers leave the condensati over the n then dust When close to 1 substrate as require keep moist it sh "as used i and 0f sub “Ecessitat. tendEncy 0‘ quality of arid up take and {00¢ A"0th it provides Math/e Ea 25 Plastic snapetop containers, 50 mm by 37.5 mm (fig. 27 b), were used instead of screwetOp glass jars, allowing assessment of the con- dition of the cultures without opening the container. A plasterractivated charcoal mixture in a 1:1 ratio, stirred with water, was poured into the containers to a depth of 20 mm and allowed to set. It was necessary to leave the container lids off until this substrate was hardened to prevent condensation on the container walls. Usually a piece of cloth was placed over the newly poured jars or they were kept in a chemical hood to keep them dust free. When in use, the cultures were maintained at a relative humidity as close to 100% as possible. Distilled water was initially added to the substrate until it was saturated, but not wet. Thereafter, each day, or as required upon inspection, distilled water was added with a pipette to keep moisture conditions constant. it should be mentioned at this point why a plastervcharcoal substrate was used instead of some other material. Daily examination of the cultures and of subsequent smaller versions (fig. 27 a) of the same container type necessitated a stable substrate that could not be shifted or spilled. The tendency of plaster to give up water in combination with the absorbent quality of charcoal guaranteed slow evaporation from the substrate surface and uptake of noxious gases evolved as by-products from fecal material and food. Another advantage was the color of the substrate. The dark background it provides made it possible to observe eggs, exuviae and juveniles with relative ease. Food for the stock cultures, and in most experiments, was provided in the form of powdered brewers yeast. Depending on the number of individuals within each culture container, yeast was added in appropriate quantities 26 every day. The stock cultures were maintained in controlled temperature cabinets at 15t2°C and ZliZOC, in total darkness. Transfer Technique Once the adults initially placed in the culture jars had reproduced, a simple method of transferring ist instar juveniles without damaging then: was needed. Eggs are usually laid in large batches, and the presence of many females in a stock jar can result in a brood numbering over a hundred at a given time. The difficulty lies in lifting a known number of juveniles from the stock jar and transferring them to test jars. in the past, a fine bristle brush, number 0000, dipped in distilled water and touched to the body of the juvenile, was sufficient. However, after a time, a high number of the transferred individuals died. Evidently the mere pressure brought on by touching them with a brush was enough to rupture internal tissues and kill them. The method finally used was simple. Stock jars where a number of teggs had hatched within a period of 12 hours or less were flooded to a depth of several millimeters with distilled water. A fine needle was carefully brought up underneath the juveniles floating on the surface, until the animals grasped it with their legs. The needle was tapped over the new container selected until the juvenile drOpped into it. All test containers were set up in this way. Very few deaths occured in the first 29 hours after transfer by this "floating technique." The e the subjec of humidi: temperatur he concludo ditions to Strebel (if 0n bionomic ..L; h 100% RH to More r and humidltl In another the same Sp ’°'° in the of edaphic , the resUlts observed, pc detailed Obs Vim" (197 One of WWW to I SUM“ at 1 various hum; 27 IV. RESPONSE TO VARIABLE RELATIVE HUMIDITY Introduction fiifi The effects of relative humidity on species of Collembola has been the subject of numerous investigations. Davies (1928) studied the effect of humidity on five epigeonistic species of Collembola. Using a constant temperature of 25°C and relative humidities of 0, 10, 20, 50, 90 and 100%, he concluded that the species studied needed saturated environmental con- ditions to survive. Additional studies by Ripper (1930), Davidson (1932), Strebel (1932), Maclagan (1932) and Agrell (l9hl) followed, with emphasis on bionomics. Davis and Harris (1936) observed the biology of Pseudosinella violenta (Folsom) and found that even this scaled species needed close to 100% RH to survive. More recently, Thibaud (1968 a) investigated the effects of temperature and humidity on the embryonic development of six species of Hypogastruridae. In another paper Thibaud (1968 b) observed the postembryonic deve10pment of the same species and found that temperature and humidity played an important; role in the habitat distribution of the animals. In a detailed investigaticnw of edaphic and cavernicolous Hypogastruridae, Thibaud (1970) brings together- the results of 115 studies and states that, in the hypogastrurid Collembola observed, postembryonic survival was highest at 98 to 100% RH. For further detailed observations on the water relationships of microarthropods, see Vannier (1970). One of the first papers reporting on the importance of relative humidity to survival of Onychiuridae was presented by Mayer (1957). He found that a 5011 species, Protaphorura armatu§_(Tullb.) was unable to survive at less than 100% RH. Choudhuri (1963) studied the effects of various humidities on three species of onychiurid Collembola at 24°C constant temperate humidltle over a 10: Stock in the lab present st (“9- 27 a for constr In or tainers we. saw, reSUl‘ A Piece of Second Con' Ethyl ether The ring me the two car The se llltc) Small applied to laps betWEe PFOdUCed a “ran the ten the Chambe r T° achi until the Cr SillCa. 9e] We 28 temperature. His data indicate that adults are more resistant to lower humidities than juveniles, but that 100% RH was necessary for survival over a long period of time. Materials andeethods Stock cultures of Onychiurus justi porteri n. ssp. were maintained t'T1‘vV‘7V‘ vv vwx—rvvvvw— in the laboratory at 70°F using the method previously described. In the present study smaller jars made of plastic, 25 mm high by 3h mm in diametew' (fig. 27 a), were employed for culturing small numbers of individuals and for constructing humidity test chambers. In order to build one humidity test chamber, two of the above con- tainers were used. The bottom of one container was cut away with a hand saw, resulting in a plastic ring a little less than 25 x 3% mm in size. A piece of fine mesh nylon screen was fitted over the Opening of the second container and by holding the screen in place with a rubber band, ethyl ether was brushed over the rim in order to fix the cloth in place. The ring made from the first container was then fitted over the second and the two cemented together. The sealing cement was made by breaking the discarded plastic bottoms into small pieces and dissolving them in ethyl ether. The cement was applied to the inside and outside seams with a brush, until there were no gaps between the upper and lower halves of the test chamber. This treatment produced a taut, even screen surface on which the Collembola could be placed. When the cement was thoroughly dried, it was possible to remove the lid of the chamber without danger of breaking the cemented joint. To achieve 0% RH, silicargel was heated in a laboratory drying oven until the crystals had all turned from blue to straw-yellow color. The dry silica—gel was introduced through a hole cut into the bottom half of the fir containers plastic te. in the to produce . 1963). 0t“ (Davis and and Zar (l:- and Kawasal the contair O'Brien, 19 be related The pr distilled t, Chosen becae harmful yap Periods of Silica RH' Specif in Order to desired RH USed (Table 29 containers; the hole was then sealed with a piece of tape (fig. 28). Ten plastic test chambers were prepared in this manner. In the past, different concentrations of sulfuric acid have been used to produce desired percentages of relative humidity (Davies, 1929; Choudhuri, 1963). Other workers have used saturated solutions of acids and alkali (Davis and Harris, 1936; Mayer, 1957; Thibaud, 1968 a,b). However, White and Zar (1968) reported that acids and alkali may give off toxic vapors, and Kawasaki and Kanou (1965) showed that sulfuric acid may be absorbed by the container surface. Saturated salt solutions (Winston and Bates, 1960; O'Brien, 19h8) have also been used, but their effectiveness was found to be related to the temperatures at which they were stored. The present study utilized different concentrations of glycerol and distilled water to obtain various relative humidities. This mixture was chosen because glycerol is easily mixed with water, does not give off harmful vapors, and maintains constant relative humidity for extended periods of time (White and Zar, 1968). Silica-gel was employed to obtain 0% RH and distilled water for 100% RH. Specific gravity tables prepared by Braun and Braun (1958) were followed in order to mix glycerol-water solutions appropriate to achieve the other desired RH levels. The following concentrations of glycerol—water were used (Table III): Table III. Specific Gravity . RH Distilled H20 100% l.0h9* 95% 1.082* 90% 1.135* 80% Silicaegel 0% T w ~v—v1 ij‘j ‘fiv Y. */ Data from Braun and Braun. 1953 All glyt animals To idities with a ' solutiOr 70°F f0! 2000 ml sensor v was sea' the poir sensor 1 i“ of ti (”to the “he i“to the Small h< After tl The tes- (25 x 3‘ and We” ten adu diarcOa The (651 mile;- v mil/lot 30 All glycerol-water solutions were incubated at 70°F for 12 hours before animals were introduced. To make sure that the solutions were actually producing relative hum- idities of the desired levels, a Honeywell humidity and temperature meter with a lithium—gold sensor (fig. 29) was employed. The glycerol—water solution was first mixed and checked with a hydrometer, then incubated at 70°F for 8‘12 hours. After incubation, the solution was poured into a 2000 ml cylinder which had been stored in the incubator. The lithium-gold sensor was lowered into the air space above the solution and the cylinder was sealed with a neoprene st0pper. A wad of putty was used as a seal at the point where the electric cord entered the cylinder. Cylinder and sensor were then put back into the incubator and given 8 hours to equilibrate“ RH of the solution was checked at the end of 8 hours by plugging the sensors into the meter and the RH read directly (fig. 30). When a desired concentration was confirmed, the solution was injected into the bottom half of the previously described test chambers through a small hole placed in the bottom half to admit a hypodermic needle (fig. 31). After the solution was injected, the hole was sealed with tape (fig. 32). The test chambers were then returned to incubators of various temperatures to equilibrate for 8 hours. While the test chambers were equilibrating, clean culture containers (25 x 34 mm) were brought up to 100% RH by addition of distilled water, and were used to hold Collembola until needed for the tests. Subsequently, ten adults of indeterminate age were placed into each of the ten plaster- charcoal jars just before the test chambers were readied for the timed test. The test chamber lids were then removed one at a time and the culture con- tainer was inverted over it and sharply tapped in order to dislodge the ten individuals onto the screen. The lid was quickly replaced. 27. 28. 29. 30. 31. 32. 31 Rearing and relative humidity techniques - list of figure captions (a): small rearing container (25 x 34 mm) with plasterscharcoal substrate. (b): large rearing container used for stock cultures (50 x 37,5 mm) with plaster charcoal substrate. Dessication chamber constructed from two 25 x 3h mm containers welded together, with silica-gel as a dessicant. The Honeywell humidity and temperature meter. Method of checking RH of a specific gravity solution. Injection of specific gravity solution into a test container. Relative humidity test container. ‘b'af‘x 32 larcua‘ ulturs ners lukewarm-3...... ' vi “a wine ,_ gravity ...M’I-u-solutlon 32 Ten test cor of individuals is to four temperatl of each test run The chambers wer microscope throu was judged to be had to be tapped assessment of in At each tes Survived fOr 10, case Of animals decline after 61 three temperatu Survival at any ‘Diendices l, I with constant h in SuerVal, In a “We Eb o 950 F tests 33 Ten test containers were used for each test run. The total number of individuals for each humidity test was 100. Collembola were exposed to four temperatures: 50°, 60°, 70° and 80°F. During the first 3 hours of each test run the chambers were checked every ten minutes for mortality. The chambers were not opened; visual assessment was made with a binocular microscope through the clear plastic lids of the containers. An individual was judged to be dead when all movements had ceased. Sometimes the chambers had to be tapped to activate the Collembola, thus permitting accurate assessment of immobility. Results and Discussion w‘fi vw—j—Vfi V‘fi At each test temperature, the control individuals held at 100% RH survived for longer periods than did those at other humidities. In the case of animals held at 80°F, even those at 100% RH showed a marked decline after 60 hours exposure (Graph 1). Results obtained at the other three temperatures indicate that the lower the temperature, the longer the survival at any of the given relative humidities (Graphs 2, 3, 4 and Appendices I. II, III and IV). The results of the experiment show that with constant humidity and increase in temperature, there is a decrease in survival. In a comparison of the four temperatures at 0%, 80% and 90% RH, only the 50°F test shows a wide range of survival. At 0% RH, there is a marked similarity between temperatures, and all animals died within one hour. Even at 80% and 90% RH survival of Q: justi porteri is limited to h hours or less. Individuals subjected to 95% RH clearly show a relation between tem- perature and relative humidity, with increased survival as the temperature is lowered. As indicat' Collembola have not many specie few research pa merge. The st 20°c:2°, can be derived from hi After 135 minut M Mao: 5‘le increase The data F W 5lit-cits to hum‘ 24°C, which CO" survive] for P minutes, and f. PreSEnt Study MW” (196 is more resist far stUdled, as a regupt of Ventral tube, WW. l:urt study clearly its: ed by Thib 511M Val of e 34 AS indicated earlier, several Species of epigeonistic and cavernicolous Collembola have been studied for temperature-humidity responses. However, not many species of edaphic Collembola have been investigated. From the few research papers on Onychiuridae a similar pattern of results seems to emerge. The studies of Mayer (1957) who examined Protaghorura armatus at 200C120, can be compared with the 70°F run presented here. The curves derived from his data show the same pattern as do those for Q, justi porteri. After 135 minutes at 93% RH, 33 armatus showed total mortality. In the case of Q, justi porteri at 95% RH, mortality reached 50% after about 10 hours and slowly increased to about 95% after 135 hours. The data presented by Choudhuri (1963) for Protaphorura fimatus, E: pgrthenogeneticus and E, imperfectus indicate little tolerance of those Species to humidities below 100%. Choudhuri's constant temperature was 24°C, which compares roughly with the present 70°F run. At 95% RH, mean survival for E: fimatus was 139.2 minutes, for f: parthenogeneticus 62.8 minutes, and for E: imperfectus 95.6 minutes. Similar conditions in the present study produced a mean survival time of 39 hours for ngchiurus [usti porteri. Comparison of the survival data of Mayer (1957) and Choudhuri (1963) to the data presented here, shows that Q: justi porteri is more resistant to dessication than were any of the related species so far studied. There is an indication that the genus Qnychiurus, possibly as a result of greater body mass or greater thickness of body wall at the ventral tube, may be more resistent to dessication than the genus £3933: phorura. Further investigations are needed for confirmation. The present study clearly indicates that the temperatureehumldity relationship sug- gested by Thibaud (1970) is a factor which must be considered important in survival of edaphic and cavernicolous Collembola. 80°F 35 .momu_v_E:; o>_um_oc o>_e new doom um >u__mucoe acoocoa ._Loucom _um:w mae:_;o>co ._ Lancw 28 car m2. 0!. n n p - $130... 2. m3:. Do on Os. on on O? 00 ON 0—. v n b p N P P P r P P n - bhnp-nbpnhbbh-pbb-nbpnhb ROOF J No UGO ION too loo '0? moon All'IVLHOH LNBOHSd qi N 00—. 36 .mo_u_v_E:; o>_um_oc o>_e ocm moon on >u__mucoe ucoocoa ._Loucom _um:H macamco>co wcaoz 2. m3: OP“ 3F 89 8 OFF 8. 8 8 2 8 0m 0Q 00 ON 9.” N w h p p p p p p . i i we .N :35 n n b bbnhb-D-LFb-bbpnb- I8 I8 I ON 100 tom 10* 100 wow 10.. LNBOUSd A111 V1.8 OH 37 .mo_u_omE:c o>_um_oe o>_m ocm doom um >u__mucoe “coocoa ._coucmm _um1H mac:_;u>co .m cameo OCOO: z. m!.... ON ON? O5 00? OO OO Oh OD Om O? on ON OP v n N r h D n D D b P b h b L P F Dru-Pbbbh-hpb-p-nnbbbpb 1 Ion IOO ION lNSOUBd ..OO x3 5. woe . on x8 .3 All'l V18 0 '4 xo .8 ION IOP 38 .momu_p_E3L o>_um_oc o>_m new doom um >u__mueoe acoocoa ._Loueom _um1H mac:_cuNcO OmN XOOP Om . a Nma L—i = ON 5 Op 0 O h bI-bnubhh-bb-pbbbpbhbbh-npP-pnnbb-hbbh-pthP-pup-pub-ub-b-bhbbbtb I: ROG @130: 2. WI.._. 5 O m v n xOO moon N w J RO .: Lamco you won ION IOm IOV vOo rON fee. .LNEOHad ALI'I V180 N The egg lay investigators (o hale, 1965 a; Sh in agreenent wit deposition. During dail the physical prc “965 a) points This position pe on the substrate In a female t° Pulsate with Seconds, Gradu; Cited above, a appearance. 0n Hing],e egg. I" genera] elongate in She needle lmfidiai of contact Witt Specks' 3v ti one ls rigid er tween SUCCESS 39 V. OVIPOSITION The egg laying process in Collembola has been described by several Investigators (Davidson, 1934; Paclt, 1956; Sharma and Kevan, 1963 a,b; Hale, 1965 a; Sharma, 1967 b; waldorf, 1971 a). Present observations are in agreement with previous descriptions of the general mechanics of egg deposition. During daily counts and measurements of Q: justi_porteri cultures, the physical process of depositing eggs was frequently observed. As Hale (1965 a) points out, the animal raises its abdomen and remains immobile. This position permits the extrusion of the egg without danger of misplacement on the substrate surface. In a female of g, justi‘porterl about to oviposit, the abdomen begins to pulsate with a series of contractions occurring roughly every ten seconds. Gradually the egg is forced out. As observed by the authors cited above, a fluid is secreted with the egg, giving it a very shiny appearance. 0n the average, it takes 9: justi porteri two minutes to lay a single egg. In general appearance freshly laid eggs are Opaque white and slightly elongate in shape. The chorion is so delicate that the touch of a fine needle immediately results in destruction of the egg. After a few minutes of contact with the air, it assumes the spherical Shape typical of the Species. By the time the succeeding egg is laid, the chorion of the previous one is rigid enough to support it. The fluid secretion provides adhesion ' between successively laid eggs. VI. EGG CANNIBALISM It was noted that occasionally an egg would not firm up and remained 40 amorphous. The adult individuals in the culture would often feed on such atypical eggs. This happened more frequently in older individuals that had reached 250 days or more in age. Eggs laid by senile females were sometimes stuck together in misshaped clumps of twos and threes. The chorion would not harden and the eggs eigher disintegrated or were eaten. In addition to amorphous eggs, what appeared to be non-viable eggs were laid. They were clear yellow In color and never deve10ped. In most cases they were eaten by the adults In the culture. The ones that re- mained grew smaller and smaller with progressing dessication. Green (1964 b) suggested that oophagy was density independent and that the amount of food was not responsible for reduction in either fecundity or egg cannibalism. A similar observation by Vail (1965) produced evidence that transparent yellow eggs were noneviable, and that those eggs were eaten by the adults. In a recent paper Waldorf (1971 b) showed that egg cannibalism in Sinella curviseta Brook seemed to be centered on non-viable and very young eggs (up to 24 hours from the time of laying). When eggs were healthy, only about 1% of them were subject to cannibalistic attack. Thus it would seem that Collembola are able to recognize non-viable or atypical eggs and destroy them. VII. EGG DEVELOPMENT Collembola eggs, as those of other groups of Apterygota, undergo holoblastic cleavage. The process begins with total equatorial cleavage leading to a typical blastula. After formation of the blastula, most of the nuclei migrate to the surface of the egg, constituting the blastoderm. At this point starts the formation of a lower layer along the entire periphery (Paclt, 1956). Figures M at 7i presents the the 3-cell s chorion take third and f The fifth c furcular b1 appendage (fig. 38\ and the s eleven d; "No; tak 5Ummary 1V. TABLE 1 Age {“ / / 41 Figures 33 to 40 illustrate the embryonic development of 0: 13351_ porteri at 70°F (21°C) constant temperature and 100% RH. Figure 33 re- presents the egg when first laid, smooth and opaque white. After 14 hours the 8-cell Stage is reached (Fig. 34). By the third day sculpturing of the chorion takes place and the egg becomes elongate (fig. 35). Between the third and fourth day the chorion splits, exposing the serosa mucosa (fig. 36). The fifth day embryo clearly shows the development of the antennal and furcular buds, as well as leg buds (fig. 37). By the sixth day the furcular appendage begins regression while the other appendages become more distinct (fig. 38). On the eighth day the embryo Shows definite body segmentation and the segments of the appendages are clearly demarcated (fig. 39). After eleven days the embryo is recognizable as a species (fig. 40). Eclosion at 70°F takes place on the average by the thirteenth to fourteenth day. A summary of the embryonic deveIOpment of Q: ju§£j_porteri is given in Table IV. TABLE IV. Onychiurus justi porteri n. ssp., 70°F: Time-table for various stages in the development of the embryo. In parenthesis: number of replicates observed ‘ Average Average dimensions of egg diam. of egg (in microns) DeveIOpment Age in hours (in microns) , Width ,Depth Length of embryo l 168,9 (5) ’ 6 191,8 r (4) I 12'14 I 4-32—celi stage 23 I ’ I 64-cell stage (Table IV continued) 42 Average Average dimensions of egg diam. of egg (in microns) Development Age in hours (in microns) Width Depth Length of embryo 24'37 200,4 blastula (4) formation 72 2l5,4 : (11 , 94—100 172,4 ’ 215,h ' 221,1 ,Ldistinct, opaque (3) (3) (3) ,embryo IOU-118 r rappendage buds visible, chorion , rupturing 1 ll8-124 184,4, 230,7 244,9 (#1) - (A1) (41) 124-150 186,7 228,3 r 246,6 'head, legs, (6) I (6) (6) abdomen visible c , 1 , a 266 189,6 L 232,6 258,6 (1) , m (1) 310-365 eclosion 2" fi v—iw After 72 hours, the egg begins to elongate to conform to the growing embryo. During these first 72 hours, the spherical diameter of the egg expands with the uptake of water from the surrounding atmosphere. The size increase of the egg up to the time of eclosion is described by Milne (1960) for Q, furcifer BUrner, 9: Gisin. latus Gisin and Q: prgcampatus Marshall and Kevan (1962) note the expansion in egg diameter in Folsomia candida Willem and state that after rupturing of the chorion no 33- 34. 35. 36. 37. 38. 39. 40. 43 ngchiurus justi porteri n. SSp. - list of figure captions Freshly laid egg (70°F). Egg, fourteen hours old, eight cell stage (70°F). Egg, three days old (70°F). Egg, between three and four days of age, showing the ruptured chorion (70°F). Egg, fifth day (70°F). Egg, sixth day (70°F). Egg, eighth daY (70°F). Egg, eleventh day (70°F). 44 further in! similar data Kevan l963 | authors sta ranains sta‘ 1930; Sedla in the egg size is that the co measurement and width f increase af it bec be made in figures in undergoeS E Qation "lea: given in te 999 C°ntim that apart mucosa may in Size is Deta c the egg Ste the effect [howhuri Spars e. I ll 45 further increase in diameter occurs. Sharma and Kevan (1963 a) give similar data for lsotoma notabilis (Schaffer), and again (Sharma and Kevan 1963 b) for Folsomia similis Bagnall. Concurrent reports by other authors state that after rupturing of the chorion, the size of the egg remains stable until eclosion (Britt, 1951; Sharma, 1967 a,b: Ripper, 1930; Sedlag, 1952; Davies, 1928). in the above cited literature, the criterion used for description of egg size is the measurement of diameter. Yet many of the authors state that the collembolan egg becomes elliptical, which would seem to make measurement of length and width necessary. Waldorf (197] a) gives length and width figures for Sinella curviseta and again indicates no further size ww— *— increase after rupturing of the chorion. it becomes apparent that three measurements of collembolan eggs should be made in order to express egg size in relation to embryonic growth. The figures in Table IV indicate that the egg, spherical at first, not only undergoes elongation but also lateral compression. Hence in this investi- gation measurements of the egg after the first 72 hours of develoPment are given in terms of width, depth and length. It can also be seen that the egg continues to expand after the rupturing of the chorion; indicating that apart from growth of the embryo, uptake of water through the serosa mucosa may further determine size of the egg. Apparently this increase in size is made possible by a certain elasticity on the part of the serosa. Data on the influence of a range of temperatures on the duration of the egg stage in a given species are not as extensive as information on the effect of a single temperature regime. There are some notable ex- ceptions where comparisons are made (Davis and Harris, 1936; Britt, 1951; Choudhuri, 1961; Sharma and Kevan, 1963 a,b); but on the whole, data are Sparse. in the course of this investigation, 9: lusti porteri eggs were suMected t0 develotrnent. nutter of day TABLE V. Eh}; the Average tOi Range “I Paralle te'"Perature at 50° and E 31% In '96 not PI'Og res prQCise dat Species E431 batch as an U927) and iten day i 46 subjected to four temperatures to ascertain their effect on the rate of development. Table V lndlcates the four temperatures and the average number of days required to reach eclosion TABLE V. Onychiurus iusti porteri n. ssp.: Number of days required for the development of the eggs from the time of laying to eclosion. 50°F 60°F 70°F 80°F Average no. of days v to eclosion 62,6 20,5 13,9 ’ 11,0 Range i 55'70 1 19-21 1 13-14 9-13 Parallel to Table V, Graph 5 indicates a close relationship between temperature and the average duration in days of the egg stage. Note that at 50° and 80°F the duration range is greater than at 60° and 70°F. This would be an indication that the optimum temperature for incubation of Q, lustl porteri eggs in the laboratory lies between 60° and 70°F. V111. EGG PRODUCTION mtreévstlen in 1965 Hale stated that the knowledge of collembolan fecundity had not progressed very far beyond Lubbock's observations of 1873. The most precise data on egg production dealt with the economically important species §minthurus viridls (Llnn.). Davidson (1934) gave 60 eggs per batch as an average number for viridls. Further investigations by Holdaway (1927) and MacLagan (1932) revealed that §3 viridls lays two egg batches in a ten day interval. 47 Am>mo c_v co_umL:o ecu cu ocaumcoaeou mo Q_cmco_um_oe ._Lmucom _um1H macsmzuxco on on .ommum mm» ecu mo Cov u¢3h<¢mm<_vc_ con mmmo mo consac ommco>m ._coucam _um:~ mac:_;o>co .op ocm m mcamcu menu; .3 «a .8. me. o e a a .9. .3. .fi. .2 C _l_ _I_ . P [ [ IN 9 n—OON wxmmg we .3. .8. on 3 «a on 8. em «a «a .8 a. or .3 a. o— m o a. a 1 1 . ; r: 1 L L e." l L L .e l L ”roe .m G .. $993 10 HSHWHN BDVHBAV 52 .moc:o_:o nocmoc Logan: 30— c_ n_m_ moon ucm oon .oom um _m:t_>_vc_ coo mama mo consac ommco>m .mcoucom _um:fi mac:_;u>co .03 new m msamcu 9.33 .3 «a. 8. .3. m o a « .3. .3. .3. .2 E E _l_ .3 IL rl .~ 9 "—00“ 9.33 . «a .9.in on 3 an on on. 8 an «a tom 3 3. .3 «3. o. m o .... .u. l I . 3 l L L I. 1N F E j l L [ F .e r. ....oe .m G .. $993 10 UBSWHN EDVUSAV (Appendix becomes a and for m The the poten temperatu of 9 ovip< recorded 1 Egg produt At both tt in egg mor TABLE Vi . 0v43051 tio \ Average finale TOtal n etching' itch in 53 (Appendix X) and those for 70°F on 21 replicates (Appendix Xi). it becomes apparent that the egg production pattern for isolated females and for mass cultures show little similarity. The present data on fecundity of single females do not represent the potential life time production of a single female kept at constant temperature. At 60°F, observation throughout 35 weeks revealed a total of 9 oviposition periods per female; at 70°F, 8 oviposition periods were recorded within a time Span of 18 weeks. Tables V1 and Vii illustrate egg production and hatching success per oviposition for isolated pairs. At both temperatures there is an increase in egg production and a decrease in egg mortality as the female matures. TABLE Vi. Onychiurus iusti pgrteri n. SSP., 60°F: Egg production and percent‘hatching perBVTposition, for pairs of male and female reared in isolation. OviPosition l 1 2 3 4 5 i 5 i 7 : 8 i 9 To‘ta'f‘noifiw ‘ ' T ; i" r of eggs ; 136 156 211 217 101 ; 84 ’ 79 . 89 i 31 Mo. females 3 P 7 ' if r V V 1: " fi if laying 9 8 7 6 y t 3 2 2 g 1 Averageper fl ‘ V fi } V * 2 if 1 “ i Fifi :Y 1 female 15,1 19,5 30,1 i36,1 25,2 28,0 [39.5 44.5 1(31) 1.1.1... ' ”71‘ hatching , 102 1112 171 191 { 85 , 72 1 76 1 86 w 28 r 1 i i . i 1 I r hatching 1 75,0 171,7 181,0 t88,0 184,1 185,7 96,2 96,6 190,3 __r uttrvn. 95 Ovipusition lbtal no. of eggs No. females laying Average per female . M. Total no . hatching M Percent hatithing \ 54 TABLE VII. Onychiurus justi porteri n. ssp., 70°F: Egg production and percent hatching per oviposition,for pairs of male and female reared in isolation. Oviposition 1 2 3 i 4 i 5 6 7 8 Total no. 1 7 ii of eggs i 259 i 221 7 152 190 .i 111 /_ 67 ,i 71 , 37 No. females 7 j ' P r laying 21 13 10 . 8 S :1 3 g 2 j 1 Avefage per 1 —7 ’ V Y3 V . 7' ,i female 12.3 17.0 15.2 23.7 22.2 ,1 22,3 " 35.5 g, (37) Total no. 77 7 v - V 7 .k.. i7 hatching 183 147 68 t 114 57 1 51 \ \ 59 y: 36 1.....t'” r g ‘r '7 '“*'“"7‘ 1 ‘ ; hatching ' 70,6 1 66,5 ’ 44,7 '1 60,0 51,3 ; 76,1 i 83,1 1; 97.3 '. ‘V V "x- ‘fi‘ wwfi ‘—‘ . f w Discussion From the data presented it is obvious that several factors have in- fluence on the fecundity of 0. justi porteri. Comparison between the effects of temperature on low number and mass reared cultures shows that an increase in temperature lowers the number of eggs produced. However, the overall oviposition pattern is similar. A slightly different situation exists in the case of isolated females, although the effect of temperature again becomes clear (Graphs 11 and 12). Furthermore, egg mortality in mass and low.number reared cultures equally reflects the influence of temperature. Table Vili compares percent survival of eggs at three temperatures. As the temperature increases, egg mortality amplifies. in a small test run where 495 eggs were incubated at 50°F, the percent survival was 78,588. The optimum e99 survival temperature would then seem to lie near 60°F, where survival was 80,512. 56 new 000 um Em— .mo_meoe umum_Om_ >5 mock mmmo mo Logan: ommeo>m ._Loucom _umaw mac:_;u>co .~_ ocm .— mxmmg . up or 2. up 9 o. o. .v put 3 .9. L Jr ® - - .. [ ".62. .3 .8 9mm? W9 3. an 8 on .0“ cu «m Gui 0.. 0.. 3. «w. .or m. a tee .N. .9 J l l .3 TI 1:1. [L rLrI .8 E L L l ".68 .3 fl 6 .... mcamco away/seas 1° USBWDN SOVUBIW 60'F 57 I Y i l l I 3 ‘8 8 iii 8 .“3 2 “’ 31VW33/8993 1° HSGWDN SSVHEIW INSTAR instar. , average number of eggs laid per female at inst porteri justi 60° and 80°F, plotted aga Onychiurus 13. Graph 501 40‘ 30a 20'1 10' 58 60°F 401 MM 204 101 V T I I I I V 1' 2 4 0 010121410 50" 40‘ aoi 201 10'1 EGGS I'I'UI'TIIU I 0fl1214 OF 40‘ 30¢ 20. 101 NUMBER rI'UT'V I'I' 2400101214 I I I I. 1010202224 r 69 YVTI'UTIU'IIVYWI U' 24001012141010 d Graphs 'rIjUIrIVIIII 2 4 0 010 VIII 12 14 1e 18 INSTARS 14 to 23. Onychiurus per ® 201 n 1111 VIVVUUUII'rYTIrj 240 010121410 30" 20:1 fl 'IiiiijfiiUVIVrT 240010121410 20' 10. 240 40-l 30-1 20-I 10"l Vitivvvrfivtivvv 2400101214 30'1 20" 10‘ 111vvvvuvtTIlu1 2400101214 INSTARS iusti porteri, egg production instar of 10 females reared at 60°F. 59 .m on um cacao; mo_mEom m. 30 cmumc_ cue co_uo:ooca mmo ._L0HLOm _um:_ macamzoxco .wm ou :N mzamco m c (pm 2. o o v N Vp Np 9 o o v N o o v N bL b p . pLL - » hrh+LipL m b b -h P p E drrrr C E C 10p top ..Op '8 ION ® ® .. ® a o v N op vp Np 9 o o v N Np Op 0 o v N h p b p bib » p n b p n h rb b h p n h u p P b r. . n p n b b E C _ _ ..op C top top .6“ r. T. .o« .o« op op vp Np Op 0 0 Q N ON up 0p 1p Np Op 0 o Q N Op 0 o v N PC b+p.-hb-h Ebb uphrfbh Lb-Ppn-pp- C : top _ _ ..op E top .ON r woN ..ON F F r. f .3 C 1 3 ran Op 0 o v N NN 8 up 9 vp Np Op 0 o v N 3 Np Op 9 o v N h b p n h P h p h p u p b h p p p p p p n n n h b - Pb - p p . b er : r : cw c ION .- I L 8 Ll 3. 100 #1- h r8 fig .. ® E .8 vp Np 9 o o v N ON op Op 3 Np 9 o o v N 2. vp Np Op 0 o v N E U E p p n p n p —|._ top 10p ..Op 10“ I8 I ION L L I. #8 [ 18 I00 ® ® ... ® moo» $993 :10 USSWON TABLE V1 11 £01an number ani series. | tapering 1 increases X111). Tl e99 produi ”1 to 23 females ri creaSe f” at 70°F (1 individUa. rhythm 58‘ Graphs i4 indiyidLlal Greer 0f 53% indiVidual 55 TABLE Vlli. ngchiurus justi porteri n. ssp.: Over—all survival of eggs produced in mass and low number reared cultures. 60°F 70°F 80°F No. of eggs left to hatch 1 4671 1 1642 506 No. of eggs 1 hatched 3761 y 1268 303 Percent survival 80,51 77,22 59.88 Comparison of the first 14 weeks of egg production in mass, low number and paired cultures at 60°F reveals a dissimilarity in these three series. individual females do not exhibit an early peak and then gradual tapering off in egg production. instead the number of eggs, low at first, increases steadily with progressing age (Graph 13 and Appendices X11 and Xill). This pattern is also reflected in Tables V1 and VII where average egg production per female increases with successive ovipositions. Graphs 14 to 23 illustrate extreme examples of egg production per instar in 10 females reared at 60°F. With few exceptions the trend is a gradual in- crease from an initial low. The same pattern occurs in individual females at 70°F (Graphs 24 to 38). Comparison of egg production per instar in individual females at 60° and 70°F (Graph 13) shows a faintly discernible rhythm seemingly corresponding to that illustrated in Graphs 9 and 10. Graphs 14 to 23 and 24 to 38 also illustrate variation in fecundity between individual females. Green (1964 b) found that fecundity was reduced in crowded cultures of Folsomia candida. Oviposition was inhibited by contact between individuals attempting to lay eggs and those searching for food. The 56 .mo_meoe team—0m_ >9 moom vcm oom um u_m_ mmmo mo Longsc ommco>m ._Loucom _um3w mac:_gmxco .N_ van _— mcamco 9mm; 33339oro a a ® - ... ..I. “— oOh mxmwi ongNmonmNoNVNNNONmpopvapopoovN 31VH3:|/8993 1° UEGWHN SSVHSAV 60°F 57 ’ v”‘ (:I ~“ ~ \ \\ ------ N- ~~~~3b “ nun-DO-.." " -‘ v:"'" \\ \\ \\ ‘ s s“ \ \\ \ \ \ \ r .I I I I I I f O 3 o in o ID 0 10 ‘¢ CO 01 cu p- ,. 31VW33/8993 1° UBBWON 39V83AV tar. ll'lS , plotted against INSTAR urus justi porteri, average number of eggs laid per female at 60° and 80°F Onychi 13. Graph ‘amo .. m w m m m 0000 no ENDED! 504 40‘ 30:1 204 10' 111111 58 60°F 401 301 10" TITIIII IIIIII 2 4 0 010121410 I I 69 .04 40- soi ..i 10' EGGS 1 1 I I I I I I I I I I 0101214 ® 0F ‘04 30. m: 10" NUMBER I 240010121410 11111 I I I 10202224 n ® 501 4m 20¢ 104 jIW‘ITHMIIIIIIIIIII 2 14 10 H71 10 Graphs jjIjIIIIIIIII 240010121410 lNSTARS 14 to 23. IIII 10 Onychiurus 1_sti 20" 10‘ H1111 30" 20-1 10" IIIIIIIII‘OIIIIIII 2 4 0 0 121410 6 20‘ 10" TIIIII—II—IIIIIIII 2 4 0 010121410 0 40' 30. 20-1 101 IIIIII 9 30" 20'4 10‘ I I I I I I I I I I I I I I I 2400101214 9 j I I I I I I I I I I I I I I 2 it e 0 «112 u INSTARS porteri, egg production per instar of 10 females reared at 60°F 59 on um oocmoc mo_meom m_ mo cmumc. can co_uo:ooca mum ..Loucom _um:_ mac:_;o>co .wm op :N mnamcw m¢........ r........Np..°—..Q....... -°;....O..... : : IOp E IOp C IOp ION ION ION r00 Ion @: ® ® IOm Op O O O N N ON Op Op vp Np Op O O V N 'p .Np N I I I I I I I I I I [II I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I .2 Z I C : .2 .2 ION ION ION .8 .8 .8 ® ® ® IOm ..Qp .Np 9 D O O N 0N Op Op 7p Np 9 O O v N Op Vp Np Op 0 N I I I I I I I I I I I I I I P I I I I I I I I I I I I I I I I 'rIer I I I I I I I I I I I I IOp IOp IOp ION ION ION IOn Ion ION ® ® ® EOOI SE39! #0 BEGIION ninber of €995 ‘ the culture. Ar for cultures of acontaminant ir inhibition of eg contamination b) egg laying in ma effects would be from the culture 3“” 27 weeks 5 cases individual the possible prc E99 product four-fold over 1 agradual decllr to approximate]) myth“ in low m isolated fentaleg rims are remark. The above ‘ at least three I I’EQUlated Sean c o W that 1 the females ln itilize Spermato Pal GS Capable 0f la‘ Ired cu'tUres a I M r initial 60 number of eggs laid was found to decrease with increasing density of the culture. Another important factor was reported by Waldorf (l97l a) for cultures of Sinelia curviseta. Yeast or bacteria apparently produce a contaminant in progresively aging cultures, resulting in chemical inhibition of egg production. The influence of crowding and chemical contamination by yeasts and bacteria may thus eXplain the decrease in egg laying in mass cultures of Q: justi porteri. Certainly the crowding effects would be minimized as individuals either died or were sampled from the culture containers. Yet egg production decreased and stOpped after 27 weeks at 60°F, 16 weeks at 70°F, and i5 weeks at 80°F. In all cases individuals lived far beyond their productive periods, indicating the possible presence of unanalyzed factors in the mass cultures. Egg production in low number reared cultures was increased at least four-fold over that in mass cultures. After an initial high fecundity, a gradual decline toward the fourteenth week was succeeded by an increase to approximately the thirty-sixth week (Graphs 9 and ii). The egg laying rhythm in low number reared cultures recalls clearly a similar rhythm in isolated females. The number of eggs laid by individual females in both runs are remarkably close. I The above discussion suggests that egg production is influenced by at least three possible factors: crowding, chemical inhibition, and regulated sexual activity. waldorf (l97l a) has shown in Sinelia curviseta that the males are capable of sensing an impending moult in the females. Immediately after ecdysis, the females are most apt to utilize spermatOphores. in mass and low number reared cultures, where males capable of producing sperm are more readily available than in paired cultures, the increased chance of fertilization possibly leads to a higher initial egg production. A g“ zation an life than average n contribut due to de receptive pass and Seve Graph 9 r case in t that live TABLE Ix. .53.: 0” "h 3 cl 3’6 laid :\ i“. t ' .atch \\ in pa i Fat female 3‘ 9995. VEri we (196 3‘r % ”Sgt as 6| A greater number of females apparently were receptive to fertili- zation and subsequent egg laying at the beginning of their reproductive life than toward the end of it. Tables VI and Vii show that while the average number of eggs per female increased for nine ovipositions, the contributing number of laying females decreased; a decrease not entirely due to death of one of the partners. The combination of many males and receptive females may thus account for an initial high fecundity in the mass and low number reared cultures. Several females produced eggs over a remarkably long period of time. Graph 9 reflects such long life spans combined with high productivity. A case in point would be a female from a low number reared culture (Table IX) that lived for 366 days at 60°F. TABLE lX. Egg production of a single female in a low number reared culture for 366 days. Days on which eggs i l 213 were laid 63l72 BS l03 13911591172 186 23ii?“3 266 283L321 Number: 3f eggs ; , ‘fi‘fv Vfif ff? ’ i "1 f inbatch 18's 9 2| soi57E6h 56 h2’62rxli7J60t63 37 fim ' v ‘— v In paired cultures the maximum number of eggs laid by one 240 day old female at 60°F was 308 eggs. eggs. At 70°F a lZO day old female had laid 222 Very little data on onychiurid Collembola are available for comparison. Hale (l965 b) made estimates of fecundity for the following four species: Erotaphorura furcifer, E: procampatus, E: latus and E: tricampatus. His culture techniques were similar to the ones in the present study, using yeast as food and an incubation temperature of l5°C (approximately 60°F). The d TABLE (I) U l ['13,] u|:u.-.tv OJ "\ C l"| '1 i mean betel itaa has , of if ‘igs Dwill 62 The data he gathered are summarized below (Table X). TABLE X. Estimated fecundity for A species of Protaphorura cultured by Hale (1965) at i5°c (60°F). -- e Average no. of i No. of Estimated no. of Species eggs/batch ' layings , . eggs/life time* 3, furcifer i lh.3 2 28 E, procampatus‘ h.6 2 9 3,73ms" ISJ 2 30 fl, tricampatus 9.7 l 2 l9 ‘fiv— V I fw- fpV—V—fv—‘VVT— ‘r—‘p ‘v Y‘. vw—Y p—Vf According to Hale, “an estimate of the number of eggs laid by a female during life can be obtained by multiply- ing the average batch size by the number of laying periods." Drawing a parallel to the data collected for 9, justi porteri at 60°F (Table VI) with an average batch size of l5.l, the result is an estimate of l35,9 eggs for a total of nine ovipositions. Adding together the averages of the nine actual ovipositions results in 269 eggs, or almost half again as many eggs. These figures suggest that fecundity estimates of other investigators have been conservatively low when dealing with euedaphic species. A singular case in point is Folsomia candida. Milne (1960) indicates 9-36 eggs per batch at l2°C. Marshall and Kevan (i962) cite 13.2 eggs as their highest average at ZAOC. Green (196h a) gives a mean total of l67.5 eggs in a life time at 25°C, the highest average per batch being 6l.7 eggs. Green (l96h b) states that the mean fecundity per female in a culture of IO individuals was i2.6 eggs. Snider (In Press) has shown that f} candida can lay a maximum of l65h eggs in a life time of l93 days. In 65 replicates of single females the average number of eggs laid in life amounted to lOll eggs. The average number of batches produced per female was l2.98, with a mean of 77.9 eggs per oviposition. [nves been revie and Snider passes thr senile moc indicates size, and Uchida anc l961i a; H; Thibaud, ' Colic i95l; Gret Stated the crease ta Thereafte (afltt, i Ashiaf, l aPillied t in a Popu 9am," on Ship betw laboratOr p.32 for 63 IX. POSTEMBRYONIC DEVELOPMENT introduction investigations on the postembryonic development of Collembola have been reviewed by Christiansen (l96A), Schaller (I970) and Butcher, Snider and Snider (i971). Most authors agree that after hatching, a collembolan passes through three main life stages: juvenile, postmaturity growth, and senile moults (Christiansen, l96h). Information available in the literature indicates that variation in the number of moults to maturity, longevity, size, and anatomical changes are species dependent (Lindenmann, I950; Uchida and Hongo, I962; Milne, l962; Sharma and Kevan, l963 a,b; Green, l964 a; Hale, l965 c, l966, I968; Sharma, I967 a; Ashraf, I969; and Thibaud, l969). Collembola continue to moult throughout their life history (Britt, l951; Green, l96h a). In previous investigations, it has consistently been stated that as the individuals pass from Juvenile to maturity, a size in- crease takes place with each moult, until attainment of maximum size. Thereafter there is no change in over-all body size with succeeding moults (Britt, i95l; Green, l96h a; Sharma and Kevan, l963 a; Hale, l965 c; Ashraf, I969). Healy (l967) found instar measurements too variable to be applied to field animals and used weight classes to determine age structure in a population. Recently, Petersen (I970 In Press) has based an investi- gation on secondary production of Protaphorura furcifer on the relation- ship between age and total body length. His work was conducted with laboratory reared specimens and field released individuals tagged with P-32 for recapture. The cultures data on postembr' 70° and 80°F, an: singles), providt The fol lowit in each exper imei iiBLE XI. Numbe in ea iulture category hass hass hass Lo" Mb" rearei LW number “are. WWW Teare. ingle mile and . Single "idle and ‘ Single male and . no femtiles Tm females Tm males It” males :{Wle females 64 Methods The cultures of Q: Justi porteri previously described also furnished data on postembryonic devel0pment.' Again, three temperature regimes, 60°, 70° and 80°F, and varied population densities (mass, low number, pairs and singles), provided a basis for comparison of the results. The following Table (XI) presents the number of individuals observed in each experimental run. TABLE XI. Number of individuals observed at three constant temperatures in each eXperimental run. Number of Length of rearing Culture category Temp. individuals time from hatching (in days) Mass 60°F #40 3lS Mass 70°F 663 238 Mass 80°F 3I5 lho Low number reared 60°F 27 336 Low number reared 70°F 32 280 Low number reared 80°F 30 196 Single male and female 60°F 28 267 Single male and female 70°F 56 l5h Single male and female 80°F lh '5“ Two females 60°F 30 l50 Two females 70°F 16 lsh Two males 60°F I8 Ihh Two males 70°F i8 l52 Single females 60°F #2 IAS Single females 70°F 20 ISA Single females 80°F 23 1&7 Single males 60°F 26 ISO Single males 70°F l3 Isle Single males 80°F 30 ISO TEE] total The data derived from these observation series provided information on: instar duration; instar size, head width and length, over-all body length; size structure of males and females; mortality; longevity; influ- ence of density and sex on growth; and senility. Al‘ individt and eacl possibli selectei run, al il‘lt This tre preparai cooled, and 5m. It measure expands Pitserv diSSeCt PEr m; i to the Pe CedUre muntec Prepare 65 All observations were made daily over a two year period. Each individual series was removed from its respective incubation chamber, and each replicate examined under a dissecting microscope as quickly as possible. In mass cultures periodic samples of each instar were randomly selected and killed, mounted and measured. At the termination of each run, all surviving specimens were killed and preserved. Individuals were killed by pouring hot 95% ethyl alcohol over them. This treatment prevented contraction of the animals, thus providing good preparation of specimens that were to be measured. Once the alcohol had cooled, the specimens were transferred to vials with fresh 95% alcohol and stored until measurement and subsequent mounting. it was felt that this method of preservation gave a more natural size measurement. Placing the animals on slides and pressing on a coverslip expands sutures and head capsule beyond their normal size. The alcohol preserved individuals were therefore measured before mounting under a dissecting microscOpe at l6x, using an ocular micrometer with lOO divisions per millimeter. The data thus obtained were converted to microns carried to the second decimal place. Permanent slide mounts were made using CMC-IO*. The mounting pro- cedure was similar to that reported by Snider (l967). All specimens were mounted ventral side up, allowing rapid sex determination. As the slide preparation “cured,” the CMC—lO penetrated the specimens and all external anatomical characters were easily observed. fiVV—rfi fiV—Y—I—f—V— */ Turtox; General Biological, Inc. Chicago, Ill. All < individua and each I possible. selected . run, all : lndi' This tree preparati- cooled, t and store it w measureme ¢Xpands s Preserveg dissecttr PEr mi ll' t0 the 5‘ Per: CedUre w‘ mounted . Preparat anatomic s/ Tufto, 65 All observations were made daily over a two year period. Each individual series was removed from its respective incubation chamber, and each replicate examined under a dissecting microscope as quickly as possible. in mass cultures periodic samples of each instar were randomly selected and killed, mounted and measured. At the termination of each run, all surviving specimens were killed and preserved. individuals were killed by pouring hot 95% ethyl alcohol over them. This treatment prevented contraction of the animals, thus providing good preparation of specimens that were to be measured. Once the alcohol had cooled, the specimens were transferred to vials with fresh 95% alcohol and stored until measurement and subsequent mounting. It was felt that this method of preservation gave a more natural size measurement. Placing the animals on slides and pressing on a coverslip expands sutures and head capsule beyond their normal size. The alcohol preserved individuals were therefore measured before mounting under a dissecting microscOpe at l6x, using an ocular micrometer with lOO divisions per millimeter. The data thus obtained were converted to microns carried to the second decimal place. Permanent slide mounts were made using CMC-l0*. The mounting pro- cedure was similar to that reported by Snider (l967). All specimens were mounted ventral side up, allowing rapid sex determination. As the slide preparation “cured,“ the CMCle penetrated the specimens and all external anatomical characters were easily observed. v—vvw—pfi _‘, v j */ Turtox; General Biological, Inc. Chicago, Ill. 66 X. [NSTAR DURATION Mass Cultures v Vf—Y‘w The duration of the stages of Q: justi porteri is clearly influenced by temperature (Table XII). While animals reared at 700 and 80°F remain in each instar for a somewhat similar length of time, individuals at 60°F show a greatly extended duration of the stages. At the same time the range of variability in duration increases with rising temperature (Append- ices XlV, XV and XVi). Graph 39 presents the duration of each instar in mass culture at three temperatures. While the 70° and 80°F cultures follow a gradual fluctuation in instar duration over long periods of time, the animals at 60°F begin to exhibit a definite rhythm after the 25th instar. It should be pointed out that daily samples taken from the time period shown on the graph reduced the number of individuals in each culture. Low Number Cultures fw—va-fi—v—w T ffiV— Cultures containing five or less individuals (Table XIII) again show similar instar durations at 700 and 80°F. Here, as in the mass reared series, the 60°F populations exhibit longer instar durations. The range of variation between individual instars is less in these cultures (Append- ices XVII, SVIIl and XIX). Graph 40 illustrates clearly that the 700 and 80°F populations depict the same gradual fluctuation of instar duration shown previously in Graph 39. The 60°F cultures, from the sixth to the thirty-eighth instar, definitely show a time rhythm of alternating long and short periods. TABLE XII. 67 TABLE XII. Summary of instar duration averages at 60°, 70° and 80°F, for mass reared cultures of Onychiurus justi porteri. Average in days instar 60°F 70°F 80°F l 3.27 5.75 “.72 2 7.9a 6,00 6,66 3 7.61 5.17 [ 4.55 h 7.55 5.68 , 5.33 5 8.38 7.20 i 5.33 6 9,00 6,58 . 5,22 7 '0938 79.0 i 5983 8 11,22 6.75 9,9h 9 11.05 7.32 5.33 10 11,16 7,21 5,00 11 12,00 6,10 5,66 12 10.76 7.37 5.83 13 10.77 6.9T ' 5.61 10 11,76 7.16 i 5.94 15 11,00 6.95 , 6,96 '6 l0.6h 6.59 5.93 17 11,17 6,8h 1 6,21 18 9.73 6.72 i 6.72 19 9.66 7.00 l 6.90 20 10,66 7.37 l 8,30 21 10,13 7.ho l 8,11 22 9:57 697] i 8200 23 11,66 6,81 . 9,60 2h 9,46 7,00 7.50 25 10,50 6,62 6,00 26 10,90 6.75 27 12,60 6,00 28 9,62 6,02 29 11,28 5.71 30 8,66 6.15 31 12,50 7,16 32 3.83 7.80 33 11,00 6,00 , 34 9.66 7.50 35 (16.00) 7.25 E 36 7.00 37 8.00 38 7,00 39 6.50 no 5.50 ’nitEXIII. 51 c1 2 68 TABLE XIII. Summary of instar duration averages at 60°, 70° and 80°F, for cultures containing five or less individuals of O_ychiurus justi porteri. Average in days Instar 60°F 70°F 80°F 1 8.37 6,00 2,70 2 8,12 5.75 6.30 3 8.25 .537 4.90 6 8 .37 5.75 6.00 5 8, 62 6,87 6,00 6 10,25 7.75 5.80 7 8.00 6.12 5.55 8 12,12 8,12 6,00 9 8.62 8.37 5.75 10 12 ,25 7,62 6,50 11 9, 00 7,28 6,62 12 11.75 7.85 6.37 13 8 .87 7.28 5.85 16 11,00 7,28 7,85 15 10,12 6,62 6,85 16 10,12 7,28 7,16 17 10,75 7,28 8,00 18 8,16 6.57 8,00 19 9.57 9.00 6.66 20 7, 28 6,85 6,66 21 10 .57 7.57 6.80 22 9, 00 9,00 6,20 23 10.57 7.71 9.00 26 7, 62 7,16 6,00 25 11,66 6,71 6,80 26 8 .33 6.57 9.66 27 12, 66 7,60 8,50 28 8, oo 6.50 29 11.83 5.33 30 8.33 7.33 31 12,00 7,00 32 8,33 6,66 33 13.00 7,00 36 8, 83 6,00 35 12. 66 7.33 36 8.83 7.00 37 11.33 6 .50 38 8, 66 8, oo ,,/ 69 'IIIIIIIIIIIIIIIIMIIIIIIIIIII '- O N G P 18 17 9 15 INSTARS 38 39 4O 28293031323334353637 26 27 23 24 25 Onychiurus justi porteri, at 60°, 70°and 80°F. 22 (in days) of mass reared individuals instar duration Graph 39. 70 Cujtures offPairs Cultures containing one male and one female eventually established a clearer picture of instar duration. Table XIV demonstrates that at 70°F the animals behaved in a basic pattern similar to the mass and low number reared cultures. The 80°F cultures did not exhibit any particular rhythm, and could be best described as erratic. Animals kept at 60°F, after the sixth instar, displayed the long-short rhythm of the low number reared series (Graph 61). The range of variation in instar duration was greater than in the two previous experiments (Appendices XX, XXI and XXII). TABLE XIV. Average instar duration, in days, for pairs of male and female of Onychiurus iusti porteri. Pairs Instar 60°F 70°F 80°F 1 9.16 5.53 6.00 2 9.57 5.66 6.00 3 11,16 5,89 6,16 6 10,85 6,16 5.57 5 10.07 5.21 9.57 6 11.92 6.67 13.57 7 10,78 7,00 12,66 8 12,62 7,21 16,00 9 10,69 6,66 9,83 10 11.33 6,69 7,60 11 10,70 6,38 13,66 12 9.90 7.05 16.66 13 11,60 1 7,22 12,50 16 10,60 7,17 7,00 15 12.60 7.35 (9.00) 16 11,11 7,91 (9.00) 17 12,00 6,18 18 11,00 1 8,28 19 13,00 1 5,60 20 9,00 T 7,00 21 12,50 22 9.50 23 13.50 26 12,00 25 (8.00) 26 (10,00) an 71 1 if III-IIIIiIIIIII-I-Ij: a: a fl # IIIEIIIIIIIIIII} fl III-lIl-llli-llllnllli INSTARS 23 24 25 26 27 32333435363738 28 29 3O 31 INSTARS low number reared (in days) of 1011 tar durat 1ns 700 and 80°F. porter1 Onychiurus individuals at 60°, Graph 60. 72 24 23 14 [[[/////////////////////[//////////////////////////////////// F [[1l/l/l/l//////////////////////////////////////////////////////////////]l_ N — lll/l/l/l/l/l/l/l////////////////////////////////////////////////////T _ V/l/l/l/l/l/l/l/l////////////////////////////////////////[////////////////// O W///////////////////////////////////////////////////////// I\ H!!!/////////////////////////////////////////////////////////// O MHZ/[Ill////////////////////////////////// n INSTARS instar duration (in days) of pairs of males and 70° and 80°F. porteri t iys Onychiurus Graph 61. females reared atT6OU, It is rhythm in i the tempera of the stag series of e influence c Cultu1 and 80°F a1 for these b0th sexes pairs (Tab XXIII, XXI irate the te“hereto. f‘uCtuatic fame is To e 'hY‘hmica pairs of the Sim; i flipper“,h 73 It is essential to comment here on what appears to be a clearcut rhythm in instar duration. Recalling the data presented so far, both the temperature and the population density seem to influence the duration of the stages. Another important factor is the sex ratio. The following series of experiments were conducted to determine what role, if any, the influence of members of the Opposite sex played in instar duration. Instar Duration ofSingle Males and Females Cultures of single males and single females were set up at 60°, 70° and 80°F and checked daily. Table XV summarizes the instar duration data for these individuals at three temperatures. At all temperatures and in both sexes the length of the stages increased over the figures given for pairs (Table XIV). The range of variation was also very wide (Appendices XXIII, XXIV, XXV, XXVI, XXVIi, and XXVIII. Graphs 62, 63 and 66 illus- trate the fluctuation in the stages of single males and females at three temperatures. No particular rhythm can be detected other than a gradual fluctuation over long periods of time. Duration of the instars in the female is in most cases longer than in the male. instar Duration in Pairs of Males and Pairs of Females To eliminate the possibility that companionship may produce a rhythmical variation in the length of the stages, pairs of males and pairs of females were observed at 60° and 70°F. Table XVI exemplifies the similarity in the duration of the instars in male and female pairs QAppendnees xx1x, xxx, xxx1 and xxx11). Clearly there appears no distinct periodicity (Graphs 65 and 66). TABLE XV . 1\1 f1 Instar \OCXDVO‘mr-wN—a TABLE XV. 76 Average instar durations, in days, for isolated males and females of Onychiurus justi porteri. Single females Single males Instar 60°F 70°F 80°F 60°F 70°F 80°F 1 9.30 .5.70 6.67 9.11 5.50 1 6.30 2 10,06 ’5.90 6,00 10.55 5.70 6,13 3 11.57 l5.60 ‘ 8,00 ' 11,11 '5,30 6,63 6 11,71 ’6,30 1 8,86 10,00 5,50 6, 80 5 10,56 16.95 8,78 ' 10,38 ,6,00 8,13 6 10,56 .6,85 9,63 10,69 '6,70 '10, 26 7 11,36 17,90 [10,72 :1 10,61 {6,60 10,96 8 10,39 6,80 10.59 ‘1 10,65 6,60 {11,33 9 12,05 17,31 112,22 * 11,68 6,60 [11,61 10 10,07 ’6,78 11,21 10,56 6,36 10,26 11 10,82 :7,00 9, 82 . 11,96 5.72 116,10 12 11,33 17,92 i11, 25 '1 9,62 7,00 11,23 13 9,20 *7,80 . 12 66 ' 13,07 6,96 12,21 16 10,83 16,85 i 9, 77 1 8,91 7,00 10,80 15 1 11,16 t6,83 16, 62 ' 12,33 ’6,80 110,37 16 8,25 [6,60 . 8,60 (8,00) 6,77 15,12 17 16,00 9, 00 1 6,88 8,50 18 ’6,80 6, 66 6,35 1 6,00 19 8.25 7. 00 , 7.18 ,(5,oo) 20 i 6.50 i(6, oo) . 6,06 ;(8,00) 21 6.75 l 7.26 22 ’7.75 T 6,60 23 ’6.66 7.73 26 1 7,00 7,60 25 * 7.23 26 i 6957 27 , ; 7,60 l 28 . 1 7,00 1 12‘ 75 12 . 60°F r i— F 12345678910111213141516 1 1 1 a 11 iii 1 '1‘72' 3 '4l'5"6 7"8"9‘Ho"11 12‘H3‘H4'H5‘36'H7'38'19'26'21‘22'23'26 26h 9d 6. m > a 344 zl .1 1 2 3 4' '5' a 7 8 9 1o 11 12 13 14 15 16 17' 38' 69 INSTARS ‘ i— Graphs 62 to 66. Onychiurus igsti porteri, instar duration of single males and single females reared at 60°, 70° and 80°F. l Ann -7 up m3L:_Loch .w: zamco .uoom ucmooo um umcmoc mo_meom p0 mc_ma e0 co_umL:u Lmumc_._coucoa _um _um:H macsmgoxco .m: cameo .uoop ucmoow um uocmoc mo_mE Io mc_ma p0 co_umL:p Lmumc_ ._LouHmm OKs—b:- NNpNONapOphpOpmpvpnprppOpaoNOOVNNp SAVO alas-... I0 agon— Np 9 Oman"! vaNnNNNpNONGpOpppOpnpvpnprppOpoOhOmvNNp 76 SAVO Op no.0: Io 2.... coo Np 77 TABLE XVI. Average instar durations, in days, for pairs of males (2) and pairs of females (2), of Onychiurus justi porter1. Two males Two females Instar 60°F 70°F 60°F 1 70°F 1 9.22 5.55 3.80 l 5.75 2 1 10,88 , 5,66 10,13 1 5.50 3 9.55 1 5.66 10.53 1 7.37 6 1 10,22 6,88 12,00 6,12 5 1 11.25 5.88 10,80 1 6,62 6 11.75 6.66 10.86 L 7.75 7 11.50 6.77 11.60 L 7.25 8 9,00 7,00 12,00 ', 6,37 9 11.37 7.33 11.07 1 8.00 10 11.57 6,66 10,66 : 6,87 11 9.33 6.66 11.00 1 3.37 12 11,80 8,11 11,27 1 8,50 13 1 12,80 6,66 12,00 1 8,00 16 1 (10,00) * 6.77 10,87 1 7,00 15 (9.50) 7.25 10.20 i 7.30 16 1 (8,00) 6,62 (11,00) 1 6,60 17 1 7,25 : 7,00 18 7.25 1 7.33 19 1 6,66 1 7,00 20 7.83 i 7.33 21 1 6,83 ’ 8,00 22 7,60 1 7,00 23 7.00 26 6,66 25 7,00 1 26 7,00 27 6,50 Discussion The data dealing with instar duration at constant temperatures have depicted three possible factors controlling the length of the stages. The obvious one is temperature, followed by population density and sexual reSponses. In large mass cultures no particular rhythm is apparent after the first six instars, not until the density of the populations has decreased. As previously mentioned, Green (1966 b) has 78 related crowding to fecundity. in addition, Waldorf (1971 a) found that males were responsive to females by their instinctive ability to sense when a female was about to moult. Mayer (1957) discovered that females of Orchesella villosa (Geoffroy) had intervmoult periods of uniform length, but that the males exhibited alternating long and short periods. This rhythm was said to be associated with spermatophore deposition. In low number reared and paired cultures of Q: justi porteri, the rhythm of long and short instar duration was most apparent at 60°F. Subsequent observations demonstrated that neither single nor paired males and females produce such a rhythm. In none of the 70° and 80°F cultures were definitely alternating long and short periods observed. These data lead to the belief that the Optimum temperature for Q: igstj_ porteri lies near 60°F. And that the presence of males in whatever ratio may induce in the females, as well as in themselves, long and short instar durations correlated with reproduction. Upon re-examination of Graphs 9 to 13, it appears that egg laying occurs at the same time as a long period in instar duration. According to Hale (1965 c) there is a gradual increase in the duration of successive instars from the first instar to maturity. He presents data for Protaphorura latus, P: procampatus, P: tricampatus and P: furcifer, all of which exhibited that trend. Choudhuri (1961) presents similar data for g: fimatus, P: parthenogeneticus and P, imperfectus. in the present investigation, 9: [usti porteri does not gradually increase the duration of its stages from the first instar on. On the contrary, the first instar is longer than the second. In the case of mass cultured individuals, duration averages decrease until the fourth instar and then gradually increase to the eighth instar. This same trend was observed in the low number and paired cultures. For 9: bhattii Yosli, Ashraf (1969) reported 79 a longer duration of the first instar as compared to the following instars. in two other cases this pattern was noted; for Hypogastrura manubrialls by Vail (1965) and for lsotoma notabilis by Sharma and wafi Kevan (1963 a). Xi. GROWTH .w—YVVII‘I—x-p Most of the literature discussing collembolan growth is concerned with the first four to six instars (Ashraf, 1969; Milne, 1960; Davis and Harris, 1936; Britt, 1951; Vail, 1965; Sharma, 1967 a; Marshall and Kevan, 1962; Sharma and Kevan, l963 a,b; Maclagan, 1932; Ripper, 1930; Uchida and Chiba, 1958; Agrell, 1968; Strebel, 1932; James, 1933; South, 1961; Falken- han, 1932; Handschln, 1926; Thibaud, 1968 a,b, 1969; Hale 1965 c; Pedigo, 1967). Only a few exceptions are to be found (Hale, 1965 c; Green, 1966 a; Uchida and Hongo, 1962). In a majority of the above cited investi- gations, growth was not observed beyond the adult instar. By definition, that would be the instar where egg laying and spermatophore deposition begin. Petersen (1970, in Press) did not use instar designation in the pre- sentation of his data on the growth of Protaphorura furcifer. He considered the instars to be too variable and instead used total body length in his measurements. His study was concluded after approximately 100 days at 15°C (60°C). Methods All measurements of body length, head width and head length were made with an ocular micrometer, using specimens taken from mass cultures. Later, 80 slide preparations of the same Specimens were examined to determine sex and morphological characteristics. were established to classify the first six instars; thereafter only measure- ments and sample data were used to recognize a given instar. were taken daily, it was relatively easy to remove freshly moulted specimens from the cultures. Headfl Lengthvandvllidth of the first Six, ins tars Both anatomical and size criteria Since samples Table XVII gives a summary of data for the first six instars in 9: justi porteri until attainment of maximum size in the head capsule. parison of standard deviation figures indicates that head width measurements are more reliable than head length. TABLE XVli. Com- Mean head length and head width, in microns, for the first six instars of mass reared individuals of Onychiurus justi porteri. (Standard deviation in parenthesis below,VLogloN above each figure). INSTAR 1 2 3 6 5 6 1 2,00 2,23 1 2,32 l 2,60 1 2,63 1 2,69 60°F 1 101,96 , 171,28 1 213,55 1 252,83 1 272,53 1 316,59 1 (8.96) 1 (17.62) 1 (21.90) l (12.07) (19.23) » (19.27) 2,06 l 2,21 2,31 I 2,39 ' 2,66 1 2,68 70°F 1 116,15 162,72 1 206,22 1 266,92 1 279,56 . 306,89 (9.03) (11.95) (16.61) » (16.65) (19.93) (19.33) 2,07 : 2,20 1 2,26 2,36 1 2,61 1 2,66 80°F 119.95 160,67 1 186,01 1 230,66 1 258,68 1 278,52 (16.71) 1 (13.68) (18.68) : (17.95) 1 (16.86) 1 (18.07) F i 2,12 1 2,28 2,36 ’ 2,66 ,5 2,69 l 2,56 60°F 132,16 192,81 230,28 i 280,07 1 311,33 ,1 367,10 (2.661 1 (17.251 (15.17) 1 (13.611 1118.651 1112.901 2,16 2,26 2.35 2,62 7 ' 2,68 1 2:52 7 70°F 160,60 175,86 225,72 267,71 1 306,29 1 338,56 (5.61) (9.86) C (10.30) (11.65) (13.96) ' (11.28) 77 2,15 2,23 ‘ 2,32 f 2,617 P 72,65w 17 2,69 80°F 166,10 173,60 210,30 261,57 1 283,08 311,07 (7.26) (11.56) (9.80) (12.691 (16.65) (16.03) fit“ ‘ri’ iVjprfip V'v‘r 8| The range of individual variation increases with temperature (Appendices XXXIII, XXXIV, and XXXV). Hale (i965 c), Ashraf (l969) and Thibaud (I969) have presented their data on the first six instars in logarithmic form. Agrell (l948) proved that three species studied by him conformed to Dyar's Rule (l890). Graphs 47 and 48 illustrate the linear growth of the first six instars of Q: justi porteri. The curves obtained are similar to those given by Thibaud (l969) for Iyphjogastrura balazugl Delamare-Deboutteville. It would fivv appear that Dyar's Rule is valid for the first six instars of Q: iusti porteri. Hale (l965 c) states for four species of Protaphorura that egg laying did not begin until they had reached maximum size (based on head capsule measurements). Ashraf (l969) indicates that ngchiurus bhattii passes through four instars before reaching sexual maturity and maximum head width in the fifth. In the present study the concept of maximum size coinciding with sexual maturity does not hold true. Graphs 6, 7, and 8 show that egg production begins in the fifth instar at 60°F and in the fourth instar at 700 and 80°F, at a time when growth is far from complete. Growth: prerfall tength ——Vv‘—V The size of each instar in total body length was obtained by adding the figures for head length and body length for each individual. Graphs #9. 50 and Si illustrate over-all length at three temperatures for cultures of mixed sex, and includes the ranges at each instar. It should be noted that with progressing age size variation increases with each instar (Appendices XXXVI, XXXVII and XXXVIII). Petersen (I970 In Press) described a significant difference in growth 82 .uoom can con .oom um nocmoc mcmumc_ .uoom ocm oom .oow um uocmoc mcmumc_ x_m umc_w 0;» Lo» zuv_3 two; on» mo x_m umc_$ mg» co» zumco_ now; one mo 0— . 2 mo; ._Loucom mumam mac:_;uxco m: cameo zoFmOJ ._Loueom mumam mac:_;u>co .m: cameo «<52. «<52. 6 n a n a _ o n a n u _ Law 1 x LEN 1 O O m m o 0 .Sa N 12a N u N N . _. = .éea w .oqa w o p p. M o m X . m 6 ton « m. . . on a .m. a. M .\ M .uvvvv 1o!" m .HHHHHW .ota w \m ”.1 $.86\u u... x. \ was \ foo . x 10nd #91 . on.“ 00 O “00% X\ r 8.“ .- CO.“ 83 .mooo um menu—3o mmmE c_ umcmoc m_m:u_>_vc_ mo Lmumc_ Log Amcoco_E c_v camco_ __mco>o ._coucoa _umJH mac:_;u>co .m: zamcw mm a -- . -1\ H... LT Lr \ [F ...I 1 LI 0 ...l Lr L1 L1 tog“ Ll mooo .1 -1 . Ll rOOQN Lr- lr. 81+ .moom um menu—nu mmme c_ uocmoc m_m:n_>_vc_ wo cmumc_ cog Amcocu_s c_v cameo. ..mLm>o ..coucom _um1H mac:_;oxco .om cameo 92.52. av 3.3.0.,”ch «.mpopn.mr~.om vm «a cu m. 2 1 Q o. m o v N .oov . . m .000 3 a . w 0. room .I 3 t N w . .009 H 6 . m. 3 .002 m - w Jfi 1m fl 0 1 l1 1 1003 1 11 11 41 .1 41 m I ._1\o o 1 I 1 6 a . / a 11 \ a fi fi fi. -fi 1 \ .82 H O 1.1 1 1 1 fl 0 IHIele e e/ of 0 fig. 11 fl 4. o .. ._. .r /\ J1 \ o o/\/ o .\ 1 11 ole e e \ 100m— ;1 0 1r 0\ / 0'0 1.. 0 1‘1 0’ \ 1 1 LI 0 ... \ 0 ll L1 1,. 1 i k. I. ..OOON 1r 1 L. I .. Lr 11 IOONN “CON 1%: If gr 1:.- T L1 1 roovm 9 a... 85 .uoom um oc:u_:u mmme c. uocmoc (5110131161 H19N3‘I Hwy/(o m_m:v_>_vcm co cmumc_ con Amcocu_e cmv guano. __mco>o ..coucom _umlw m1c3_;uxco .pm gamco .3352. b n n n p h n h n n n b h n h on“ - Vb" - Np“ - an“ m— 0— N— OP w 0 V N H .... .000 \H .08 . . .000— - o .oon_ a F . a a . -fi - H . HI/ .— \ .oo: 0 1 moom S .000— Icem— .ooom .OONN .oovu 86 rate between males and females of Protaphorura furcifer. When the data for Q, justi porteri were separated according to sex, the same divergence in the growth patterns was found. Graphs 52. 53 and 56 indicate male and female growth. Compared with the graphs for combined sexes, separation of the sexes in the analysis of the data led to narrower size ranges at each instar (Appendices XXXIX, XL, and XLI). vT—vav—V In the literature there is frequent reference to the attainment of maximum size together with sexual maturity (Hale l965 c; Ashraf, I969). From the data gathered in this investigation, maximum size apparently is not reached until a later instar, irregardless of head capsule size. Previous investigators have based their statements on head capsule measurements and a limited observation of the animal's life history. Petersen (I970 In Press) demonstrated for E: furcifer a growth pattern similar to the one in Q: justi porteri. He states that it took lOO days to reach maximum body size at l5°C (60°F), a time period corresponding to the l2th instar of Q, justi porteri at 60°F, and in particular relating to the females. At the same time, the males undergo a decrease in average size (Graph 52). Maximum size in Q: lusti porteri is reached in the l2th to ihth instar. Thereafter there is a gradual decrease in size of both male and female individuals at all temperatures. The females develop more rapidly than the males and attain a larger size. Graphs 52 and 53 indicate that the males live longer than the females. At 80°F the life history ends in the 26th instar, probably due to the lethal influence of the temperature. One aspect of growth not observed in other studies is retrograde 87 uoom um menu—no mmme c_ nocmoc mm_meom new mo_me mo cmumc_ cog Amcoco_e c_v sumac— fitum1.pn.o.«.o.«_e.~.fia.p«. __mco>o ._Loukmm _HWMH mac:_;o>co mmo ._Loucom _um:fi mac:_;o>co N-VDObQLth P fiLfifibme-O-nPw-N - MN.¢.N.NNPWN.Q._. or 3 9.0.. m D V N - wmo ._Loucom _um:h mac:_£wxco .qm camcu 225:. o... o o e a b p r b - p - . ow. . a." . um . an m. . cm x. . mp n n - (SUOJOIW) H.19N3'l TWHSAO 3‘2"! /(\ 3329311.... meow .oooN 9O devel0pment. Data for 9: lg§£i_porteri at all three temperatures prove that after the attainment of maximum size there is a steady decline in body length with successive instars. This phenomenon is most apparent at 700 and 80°F. At 60°F (Graph 52) size decrease in the female does not occur until after the 20th instar. It is known that clothes moths and carpet beetles will continue to moult under starvation conditions (Frost, l962). However, in this study, food was provided throughout the life of the animals. There is a possible correlation between egg production and retrograde development in 9: justi porteri. Graphs 9, II and 12 for egg production show the peak periods in egg laying. As fecundity decreases, the average body length of the animals decreases as well (Graphs 69, 50 and 51). There appears to be a relationship between sexual activity, metabolism and age. The information presented leads to the conclusion that the use of size categories for the assessment of age groups in field populations of Col- lemboia could result in erroneous data. The method described by Healey (1967) for estimating age structure in field papulations could lead to the inclusion of young adults and senile adults in the same age category. XII. DEVELOPMENT OF INSTAR CHAETOTAXY 09:salfi§etae of the Fifth Abdominal Segment The only work considering the development of collembolan chaetotaxy has been furnished by Hale (l965 c). Chaetotaxy and arrangement of the Pseudocelli on the fifth abdominal segment had been used by Gisin (l952) in dividing up the Onychiurus armatus group. Gisin (l952) developed a 9i labelling method for key setae of the fifth abdominal segment; his not- ation is followed in this study. Figures hi to SI illustrate the successive changes in setal pattern for each instar Up to the seventh. Solid black illustrated setae are those found on the instar indicated. Open illustrated setae are those lying under the exoskeleton in animals about to moult. Dotted setae are those that appear infrequently in random individuals. Figures hi to SI indicate the addition of setae up to the 5th instar. From that instar on, the normal pattern and the number remain constant. Some variation occurs as to number and position; figures 65, #9 and SI show possible setal additions. Salmon (i959) points out that the setal pattern of Onychiuridae may vary in number from one side of the body to the other. A similar situation exists in Q, justi porteri. Figures 52 and 53 indicate the occurence of an unequal number of setae on the two sides of the same segment. Likewise the number of pseudocelli may be unequal. Figure 56 shows the three pseudocelli typical of Q, iusti. This arrangement appeared in only two specimens of Q, justi porteri in over 2000 examined during the investigation. Hale (l965 c) noted that E, furcifer had the fifth abdominal pseudocelli arranged at an angle to the line joining M and M' and not parallel as in the I'armatus” group. The same arrangement was found in Q: justi porteri (Fig. 5|). Hale also indicates that seta s is short in the first instar and becomes increasingly longer with each moult. The first instar of Q, iusti porteri exhibits a very long seta s which is then reduced in the second instar (Figs. Al, #2 and A3). Dorsal Setae of the First Thoracic Segment In a taxonomic study evaluating anatomical characteristics, Hale (l968) 92 Onychiurus justi porteri n. ssp. - list of figure captions Fifth abdominal segment dorsal setal pattern* 4i. First instar 42. First instar about to moult 43. Second instar 44. Second instar about to moult 45. Third instar 46. Third instar about to moult 47. Fourth instar 48. Fourth instar about to moult 49. Fifth instar 50. Sixth instar 5]. Seventh instar 52. Atypical fifth abdominal segment setal pattern showing unequal number of setae on the same individual. 53. Atypical third abdominal segment setal pattern. 54. Seventh instar individual illustrating the pseudocellar pattern typical of the species. */ Black setae - typical of the instar indicated; open setae - setal pattern of next instar; dotted setae - setae that can be present or absent. 93 94 described the dorsal setae of the first thoracic segment as being too variable for species determination. During this investigation it was thought that the setal pattern of the first thoracic segment might be instar specific, at least to the seventh instar. Figures 55 to 69 illustrate the thoracic setae of the first seven instars of Q: justi_ porteri. The illustrations indicate that variation from instar to instar and within instars is too great to be of significance. However, the patterns for instars one and two remain characteristic and are used in helping to determine instar number on a morphological basis. Figure 67 illustrates the variations of setae from one side of the body to the other. Chaetotaxy of the Male and Female Genital Plates ' The plates surrounding the genital openings do not develop until the fourth instar, in either of the sexes. Figures 70 to 75 illustrate the development of the setae on the female genital plate from the fourth to the seventh instar. Figures 76 to 8i illustrate the development of the male genital plate setae. Figure 76 shows the male third instar juvenile. A pore is located where, in the next instar, the genital plate will be developed. Figure 77 shows a third instar juvenile about to moult; the fourth instar structures can be seen lying underneath. The number of setae on the female genital plate increases from the fourth to the seventh instar. Table XVIII indicates the average number of setae per instar, from the fourth to the seventh, and their ranges, demonstrating a certain degree of overlapping between instars; and proving that the number of setae on the genital plates can only be used in conjunction with other morphological criteria in the determination of Onychiurus justi porteri n. ssp. - list of figure captions First dorsal thoracic segment setae: First instar Third instar Fourth instar Fifth instar Atypical fifth instar showing unequal number of setae from one side of the body to the other. 55. 57. - 6l. 62. - 63. 64. - 66. 67. 68., 69. Sixth instar 2 / u xxfl u a ”\W ....\\ / «\ _--.\1-11/.o. 1 ..l/ // \\o b {\o / 1. o /. mp 96 (9“ S /0//( 81 4x) \\ 5 5 // 5 5 / 5 0 a. 70/1 2 /. / Onychiurus justi porteri n. ssp. - list of figure captions Female genital plate setal pattern* 70. Fourth instar 71. Fourth instar about to moult 72. Fifth instar 73. Sixth instar 74. Sixth instar about to moult 75. Seventh instar Male genital plate setal pattern* 76. Third instar (oil) 77. Third instar about to moult (oil) 78. Fourth instar (oil) 79. Fifth instar 80. Fifth instar about to moult 8i. Sixth instar */ Black setae represent setal patterns typical of the instar indicated; open setae represent setal patterns of the next instar. 99 the first six or seven instars. TABLE XVIII. Number of setae per instar on the genital plate of Onychiurus justi porteri. Instar (FEMALES) 4 5 6 7 Average 8,52 l6,05 25,l0 32,4l Individuals observed I9 34 37 l2 Range 6-l8. 12-20 ZI-30 30-38 Instar (MALES) 4 5 6 7 Average 24,20 38,75 50,50 - Individuals observed l5 l6 l0 - Range I5'3O 36-48 42-57 ' Chaetotaxy of the Male Ventral Organ of Abdominal Segment ll. The male ventral organ of Q: justi porteri is located on the ventral surface of the second abdominal segment. It consists of four (rarely five) setae, larger in diameter than body setae, and arranged in a transverse row. The type of male ventral setae found on Q: justi porteri consists of a seta-like thick median shaft, wrapped in a broad cover which is slit longitudinally on one side. Stach (l954), in his revision of Onychiuridae, did not mention any morphological changes in the male setae. As a result his description and illustrations typify setae of certain size and shape for certain Species. The present study shows that the male ventral setae undergo changes from instar to instar. And as the individual reaches senility, bizarre dichotomy of the setae takes place. Figures 76 to SI illustrate the IOO changes in shape adopted by the male ventral setae at various instars. Figures l6, I7, l8 and I9 illustrate setae of two 339 day old individuals reared at 60°F. The general outline is markedly different from fourth instar setae (Fig. 82). Figures 83 to 90 show the variation of the male ventral setae at various instars between the fifth and seventeenth. Figure 9i shows an individual about to moult. The eighteenth instar seta is tightly rolled and long, while the nineteenth instar seta lying underneath is short and lamellate. Figures 92, 93, 94, 95 and 96 show 25th instar male ventral setae, with their outer wrapping split into fragments. This condition is always seen in older individuals. The examples presented here negate the use of any general description of the male ventral setae for specific identification. Variation within a population is directly related to age of the individual. Stach (I954) did not recognize any such variation in the thousands of samples examined while revising Onychiurus. His specimens were field collections. It would appear that individuals of the age category in which setal variation occurs were not collected; leading to the question whether or not individ- uals of the 25th to 34th instar occur in nature. XIII. DIETARY INFLUENCE ON GROWTH AND FECUNDITY Introduction Most laboratory studies have attempted to simulate field conditions or at least provide natural foods while manipulating temperature and humidity factors. As a result it is common to use foods such as fungi, yeasts, Spores, leaf material and detritus. The influence of specific diets on growth has been, for the most part, a neglected area of investi- gation. Knight and Angel (l967) cultured Tomocerus flavescens (Tullberg) 82. 83. 84. 85. 86. 87. 88. 89. 90. Si. 92. l0l Onychiurus justi porteri n. ssp. - list of figure captions Male ventral setae of the second abdominal segment: Fourth instar, lanceolate setae Fifth instar, spatulate setae Fifth instar, spatulate setae Fifth instar, lanceolate setae Sixth instar, lanceolate setae Sixth instar, spatulate split seta Eleventh instar, spatulate seta Twelfth instar, lanceolate split seta Seventeenth instar, lanceolate setae Eighteenth instar about to moult; note (arrow) spatulate seta formed under lanceolate seta - 96. Twenty-fifth instar, split setae typical of senile adults. #1 ""'_ ..- l02 l03 on fungi found in forested areas and classified food preference by gut content analysis. However, no studies were pursued to determine the effect of those foods on growth. While studying cellulose decomposition by several species of Collembola, TUrne (l967) showed that the population dynamics of the Species were regulated by microbial influence on food material in the gut. The effects on fecundity and general biology of Hypogastrura manubrialis (Tullberg) by feeding yeast, liver, mushroom, banana, algae and blood agar base were noted by Vail (I965). He demon- strated that 5L manubrialis was a general feeder, but did best on yeast. Up to the time this investigation commenced, brewer's yeast was used as a basic food source in all the cultures. Where other species in culture were observed, it became increasingly evident that not all of them survive well on yeast. Some p0pulations died out after a brief period of growth, others would not reproduce. It was soon apparent that readily available and uniform food sources needed to be tried. A preliminary testing of food materials other than fungi that might influence growth and fecundity was undertaken. Materials and Methods Laboratory cultures of 9: justi porteri were maintained at 70°F and used as a source of eggs. The eggs were transferred from the stock cultures ‘with a needle to small containers with plaster-charcoal substrates, of the type previously described. The culture containers were moistened with distilled water at daily intervals to maintain them as close to l00% relative humidity as possible. After an incubation period of l4 days at 70°F, the eggs hatched. The juveniles were floated on water and trans- ferred with a fine needle in groups of ID to fresh containers. In all, 104 77 containers with ID individuals per container (770 individuals) were set up. The diets used consisted of brewer's yeast, commonly used in many investigations, and two ccmmercially prepared foods designated here as diet "A”* and diet ”B”*. A control was set up with no food at all. Diet "A" has the following ingredients: fish meal, fish roe meal, fish liver and glandular meal , typical crayfish meal, dehydrated kelp meal, insect larvae meal, mussel meal, brine shrimp meal, wheat germ and cod liver oil.” The ingredients of diet ”8” are as follows: "egg yolk, .032 cod liver oil, tapioca, wheat and corn flower and corn starch.” Table XIX indicates the guaranteed analysis by the manufacturel'for both diets. TABLE XIX. Constituents of diets ”A” and ”B“ as provided by the manufac turer. DIET ”A” DIET ”8" Crude protein . . . . . not less than 45% . . . not less than 3,4Z Crude1fat . . . . . . . not less than 4% . . . not less than 0,92 Crude fiber . . . . . . not more than 9% . . . not more than 0.5% Ash . . . . . . . . . . not more than I5% . . . not more than lOZ Small amounts of )east, diet ”A” and diet ”8” were added to the cultures each (by as required. Food not eaten wifihin 24 hours was removed. If the food showed signs of contamination, it was removed and replaced. As the cultures were examined each day during the IOO days of the experiment, it was a simple matter to scrape the substrate surface to keep it relatively free of molds. */ Diets ”A" and ”B" were manufactured by Hartz Mountain Products Corp., New York, N.Y. l0003 l05 Ultimately, then, there were four runs in the experiment, designated as yeast (l5 replicates), diet ”A” (25 replicates), diet "B” (30 replicates) and control (7 replicates). The number of individuals observed is indicated in Table XX. TABLE XX. Number of individuals of Onychiurus justi porteri used per diet. Diet ”A” . . . . . 250 Diet ”3" . . . . . . 300 Yeast (brewer's) . . . . . . I50 Control (no food). . 70 Total individuals = 770 As deaths occured, awe bodies were removed and their number noted. Ecdyses ‘were recorded by counting and removing the exuviae. The number of eggs laid were recorded by batch. Once the eggs hatched, the juveniles were counted and killed. All individuals surviving to the end of the experiment were preserved in hot 95% ethanol for later measurement with an ocular micrometer. Results As previously mentioned, the eggs took l4 days to hatch at 70°F. The following table (XXI) shows the duration of instars for each of the four I’LII'IS. TABLE XXI. Instar duration in days (average of all replicates per diet) INSTAR 1 2 3 6 5 6 7 8 9 10 11 12 13 16 15 Control 6,9 8,6 10,6 8,3 8,6 9,9 8.6 7,9 9,6 7,6 7,6 8,6 7,8 8,6 7,0 Diet ”8” 7.3 7.0 7.) 7.3 3.4 9.3 3.9 8.0 9.0 3.3 9.2 8.3 3.6 9.2 9.) Diet ”A” 6,0 5,8 5,5 5,8 7,2 8,7 8,8 8,5 8,0 7,0 7,6 7,5 8,6 7,5 7,6 Iffst 5.9 6.6 5.3 5.5 6.9 6.9 6.9 7.5 7.7 7.3 7.5 6.7 7.1 7.0 7.2 l06 There is an dwious similarity of effect between the individuals reared on yeast and those reared on diet "A.'I Bofl1 resulted in a more rapid rate of growth as indicated by instar duration. After the fifth instar, there is a marked similarity between the control and diet ”B“ in instar duration. This may be the result of bacterial build-up in the substrate of the control cultures. Control specimens were seen eating the substrate and the black contents of the gut were clearly visible through fl1e body walls. The similarities in growth rate can also be graphically shown by calculating the numbertaf days lived through from the day of hatching to the beginning of each instar. Graph 55 (dearly shows the diversity of growd1 rate between yeast, diet ”A,” control, and diet ”B." Here the lag in instar duration shows up after the first UM) instars. Mortality can be inferred from figures for percent survival of the total pOpulation. The following table (XXII) shows the survival rate of each run after periods of 25, 50, 75 and l00 chys. TABLE XXII. Influence of various diets on the percent survival of 0nyd1iurus justi porteri. Age in days 25 . 50 75 IOO Control 78,6 6l,4 34,3 27,l Diet ”3” ‘ 37.5 77.0 73.3 7I.3 Diet ”A” 96,0 92,4 78,8 6I,6 Yeast 89.3 83.3 67.3 56.6 By calculating survival on a daily basis (Graph 56), the expected downward sl0pe of fl1e control populations, reaching 50% after about 55 days, becomes exceedingly clear. It is interesting to note that with 107 .uoom um ..oeucou ecu .m gout .< Home .ummo> co nmcmoe moeau_:o c_ Lmumc_ some e05 eoc_:auc os_u ._coueom _um:~ mac:_cu>co 2: = as: - ae .x .1 .m am an aw am a“ e — — u n ......_ 5 .& n a «...... i _..... v n .m ..... . n .5. a a a a .. a \ .7... \A. 5 5...» 5 \\\_ .7 \5 . ....... u \\A I P. . .\. a o. a \\.s ..... . .... o. _ 2 \A 6— ........ a .5. : ......_ = \A «109 .. = x“. )0‘ «— . ..... _ a. \\fi fi— . .. a. \N— as... a. \\A ...n. as? 2 3 ova/o 3 «W4 .3 a O \\3 2 «a, \A A \2 3 \fi 0. \2 Acozuavoi mmo *0 055.5093 \t. Aomocgov «<52. :08 2 02.52: 56: m2: . .mm Lento IIISII 108 ‘70 Survival of 70'F (2l.ll'C) no \ l‘...“-----------.. ..... \. ---- 5..‘x .G‘ $_ ‘ ‘ .90 “M‘s \éwl .¢ ..-.. .............. Q L” ' ’I’” \ b.0 u. ”"~.,_" s~-‘ ..... "uuuuuoouu \\ ..... .....\.................., ’m ‘ p70 ‘7. “\ 5.4 5.0 5“ P————_ —————— —- - ——————— — —bso 401 540 “Mm am no xii do 5 1m no a. o 1 2 a 40 s o 0 so no III! II IIIS Graph 56. Onychiurus justi porteri, percent survival of individuals reared at 70°F for yeast, diet A, diet B, IOO days and fed and control. l09 diet "B,” not the best diet for growth, survival stabilizes out after approximately 50 days and mortality is at a minimum. 0n the other hand, both yeast and diet ”A” produce similar trends of survival, gradually sl0ping downward between 50 and l00 days. Egg production was recorded for each of the four runs. The control did not produce eggs at any time during the lOO-day period. However, egg production was observed in the other three runs. Since the cultures were each started with ID individuals, it was impossible to consider egg pro- ductlon on a per female basis. Therefore average weekly egg production was calculated by using the average number of individuals surviving each week. It must be noted that this figure, as in the mass rearing experiment, includes the males present in each run. Graphs 57, 58, and 59 indicate egg production according to the formula: Egg production per individual = Number of eggs/week ave. number individuals/week Fecundity appeared highest among individuals cultured on diet I'A.” Yeast fed individuals were next, followed by those kept on diet ”B.” Egg laying started during the 5th instar, occuring in the fourth week after hatching in both the diet "A” and yeast fed runs. It is interesting to note that individuals reared on diet ”8" did not begin egg laying until the seventh week, at a time when the seventh instar had been reached. Of equal Significance is the relatively low fecundity in the diet "B” fed individuals. While diet “A" induced the laying of as many as 50 eggs per clutch, and yeast fed individuals produced nearly as many, those fed diet "8" never laid more than l7 eggs per clutch. 0n the average, the diet ”8” run produced 5-8 eggs per clutch. llO 2:: @ -1...“- 2‘ ill llllltllll: . L—a ll. IIIVIIII 111.11. lIllI/IIII 33' _‘ NTQNMI - fiL.) L5" 4 _ r '( —I—J '0‘ ‘— 1 .._J Dhi'fi? “a euw ' 2 ' a e I 10 12 14 WEEKS imfiwdufl 25 j J E 1 -7 I l i H Diet "B" e36 1 g ‘2" '4' '6' I w u u “5 WEEKS u. 1." 1—— 3 E a Z. I l ] J i:. J I L l E .3. Yeast 0.2.- ' 2 ' 4 6 0 IO I: I. TIME in WEEKS Graphs 57 to 59. Onychiurus justi porteri, average number of eggs laid per week by individuaTs reared on diet A, diet 8, and yeast at 70°F. lll Egg viability was lowest in the run fed on diet ”A.” Of the 299] eggs laid that were observed, 2359, or 78%, hatched. In the case of diet ”B,” of 562 eggs observed, 476 were viable, or 84%. Yeast showed BIZ viability for I373 eggs observed with lll4 hatching. The juveniles were not reared and no figures are available for their survival. At the end of the IOO-day period, the individuals of each run were killed and slide mounted for measurement. Not all runs were killed at the same time. Some replicates were still producing eggs, and it was necessary to allow some clutches of eggs to hatch before killing the parent individuals. Table XXIII indicates the average size of individuals killed at various time periods after IOO days. When the egg hatches, the lst instar juvenile is on the average 545 microns in length. The figures in table XXIII indicate that the controls grow very little throughout the experiment. In fact, their size after l00 days lies between 840-l066 microns, which is the average size of 3rd instar juveniles fed yeast. The control individuals were actually in the l4th instar at the time of killing. They underwent ecdysis even though no appreciable size change was attained after reaching the 3rd instar Size. Diet UA” and yeast produced individuals of approximately equal size after l00 days. Diet ”B” fed individuals were small by comparison. Their size compares with yeast-fed 4th to 5th instar Individuals raised at the same temperature. The figures in table XXIII indicate size fluctuations between l05 and I45 days. This condition seems to be quite normal for individuals after the 7th instar. Previously presented data indicate that after the 7th instar, size (length) fluctuates. An apparent rhythm in size increase and decrease continues until the animals reach senility, when they finally decrease a small amount with each instar until death. ll2 TABLE XXIII. Mean over-all lengths (in microns), at the end of various time periods, of Onychiurus justi porteri reared on various diets. Diet ”A” Diet ”B” Yeast Control (12)* (62) (18) 105 1722,4 1280,5 1632,6 ---- (18) (22) E. 107 1689,1 ---- 1737.1 ---- '5 (55) (5) :3 108 ---- 1369,6 ---- 870,3 3 .,. (54) (1) 3 112 1583,2 ---- ---- 1066,8 3 z: (16) (33) 3 113 1602,0 1257.2 ---- ---- z (24) (24) (7) ‘3 114 1852,9 ---- 1800,8 840,7 (16) (32) . 145 ---- 1256.3 1659.6 ---- */ Number contributing to the mean Discussion The results of this preliminary study indicate that the type and quality of diet can influence growth and fecundity of Q: justi porteri. The amount of protein and fat in diets "A" and "8” probably are, to an extent, responsible for these differences. It should be noted that no biochemical analysis has yet been performed on any of the diets. Therefore, it cannot be stated with accuracy whether a specific protein(s) was responsible for the resultant growth and fecundity patterns. Considering the differences in protein content as a whole, we can rank the three food runs on the basis of high protein to low: diet "A" :7.» L". ll3 (45% protein), yeast (approx. 40% protein), diet ”B” (3,42 protein). Referring to Graph 55 showing rate of growth, and Table XXI indicating instar duration, differences are apparent. Diet "B‘I has the longest instar durations, followed by diet ”A,” and yeast the shortest. Even though yeast contains somewhat less protein than diet ”A,” the yeast's protein may be easier to assimilate by the Collembola. Survival, as indicated in Graph 56 and Table XXII, presents some interesting aspects. After an initial decline up to 35 days, diet ”B” fed individuals stabilize through the rest of the 100 day period. Meanwhile, both diet ”A” fed and yeast fed individuals begin a steady decline after 42 days. These survival patterns may be due to a multiplicity of factors. Perhaps diet "8” fed animals adjusted to the low protein food, with higher assimilation efficiency under stress conditions. It may be that the animals reacted much like dermestid larvae placed on starvation or near starvation diets (Dr. Stanley Beck, in litt.) One of the most interesting deveIOpments was the discrepancy in egg production. As expected, the controls (starved) produced no eggs. Diet ”8,” low protein, produced few eggs compared to diet ”A” and yeast-fed individuals. Moreover, diet ”B”-fed cultures lagged in egg production until the 7th week of the experiment. Diet "A"-fed cultures had the highest rate of egg production followed by cultures reared on yeast. But eggs in diet I'B"-fed cultures showed the highest viability, followed by yeast and diet ”A”-fed cultures. Finally, there is a marked difference in size between the four runs after lOO days on their respective dies. For over-all size, the diet ”A“- fed individuals were largest, followed by yeast-fed, diet ”B"-fed and the control. As has previously been mentioned, every attempt was made to keep the ‘3 51’: lI4 cultures as clean as possible throughout the duration of the experiment. Food was not left in the containers for more than 24 hours, after which it was replaced by fresh. Fungal growth was kept at a minimum by scraping the substrate surface whenever the food was replaced. However, no control of bacteria was feasible; and it is possible that such contamination may have supplemented the diets. In the case of the control, it is very probable that contamination allowed some of the individuals to survive the 100 days of the experiment. But it is still striking that they survived at all and continued to moult without appreciable size increase at regular intervals. The data presented here make it evident that food quality as well as temperature and humidity play an important role in collembolan growth and fecundity. Type of food and its availability must be taken into account in studies of biomass and age structure of collembolan populations in labor- atory and field. As previously pointed out, the size of individuals, however advanced in age, bears no relation to the instar they are in, if maintained on an insufficient diet. For instance, the control and diet ”B“-fed In- dividuals produced a similar growth rate pattern, but were of different sizes in the 14th instar. If we were to categorize the l4th instar on the basis of biomass or size, we would determine It to be the 4th or 5th instar. A similar situation is reflected in the data presented on growth rate at three different temperatures. In addition to size differences, food quality affects egg production and may be a decisive factor in populatkmadynamics of a given species. As seen from the data presented here, Collembola will live and reproduce on both high and low protein foods. But the constituents of these foods may determine their survival and fecundity. ll5 x1v. SURVIVAL AT 60°, 700 AND 80°F Introduction The influence of temperature on the activity of Collembola has been documented both in the laboratory and in the field. Some species become inactive between +4°C and -4°C (Nosek, 1959; An Der Lan, l963; Janetschek, 1963). Others may survive between -5°C and -50°C (Paclt, I956; Pryor, I962; Agrell, I941; Kuhlmann, 1958; An Der Lan, 1961). Temperature regimes between 80 and 24°C have commonly been used in life-cycle studies (Britt, l95l; Ripper, 1930; Hale, l965 a,b,c; Choudhuri, I96]; Milne, 1962; Davis and Harris, l936; Sharma and Kevan, l963 a,b; Vail, 1965; Marshall and Kevan, 1962). Very little comparative work exists on longevity of individuals or small populations at selected temperatures. Hale (1966) states that the only precise information he could obtain on longevity concerned Onychiurus lgtgs: In the field the average time from hatching to egg laying was l0 to II months. Adults of 0: 133233 put into culture at 8°C at the time of egg laying, lived for another 120 days; giving a life span of over 400 days. Recent work by Thibaud (I968 a,b; 1969) has been centered on lethal temperatures and the effects of temperature on postembryonic development. Ashraf (1971) investigated dwaeffect of nine different temperatures on Q. bhattii Yosii, with ranges from 0° to 50°C. His experiments were conducted over a 24 hour period. Survival in Mass Culture Mass cultures of Q: justi porteri were observed for a year (from hatching to death). Periodic samples were taken for growth studies; in I) 116 addition, deaths occurred in the populations. The ensuing changes in population densities were recorded and later tabulated on a weekly basis. In order to determine the mortality or percent survival of the mass cultures, a theoretical mortality of the individuals sampled each week has to be calculated. 1 am indebted to Dr. Ralph Pax, who helped derive a formula for the theoretical mortality of sampled individuals. The following is the procedure used to determine the mortality of cultures being sampled on a weekly basis: a) Count the total number of individuals on day l of the week (including deaths and samples taken out on this same day, if any); b) Count the number of deaths in the week; c) Calculate the percent mortality; d) Count the total number of individuals sampled during the week; e) Calculate the ”theoretical percent mortality” of the samples: percent total mortality 100 No. of sampled individuals x = percent mortality in samples; f) Add the mortality of the total population to the mortality of the samples. Note: Both the mortality of the total population and the theoretical mortality of the samples were cumulated for the duration of the experiment (Appendices XLII, XLlll and XLIV). Graph 60 illustrates the percent survival of O: justi porteri at three temperatures. At 80°F, 50% of the animals survived to the 17th week; ex- tinction was reached in the 19th week (133 days). At 70°F, 50% survival .uoow.oom.oom um moo:u_:o nocmmc mmmE mo _m>_>L:m ucouLoa .WLOucoa _umaw mac:_coxdd .oo zomeo ll7 4-9.5.8....» 3 r IfiPfiDQDNPONb¢D~DNPNF8 9. 0.. 1D I P mxmmg 5 m5: 3. «prop o a Q N meow D b (P P D I P “.98 noon 'IVMAHI'IS % II8 occurred in the 22nd week and death by the 3ist week (224 days). Survival at 60°F was much higher, with 50% living to the 34th week and finally reaching a low in the 45th week (315 days). At all three of these temperatures, there were individuals that lived longer. At 70°F a few lived for 237 days, while at 60°F some survived 365 days. Survival in Low Number Reared Cultures In cultures of five or less individuals, no samples were taken. As a result, mortality could be calculated in the customary way (Appendices XLV, XLVI and XLVII). Graph 6i illustrates the percent survival at three temperatures. Compared to the mass cultures, mortality is initially more pronounced. At 700 and 80°F, the low number reared individuals reach 50% mortality much sooner than the mass reared cultures. Even at 60°F, mortality among juveniles is higher than in mass cultures. Survival in Cultures Containing Single Individuals and Pairs In cultures of single males, single females, pairs of male and female, pairs of males and pairs of females, the pattern of survival in the 15 week run is similar to that in low number reared cultures (Tables XXIV, XXV and XXVI). It is apparent that at 70°F an unknown factor is producing high mortality in the cultures containing pairs of male and female. At 70° and 80°F single males and females show a higher mortality rate than at 60°F. Of similar interest is the high mortality in pairs of males over that of pairs of females at 60° and 70°F. 119 .moom new oom .oom um macaw—so pounce 5035:: 30. mo _m>_>csm ucoULoa ._Loucoo _um:m macamcuxdo .pm samco seam}. mi: 09 a 0 Q N h b P (P b bi P LI 'IVAIMII'IS 96 l20 TABLE XXIV. Percent mortality at 60°F in cultures containing single and paired individuals of Onychiurus justi porteri. PERCENT MORTALITY Single Single Pairs of Pairs of Pairs of WEEK males females males females male+female I - - - .. - 2 .. .. - .. .— 3 .. .. .. - .. 4 - - - - - 5 - .. - .. - 6 - - - - 3.57 7 - _ .. - _ 8 3,70 - - - - 9 - - 5,55 3,33 - lO - 2,38 11,11 6,66 - 11 - - - - 7,16 12 7,40 7,l4 - - - l3 - - l6,66 - - I4 - - - - - 15 - - - - - TABLEZXXV. Percent mortality at 70°F in cultures containing single and paired individuals of Q, justi porteri. PERCENT MORTALITY Single Single Pairs of Pairs of Pairs of WEEK males famales males famales male+female ‘ ' ’ ' 1.79 9’09 - - 8993 I2,50 23907 - - - 16,07 ' '8.'8 5.55 6.25 23.21 30.77 27,27 II,II I2,50 32,I4 38.46 45.95 16.67 ' 39.23 ' ' 22,22 - 42,86 ’U‘l-L‘WN—OWONO‘U'I-k'WN—I \I '0 I 0‘ \O I l I IZl TABLE XXVI. Percent mortality at 80°F in cultures containing single and paired individuals of Q: justi porteri. PERCENT MORTALITY Single Single Pairs of WEEK males females male+female I - - - 2 _ _ _ 3 .. - _ 4 - - - 5 .. - .- 6 3.57 ' ' 7 - _ .. 8 7,14 - - 9 10,71 - - l0 - - - 11 14,28 - 7,14 12 25,00 - - 13 28,57 16,28 - 14 32,14 - 14,28 '5 ' 19905 2‘9h3 Discussion From the data presented, it appears that mortality is influenced not only by temperature but also by the total number of individuals in a pOpulation and possibly by their sex. In mass culture, survival is higher in the initial few weeks, indicating less juvenile mortality. In the low number reared cultures there is a higher juvenile mortality, although the adults exhibit a prolonged survival time. Cultures of single individuals have an initial high rate of survival, but after the seventh or eighth week, respond in a pattern similar to the low number reared cultures. Males in the first 15 weeks show a high mortality. However, examination of Graphs 52, 53 and 54 for mass culture reveal a corresponding decrease in size of males in the same time period (approximately llth instar or 105 days at 60°F and 16th instar or 105 days at 70°F). 122 The information on survival and the data on growth rate suggest that mortality may be directly related to temperature - humidity, population density, sex, age and metabolism. And judging by the data in the previous section, diet certainly plays an important role in the survival of Collembola. 1. XV. SUMMARY A new subspecies, Onychiurus justi porteri, is described from Michigan. The culture techniques used in this investigation were those described by Snider, Shaddy and Butcher (1969). Two culture container sizes were employed; 50 mm x 37,5 mm and 25 mm x 34 mm. Transfer of individuals from culture to test containers was accomplished by floating the juveniles on water and lifting them with a fine needle. 9, justi porteri was subjected to o, 80, 9o, 95 and 100% RH at 50°, 60°, 70° and 80°F, using various concentrations of glycerol. Survival was shown to be highest at 100% RH andaatemperature of 50°F. As temperature increased and RH decreased, survival decreased accordingly. The egg laying process of Q, justi porteri is described. Egg cannibalism was found to occur in the case of non-deveIOping eggs. The embryonic development of Q: justi porteri is described and a time table for 70°F is presented. As temperature decreases, between the temperatures of 500 and 80°F, the time required for development of the egg increases. 123 Fecundity in mass cultures was calculated according to the formula: Average egg production _ Total number of eggs in that week per individual ‘ Average no. of individuals in that‘week In mass cultures the greatest number of eggs per individual was laid at 60°F and egg production lasted until the 27th instar. Fecundity in low number reared cultures (five individuals or less) was higher than in mass cultures. Egg production continued until the 42nd instar at 60°F. In general, an increase in temperature lowers the number of eggs produced. Over-all survival of the eggs was greatest at 60°F and decreased at 70° and 80°F. Fecundity was demonstrated to be much higher in 9: justi porteri than in any other species of Qnychiurus so far observed and reported. Instar duration was shown to be related to temperature. At 60°F a rhythm of alternating long and short instar duration was indicated. Isolated males and females did not produce such a rhythm. It is suggested that the duration of the stages may, in addition to temperature, be governed by the presence or absence of individuals of the opposite sex. Measurements of the head capsule of thefirst six instars indicate that growth of Q: justi porteri conforms to Dyar's Rule. Over-all body length was observed at 60°, 70° and 80°F in mass culture. A size difference betweenrmales and females was shown. Females develop more rapidly thaImales and attain a larger size. Maximum length of both males and females is reached between the 4 12th and 14th instar; thereafter a decrease in size occurs at all temperatures investigated. 10. 11. 12. 124 A possible correlation between egg production and retrograde development is suggested. The size structure of a population of Q: justi porteri may be determined by a relationship between sexual activity, metabolism, and age. The chaetotaxy of the fifth abdominal segment is described in a manner similar to Hale's (1965 c) investigation. The development of the setal pattern is illustrated from the first to the seventh instar. The dorsal setal pattern of thefirst thoracic segment was investi- gated in the hope of finding a correlation with instar number. However, beyond instars one and two variation was too great to allow its use. The chaetotaxy of the male and female genital plates is illustrated. Setal patterns of the genital plates of both sexes do not develop until the fourth instar. The maximum number of setae is attained by the seventh instar. The chaetotaxy of the male ventral organ is described and illustrated. From the present investigatRXIit was possible to negate the use of male ventral setae morphology for specific instar designation. An investigation comparing yeast, a high protein food, a low protein food, and control (no food) was undertaken. Indications are that food quality can influence growth, fecundity and mortality. Retrograde deve10pment was observed in the control individuals. Survival at 60°, 700 and 80°F was found to be highest at 60°F. In mass culture, juveniles appear to have a higher survival rate. Whereas in low number reared cultures, the adults exhibit a prolonged survival time. \ m»? ‘«*s.‘:\\ . 3" .... _.-I 53.1 311{ l” (L 125 LITERATURE CITED Absolon, K. 1901. Weitere Nachricht Uber europHisdwe HBhlencollembolen und Uber die Gattung Aphorura A.D. MacG. Zool. Anz., 24: 385-389. Agrell, 1. 1941. Zur Ukologie der Collembolen. prsc. Entom. Supp; 111, 1-236. Agrell, 1. 1948. A dubious biocoenological method. qusc. Entom., 13 (2): 57-58. An der Lan, H. 1961. Zur Winter-Okologie des Gletscherflohes. Die Pyramide, 1: 33-34. An der Lan, H. 1963. Tiere im Ewigschneegebiet. Umschau Wiss. Technik, 2: 49-52. Ashraf, M. 1969. Studies on the biology of Collembola. Rev Ecol. Biol. S91, 6 (3): 337-347. Ashraf, M. 1971. Influence of environmentfl factors on Collembola. Rev;_ Ecol. Biol. 501, 8 (2): 243-252. Bellinger, P.F. 1954. Studies of soil fauna with special reference to the Collembola. Connect. Agric. Exp. Sta. Bull., 583: 1-67. Bonet, F. 1931. Estudios sobre Collembolos cavernicolos con especial referencia a los de la espanola. Mem. Soc. eSpana. Hist. Nat. Madrid, 14: 231-493. BUrner, C. 1906. Das System der Collembolen, nebst Beschreibungen neuer Collembolen des Hamburger Naturhistorischen Museums. Mitt. Nat. His. Mus. Hamburg, 23: 147-188. BUrner, C. 1913. Die Familien der Collembolen. Zool. Anz., 41: 315-322. Braun, J.V. and Braun, J.D. 1958. A simplified method of preparing solutions of glycerol and water for humidity control. Corrosion, 14: 17-18. 126 Brimley, C.S. 1938. The insects of North Carolina. Raleigh, N.C. (Orders Thysanura and Collembola) (Collembola pp. 14-17). Britt, N.W. 1951. Observations on the life history of the Collembolan AChorutes armatus. Trans. Am. Micros. Soc., 70: 119-132. Burges, A. and Raw, F. 1967. Soil biology. London and New York: Academic. 532 PP~ Butcher, J.V., Snider, R. and'Snider, R.J. 1971. Bioecology of edaphic Collembola and Acarina. Ann. Rev. Entom., 16: 249-288. Chamberlain, R. w. 1943. Four new Species of Collembola. Great Basin Nat., 4: 39-48. Choudhuri, D.K. 1961. Influence of temperature on the development of Onychiurus furciferus (BUrner) and its mathematical representation. Proc. 2001. Soc. Calcutta, 13 (2): 123-128. Choudhuri, D.K. 1963. Effect of some physical factors on the genus Onychiurus (Collembola). Proc. Nat. Acad. Sci. India, 33: 539-546. Christiansen, K. 1961. The Collembola of Hunters Cave. The Nat. Speleol. Soc. Bull., 23 (2): 59-63. Christiansen, K. 1964. Bionomics of Collembola. Ann. Rev. Ent., 9: 147-178. Christiansen, K. 1967. Competition between collembolan species in culture jars. Rev. Ecol. Biol. Sol, 4(3): 439-462. Christiansen, K. 1970 a. Experimental studies on the aggregation and dispersion of Collembola. Pedobioi., 10: 180-198. Christiansen, K. 1970 b. Survival of Collembola on clay substrates with and without food added. Annales de Speleol., 25: 849-852. Colioque International sur les Collemboles. 1970. Proceed. in: Rev. Ecol. 8101. $01, 8 (1): 11-198 (1971). IV. Colloquium Pedobiologiae. 1970. Proceed. (Annales de zoologie, ecologie animale; I.N.R.A., Paris). 127 Davidson, J. 1932. On the viability of the eggs of Sminthurus viridis in relation to their environment. Aust. J. Exp. Biol. and Med. Sci., 10: 65-68. Davidson, J. 1934. The ”Lucerne Flea” Sminthurus viridis L. in Australia. C.S.I.R. Bull., 79: 1-66. Davies, H.M. 1928. On the economic status and bionomics of Sminthurus viridis, Lubb. (Collembola). Bull. Ent. Res., 18: 291-297. Davies, H.M. 1929. The effect of variation in relative humidity on certain species of Collembola. Brit. J. Exp. 8101., 6: 79-86. Davis, H. and Harris, H.M. 1936. The biology of Pseudosinella violenta (Folsom), with some effects of temperature and humidity on its life stages. (Collembola: Entomobryidae). Iowa State C011. J. Sci., 10 (4): 421-430. Denis, J.R. 1929. Notes sur les Collemboles recoltés dans ses voyages par la Professeur F. Silvestri. Boll. Lab. 2001. Portici, 22: 166-180. Denis, J.R. 1938. Collemboles d'ItaIie (Principalement cavernicoles); sixiéme note sur la faune itaiienne des Collemboles. Boll. Soc. Adriat. Sci. Nat. Trieste, 36: 95-165. Dow, R.P. and Smith, J.B. 1909. A report on theinsects of New Jersey. Part 11. Rep. New Jersey State Mus., Collembola: pp. 34-36. Dyar, H.G. 1890. The number of moults 0f lepid0pterous larvae. Psyche, 5: 420-422. Edwards, C.A.T. 1955. Simple techniques for rearing Collembola, Symphyla, and other small soil inhabiting Arthropods. 12; Soil Zoology, Butterworths, London, pp. 412-416. Falkenhan, H.H. 1932. Biologische Beobachtungen an Smhthurides aquaticus (Collembola). Zeitsch. Wiss. 2001., Leipzig, 141: 525-580. 128 Folsom, J.V. 1917. North American Collembolous Insects of the subfamily Onychiurinae. Proc. U.S. Nat. Mus., 53: 637-659. Folsom, J.V. 1933. The economic importance of Collembola. Jour. Econ. 52529;) 26: 934-939. Gervais, P. 1841. Designation of Type and Description of genus ngchiurus. Echo Monde Savant, 8:372. Gisin, H. 1952. Notes sur les Collemboles, avec demembrement des ngchiurus armatus, ambulans et fimetarius auctorum. Mitt. Schweizer Entom. Ges., 25 (1): 1-22. Gisin, H. 1956. Nouvelles contributions au démembrement des espéces d'Onychiurus (Collembola). Mitt. Schweizer Entom. Ges., 29: 329-352. Gisin, H. 1957. Sur la faune européenne des Collemboles 1. Rev. Suisse 2001., 64: 475-496. Gisin, H. 1960. Collanbolenfauna Europas. Mus. Hist. Nat., Geneve, 312 pp. Gisin, H. 1961. Collembolen aus der Sammlung C. BS'rner des Deutschen Entomologischen Institutes. Beitr‘ége zur Entom., 11: 329-354. Gisin, H. 1962. Sur la faune européenne des Collemboles IV. Rev. Sulsse 5921;, 69 (1): 1-23. Gisin, H. 1963 a. Collemboles d'Europe V. Rev. Suisse Z001., 70 (1): 77-101. Gisin, H. 1963 b. Pour une réfo rme de la taxonomic, appl iqube a1x C01 lemboles (Insects Apt'erygots). Arch. (216 Sciencs, (Senate, 16 (2): 212-216. Gisin; H. 1964 a. Collemboles d'Europe VI. Rev. Suisse de 2001., 71 (2): 383-400. Gisin, H. 1964 b. Collemboles d'Europe VII. Rev. Suisse 2001., 71 (4): 649‘678. Gisin, H. 1968. Onychiurus ’severini Willem, 1902 (Collembola). Rev. Sulsse 2001., 75 (1): 1-3. 129 Goto, H.E. 1961. Simple techniques for the rearing of Collembola and a rote on the use of a fungistatic substance in the cultures. Entom. Monthly Mag;, 46: 138-140. Green, C.D. 1964 a. The life history and fecundity of Folsomia candida (Willem) var. distincta. Proc. Roy. Ent. Soc. London Series A, 39: 125-128. Green, C.D. 1964 b. The effect of cnwding upon the fecundity of Folsomia candida (Willem) var. distincta (Bagnall). Ent. Exp. et App1., 7:62-70. Guthrie, J.E. 1903. The Collembola of Minnesota. Rep. Geol. Nat. Hist. Surv. Minn., 2001. Ser., 4: 1-110. Hale, W.G. 1964. Experimental studies on the taxonomic status of some members of the Orychiurus armatus species gtoup. Rev. E001. Biol. Sci, I (3): 501-510. Hale, W.G. 1965 a. (lase'rvations on the breeding biology of Collembola (I) . Pedobiol., 5: 146-152. Hale, W. G. 1965 b. Observations on the breeding biology of 001 lenbola (II). Pecbbiol., 5: 161-177. Hale, W. G. 1965 c. Post-embryonic development in some species of C01 lembola. Pecbbiol. , 5: 228-243. Hale, W.G. 1966. The:CoIIemboIa 0f the Moor House National Nature Reserve, Westmorland: a moorland hdaitat. Rev. Ecol. Biol. 501,3 (1): 97-122. Hale, W.G. 1967. Collembola. 12; Soil Biology (Burges and Raw eds.) 398-411. Hale, W.G. 1968. A quantitative study of the morphological structures used as taxonomic criteria in the Onychiurus armatus group (Collembola, Onychiuridae). Rev. Ecol. Biol. Sol, 5: 493-514. Hale, W.G. 1969. Preliminary stereoscan studies of the genus Onychiurus 130 Gervais (Collembola, Onychiuridae). In; The Soil Ecosystem. Public. no. 8, The Systematics Assadation (London), 169-186. Handschin, E. 1926. Collembola. In; Schulze, Biologie der Tiere Deutschlands. Tell 25: 7-56. Healey, I.N. 1967. The energy flow through a population of soil Collembola. 125 Secondary productivity of terrestrial ecosystems, ed. K. Petrusewicz: 695‘708. Holdaway, F.G. 1927. Bionomics 0f Sminthurus viridis Linn., the South Australian Lucerne Flea. Council Sci. and Ind. Res. Melbourne Pamp,, 4: 23pp. International Symposium on Pesticides in the $011. 1970. Proceed. (Michigan State University, East Lansing). James, H.G. 1933. Collembola 0f the Toronto region, with notes on the biology of lsotoma palustris Mueller. Trans. Canad. Inst., Toronto, 19: 77-116. Janetschek, V.H. l963. Uber die wirbellose Landfauna des Rossmeergebietes (Antarktika). Anz. SchéUlingsk., 36: 8-12. Kawasaki, K. and Kanou, K. 1965. Control of atmospheric humidity by aqueous sulfuric acid solutions. 121. A. Wexler (ed.), Humidity and Moisture Measurement andControl in Science and Industry, 3: 531-534. Knight, C.B. and Angel, R.A. 1967. A preliminary study of the dietary requirement of Tomocerus. Am. Midl. Nat., 77: 510-517. Kuhlmann, D. 1958. Freilandbeobachtungen an lsotoma viridis Bourlet. Beitr. Entom. Berlin, 8: 375-377. Lindenmann, W. 1950. Untersuchungen zur postembryonen Entwicklung schweizerischer Orchesellen. Rev. Suisse 2001., 57: 353-428. Linnaeus, C. 1758. Systema Naturae (Aptera), ed. 10, pp. 608-609. 131 Lintner, J.A. 1885. Notes on Lipura fimetaria L. in a cistern and in a well, in the State of New York. Second Rep. Ins. N. York, 208-210. LBnnberg, E. 1894. Florida Aphoruridae. Can. Ent., 26: 165-166. MacGilIivray, A.D. 1891. A Catalogue of the Thysanura of North America. Can. Entom., 23: 267-276. MacGilIivray, A.D. 1893. North American Thysanura, I-IV. Can. Ent., 25: 127-128, 313-318. Maclagan, 0.5. 1932. An ecological study of the”Lucerne Flea,” (Smhthurus viridis Linn.), I, 11. Bull. Ent. Res., London, 23: 101-145, 151-190. Marshall, V.G. and Kevan, D.K.McE. 1962. Preliminary observations on the biology of Folsomia candidaWillem, 1902. Can. Ent., 94: 575-586. Mayer, H. 1957. Zur Biologie und Ethologie einheimischer Collembolen. 2001. Jahrb., 85 (6):501-570. Maynard, E.A. 1951. The Collembola of New York State. Comstock, New York. 339 pp- Milis, H. B. 1930. A preliminary survey of theibllembola of Iowa. Eag;_ §g£;J 62: 200-203. Mills, H.B. 1934. A Monograph of the Collenbola of Iowa. Monograph no. 3,,Div. Ind. Sci., Iowa State 0011., 143 pp. Milne, S. 1960. Studies on the life histories of various species of Arthr0p1eone Collembola. Proc. Roy. Ent. Soc. London, (A), 35: 133-140. Nosek, J. 1959. Die Untersuchung der Bodenfauna als ein Teil der Waldbiozenoseforschung, mit Bemerkungen zur Bodenfauna vom Standpunkt der Bodenbiologie. (In Czech). Biol. Works Slovak. Acad. Sci., 3: 156. O'Brien, F.E.M. 1948. The control of humidity by saturated salt solutions. Jour. Sci. Instruments, 25: 73-76. 132 Packard, A.S. I871. Bristle-tails and Spring-tails. Amer. Nat., 5: 91-107. Packard, A.S. 1873. Synopsis of the Thysanura of Essex County, Mass., with descriptions of a few extralimital forms. Rep. Peab. Acad., 5: 23‘51. Paclt, J. 1956. Bionomie und Bkologie, ig_Biologie der prier FIUgellosen Insekten, 91-117 (Gustav Fischer Verlag, Jena, 258 pp.) Pedigo, L.P. 1967. Selected life history phenomena of Lepidocyrtus cyaneus f. cinereus Folsom with reference to grooming and the role of the c0110phore. Entom. News, 78 (10): 263-267. Petersen, H. 1970. Methods for estimatIOIof growth of Collembola in cultures and in the field, exemplified by preliminary results for Onychiurus furcifer (BUrner). Proc. IV. Collggu. Pedobiol. (I.N.R.A. Paris), (In Press). Pryor, M. 1962. Some environmental features of Hallet Station, Antarctica. Dissert. Abstr., 22: 3308. Ripper, W. 1930. Champignon-Springschwanze. Biologie und Bekampfung von Hypogastrura manubrialis Tullb. Z. Angew. Entom. Berlin, 16: 546-584. Salmon, J.T. 1941. The Collembolan fauna of New Zealand, including a discussion of its distribution and affinities. Trans. Roy. Soc. N.Z., 70: 282-431. Salmon, J.T. 1942. A new species of Onychiurus (Collembola) from New Zealand. Trans. Roy, Soc. N.Z., 72 (2): 158-159. Salmon, J.T. 1959. Concerning the Collembola Onychiuridae. Trans. Ent. Soc. London,_lll (6): 119-156. Salmon, J.T. 1964. An Index to the Collembola, I and II. Bull. Roy. Soc. New Zealand, 7: 644 pp. Schaller, F. 1970. Collembola (Springschwfinze). Handb. 2001. Berlin, 4 (2) : 1-72. 133 SchUtt, H. 1891. Beitnge zur Kenntnis Kalifornischer Collembola. Bih. K. Svenska Vet. Akad. Handl. 17, afd. 4 (8) : 1-25. SchUtt, H. 1894. Lipurider fran Florida. Entom. Tidskr. Ang}, 15, Stockholm, 128. Scott, D.B. jun. 1937. Collembola found under the bark of dead trees in California, with descriptions of two new species. Pan. Pac. Ent. San Francisco, 13: 131-135. Scott, D.B. jun. 1942. Some Collembola records for the Pacific Coast and a description of a new species. Pan. Pac. Ent. San Francisco, 18 (4): 177-186. Scott, H.G. 1961. The Collembola of New Mexico. III. Onychiurinae. Entom. News, 72: 57-65- Sedlag, U. 1952. Untersuchungen Uber den Ventraltubus der Collembolen. Wiss. Z. Martin-Luther Univ. Halle, math.-naturwiss. Reihe, 1: 93-127. Sharma, G.D. 1967 a. Observations on the bifiogy of lsotoma olivacea Tullberg 1871. Pedobiol., 7: 153-155. Sharma, G.D. 1967 b. Bionomics of Tomocerus vulgaris. Proc. Roy. Ent. Soc. London, 42: 30-34. Sharma, G.D. and Kevan, D.K.McE. 1963 a. Observations on lsotoma notabilis (Collembola: Isotomidae) in Eastern Canada. Pedobiol., 3: 34-47. Sharma, G.D. and Kevan, D.K.McE. 1963 b. Observations on Folsomia similis (Collembola: Isotomidae) in Eastern Canada. Pedobiol., 3: 48-61. Snider, R.J. 1967. The chaetotaxy of North American Lepidocyrtus 5. str., (Collembola: Entomobryidae). Contrib. Am. Entom. Inst., 2 (3): 1-28. Snider, R.J., Shaddy, J.H. and Butcher, J.W. 1969. Culture techniques for rearing soil Arthropods. The Michigan Entomol., 1 (10): 357-362. South, A. 1961. The taxonomy of the British species of Entomobrya, Proc. Roy. Ent. Soc. London, 113: 387-416. 134 Stach, J. 1934. Die in den HUhlen Europas vorkommenden Arten der Gattung Onychiurus Gervais. Ann. Mus. Zool.gpolon., Warsaw, 10: 111-222. Stach, J. 1954. The Apterygotan fauna of Poland in relation to the world-fauna of this group of Insects. Family: Onychiuridae. Polska Awad. Nauk. Inst. 2001., 1-219. Strebel, 0. 1932. Beitrage zur Biologie, akologie und Physiologie einheimischer Collembolen. Z. Morph. 6kol. Tiere, 25: 31-153. Symposium on Soil Microcommunities. 1971. Proceedings (In Press). Tarsia in Curia, I. 1943. Contributo alla conoscenza di Collemboli cavernicoli d'Italia. Boll. Soc. Nat. Napoli, 53: 43-68. Thibaud, J.-M. 1968 a. Contribution a l'étude de I'action des facteurs température et humidité sur la durée du développement embryonnaire des Collemboles Hypogastruridae. Rev. Ecol. Biol. 501, 5 (I): 55-62. Thibaud, J.-M. 1968 b. Contribution 5 l'étude de l'action des facteurs temperature et humidité sur la durée du développement postembryonnaire et de l'intermue de l'adulte chez les Collemboles Hypogastruridae. Rev. Ecol. Biol. Sol, 5 (2): 265-281. Thibaud, J.-M. 1969. Contribution 5 l'étude du développement postembryon- naire chez les Collemboles Hypogastruridae épigés et cavernicoles. Rev. Ecol. Biol. 501, 6 (2): 209-220. Thibaud, J.-M. 1970. Biologie et ecologie des Collemboles Hypogastruridae Edaphiques et cavernicoles. Mem. Mus. Nat. d'Hist. Nat., Serie A, 61 (3): 83-201. TUrne, E. von. 1961. Dkologische Experimente mit Folsomia candida (Collembola). Pedobiol., 1: 146-149. Uchida, H. and Chiba, S. 1959. Studies on thedevelopment of Tomocerus minutus Tullberg. Zooi. Mag. (Dobutugaku Zassi), 68: 200-204. 135 Uchida, H. and Hongo, T. 1962. Studies on the development of Tomocerus minutus Tullberg, III. Statistical analysis on the deve10pmenta1 stages. Zool. Mag. (Dobutugaku Zassi), 71: 91-97. Vail, P.V. 1965. Colonization of Hypogastrura manubrialis, with notes on its biology. Ann. Entom. Soc. Am., 58: 555-561. Vannier, G. 1970. Reactions des Microarthropodes aux variations de l'état hydrique du sol. Techniques relatives 5 l'extraction des Arthropodes du sol. Editions du Centre National de la Recherche Scientifique, (Progr. no. 40), Paris, 320 pp. Waldorf, E.S. 1971 a. The reproductive biology of Sinella curviseta (Collembola: Entomobryidae) in laboratory culture. Rev. Ecol. Biol. S21, 8 (3): 451-463. Waldorf, E.S. 1971 b. Selective egg cannibalism in Sinella curviseta (Collembola: Entomobryidae). Ecology,52 (A): 673-675. Waldorf, E.S. 1971 c. Oviposition inhibition in Sinella curviseta (Collembola: Entomobryidae). Trans. Am. Microsc. Soc., 90 (3): 314-325. Wharton, G.W. 1946. Observations on Ascoschongastia indica (Hirst, 1915) (Acarinida: Tromblculidae). Ecol. Monogr., 16: 151-184. White, J.J. and Zar, J.H. 1968. Relationships between saturation deficit and the survival and distribution of terrestrial Isopods. Ecology, 49: 556-559. Wilkey, R.F. 1959. Preliminary list of the Collembola of California. The Bulletin, Dep. Agric., State of Calif., 48: 222-224. WiIlson, M. 1960. The effect of temperature and light upon the phenotypes of some Collembola. lowa Acad. Sci., 67: 518-601. Winston, P.W. and Bates, D.H. 1960. Saturated solutions for the control of humidity in biological research. Ecology, 41: 232-237. 136 Wray, D.L. 1950. Insects of North Carolina, Second Supplement. Publ. Nth. Car. Dep. Agric., (Collembola: pp 6-8). Wray, D.L. 1967. Insects of North Carolina, Third Supplement. Publ. Nth. Car. Dep. Agric., (Collembola: pp 6-12). Wray, D.L. and Knowlton, G.F. 1956. Further additions to the list of Collembola of Utah. Great Basin Nat., 16: 7-8. 137 APPENDIX 1 Onychiurus justi porteri n.ssp., 80°F: Percent mortality of adults at various relative humidities. TIME PERCENT R.H. 80 90 95 100 10 min 20 30 40 50 60 70 80 90 100 110 120 130 140 3 hrs 18 21 42 47 77 140 171 217 96 100 10 25 56 80 93 100 44 90 93 98 100 10 22 30 42 138 APPENDIX 11 Onychiurus justi porteri n.ssp., 70°F: Percent mortality of adults at var ious relative humidities. PERCENT R.H. TIME 0 80 90 95 1100 10 min - 20 27 30 98 40 100 - 50 2 60 10 70 22 80 69 - 9O 93 5 100 100 10 110 22 120 48 130 58 140 72 150 85 I60 96 170 100 3 hrs - 17 68 - 48 87 1 90 94 3 138 96 4 216 6 139 APPENDIX III Onychiurus justi porteri n.ssp., 60°F: Percent mortality of adults at various relative humidities. PERCENT R.H. TIME 0 80 90 95 100 10 min - 20 - 30 32 40 93 50 100 60 80 3 90 11 100 49 110 72 120 88 - 130 96 7 140 100 12 150 16 160 30 170 46 180 62 4 hrs :00 - 17 4 45 53 - 67 56 1 96 68 I 138 73 2 2 I 6 I. 140 APPENDIX IV Onychiurus justi porteri n.ssp., 50°F: Percent mortality of adults a t va r ious relative huni dities. PERCENT R.H. THE 0 8O 90 95 100 10 min - 20 - 30 7 40 40 50 94 60 100 - 2 hrs 3 3 34 4 90 - 5 100 12 6 28 7 44 8 65 9 84 10 100 '- 18 2 42 23 63 112 90 50 138 65 - 258 7] - 141 APPENDIX V Onychiurus justi porteri, 60°F: Average egg production per week, for ‘_______, 3 r,¢j i\/iduals reared in mass cultures. Average egg production = Total "0' 0f eggs/week Average no. of individuals/week AVERAGE NO. OF INDIVID. AVE. EGGS/ INDIVIDUAL TOTAL NO. OF EGGS WEEK 28 142 APPENDIX VI Onychiurus justi porteri, 70°F: Average egg production per week, for ? "dividuals reared in mass cultures. Total no. of eggs/week Average egg production = Average no. of individuals/week sé . a: m2 2.6 32 GO (.5 NJ— m:—- I<|u --— I.” l— 11.10 WEEK 3'28 8‘5 3:5 4 645,42 257 0.3981 s 590.42 523 0.8858 6 551,28 302 0,5478 7 511.23 55 0,1075 3 663,23 256 0,5666 9 622,23 :07 0,2533 10 378,71 47 0,1241 11 340,28 :94 0,2762 12 287,71 65 0,2259 13 268,42 35 0,1303 14 266,23 65 0,1842 15 226,57 12 0,0529 16 207,28 9 0,0434 143 APPENDIX VII Onychiurus justi porteri, 80°F: Average egg production per week, for individuals reared in mass cultures. Total no. of eggs/week Average egg production = Average no. of individuals/week czié . a: m2 Sm 83 on (D 12.1— 0 (.5: 1.1.1— 20': (.50 (DO (5 1.1.1— m- (m .— “12 "u §° > 0 2 WEEK <0 1—o <- 00 4 145 APPENDIX 1X Onychiurus fisti porterL 70°F: Average egg production per week, for F ndividuals reared in groups of five or less. Total no. of eggs/week Average egg production = Average no. of individuals/week AVE. EGGS/ INDIVIDUAL TOTAL NO. OF EGGS WEEK N # AVERAGE NO. 0" OF INDIVID A46A.-.lvlb miV IrbAV. ..ulflvufliufon Fina ‘Wf51-0H11VL thaws-CUVI. “V'LMV ..lU—FWP-s .‘AV Jul-IshhflvA-h LAU‘ (Jean‘s); Lari cflfih hL-\\r\1hlh CI:\I,H 6.5.5ch h1t1‘lhl\c Kline's-N nv‘n.§§~\ I\li>u\fii\ 146 x x_ozu¢¢< - - - - - - - - - - mm-m. - sm-nm - moz<¢ ..m. - - .Ns. - ..s. - .Ns. - - m.NN .mN. m.ms .N.. uu<¢m>< . - - . - . - . - - N . N . uz.><4 mm4< N s N a N m - . m . N N . N r . uz.><4 mm.<:m. .oz mm mm mm go. no mm - NN N6. N. NN mN m. m. - w. muam .0 .oz .< N _ M - . I. M N 6 M 6 M N M. M N 62:26 MM6- afi}: ‘5 U) 00 -< mu: 2 2 ol— O_I >u. < — Z Z <[ a: 5 18 1 (18) - 6 25 2 12.5 7-18 8 23 2 16,0 10-18 9 110 6 27,5 18-63 10 77 3 25,6 8—62 11 93 3 31.0 26-37 13 160 5 28,0 13-39 16 70 3 23,3 16-33 15 151 5 30,2 11-66 16 101 3 33.6 18-56 I7 38 1 (38) - 18 66 2 33.0 19-67 19 61 1 (61) - 20 - - - - 21 62 1 (62) - 22 - - - - 23 31 1 (3|) - 169 APPENDIX XIII Onychiurus justi porteri, 70°F: Egg production per instar, for pairs OF male and female reared in isolation. (21 reps) m o: ‘3 E m <1: 62 8 .1 E g 25‘ 3 < u.1 < u. - <1: <: m 1— 1— >- o: z c: m - o - <£ 1.1.1 1.1.1 2 Z O 1— O ....I > LL < . M 6 M M M N M o. .. N. MMM=N6MM no .02 MM 6M MM NM .M oM MN MN NN MN MN m< M. 6. 6. M. M. M. M. N. N. N. N. M. MMMMN666 Mo .02 6N MN NN .N MN M. M. N. M. M. 6. M. M< N., M. M. M. M. M. M. M. M. M. M. M. MMMMN66M Mo .oz N. .. o. M M N M M 6 M N . M<6Mz_ 63...... ...... ...... .... ...... .. 5...... 3...... EM... >.x x32mm¢< was 53...... Egg 151 M1M N1M M1M o.1N M1M M1N c.1m N1M M1N M1M M1M M16 MM2< N N N M 6 6 6 6 M M N N MMM=N6=M .6 .oz 06 MM MM NM MM MM 6M MM NM .M oM MN m< N N M M o. .. 6. M. M. N. M. M. NN MN MMMMN.=M .0 .oz MN NN MN MN 6N MN NN .N oN M. M. N. M. M. MMNMz_ N.1M o.1M ..-M M1M M1M M1M M1M 0.1M M1M M1M M16 M16 M16 M1M MMz< 6N MN MN MN MN MN MN MN MN MN MN MN MN MN MMMMN66M .6 .oz 6. M. N. .. o. M M N M M 6 M N . Mx x_o2mmm< 26...... .. ...... ...... ...... s... .1611. {A 04-75 ~.~1§t\ 152 M1M M1M o.-M c.1M M.-M N.1M o.16 M1M M16 M1M M1M M-6 MMz< N 6 M N M o. .. .. 6. M. M. M. MMMMN63u no .oz MN 6N MN NN .N MN M. M. N. M. M. 6. M< M. M. M. M. M. M. M. M. M. M. M. M. M. MMMMN63M .0 .02 M. N. .. o. M M N M M 6 M N . M6NM2. .>x x.azusa< .Mo.=._=u Macao. MMMe Lo. .MNMM c. .MMMM.M>N 60.66.6M .MMMc_ .NoMM ...outoa ..MMM.NMMMMMMNNM In"! 1111 1111- 1 1 I Q): xii-Z Oatnhl\ 153 __1M N_1__ M1M 0.1—— M_1w m_1__ o_1M 6...... N_1N 6.1M o.1N v.1.— mwz<¢ MM.M mm..— MM.M MM.N. MM.M 00.n— MM.M oo.N_ MM.M Mm..— oo.w MM.N. ma<¢m>< mumshgzu no .02 MM NM MM MM 6m MM NM .M om mN wN NN ¢< mm136420 no .02 wN mN 6N MN NN NN 0N m. mp N— M— m. :— ¢< mmmthau no .02 M— 32 .o 2.: 655...... 3.3.... .... 5..... ... 6.2.2.... .36.. OMEN... ......M . 2... 562.6%... N— __ o— M: $.43 ¢.uc. gm VA c A~z -.~§\/\ 151! m-N N-M M-M m-M m-q M-M m-M M-M m-m M-M m-m o.-m moz< N N M M M M M M M M a m mmm:N.:u .o .02 MM NM MM MM :M MM NM .M 0M MN MN NN m< N N N N N N N N N N N N N mmxzp.:u no .oz MN MN :N MN NN .N ON M. M. N. M. m. :. ¢< N N N N m m m M N w w M w mmm:p.:u .0 .02 M. N. .. o. m M N M m a M N . . m.uc. 34% ... .3 \N . ..z ...—53.8 35:3 .... ...... .... .522... .32... as»... ......N 3%. ...m. ...>x x.ozuaa< VA. '5 b 9021'.\I\l\ 155 ..-M :.uN o.u: N.-M ..uM M.:M o.uM ..-: N.-M muz<¢ OM.w MM.M om.M oo.m MM.M oo.m oo.w a..N MM.M mw<¢m>< mumahqau no .02 NN MN MN MN NN .N 0N m. m. N. M. M. m< o. o. o. o. o. o. mmmah4=u no .02 :. N. o. ¢.uc. g. a a... .553... .33... ... .... .. ...... ...... as... ...... EN... .....me x.x x.ozua¢< xx Xhhlz IIIIII‘ 156 M.-.. N.-o. o.-M M.-o. o.-M M.-.. M.-M M.-.. NN-M M.-M M.-M M.-M MM2< N N N N N M M M M o. o. o. mmh< o. o. N. M. M. M. M. M. M. M. M. M. MM. <: — 21 <12 0: 1 28 5,53 5'7 3 28 5;89 “-9 h 28 6,14 h-9 5 28 6,21 3'10 6 28 6,67 5710 7 28 7,0 h-IO 8 28 7,21 5'12 9 27 6,hh h-ll 10 26 6,69 h-IO 11 21 6,38 h-9 12 18 7,05 “-11 13 18 7,22 h-ll 1h 17 7,17 5-10 15 1“ 7,85 h-ll 16 12 7,91 6-11 17 11 6,18 5-11 18 7 3,28 6'12 '9 5 5960 “-7 h uxx XhA1uz‘d-§«§I\ 158 oN-N N.-M ..-M N.-M MN-M MN-M MM-N M.-M M-M M-M M-M N-M MMz< M M M M M M N N N N N N mmh< M M M M M M M M M N o. MMp< M. M. M. M. MN ON ON oN MN oN ON ON mup_xx x.ozmmm< 161 APPENDIX XXV Onychiurus justi porteri n.ssp., 80°F: Instar duration, in days,for isolated females. V) 1.1.1 '— XX X~CZ¢~QL< 162 M-N M.-M M.-M MN-M M.-M N.-M .N.-N M.-N M.-N M.-M NN-N M.-N N.-N M.-M M.-M o.-M MMzMM o.M MM.N. .M.M NM.M. NM.M MM... MM.M. MM.M. MM.M. .M.o. MM.M. MM.M. o.o. ..... MM.M. ...M MM< M M N. M. M. M. MN MN MN MN MN MN NN NN NN NN MM.xx x.ozmmm< mam ma.:.;uxco 163 M-N M-M ..-M ..-M N.-M M-M M-M M-M ..-M ..-M M-M M-M o.-M MM2<¢ oM.N NM.M MN.N oM.N MN.N MM.M MN.N MM.M M..N MM.M MM.M NN.M MM.M MM< M N M. M. M. M. M. M. M. N. N. M. M. mmN< M. N. M. .. .. o. o. o. o. o. o. o. o. o. mupco __>xx x_azmmm< 16h APPENDIX XXVIII Onxgbiurus lystl porteri n.ssp., 80°F: Instar duration, in days, for isolated males. U" t3 < 1.1.! (K LL) (D E 0: 3e 3 U) 'Q. LL] 2 Z OUJ > < — 2“ <[ M 1 30 6,20 5‘9 2 30 6,13 4'12 3 30 6,h3 5'10 h 30 6,80 “-11 5 30 8,13 “'24 6 29 10,2“ 4'25 7 29 10,96 5'32 9 26 11,61 5'29 10 23 10,26 5'23 II 20 14,10 5'38 12 17 11,23 6'22 13 14 12,21 5'23 1“ 10 10,80 5'28 15 8 10,37 7'22 16 8 15,12 9'29 18 3 6,0 6 165 ..-M M.1o. N.1M M.-M N.-M M.-M N.-N M.-M M.-o. M.-M M.-N ..-M M.1M 0.1M Moz<¢ o.o. oM.N. MM... MM.M NM... NM... o.M MM... MN... MN... NN.M. MM.M MM.M. NN.M Mu<¢M>< M M M M N M M M M M M M M M mmNco x_xx x_ozmmm< 166 M1M M1M M1M ..-M o.1M ..-M moz<¢ oo.N oo.N MM.M MM.N MM.M MN.N uc<¢m>< mmh< mmhmc c. .co.um.:u .mumc. "moON ..amm.c ..0u.om .umam m3.:.;uxco 167 N.1m N.1m M.um M.1M M.1N M.-M M.-M MN-M M.-M MN-M M.-M .N-M M.-M ..-M ..-M MM2<¢ MN.M. NM.M. o.N. NN... o.o. MM.M. No... o.N. MM... MM.M. MM.M. o.N. MM.M. M..o. MM.M MM<¢M>< M M o. .. .. N. M. M. M. M. M. M. M. M. M. mmN< M M M M a M M M M M M M M M M M M M M M .u.4mmm mo .02 ON m. M. N. M. M. M. M. N. .. o. M M N M M a M N . mco __xxx x.ozmmm< I69 MM.N. MM.M. .M.M. N..M. MN.N. MM.N .M.M M.MMM-M.M.M ..MMM-N.MMN N..MM-M.MMN ..MMN-....N M.MNN-M-MM. M.MM.-M.MN. MM2< I.N.: NN.M. MN.M. NM.N. oM..N NM.N. MM.M .M.M M.MMM-M.MNN M.M.M-M.MMN N.NMN-M.M.N M.MMN-o..M. M.MM.-M.NM. o.N..-M.MM MM2< MNMZMM MN MM M. N M. M MMN.vc. Mo Laumc. x.m um..m ecu c. MNM.3 Mao; Mam Lumen. Mme: "mooM ..amm.c ..ou.oa .umaw m:.:.cu>co 170 MN... MM.M. MM... MM.M. MM.M .M.M .M.M N.NMM-M.M.M ..MMM-M.MNN N..MM-M.MMN N..MN-M.M.N M.MM.-..MM. M.MM.-M.MN. MM2< MNM_3 MM.M. MM.M. MM.M. .M.M. MM... MM.M .M.M M.MMM-M.NMN M.NNM-M.MMN ..oMN-M.MoN N..MN-M.NN. M.NN.-M.MN. M.NM.-M.Mo. MM2< INMzMM oM MM .M MN MN NN mmN.nc. mo memumc. x.m um..m ocu c. zuu.3 two; ucm cameo. Mao: "MOON >_xxx x.ozmmm< .o.:u.:u mmme c. MoLmo. ..amm.c ..uu.om .umaw m:.:.;u>co 171 MM.M. MM.M. MM.M MM... MM.N. MN.N .M.M M..MM-N.NMN M.M.M-M.MMN M.MNN-M.MMN M.MMN-o..M. M.MM.-M.oM. ..MM.-M.MN. MM2< :NM_: NM.M. MM.M. MM.N. MM.M. MM.M. .N.M. .M.M M.o.M-N..MN N.MNN-M.MNN M.MMN-M.MoN M.M.N-M.MM. M.NN.-M.oN. .M.NM.-..MM MMz< :NMZMM NN MN o. NN MN 0N MMNxxx x.ozmmm< .o.:~.:o mmmE c. Mega». M.m:u.>.uc. Mo menumc. x.M Mme.» ecu c. sun.3 Mao; Mcm :umco. Mme: "NOOM ..amm.c ..oMLOQ .ummw m:.:.;u>co 172 APPENDIX XXXVI Onychiurus lysti porteri n.ssp., 60°F: Over-all length in microns. INSTAR NO OF REPLICATES AVERAGE RANGE I -22 -200 0 I 11 -l 1 2-1 - 0 1 20 '2012 173 APPENDIX XXXVII Onychiurus justi porteri n.ssp., 70°F: Over-all length in microns. AVERAGE RANGE REPLICATES x < ... (D 2 NO. OF 174 APPENDIX XXXVIII Onxghiurus justi porteri n.ssp., 80°F: Over-all length in microns. NSTAR 0. OF EPLICATES AVERAGE RANGE N O 0 175 x_xxx x.ozm¢m< - - - - . MM.MMM.. .1mM - - - M.MMM.-o.ooN. M M.MMN. 1mm1 - - - 1M.N.oN-M.oNM. M M.MMM. .m - - - - - - o - - - mwMMoN-o.MMM. M ..oMN. MN - - - M.MMM.-N.NMM.1 M M.NMNN MN - - - .M.MMM.-M.MMM. o. M.MMM. 1NMN M.NMM.-N..NM.1 N 1M.NMM. M..MMN-M.MMM. M NNNoM., 1MN - . No..NN.. N.MMNN-N..MM. M. M.MNM. 1MN ..MMM.-M.oMM. N M.MMM. N.MM.N-..MMM. M. M.MNM. MN - - - .M.MMM.-M.MMM. N. N.M.M.. MN N.MMMN-M..NoN M M.NN.N .M.MNMNnm.MMMN N M.NMM. NN IIN.MM.NJM.MMON N .M.NMMN M.NMM.-M.NNM.1 o. M.MMM. .N M.MmMN-M.MMNN 1M M.MMMN M.N..N-N.MMM. M M.NNM. MN M.NMM.-N.NMM. N M.NNMN11 M..MNN-M.N.M. o. ..MNMN M. MNNM.N1M..NN. N M.NMM. M.NMoN-M.MMN. N ..MMM.1 .mr M.MM.N-..MNN. M M.NMMN .M.MoM.-M.N.MN M. M.NMN. N. M.NMM.-M.MMM. N .N.MMM. M.Mm.N-M.MMN. M M.MMM. M. M.MNMN-M.MMM. 1M N.MMNN M.NMoN-M.MNM. 1M M.NMM. M. ..MMNN-N.MMM. M. .N.MNM. M.NM.Nuo.NMM. N M.NMM. M. M.MMMN-M.N.M. N. M.M.M. M..MNN-M.MMM. M M.MMM. 1m. .M.MMoN-M...M.1 M M.MNM. M.MMM.-o.OMM. .N M.NNN. N. ..Mo.N-M.MMM. 1M M.NoM. .M.MMM.-N.MMM. o. ..MMm. .. M.NMMN-M.MNM. M. .M.MMM. .MMMM.N-..MMM. 11M ..MMN. o. .M.MNNN-M.MMM. M. M.MMMN1 -M.MMM. . .N.M.oN. M M.MM.N-M.MNNN, N. .N.MMM. - - - M M.MMNN-M..MM. MM M..MM.1 M.MNM.-M.NoN. N N.MMN. 1N M.NoM.-M.MMM. N. ..MMM. ..NNM.-M.MNM. M 11N~NoM. M. ..MMN.-..MNN. .M1 M.MMM. M.MMM.-N.NMN. o. M.MNM. M M.MMM.-M.MMo. N.1 M..MN. M.MMM.-N.NM.N1 M N.MMN. M MM2< MM2< «o ommco>< "MOOM ..qmm.c ..oucom .um3M m:.:.;oaco 176 APPENDIX XL Onxchiurus jysti porteri n.ssp., 70°F: Average over-all length, in microns, for males and females. M A L E S F E M A L E S INSTAR AVERAGE REPL. RANGE AVERAGE REPL. RANGE 177 - . M.MMM. M.MMM.-..NMM. M M.MNM. 11mw - - - Madam.-NqNoM. M 11NMMMM. MN M..MN.-N.MNM. M mfiMMM. NMMNM.-M«NMM. .. ..MNM. MN - . M.MNM. N.MMN.-M.MMM. N N..MM. NN N.NoM.-NmMMM. N M.MMM. M.MMM.-N.MNM. N. MqMMM. .N MmM.oN-N«NMN. M .M.MNM. M.MMM.-N.MMM. M N..MM. MN - - - M.MMM.-M.MM.. M M.MMN. M. M.MMM.-..MMM. M M.MMM. M.M..N-MMNNM. M. M.M.M. 1M. M.MM.N-M.MMN. 1w, M.MMM. MNMMNN-M.MMM. o. N«M.M. 111M. MMMM.N-M.MNM. M M.MNM. 1mwMNM.-..M.M. M. N..NN. M. M.MMM.-M«MNN. M N.MoM. M.MMM.-M.M.N. “W1 N.MMN. 1m. M.MMoN-M.oMM. M N.MMM. M...oN-M.oMN. M wwMMMN1 M. M.NMNN-N..mN. M oqNMM. M.M.M.-M.MMM. M WNMMMM. M. M.MM.N-N.MMM. M. M..MM. - . NMMNM. N. M.MM.N-o.M.M. M. N.NMM. M.M.oN-N.MMm. 1m11. 1M.ONM. .. N.MNM.-M.NNM. M 1N4MMN. M.M.N.-..MMM. M N«MNM. o. M.MMM.-M.NNM. M. MMMMN. - . .M.M.M. M M.MMM.-N.MMMN1 .N M.NMM. ..MMN.-M«NNM. N NMMNN. m ..MMN.-M.MMM. M. M.MMM. .«N.M.-M.MoM. N o...M. N o.M.M.-M.MNM. M. N.MNM. M.MNM.-M.MMM. N M.MMM. M ,MMMMM.-M.mNN. MN MMNNM. N.MMM.-M..NN. M M..NM. M M..MN.-N.No.. N N.MM.. MNMNN.-N.MMN. N MMMMN. M MMz< MM2< MMNMz. M M M < x M M M M M < z .mu—mEow ..x x.ozmmm< ucm mo.mE .oN .mcocu.E c. .gumco. ..w1.o>o ommco>< "MoOM ..amm.c .coucon .uwmd m:.:.cu>co 178 APPENDIX XLII Onychiurus justi porteri n.ssp., 60°F: Percent mortality in mass reared cultures. .230 .hxoz .Nmmomzh+ .Mazau .xmmzN..moz M>.N<.=zsu .MMM3N >N_M<.Mox ..MMMMMN .>_oz_ QMM¢2h_4_NN_M<.Moz NZMMMM. xmm3N>h_._oz_ 4_oz_ 4_h<4:z:u .xmm3N .Nxcz 4.oz_ omqmzk_4_.N_MN_4_oz_ .(NOP xumz Iu_oz_ 4_N_az_ om4mzN.4.NN_MN_4_oz_ 4.az_ 4h_4_oz_ no .02 xmmz mmo. .o o>.m .mxooz M: ecu mo wee ocu um noumc.Ecou mm: mo.com och .m.m:o.>.vc. mc.c.mMcoo Mocau.:o c. .xooz con .Nu..mu.oe acoocom "MOMM ..amm.c .coucom .umaw m:.:.;uxco >4x x.ozwmm< 182 APPENDIX XLVI Onychiurus justi porteri n.ssp., 70°F: Percent mortality, per week, in cultures containing five or less individuals. WEEK N0.0F INDIV. IN CULTURE DEATHS PERCENT MORTALITY I83 APPENDIX XLVII Qnychiurus justi porteri n.ssp., 80°F: Percent mortality, per week, in cultures containing five or less individuals. N0.0F INDIVID. IN CULTURE MORTALITY DEATHS PERCENT x m Lu 3