ACARINA ASSOCIATED WITH MECHIGAN
EOMBINAE

Thesis for fhe Degree of Ph. D.

MICHIGAN STATE UNIVERSITY

Rainer? Wayne Husband
1965

TH '9‘ $11 I S

LIBRA 1:: “1 '

Michigan State
University

       

This is to certify that the E
thesis entitled

ACARINA ASSOCIATED WITH

MICHIGAN BOMB INAE

presented by

Robert Wayne Husband

has been accepted towards fulfillment
of the requirements for

_Eh_-L~__ degree in JQQJQQL

flew

Majorrprofflr

 

Date November 28, I966

 

0-169

ABSTRACT
ACARINA ASSOCIATED WITH
MICHIGAN BOMleAE

by Robert W. Husband

This study is concerned with the distribution, associ-
ations and descriptions of Acarina found in or on Michigan
Bombinae or in Bombinae nests.

Locality information for more than 15,000 Michigan
Bombinae was used in determining Bombinae distribution.
More than 6,000 Bombinae were collected since 1963. Mites
were removed from bees and their nests and placed on slides
or in 70% alcohol. Determinations were accomplished by the
use of the available literature and all mites appearing in
the thesis were determined or confirmed by the authorities
which are listed.

Seventeen of 19 species of Bombinae in Michigan have
ranges that terminate at latitudes within the state or at
the borders. Bombinae distribution patterns appear to be
most closely related to rodent distribution, the 700F July
isotherm, rainfall, vegetation, terrain elevation and host

distribution for Psithyrus spp. Acarina were common to 26

 

of 27 Bombinae nests examined.
Techniques for examining Bombinae for mites are presenUaL

Locustacarus (Bombacarus) buchneri (Stammer) 1051, new com—

 

 

bination, is redescribed and discussed in detail. The relative

Robert W. Husband

abundance of Michigan Bombinae with mites is highest in ApriL
steadily decreases until August and reaches a second peak in
October. Queens and males in nests had a higher percent of
infestation with hypopi. The propodeum and abdominal segment
I are demonstrated to be the most likely areas for occurrence
of mites and the areas most likely to bear the highest num-
bers of mites. A check list of twenty five families of mites
found with Bombinae is provided. Distribution records and
species associations of mites and bumble bees collected at
flower and in nests are presented.

The distribution of Pneumolaelaps spp. in North America

 

is discussed and Pneumolaelaps longanalis n.sp. (Acarina:

 

Laelaptidae) is described. Kuzinia laevis and Scutacarus

 

 

acarorum were found on most Bombinae throughout Michigan.

Pneumolaelaps spp., Parasitus spp.and Proctolaelaps spp.

 

 

 

occurred with less frequency. Locustacarus buchneri is

 

relatively host specific and is found primarily in the air

sacs of Bombus bimaculatus. Michigan mites found with Bom-

 

binae range from mites which feed upon decaying leaves in

the nest to fungivorous, predaceous and parasitic mites.

ACARINA ASSOCIATED WITH

MICHIGAN BOMBINAE

By
Robert Wayne Husband

A THESIS

Submitted to
Michigan State University
in partial fulfullment of the requirements
for the degree of

DOCTOR OF PHILOSOPHY

Department of Zoology

1966

@Copyright by

Robert Wayne Husband

‘1967

ACKNOWLEDGEMENTS

For stimulating my interest in Acarina initially,
encouraging my efforts of several years, for teaching me
what I know about invertebrate zoology, for in-the-field
training and for guidance with this work, my sincere
gratitude goes to my major professor, Dr. T. Wayne Porter.

I am grateful to the members of my committee;

Dr. Roland Fischer for help with problems associated with
the Bombinae, Dr. M. Max Hensley for assistance with
ecological problems and Dr. David Clark for help with
parasitic acarina. All have contributed much to my under-
standing of these areas.

I wish to thank Michigan State University for use of
facilities at the Gull Lake Biological Station. I am grate-
ful to Adrian College for use of facilities and two research
grants for the summers of 1965 and 1966. The assistance of
the library staff of Adrian College, particularly Mrs. Helen
Barone in securing references, was very helpful and is much
appreciated.

I wish to thank Dr. Edward Baker not only for identi-
fications of Acaridae but also for permitting me to look at
slides and references in his private collection and for
advice on various acar010gical topics.

I am also very grateful to Dr. Preston Hunter of the
University of Georgia for guidance, encouragement and a

great deal of help with Pneumolaelaps spp.

 

ii

Dr. Earle Cross, Dr. Joseph Camin, Dr. Donald Johnston
and Dr. J. R. Hoffman have provided identifications and
encouragemen t .

Fellow officers and airmen in the Michigan Air National
Guard were very understanding and cooperative in collecting
efforts. I am grateful for their support.

I would like to thank the National Institute of Health
for a fellowship to the Institute of Acarology at the Ohio
State University in 1965.

I would 1 ke to thank Mr. Wayne Lancaster for the use of
his camera and technical assistance with photos of Bombinae.

Mrs. Bernadette Henderson, secretary of the Department
of Zoology, put forth many efforts in my behalf in the past
several years and they are much appreciated.

Finally, I would like to express a special note of
gratitude to my wife, Patricia, without whose efforts,
encouragement and understanding this thesis would not have
been possible. She helped in the collecting, did nearly all
of the typing and has been a constant and steady source of

inspiration throughout the years.

iii

TABLE OF CONTENTS

PART I
MICHIGAN BOMBINAE
Page No.
INTRODUCTION ...................... .............. . ..... .1
METHODS AND MATERIALS ................. ...... . ...... ....l
ANATOMY OF BOMBINAE .............. .................... '. 2
SYSTEMATICS OF MICHIGAN BOMBINAE ------- - ooooooooo ..... 6
KEY TO SPECIES OF MICHIGAN BOMBINAE ................... 9

DISTRIBUTION OF MICHIGAN BOMBINAE .....................15
ECOIOGICAL FACTORS WHICH MAY INFLUENCE

MICHIGAN BOMBINAE DISTRIBUTION o..................4l
NESTS OF MICHIGAN BOMBINAE ............... ..... ....... 58

PART II
ACARINA ASSOCIATED WITH MICHIGAN BOMBINAE
INTRODUCTION ..........................................65
METHODS AND MATERIAIS ................................ 66
THE BIOLOGY, DISTRIBUTION AND NEW COMBINATION OF

Locustacarus (Bombacarus) buchneri (Stammer)1951..75

 

THE RELATIVE ABUNDANCE OF MITE-INFESTED BOMBINAE IN

TWO SELECTED NESTS ...............................86
POSITION AND NUMBER OF MITES ON VARIOUS ANATOMICAL

PARTS OF MICHIGAN BOMBINAE .......................93’
CHECK LIST OF MITES ASSOCIATED WITH MICHIGAN BOMBINAE~JO4
ACARINA ASSOCIATED WITH MICHIGAN BOMBINAE IN NESTS ...107

ACARINA ASSOCIATED WITH MICHIGAN BOMBINAE AT FIOWER...llO

iv

.11! llllvlllll‘ll‘llll.lllllllll

Page No.

THE DISTRIBUTION OF Pneumolaelaps spp. IN NORTH

 

AIERICA WITH DESCRIPTION OF A NEW SPECIES

(ACAIRIM: MEMPTIDAE)OOOOOOOO00.00000000000000009117

RELATIONSHIPS BETWEEN ACARINA AND BOMBINAE,,,,, ,,,,,,,, .150
SUTflMARYoooeooeeoeeeocoo.o oooooooooo coo oooooo c ooooooo 0000145
APPENDIX 0.0000000000000000... ...... ooeooooe oooooo 000000148

LITE-IRA’I'URE CITEDOOOOOOOOO 00000 0.00.00.00.00...0.0.0.0...157

Table

Table

Table

Table

Table

Table

Table

Table

Table

Table

Table

Table

7.

8.

10.

ll.

12.

IJST OF TABLES

Page No.

Invertebrates found in 27 Bombinae nests.......63

Locustacarus buchneri, female, leg

 

ChaetOtaxyoo...........o....o..........o....oo '79

Locustacarus buchneri, male, leg

 

chaetotaxy............. ................. ...... 82
The seasonal occunence of Acarina on

Michigan Bombinae............................. 87
Frequency of mite-infested Bombinae collected

at flower in 1964 and 1965.....................89
Frequency of upper peninsula,mite-infested

PSlthJYI’US spp. .90000000000000 ccccc 00.00000... 90

 

Incidence of mite-infested Bombus bimaculatus..92

 

Position of mites on Michigan Bombinae
cellected in 1963.00.00.00000000000000.0.00.00098
Number of mites per body part for 29 male

Bombus pgnnsylvanicus.........................lOO

 

Number of mites per body part for 17 queen

Bombus pennsylvaniqug.........................lOl

 

Number of mites per body part for 48 worker

Bombus pennsylvanicus.........................102

 

Summary of mites per body part for

93 Bombus_pennsylvanicus .....................105

 

vi

Table

Table

Table

Table

Table

15.

14.

15.

16.

17.

vii

Distribution of Pneumolaelaps

 

mistipilus Hunter 1966 -....... ..... ..

 

Distribution of Pneumolaelaps

 

aegualipilus Hunter 1966 .............

Distribution of Pneumolaelaps

 

longipilus Hunter 1966.........

 

Pneumolaelaps longanalis n.sp.,

female leg chaetotaxy ........

Distribution of Pneumolaelaps

 

longanali: n.sp. ...............

 

Page No.

... 118

... 119

00.0.000000119

...124

...129

Figure
Figure
Figure

Figure

Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure

Figure

l.
2.
5.

4.

19.
20.

IJST OF FIGURES

Bombus nevadensis,

 

Bombus nevadensis, female, dorsal aspect...

 

Page No.

fen/13160000000000.0000.coo5

. 5

Bombus nevadensis, female, ventral aspect... 7

Map of Michigan counties with scale,

latitude and
Distribution
Distribution
Distribution
Distribution
Distribution
Distribution
Distribution
Distribution
Distribution
Distribution
Distribution
Distribution
Distribution
Distribution
Distribution
Distribution
Distribution
Distribution

Distribution

longitude-.

of
of
of
of
of
of
of
of
of
of
of
of
of
of
of
of
of
of

of

Bombus affinis.

 

Bombus

bimaculatus........

 

Bombus

borealis ..

 

Bombus

fervidus

 

Bombus

frigid-us 00000000000

 

Bombus

ggiseocollis.

 

Bombus

impatiens...........

 

Bombus

nevadensis.. ........

 

Bombus

pennsylvanicus......

 

Bombus

perplexus.......

 

Bombus

rufocinctus.........

 

Bombus

ternarius....

 

Bombus

terricola ..........

 

Bombus

vegans

 

Psithyrus

Psithyrus

aShtoniIoooooooeo

fernaldae........

 

Psithyrus

insularis........

 

Psithyrus

laboriosus.......

 

Psithyrus

variabilis.......

 

viii

00.0000018

19

..20

21
22
25
24
25
26
27
28
29
30
51

55
54
35
36

37

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

24.

26.

27.

29.

50.

51.

52.

65.

55.

56.

57.

ix

Page NO.

Northern limits of selected Michigan

I'OdentS-......... 0000 42

Southern limits of selected Michigan
rOdentSOO.....OOOOOOOOOOO00.0000000000000009045

Average July isotherms, 1951—1960............47

Average annual precipitation, 1951-
1960, in inches.......
Average date of last temperature of

SZOF or lower.000.00.00.00...00.0.0000000000049

 

 

 

 

Present Michigan forests.....................50
Terrain elevation in Michigan in

feet above sea level........................ 52
Locustacarus buchneri, dorsal aspect,

young female................................ 77
Locustacarus buchneri, ventral aspect,

younge female .............................. 78
Locustacarus buchneri, dorsal aspect,
male........................................ 80
Locustacarus buchneri, ventral aspect,
male........................................ 81
Position of mesostigmatid mites on

Michigan Bombinae........................... 95

Acarid hypOpi on thorax, wing and
abdominal tergite I of Michigan Bombinae.....96
Acarid hypopi on abdominal tergites

Of MiChigan Bombinae........................ 97

Figure

Figure

Figure

Figure

Figure

Figure

38.

69.

40.

41.

42.

45.

Page No.

Pneumolaelgps longanalis n.sp.,

 

dorsal BSRCt, female OOOOOQOOOOOOOOOOOOOOOOO 121
Pneumolaelaps longanalis n.sp.,
ventral aspect, female ...................... 122

Pneumolaelaps longanalis n.sp.,

 

dorsal aspect, male......................... 125

Pneumolaelaps lcnggnalis n.sp.,

 

ventral aspect, male ........................ 126

Scutacarus acarorum (Goeze), Kuzinia

 

laevis (Dujardin) and Pneumolaelgps

 

miStipiluS Hunter....OOOIOOOOOOOOOOOOOOO....V151

 

Locustacarus buchneri (Stammer)............. 132

 

ACARINA ASSOCIATED WITH MICHIGAN BOMBINAE
Introduction

Acarina were observed in bumble bee nests in America as
early as 1865 (Putnam 1864). Since 1864, many incidental re-
ports of mites in nests or on bumble bees have been made.
Although some studies have been accomplished in Europe (Posmmn~
1951), no intensive work on the mites associated with bumble
bees exists in the Americas. The present work is concerned
with the distribution, associations and descriptions of mites
found in or on bumble bees or in their nests.

Inasmuch as the distribution, anatomy and biology of the
Bombinae in Michigan are critical to the distribution of mites
associated with them, this study will begin with a report of
the present knowledge of Michigan Bombinae. The second part
will consider various relationships of Bombinae and Acarina.

PART I a MICHIGAN BOMBINAE

The contributions in this study on Michigan Bombinae are
unique to the extent that more recent data on systematics,
distribution and possible environmental relationships are now
available. The sections which follow provide a basis for
discussion of mite and bee relationships.

METHODS AND MATERIALS OF DEALING WITH BOMBINAE

locality information for more than 15,000 Michigan Bom-
binae was used to determine the ranges of the seventeen species
which occur in Michigan. Approximately 11,000 bumble bees
are in the Entomology Museum at Michigan State University

and the remaining specimens are in the Museum of Zoology,

l

2
University of Michigan. I have collected approximately 6,000

bumble bees in Michigan in the past three years. Determi-
nations were made by utilization of several published and un-
published keys and by comparison with specimens identified
by Frison, Franklin, Milliron and others. In some cases,
genitalia were removed. In a few cases, genitalia were pre-
served in alcohol or put on slides. The keys used are by
Chandler (1950), Fischer (unpublished key to workers),
Franklin (1915), Medler and Carney (1965) and Milliron (1959,
1961). The bees are deposited in the Museum of Entomology,
Michigan State University and the Museum of Zoology, Univennty
of Michigan.
ANATOMY OF BOMBINAE

Mites crawl over all external structures of bumble bees
but are more commonly found in definite areas on the bees.
A brief generalized description of the anatomy of the bumble
bee will facilitate the identification of the areas of po-
tential mite infestation.

A female Bombus nevadensig is chosen for illustration

 

as females are much more likely to be encountered. Males

and female Psithyrus sp. lack the pollen basket (corbicula)

 

on the metatibia (figure 1). Males possess an additional
antennal segment and abdominal segment. The terminology of
various structures is based on terms common to various keys
to Bombinae and terms used by Snodgrass (1956). Terms in
common use in keys are employed when conflicts are found.

A queen Bombus nevadensis with hairs removed is the model

 

OI

METACOXA PROPODEAL SPIRACLE

INTERSEGMENTAL PETIOLE
GROOVE 3 TERGHE
PRONOTAL

SPRACULAR SPRACLE
LOBE

  

STERNITE

ANTERIOR WING

/

METATIBIA

Figure 1. Bombus nevadensis, female

4

for illustrating approximate positions of various anatomical
structures. The proportions of the various parts differ
from.species to species but one set of terms is sufficient
for describing the positions of mites on bees.

A side view of Bombus nevadensis is illustrated in

 

 

figure 1. A view of the front wing and hind tibia are in-
cluded as these are common sites of acarid mite attachment.
As mites are rarely found on the head, a detailed descriptimn
is not given. The terminology necessary for understanding
the keys to species of Bombinae are presented in the next
section.

The thorax of the adult bumble bee is composed of four
segments. The pr0podeum which constitutes the fourth thonufle
segment of Bombinae is the first abdominal segment of many
insects. The prothorax is small in comparison to the rest
of the thorax. The procoxae and profemora fit into a groove
in the sides of the prothorax. The spiracle between the pro-
thorax and the mesothorax is protected by stiff hairs and
covered with the pronotal spiracular lobe. Dense body hairs
are usually found posterior to the spiracle on episternite
two. Thus, the spiracle is difficult to detect in Bombinae.
The large mesonotum is divided into a scutum and scutellum
(figure 2). The tegulae are sometimes confused with mites
by the uninitiated. A major portion of the pleura and ventor
is composed of fused sternites and episternites of the meso-
thorax. The third segment is reduced and separated from the

pr0podeum by the third intersegmental groove. A large

4n. PRONO TUM
ull§

SCUTUM

‘ \ TEGULA
SCUTELLUM
I-
H
III
IV

PROPODEUM
Figure 2. Bombus nevadensis, dorsal aspect, female

 

 

 

 

6

propodeal spiracle is found on the posteriolateral aspect
of the thorax. A deep constriction separates the pr0podeum
from the remaining primary abdominal segments. Inasmuch as
the first segment posterior to the constriction is con-
sistantly named abdominal segment 1 in keys to bumble bees,
to name this segment abdominal segment 2 (Snodgrass 1956)
would result in unnecessary confusion. Ventrally, the pro-
podeum is represented by a small sternite surrounded by
non-sclerotized tissue (figure 5). The narrow connection
of the abdomen and thorax is termed the petiole. Very small
spiracles may be found at the sides of each abdominal ter-
gite. The ventral sclerites are known as abdominal sternites.

SYSTEMATICS OF MICHIGAN BOMBINAE

While the systematics of various species of mites
associated with Michigan Bombinae are poorly known, the
systematics of Bombinae are fairly well known. Milliron
(1959, 1961) published on this subject in recent times. The
taxonomy used in this report differs from other publications
in ignoring subspecies and color variants, in the omission
of one species and the addition of another.

The sub-family Bombinae is one of the sub-families of
the fmnily Apidae. Bombinae may be distinguished from other‘
Apidae by the presence of two apical spurs on the hind tibia.
Other characteristics are: relatively large size, distinct
Inalar space (distance between eye and base of mandible) in

Inost and a distinct transaction of the first submarginal cell.

PROCOXA
MESOCOXA

METACOXA

PROPODEAL
m STERNITE

 

 

 

 

 

Figure 5. Bombus nevadensis, ventral aspect, female

8
Two tribes, Bombini and Psithyrini, are recognized

(Milliron 1961). Bombini are social bumble bees and Psithy-
rini are their social parasites.

Female Bombini and Psythrini have 12 segmented antennae,
six visible abdominal tergites and the last abdominal segment
is pointed. Female Bombini possess a corbicula on the outer
surface of the metatibia, wide, strongly curved mandibles and
a rectangular labrum. In contrast, Psithyrini lack a cor-
bicula, have long, weakly curved mandibles and a triangular
labrum.

Male Bombini and Psithyrini have 15 segmented antennae,
seven visible tergites and the last abdominal segment is
broadly rounded. Male Bombini have distally widened metatibfla
with little or no hair on the outer surface-~1onger hairs on
the lateral margins, closely spaced hair and shallow punchnes
on the head, the head triangular to oval in most and with
strongly sclerotized genitalia volsella and squamae. Psithy-
rini males have a narrow metatibia uniformly covered with sham
hairs, more widely spaced hair and deeper punctures on the
head, the head square to spherical, and with weakly sclerotized
genitalia volsella and squamae.

For the purposes of this project, the familiar generic

designation Bombus is used instead of utilizing Bombus, Mega-

 

bombus and Pyrobombus as suggested by Milliron (1961). The

 

reasons for utilizing a single generic taxon are familiarity
with the generic taxon Bombus and reduction in complexity of

names of bees with which.mites associate. The basic

9
characteristics which resulted in the naming of three genera

are not ignored and may prove to be important in showing
patterns of mite-bee associations.
KEY TO SPECIES OF MICHIGAN BOMBINAE
The following key is not designed to cover the many pre-
viously described color variants found in Michigan. It is
based upon keys by Fischer (unpublished), Chandler-Indiana
(1950), Medler and Carney-Wisconsin (lees), Milliron-Michigan
(1959) and upon specimens found in the Museums of Michigan
State University and the University of Michigan. It includes
Psithyrus variabilis since this species may be found in
southern Michigan.
1 Twelve segmented antennae, six visible abdominal
segments, abdomen with a conical tip posessing a

sting....Female Bombus and Psithyrus.........2

 

Thirteen segmented antennae, seven visible
abdominal segments, abdomen bluntly rounded
apically, no sting...Male Bombus and

PSithyrIJ-SOOOOOOOOOOO...0.00.0.0...00.0.03

 

2 Outer surface of metatibia bare with a fringe of
long hairs on the lateral margins (corbicula),
wide-strongly incurved mandibles, rectangular
labrum...Bombus..............................7

Outer surface of metatibia uniformly covered
with hairs (no corbicula), narrower-weakly
curved mandibles, triangular labrum...

PSitEJ-LNSOOOOOOOOCOOOOOOOOOOOOO0.0.0....25

10
Metatibia distally widened with little or no hair

on the outer surface and long hairs on the lateral
margins of some, closely spaced hair and shallow
punctures on the head, hair with or without yellow
hairs, strongly sclerotized genitalic volsella and
squamae...Male Bombus........................4
Metatibia uniformly narrow, covered with short
hairs; more widely spaced hair and deeper
punctures on the head; face without yellow
hairs, weakly sclerotized genitalic volsella

and squamae...Male Psithyrus............50

 

Large bulging eyes, ocelli well below supraorbital

line.........................................Ei
Eyes not bulging, ocelli near supraorbital
line....................................7

Tergite I yellow; Basal middle of tergite II

rusty, remaining tergites black...§. griseocollis

 

(DeGeer), m.
NOt as abOVeOOOOOOOOOCOOQOOOO 00000000 ...6
Tergites I, II, III yellow, remaining tergites

black, large (usually over 16mm)...§. nevadensis

 

Cresson, m.
Not as above, smaller (usually less than

15mm)...§. rufocinctus Cresson, m.

 

Tergite I yellow, remaining tergites black...

.B. impatiens Cresson, m., f.

 

NOt as above.00.000000000000000...00000.8

10

11

12

15

14

11
Tergite I yellow, tergites II and II red-orange

or red, remaining tergites variable..........9
Tergites usually only yellow and black (some
variants have scattered rusty hairs)....10

Tergites I yellow, tergites II and III red-orange,

tergite IV black; wide, black interalar band form-

ing a distinct V on scutellum...§. ternarius Say,

 

m., f.

Not as above...§. rufocinctus m., f. (in part)

 

Pleura mostly black, yellow thoracic hairs not

extending much below anterior wing base......1l
Pleura mostly yellow, yellow hairs to or
nearly to leg bases.....................l6

Dorsum of thorax yellow...§. perplexus Cresson, f.

 

Dorsum of thorax with black.............12
Tergites I, II, III, IV yellow or red-orange...l5
Not as above.................-..........l4
Face and occiput black, tip of abdomen red, yellow
or black...§. pennsylvanicus DeGeer
Face with (female) or without (male) yellow
hairs, occiput yellow, tip of abdomen black
... B. borealis Kirby, m., f.
Last two tergites with.yellow on posterior margin,

tergite I black..ߤ. terricola Kirby, m., f.

 

Last two tergites entirely black, tergite I

Usually with some yellow hairs..........15

15

16

17

18

19

2O

12
Large ocelli well below supraorbital line, occiput

yellow, tergite I black in middle...§. nevadensis f.

 

Smaller ocelli near supraorbital line, occiput

black, tergite I mostly yellow...B. pennmflyanhxm

 

f.
Tergite I yellow, tergite II with basal middle
yellow or rusty, remainder of abdomen b1ack......l7
Tergites I and II mostly yellow.............l9

Interalar space b1ack...§. rufocinctus f. (in part)

 

Interalar space mostly yellow...............18
Tergite II with rusty basal portion broadly curved
to margins, the remaining posterior segments black,

occiput b1ack...§. griseocollis f.

 

Tergite II with basal midian portion yellow,

occiput yellow..ߤ. bimaculatus Cresson, m., f.

 

Tergites I, II, III, IV entirely yellow...B

fervidus (Fabricius) m., f.

 

Tergites I, II, III, IV not entirely yellow..20
Malar space wider than long or square, occiput
mostly black, interalar blackspot or band........21

Malar space longer than apical width, occiput

yellow, with or without interalar black spot

oeeoooeo oooooooooooo o ooooooooooo 00.000.000.23

21

25

24

25

15
Tergite I yellow, tergite II basal hairs usually

orange, posterior margin of tergite II hairs with
a distinct median notch, usually no yellow hairs
on tergites IV, V, VI or VII...§. affinis Cresson,
m., f.
Tergite II without orange basal hairs or
distinct posterior median notch, yellow hairs
may be present on tergites IV, V, VI and VII
...........................................22
Ialar space square, head rounded...§. frigidus m.,f.
Malar space distinctly shorter than its
apical width, tergite I yellow, tergite II

with black hairs on posterior margin...§.

rufocinctus m., f. (in part)

 

Female, yellow occiput, long malar space...§. vegans

F. Smith, f.

Male, yellow occiput, long malar space....24
Tergites III black, if tergite III yellow tergite
VI also yellow...B. vegans f.

Tergite III yellow, tergite VI black... B.

perplexus m4

 

Yellow hairs of pleura not extending to leg bases..

00000009000000 000000 0 000000 000000 000000 00000000026

Yellow hairs of pleura extending to leg

bases.0.00000.0000000000000000000000000000027

26

27

28

29

SO

31

32

55

l4
Occiput largely black, tergite IV and apical sides

of III and V yellow..a§. ashtoni (Cresson), f.
Occiput yellow, abdomen usually black and

bare...§. variabilis (Cresson) f.

 

Tergite IV entirely yellow, hair above antennal

bases black..ߤ. fernaldae Franklin, f.

 

Tergite IV mostly black, hair above antennal
bases usually yellow....................28

Abdominal tergites black...§. laboriosus

 

(Fabricius),f. (in part)
Considerable yellow on tergite III, some yellow
hairs may appear on tergites II and IV...29
Mesonotum with black hair, tergites II and IV with

parallel lines of yellow hair at sides...

'2. insularis (F. Smith), f.

 

Mesonotum with few or no black hairs, tergite

IV usually black...§. laboriosus f. (in part)

 

Yellow pleural hairs not extending to leg bases..51
Yellow pleural hairs extending to leg bases..:52

Third and fifth antennal segments equal.a§.ashtoninu
Fifth antennal segment near twice the length

of the third...§. variabilis m.

 

Tergite VII with a ring of orange (yellow-orange)

hairs..ߤ. fernaldae m.

 

Tergite VII black.........................ss

Tergite IV entirely black...§. laboriosus m.

 

Tergite IV with yellow at sides..§. insularis m.

DISTRIBUTION OF MICHIGAN BOMBINAE

Precise knowledge of the distribution of Bombinae is
essential in order to understand the distribution of mites
associated with them. The purpose of this section is to
review and analyze what is known, to present the data col-
lected and interpret the present knowledge of the distri-
bution and abundance of Michigan Bombinae.

The distribution of Michigan Bombinae was first system-
atically studied by Milliron (1959) although Cockerell (1916)
and Lutz and Cockerell (1920) did some work with Michigan
Bombinae. Franklin (1915) listed 17 species of Bombinae
from Michigan. Milliron (1939) listed 18 species including

Bombus fraternus (F. Smith) on the authority of literature

 

by Franklin and Frison and adding §. frigidus var. couperi

to previous records. Mitchell (1962) lists g. fraternus

 

from Illinois but not from.Michigan. Specimens of §.:fiatenmm
collected in Michigan are lacking in Michigan collections.

No g. fraternus were collected in the course of this study.

 

Chandler (1950) reported two specimens, one from central
Indiana and one from southern Indiana. Some doubt exists
whether this species which is rare in Indiana and absent
from Wisconsin is established in Michigan at the present tum»

fi. frigidus couperi has not been collected in recent years

 

and the presence of this species is uncertain. Hobbs finds
g. frigidus above 4500 feet in the foothills near Alberta,

Canada. Psithyrus variabilis which has been found in

 

southern Wisconsin and in two Indiana counties near the

15

16
Michigan border has not yet been found in Michigan. Thus,

the present Bombinae found consists of 1? established
species and a possibility of 19 total species.

While useful in studies of broad areas, county infor-
mation is not always sufficient when attempting to test the
possible relationships of distribution of bees and factors
such as terrain elevation, isotherms and distribution of
other animals and plants. In far too many museum specimens
of Michigan Bombinae, the county was used to designate the
collecting site.

Latitude, longitude and all of the counties are illus-
trated in figure 4. Known collecting sites appear as small
circles in figures 5 through 23. Lightly shaded counties
are those in which Bombinae were reported by Milliron (1939).
The darker shaded counties are additional records for these
species. If no circles appear in a county, only county in-
formation was present on the insect label. The lack of
shading on a county indicates that the species has not yet
been collected in the county.

Several collecting trips have been made throughout cen-
tral Michigan, and in the upper peninsula by T. W. Porter,

R. L. Fischer, R. B. Willson, R. W. Husband and others.
However, over 90% of the total specimens of Michigan Bombinae
in Michigan collections are from the lower third of the state.
All of the specimens which were collected in the course of

of this study are deposited in the Entomology Museum at

MiChigan State University. Specimens from the museums of

17
the University of Michigan and Michigan State University

are included in the report.

Milliron used the categories rare, not common and
common to indicate a rough index of relative abundance.
Acknowledging the subjectivity of these categories based
on personal observations, the only species that does not

fit the designation given by Milliron in 1959 is Psithyrus

 

laboriosus. Milliron listed 3. laboriosus as not common

 

 

but it is now represented by nearly as many specimens as

Psithyrus ashtoni which is listed as "probably the most

 

common".

18

 

 

I ,
/ flan. 48°N

 

 

90" W a7°w e4 °w
T4!!"
.4‘ g] r4 1 .
Lab-.1 L ! [Mm ,u’c‘ I
' ..L. _, '. ... .
\ L...— :m ‘lL i. .1. Jr “'5'! 'm It
'\- ragga L_"_I- L._..l !

 

 

 

. I ‘
MICHIGAN "."j y'ga‘mtim'iw
“'m'i ! i
'7 W-'—.W'“'Tm'*:m7(3w_
' ' o
SCALE INMILES m.,—M L'Fh‘L-raLTTB-“L-
. l '

0 .0
l A A j

l. _ A

 

 

 

 

 

 

 

 

 

 

 

———

 

 

 

 

s7°w 84°W
Figure 4. Map of Michigan counties with scale, latitude and
longitude -

 

 

 

19

 

 

 

Figure 5. Distribution of Bombus affinis

 

 

 

20

   

MICHIGAN

Figure 6. Distribution of Bombus bimaculatus

 

 

21

 

  

MICHIGAN

 

 

 

0:55; .uwmo

 

 

 

 

 

 

 

 

 

{Fifi—"nm-m WIE.LZMW m

222::

 

Figure '7. Distribution of Bombus borealis

 

   
 

 

 

22

 

 

 

     

MICHIGAN

Figure 8. Distribution of _I_3_og:bus fervidus

 

 

 

23

 

 

MICHIGAN

I
”mu ._.'._... -.__.. ' ....
--.... w « lawman—Moscow TERM
0"" !mnnu ‘ I | I
I . '
mufw—aiofitmfiiImlImmfir'
I i

mo‘u‘nL'Tosab' Fw'z‘rahmfir'

' ' I . an:

- — I h u— I I C . - u .

octmu Insure-{I Mama ,I am £75504
I

l . .

.LFE‘Lw“ i p-L-TWIH.

ofrfi'm I mm alum - [fin-Ti
l i - L_.I

“‘2ijva Tani—[75.71% .....Im "m" I .

 

 

 

 

 

 

. ! I
.... J __I_. I__ _
I mafia—wu—fi'wm mm' mmuflwm
'1 i I i '
. ,,, 53—Fom—t'mmifit1’JLumvé'Tinu-a
i i i I I

 

Figure 9. Distribution of Bombus frigidus

 

 

 

24

 

 

MICHIGAN

 

 

 

 

 

 

 

 

I.’
' .f.
I;
:\)\:

Inui-
.n ....

Figure 10. Distribution of Bombus griseocollis

 

25

 

 

     

MICHIGAN

 

 

Figure 11. Distribution of Bombus impatiens

 

 

 

26

 

 

MICHIGAN

Figure 12. Distribution of Bombus nevadensis

 

 

 

27

 

I
. , m i] r4 .
' I
"L F i“ am .
'W L . we: I
L--——n Ith.--— ‘1 1 r.—--—i l '
\ I . _J cm. Ian»:
\.' Riva" i ' . .J. 1
W I Immune L...—
va '

MICHIGAN

 

Distribution of Bombus pennsylvanicus

Figure 13.

 

 

 

28

 

: "7 '
[Mime I

’
maIwmoaTWafin I”; away you»

 

 

 

 

«'73:. I Tim—Iain . I
I

 

 

,:

., I w
.u-u:
.I

 

Figure 14. Distribution of Bombus

 

mm

54mm

         
   

 

 

29

MICHIGAN

 

   

I
l

 

    
  

 

   
 

  

"bu—mmj'm Imam: mum 'm

I

 

Figure 15. Distribution of Bombus rufocinctus

 

 

50

 

 

    
     

MICHIGAN

 

 

 

 

 

 

 

 

 

17.7.; uJa'fiémJ—Tm ... '
'1 i ! ' .
“ Isa.— 'irzsm‘II'N‘m—{umtgmtu-rm
. I
I I '

Figure 16. Distribution of Bombus ternarius

 

 

 

31

  
      

MICHIGAN

"Iai‘~"iI_SE-nifirmuwmt.umvfijm
i I

Figure 17. Distribution of Bombus terricola

 

 

 

52

     

MICHIGAN

 

 

 

 

 

Figure 18. Distribution of Bombus vegans

 

 

 

 

35

     

MICHIGAN

 

Figure 19. Distribution of Psithyrus ashtoni

 

 

 

54

   
 

MICHIGAN

 

 

 

oct'aTu‘ Havana MW‘Ifim—LU InfidzoI

I ,

 

_I ”Elli. 7‘}er '05:.

L a .3.
0mm riI m—II—l IA—‘I'an Ema—mui LTr filo—In

MfifiL—Dun'r?£_flwm~WfiLfirfihk-rgiq

I
« mm rxTuL'a'wm J—TL‘“ -J|Ifiu'mu!w mm —J—
‘I I I

... Iar‘iIu‘mm—Ifu-a'fmzimflzu‘rm
' . I
I I , .

 

Figure 20. Distribution of Psithygus fernaldae

 

 

55

  
 

MICHIGAN

 

 

 

D
ufiiumnonmmftfififihfiua

 

 

 

 

 

 

 

Figure 21. Distribution of Psithyrus insularis

 

 

 

56

MICHIGAN

 

Figure 22. Distribution of Psithyrus laboriosus

 

5'7

 

 

‘Os {J 5
.L'j I. I I'm" we: |
Lu.Jfifié'"'"i I";;;I i.. ‘5
“~' I "” I I'J I. .I i
\- ”"1 I,____. -..'~.'. L... ..
I I I'Euu 1 I
r" J , I o- '“J‘
98' “o
I . ‘ !°""'""i
‘ I im

 

 

0 .
I
IAI(3IIICLAIQ 4:23.} \errfiifii%u_ufl_n._
'7Iwwm“"lmun:'“'T"* safw
I
we. TeaIarlaI-IrI-L'T-W'I-
. I I I I-
. - _ ,Iu

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

no
r‘I‘II'

Mm

 

Figure 23. Distribution of Psithyrug variabilig

 

 

38
DISCUSSION

The information concerning distribution of Michigan
Bombinae has increased many times in the past twenty-five
years. The collections of Michigan Bombinae in Michigan
museums contain species of Bombinae from 385 counties in
addition to the counties listed by Milliron (1939). In
other words, 385 county records are contained in this re-
port. More important, many areas are represented by long
series of specimens and more specific locality information
is known. Many entomologists have contributed to the records.
Most of the additional records were collected by R. Dreis—
bach, R. L. Fischer, T. W. Porter and R. W. Husband.

Seventeen of the nineteen species of Bombinae listed
in the preceding pages have ranges that terminate at lati-
tudes within the state or at the borders. Thus, Bombinae
are very useful in investigations of limiting factors and
associated problems.

The center of the distribution of species is a useful
category for analysis of distribution of Bombinae. If the
center of distribution is south of Michigan, the term southeni
species is employed. If the center of distribution is within
Michigan, the term cosmopolitan species is used. If the cen-
ter of distribution is north of Michigan, the term northern
species is used. Eastern or western categories are not used
as east-west patterns of distribution are not apparent in
Michigan or in adjacent states. The northern species are:

Bombus borealis, g. fri idus, g. perplexus, g. rufocinctus,

 

 

39
B. ternarius, g. terricola, Psithyrus ashtoni, E. fernaldae

 

 

 

 

and E. insularis. The cosmopolitan species are: Bombus

 

affinis, g. fervidus and g. vagans. The southern species

are: Bombus pennsylvanicus, g. nevadensis, 8. bimaculatus,

 

 

 

 

E. griseocollis, g; impatiens, Psithyrus laboriosus and 2.

 

 

variabilis. Following the possible origin of these species

 

from either Eastern or Western Hemisphere as suggested by
Milliron (1961), no apparent relationship appears to exist
between the distribution of the bees in Michigan today and
their possible origins. Thus, the Mendax line which is
thought to have originated in the Eastern Hemisphere and
moved into the Western Hemisphere in the Tertiary and Quar-
ternary has the expected northern representative g.‘mxealis
but also includes the cosmopolitan E. fervidus and southern

g. nevadensis. The entire state was covered by ice approx-

 

imately 20,000 years ago and Bombinae populations have
entered and reentered the area many times in the past millflx1
years. That present distributions are not clearly related
to geographic origins a few million years ago is not sur-
prising.

The ranges of Bombinae in Michigan have changed very

little since 1939. Bombus borealis, although not common,

 

has been frequently collected in recent years in the mor-

raine areas of extreme southern Michigan. .8. griseocollis

 

and g. impatiens have been found along the southern coast

 

of upper Michigan. Whether these are relict or pioneer

colonies is not certain. Bombus rufocinctus appears less

 

40
frequently in the southern part of its range. Psithyrus

 

ashtoni has been found further south than in previous times.
One University of Michigan specimen is catalogued from
Miller, Indiana. Chandler (1950) expressed doubt that this

species occurs in Indiana. Psithyrus fernaldae has not been

 

collected further inland than 16 miles from the coasts of

the Great Lakes in Michigan. It has been found further in~
land in Wisconsin. Although the sample size for this species
is low, this distribution pattern is rather unusual. Psithygus

insularis has been found much further south than previously

 

recorded. This may be due to more extensive collecting in

some areas since this species is rare. Psithyrus laboriosus

 

was reported from one county in western Michigan in 1939.
Now it is known to be common throughout the lower peninsula.
Psithyrus variabilis is listed as one of the most common in
Indiana (Chandler 1950) and has been collected in one county
in Indiana on the Michigan border and another Indiana county
close to the border. It may be moving northward in associ-
ation with Bombus impatiens, Q. pennsylvanicus and g. vagans
which are very common in lower Michigan. Milliron (1939)
listed g. frigidus from Isle Royale. The museum collections

now include specimens of Bombus borealis, §._perplexus, g.

 

ternarius, p. terricola, g. va ans, Psithyrus ashtoni and

 

 

.2. fernaldae.

 

ECOLOGICAL FACTORS WHICH MAY INFLUENCE BOMBINAE DISTRIBUTION

There are many factors which influence Bombinae distri-
bution. This study is concerned with a few of these factors
in Michigan. Rodents with which Bombinae may be associated
and various climatic and geographic factors will be presented.

In other geographic areas, a few studies exist on such
topics as diseases of Bombinae but it is not the purpose of
this report to present an encyclopedia of all that is known
about the ec010gy of Bombinae. Thus, while such factors as
disease, predation, parasitism, interspecific competition
and intraspecific competition may influence Bombinae distri-
bution they are not the main subject of this report.

BOMBINAE AND MICHIGAN RODENTS
Bombinae frequently utilize rodent nests as nest sites.

The skeletal remains of Peromyscus sp. indicates that Bombus

 

fervidus may utilize nestsof this genus. Plath (1934) sug-
gests that rodents may destroy newly constructed nests while
the queen is foraging. He also suggests that skunks and
other mammals may destroy nests.

The ranges of several rodents terminate in the same geo-
graphic area as the ranges of several Bombinae. However,
the relationship of Bombinae and rodents may not be a close
one since Bombinae are not restricted to the selection of
rodent nests as nest sites.

In figure 24, the northern boundary of the ranges of

the following rodents are plotted: Rattus norvegicus Berken-

 

hout, Mus musculus Linnaeus, Sciurus carolinensis Gmelin,

 

41

SCIURUS CAROLINENSIS

Figure 24. Northern

 

42

RATTUS NORVEGICUS \

MUS muscuws /

 

 

 

 

 

IIIII
I r.
"M . '
rucLfi [5 I“. b
a. . I I‘m" ....
7, _L —I .... I
. L..__.mo~ '_- . .u " EbI-mfi Icm»: (
\. I l._. I J i_ ' 'fi
\. ”'"mI (BI—"ii inf-TA}: L._._ ‘.
i ' Lu ' I
Psaomscus LEUCOP r-w-J 4 I . e. \‘K‘
GLAUCOMYS VOLANS ' ago R.
CITELLUS TRIDECEMLINEATU film,”
Ci 9° i I"
SCIURUS NIGERJ 2 j; W
., .I. ._1_.
M L. aw Imam
PITE vs PINETORUM AN 00 m Fm?
h ._'._.- .___.' .—
MICHIG $3! ,flmm
‘Imrmri I I I
itmem'm ImsquI‘mIoumG'ITw— —'
I I I
I
m. an “at. uuirra‘mzdc—
I I ....
._ I“
«(minimise hymn—:II—suttuIFITaw MIDI
I I , “jifik
‘—I— bno'm—aii"7u"-1y°-I;: I
dew-I I Fermi"
in"! firm-557W i Fm“
PEDOMYS ocuaomsrsa I ! L1
A
mhfiL‘Iifak 1'57!" .nunm LIV—I. I”: ”—Imw'
I
._ I I_ _L
Iaimuifififififi'jfimmm mmmuwfimfl
I I
MIR?" 53mm Imumuilunevzifiinl
l i
I I i -

 

 

limits of selected Michigan rodents

 

45

 

 

PHENACOMYS INTERMEDIUS
MICROTUS CHROTORRHINUS

 

 

 

 

 

L ,M J
C 1h.j [- I (”MW “1‘! I
. L.__.uéu‘L""I .M ‘1 Emcfi Immzm (
\.\I I—-—-~ I H L «I ‘
. I°°""’°"I 5:1?‘4'1 Imiw—Iuc L._._ )7
a I v D .
. J _. x‘
r-T I >JI ....a~‘-I..I. ‘i‘il”
"3? j ' '
L? NEOZAPUS 9°
, INSIGNIS
EUTAMIAS MINIMUS “ 00
MICHIGAN CLETHRéONOMYs h_mu ,'
"Wins!
hm,
I
ERETHIZON DORSATUM W “I
~ I , I” u”
ocmuumumo Mm ,m‘m _ ..
GLAUCOMYS SABRINUS I I I I , sew-I651»
- ' ' ' 4
m—mm 'r“.' r I
CASTOR CANADENSIS I—- "Mr-7 i LTJZn‘I-II-I
. , , I‘— ' ....
afram ' Win—IE7. ""61! [Tim

I I
Au'uWL—I'inuv' 'I—‘v'uvL—r im'mm I IIW‘M;—rmi

 

MM IRA—um'aweow TAIExs—m' JI'w—dunqu Om"! ‘L
'I i I i
“ Im— W‘I’m bum: [aura—rm-
. I ' i

i I j

Figure 25. Southern limits of selected Michigan rodents

 

44
Peromyscus leucopus Rafinesque, Citellus tridecemlineatus

 

 

Mitchell, Sciurus niger Linnaeus, Glaucomys volans Linnaeus,

 

 

Pitemxs pinetorum LeConte and Pedomls ochrOgaster Wagner.

 

 

In figure 25, the southern boundaries of the following rakmts

are plotted: Phenacomys intermedius Merriam, Microtus

 

chrotorrhinus Miller, Eutamias minimus Bachman, Neozapus

 

 

insignis Miller, Clethrionomysggapperi Vigors, Erethizon

 

dorsatum Linnaeus, Glaucomxs sabrinus Shaw and Castor cana-

 

 

densis Kuhl. The ranges in both figures read from north to
south in sequence as the species are listed above and were
obtained from Burt (1957). The ranges which very closely
approximate ranges of species of Bombinae which are discussed
in the nest section. There are several species of rodents

which are found throughout Midhigan.

CLIMATIC FACTORS AND MICHIGAN BOMBINAE

Climatic factors and Bombinae distribution in North
America have been discussed by Medler and Carney (1965),
Neave (1955) and others. The comments of Medler and Carney
are based in part on the observations of Curtis (1959) on
Wisconsin zones. Curtis describes a tension zone running
northwest to southeast in Wisconsin. The geographic lhnflm
of 182 species of plants are found in this zone. Fewer
range boundaries are found on either side. Although such
a study has not yet been completed for Michigan, there is
considerable evidence that such a zone occurs in Michigan.
In the early 1900's, Merriam.et a1.(l9lO) divided Michigan
into Boreal, Transition and Upper Austral life zones.

Dice (1945) divided the state into the Canadian Biotic pro-
vince above a line from Ottawa County to St. Clair County
and the Carolinian Biotic province below this line.

Curtis (1959) and others at Wisconsin studied a variety
of climatic factors throughout Wisconsin. A few of the
factors which tend to correlate with the tension zone are:
average summer temperature of 67°F, average July temperature
of 70°F (Medler and Carney 1965), average annual snowfall
of 48", average evaporation in July of 5", and sixty days per
year with average temperature of 680F.

Much of the data on Michigan climate has been summarized
from the U. S. Weather Bureau records by Senninger (1965).
Other sources include the Michigan Freeze Bulletin (1965),

McNeel and Goff (1961), U. S. Department of Agriculture CKMl)
45

46

and recent records supplied by the U. 8. Weather Bureau in
East Lansing. Briefly, three large air masses are respon-
sible for most of the weather in Michigan. A dry contimmuml
air mass from the west, a dry polar air mass from the north
and a moist southern air mass. The prevailing winds are
from the southwest. When the wind is strong semimarine
weather exists. When no wind is present, continental weather
patterns exist.

The majority of the precipitation occurs in the spring
and fall as the warm.moist air masses from the south are
displaced upward when meeting the cold northern air masses.
The winter periods are mainly under the influence of conti-
nental dry westerly or northern air masses.

Figure 26 shows the average July temperature during the
years 1951-1960. The 70°F isotherm is indicated by a solid
line. Figure 27 shows the average annual precipitation for
the years 1951-1960. The U. S. Department of Agriculture
(1941), using averages from an earlier period published simi-
lar map although the climate was less moist during that
period. The area with less than 50 inches of precipitation
is displayed with light shading. The area with over 55 inches
is displayed with dark shading. Figure 28 shows the average
date of the last temperature of 52°F or lower in the spring.
Areas which have a date between May 10 and 20 are displayed
with light shading. Areas with a date before May 10 are
displayed with dark shading. No shading indicates the last

date of 52°F is between May 20 and June 19. Figure 29 indicamxa

4'7

 

 

... .f 5 PW» _lm. I
....L.—-L ---i . .—---. .
‘ L I” 1m, ) r’mL.__'t°" Q.
‘ o ’ ~~ | m—u—o-l.! !" I: Lo- —-
:‘2 "x - I 1" “

Figure 26.

 

 

\ " 0 ~ \‘.P.”"i
Q .i‘\ E: ’GG‘F
0° *3'3'1 i 33' ~ .Ie‘r'F
/ ’ I. I l ’I
- , flaur-TffiiiWWHE’v
51mm ' l 3“ ,I
’Li-ftta;a¢-"—]afiarmw;'
I i
6‘!“ " ..., 4'4..- . ,_L.,_.JL_..
" ‘OS’W [an «arm--
ga-i. - ear

 

 

 

 

 

 

 

 

 

\
”rum \ . s
70° t '- '~£5::~_‘Em if, "’53"
' “ ',’ ’ ..Far
I I \ ' - ‘ .
o; wfiL‘UEnL m ”Jim .
7‘ ’ I. ll ‘F.‘\ i I" I I "
rvaiqaaaayzfia"yzdaia ' ."'+" 7*?
’;,{ -..»‘s! j I" ..
72%— , . "Tr mmm Tm f'
'H’F " T“

Average July isotherms, 1951-1960

 

 

 

 

  
  

MICHIGAN

 

      
 

AumL—lria.’7 Tfi'mLfcioTvl; m
. !

l
. It

Figure 27. Avera 9 annual precipitation,
1951- 960, in inches

 

 

 

 

 

49

 

     

MICHIGAN

Figure 28. Average date of last temperature of 52° F or lower

 

 

50

 

  
 

 

MICHIGAN

 

 

 

 

M
. . I ' . .
MEL—{5.71.7 Tm. fiufifimwrrlfil
- I i I I
'qu mule—aw; AWL- minimum-.L
'1 g I ' . '
"bk—‘Ffi'fiafimmfiumvfijdm

 

L Figure 29. Present Michigan forests

 

 

51
the present forests of Michigan in dark shading. Figure 50

shows the terrain elevation in Michigan. No shading incidataa
an elevation under 800 feet above sea level. Light shading
represents an elevation between 800 and 1000 feet above sea
level. Dark shading indicates a terrain elevation above

1000 feet. Elevations above 1400 feet are indicated by

horizontal lines within the dark areas.

52

 

 

 

  

MICHIGAN

 
     
  
 

LI

I m
. “I"
.J-
momm-
-- WWW";

 

  
 

'800' TO 10005

w "7

V 9'6

  
 

 

Figure 50. Terrain elevation in Michigan
in feet above sea level

 

 

55
DISCUSSION

The distribution of Michigan Bombinae appears to be
related to several ecological factors. A few factors which
are better known are rodent distribution and several clhmflfic
factors. These will be discussed for each species of Bombinae
found in Michigan.

Bombus affinis has a unique distribution with limits at

 

the southern border of the state and the straights area be-
tween the two peninsulas. The northern limit matches limits

of Sciurus niger, Citellus tridecemlineatus, Glaucomys volang

 

 

Pitemys pinetorum and Peromyscus leucopus. B. affinis pro-

 

bably utilizes Citellus and Peromyscus nests. The nearest

 

relative in Michigan to B. affinis is B. terricola. They

 

compete in the northern part of the lower peninsula.

Bombus bimaculatus has a northern limit approximating

 

that of B. affinis. The center of the range is south of
Michigan. The mammals which have terminal ranges closely

approximating the northern range limit of B. bimaculatus

 

are the same as those listed for g. affinis. ‘B. bimaculatus

 

is a long tongue species related to B. vagans. It is one

of the earliest species to appear. One stress period occurs
in early spring. Several days of cold wet weather in early
May could eliminate this species. In May of 1965, over four
inches of rain fell in the upper lower peninsula. The aver-
age 1ast day of temperatures of 52°F or lower (figure 28) is
after May 20 in this area. Another stress period is mid-July

When yOung queens and males emerge. Cold wet weather at this

54
period could weaken the colony. This kind of weather is

unusual in northern Michigan in mid-July and is probably
not as limiting as the May weather.

Bombus borealis is a northern species which is one of

 

the latest species to emerge in the spring. In the southern
third of the state, the species has been limited to elevations
above 800 feet above sea level. It has not been found in
extreme southwestern Michigan where average annual precipi-
tation exceeds 55 inches annually.

Bombus fervidus, a long tongue, cosmopolitan species

 

related to B. borealis, B. nevadensis and B. pennsylvanicus,

 

 

has not been found.in the western upper peninsula. The sofls
in this region are listed as non-limy and a range of elevatknm
over 1400 feet separates this region from the rest of the
state except along the northern boundary. This species is

one of six species Which have colonies maturing in late sum-
mer in Michigan.

Bombus frigidus, a short tongue northern species, was

 

reported on Isle Royale and in a few scattered localities
along the southern shore of lake Superior in Michigan. This

range boundary is near the boundaries of Rattus norvegicus,

 

Mus musculus, Sciurus carolinensis, Microtus chrotorrhinus

 

 

and Phenacomys intermedius.

 

Bombus griseocollis, an intermediate tongue southern

 

species, has a range similar to B. bimaculatus. The colony

 

develops more slowly than B. bimaculatus. Males occur in

 

late July to early August. Known upper peninsula records

55
are from the shore of Lake Michigan.

Bombus impatiens, an intermediate tongue southern spe-

 

cies, has a range similar to B. bimaculatus. Although the

 

queens emerge as early as those of B. griseocollis, males

 

appear later, from mid to late August.

Bombus nevadensis, a long tongue, large southern species

 

has a northern boundary near the southern boundaries for

Castor canadensis, Glaucomys sabrinus and Erethizon dorsatum

 

 

(figure 25). This is near the 70°F July isotherm (figure 26)
and the southern limit of extensive forests (figure 29).

g. nevadensis occurs more frequently at elevations below 800
feet (figure 50) and is common in southwestern Michigan
where precipitation exceeds 55 inches annually.

Bombus pennsylvanicus, a long tongue, large southern

 

species, appears in mid to late May and males appear in late

August. The range is very similar to B. nevadensis in

 

Michigan.

Bombus perplexus, an intermediate tongue northern specifig

 

has a range similar to B. borealis. Males appear in early
July. Although widely distributed, relatively few specimens
of this species have been collected.

Bombus rufocinctus, a short tongue northern species,

 

appears in late May. The range 50-60 years ago approximated

.§° borealis and B. perplexus. Recent records near the limit

 

of the species are near (1) the limits of the rodents Castor

canadensis and Glaucomys sabrinus (figure 25) (2) the 70°F

 

 

July isotherm (figure 26) (5) the less than 50 inches of

56
annual precipitation line in the lower peninsula (figure 27)
(4) the present extent of forests (figure 29) and (5) the
over 800 feet terrain lines in southern Michigan (figure 50).

Bombus ternarius, a short tongue northern species, has

 

a range similar to B. rufocinctus. It appears earlier in the

 

spring and males appear earlier than in B. rufocinctus.

 

Bombus terricola, a short tongue northern species, has

 

a range similar to B. rufocinctus but is much.more common.

 

The nearest relative is B. affinis.

Bombus vagans, an intermediate tongue cosmopolitan spe-

 

cies, is found in all but 11 of the 85 counties. It is com-
mon throughout the state. Males occur in early July.

Psithyrus ashtoni is a northern species which has a

 

distribution pattern similar to B. terricola with the excep-

 

tion of a few southwestern Michigan records. It is known

 

to associate with B. affinis as well as B. terricola.

Psithyrus fernaldae is a northern species with a unique

 

distribution pattern since all Michigan records so far are
within 16 miles of the coast of one of the Great Lakes. It
has a northern distribution and males appear in early to mid
July. The ranges and dates of appearance of queens and males

suggest that B. fernaldae may be associated with B._perplexus.

 

 

Psithyrus insularis is a northern species which is known

 

to be associated with B. ternarius. Most specimens have been

 

collected in northern Michigan. It was recently found in

Kalamazoo County.

57

Psithyrus laboriosus is a southern species which is

 

found throughout most of the state. Wisconsin and Keweenaw
County records suggest it will eventually be collected in
the remaining five western counties. It appears in early
June and is known to be associated with B. vagans, B.

impatiens and B.pennsylvanicus.

 

 

Psithyrm variabilis is a southern species which is

 

known to be associated with B. pgnnsylvanicus. It appears

 

in late June and.males appear in late August. It has not
yet been collected in Michigan but appears in two counties
close to the border.

In summary, many factors, usually in combination, in-
fluence Bombinae distribution. Among the most significant
are temperature, rainfall, vegetation, terrain elevation,

host distribution in Psithyrus spp., rodent nest sites and

 

predation. Future intensive studies of one or two species,

such as B. pgnnsylvanicus and B. borealis would be very pro-

 

fitable in discovering more precisely the reasons behind the
distribution of these species. .
SUMMARY
More than 15,000 bumble bees were examined in order to

determine ranges, variation and occurence of mites associ-
ated with the 19 species of Bombinae which have been col-
lected in Michigan or reported from counties in Indiana whhfli
border Michigan. Based upon the location of the center of
the range, in relation to Michigan, nine species of Bombinae

are noted to be northern species, three are cosmopolitan

58

species and seven are southern species. Rodent nests are
frequently selected as nest sites and since rodents destroy
Bombinae nests in early spring, the ranges of selected
rodents were discussed. Similar patterns of both Bombinae
and rodent distributions were noted. Finally, selected
ecological factors which may influence Bombinae were pre-
sented. Temperature, rainfall, vegetation and host distri-

bution for Psithyrus sp. are among the more significant of

 

the factors considered.
NESTS OF MICHIGAN BOMBINAE

In order to understand relationships between mites and
bumble bees, a knowledge of the nesting habits and life
history of bumble bees is essential. The following section
was planned to consider the life history of a Michigan bumble
bee, presentation of nest data and a discussion of these data.

In Michigan, from mid-April to mid-June, Bombus spp.
queens emerge from hibernation in soil or elsewhere and.search
for nest sites. Usually, but not always, the site is a former
rodent nest. Competition for sites may be severe. Several
dead queens have been found outside a new nest site (Frison
1928, Plath 1954). Once the nest site is selected, wax which
is exuded between abdominal segments accumulates on the floor
of the small cavity at the center of the nest site. This is
formed into a wax thimble-sized structure known as a honey-
pot. An egg cell may be constructed before the honey-pot.
Usually, seven to eight eggs hatch in three to four days.

At first the larvae feed on pollen in the closed egg cell.

59
In some species, the queen has been observed to open the

cell and regurgitate into it. The larvae have been observed
to feed upon this product. In other species, the larvae
feed on pollen deposited directly into pockets at the sides
of the egg cell. About a week after hatching, larvae spin
cocoons and become pupae. The cocoons are incubated by the
queen for about 11 days. During this time, additional egg
cells are constructed at the side of the first clumps. The
bees in cocoons immediately under the queen emerge first.
The queen aids in cutting open the cell. In two or three
days the worker begins foraging. Nests may contain as many
as 500 to 1000 bees but in Michigan the largest number per
nest collected thus far is 227. From early July to Septem-
ber, depending upon the species, males and young queens
begin to emerge. After mating, young queens usually burrow
into the ground near the site of the nest from Which they
originated. The winter is spent in hibernation. They emerge
the following spring and the cycle is repeated. Inclement
weather or disruption of the nest may cause variations from
the pattern described above.

The twenty-seven nests Which are tabulated in the appen-
dix were all collected at night. Most of the records are
for late species of bees since the majority of the nests were
collected in September.

As the nest was jarred a few bees would exit. The bees
were picked up one or two at a time and placed in a covered

wide mouth gallon jar. Heavy gloves prevented injury to the

60

bees or the collector. A weak light from a covered flash
light provided visibility. Under these conditions, the bees
rarely flew. A small amount of tissue paper on the bottom
kept the jar relatively dry. The bees were unable to crawl
up the smooth sides of the jar and did not attempt to fly
out when the lid was removed. When no more buzzing was
heard in the nest, the nest was carefully opened and exmnined
for any remaining bees. The nest was then transferred to
a second gallon jar, covered and transported to the labora-
tory.

In six cases, the nest and bees were transferred to
boxes and maintained on sugar water for periods up to 50
days before removing bees and placing the nest in a modified
Berlese funnel. The Berlese apparatus consisted of a covered
sheet metal funnel. An opening in the top of the cover ad-
mitted a cord for a 40 watt light bulb. A screen in the
funnel held the nest and premitted arthropods to move through
the screen away from the heat and desiccation. Jars of 70%
alcohol were taped to the bottom of the funnel. In five cases
that are noted, modifications of this procedure were used.
In one instance, an Open glass funnel was used. In three
cases, the light and cord were removed and cotton was placed
in the opening at the top of the funnel. Chloropicrin (tear
gas) was dropped on the cotton to drive arthropods into the
alcohol. In one case a dish of alcohol and glycerine was

placed below a nest in a field.

61
Two of the nests were collected by an undergraduate

student and placed in the center of a field. The nests were
in a declining state when mite samples were collected. Very
few bees remained in the nest.

Most of the nests were placed within the modified Ber-
lese apparatus within a few hours after collection. Most of
the bees were killed with carbon tetrachloride, pinned,
labeled and stored in separate boxes to be examined for mites
in the following few days. Some of the killed bees were
stored in 70% alcohol. Others were refrigerated or frozen
in individual vials. In some instances living bees were
stored in vials and boxes in the refrigerator and freezer
after being anethetized with ether and examined for mites.

After periods in the Berlese funnel varying from nine
hours to a few days depending upon the size and construction
of the nest, the nests were stored in plastic containers.
Later, each nest was examined with forceps for bones, seeds
or other clues which might indicate former inhabitants. The
construction materials were noted at this time.

Some of the nests were used in unsuccessful attempts to
initiate new colonies in the spring of 1964. About half of
the nests are stored in insect trays at the Entomology Museum

at Michigan State University.

62
DISCUSSION

All of the nests described in detail in the appendix
were collected in the southern counties of Michigan. The
nests were all mature or declining. No early nests were
examined. The dates of collection ranged from 7 July to
12 September.

More than half of the nests may be former rodent nests,
based upon the location of the nest and presence of seeds,
hair or skeletal remains. Two nests had identifiable skel-

etal remains of Peromyscus sp. Most of the nests were removed

 

from a location near buildings. This is due to the fact
that reports of nests by man were the main source of infor-
mation concerning locations of nests.

ArthrOpods associated with Bombinae were found in all
of the twenty-seven nests obtained. Acarina were common to
twenty-six of the twenty-seven nests. Nest contents are
summarized in table 1. The number of nests in Which the
animals were found follows the name of the group.

No measurements of environmental conditions within the
nest were taken in this study. Based upon the variety of
locations of the nests and the difference in numbers of
animals in the nests, the internal microenvironments may be
quite different from one nest to another. Likewise, the
various construction materials have quite different insulat-
ing properties. A nest composed of leaves and situated

two feet underground may have an internal environment quite

65

unlike that of a nest of macerated twine on a shelf in a
garage or a nest of cotton inside a washing machine in a
field.

Table 1. Invertebrates found in 27 Bombinae nests

Invertebrate taxa Number Invertebrate taxa Number
of nests of nests

Acarina 26 Siphonaptera 4
Coleoptera 18 Chilopoda 5
Lepidoptera l8 Orthoptera 5
Collembola l2 Araneae 2
Diptera lO Diplopoda 2
Hymenoptera 10 Annelida l
Psocoptera 9 Mollusca l
Isopoda 4 Nematode 1
Pseudoscorpiones 4

Studies of rodent nests and Bombinae nests indicate that
the microenvironment inside the nest differs considerably
from the surrounding environment. Hasselrot (1960) has ex-
perimented with the ranges of temperatures and relative
humidities of bumble bee nests in Sweden. He found that re-
lative humidity remained between 60% - 70% throughout the
season. He also found that temperature variations were more
pronounced in nests early in the season than in mature nests.
The temperature of an occupied nest was never lower than the
outside temperature.

Future comparative studies of nests occupied by rodents,

nests occupied by Bombinae and unoccupied nests may prove to

64

be very interesting in terms of the ecology of the arthro-
pods associated with these two groups of animals.

In summary, Acarina were common to 26 of 27 nests of
Bombinae obtained. Coleoptera and Lepidoptera were found
in 18 nests. Six other orders of insects were obtained as
well as Arachnida, Crustacea, Chilopoda, Diplopoda, Annelida,
Mollusca and Nematode. Most of the nests may have been pre-

viously occupied by rodents.

PART II
ACARINA ASSOCIATED WITH MICHIGAN BOMBINAE

Acarina have been observed on American Bombinae and in
their nests for over 100 years (Putnam 1864). Some of the
first adequate descriptions of mites on bumblebees began in
Europe with Canestrini in the late 1800's and were followed
in the early 1900's by Oudemans and Berlese. Zakhvatkin
(1941) and Vitzthum (1950) investigated Bombinae mites in
the 1950's. They were followed by Stammer and Postner in
the 1940's and 1950's. No work such as was attempted by
Vitzthum, Stammer and Postner has been accomplished in the
Americas although reports of mites associated with Bombinae
are fairly common. Banks, Ewing and Frison are responsible
for some of the early reports.

Plath (1954) reported mites in bumble bee nests in the
Eastern United States. E. A. Cross in the 1950's found mite;
on pinned Bombus sp. in the collection at the University of
Kansas. Medler found mites in the nest of B. huntii in New
Mexico and Hunter has described mites from bumble bees in the
University of Georgia collection. Lindquist and Thorp ob-
served mites on bumble bees collected in California. Since
1962, several thousand mites have been taken from pinned and
freshly caught bumble bees and from bumble bee nests in the
state of Michigan. Thus, mites are known to be associated
with bumble bees throughout the United States.

Reports of mites associated with Bombinae are not common

outside of the United States and Europe. Bumble bees occur

65

66
in Africa north of the Sahara, in North and South America

and in Asia. They have been introduced in Australia and New
Zealand. Zakhvatkin (1941) reports three commensal mites
associated with Bombinae in Russia. Cumber (1949) mentioned

an internal mite in Bombus lucorum near London, England.

 

Stammer (1951) described it as Bombacarus buchneri and found

 

it in several Bombinae in Germany. Postner (1951) reported
three mite species in abundance in bumble bee nests in Ger-
many. Skou, Holm and Haas (1965) reported three species of
mites associated with Bombinae in Denmark. Kielczewski in
an unpublished abstract from the First International Insti-
tute of Acarology reported mites from nests of Bombinae in
Poland. As the Asian and South American species are studied
more intensively, mites will probably be found to be associ-
ated with bumble bees throughout the world.

The scope of this study is to deal with the distribution,
associations and descriptions of mites found in or on Michigan
bumble bees or in their nests.

METHODS AND MATERIAIS

Few descriptions of techniques dealing with mites associ-
ated with hymenoptera were found in the literature. Several
techniques were used initially. In general, the following
objectives were considered desirable. (l) The collecting
techniques must be efficient to permit rapid collecting and
handling of large numbers of bees. (2) Mite transfer from
bee to bee and loss of mites from bees must be minimal to

give an accurate concept of associations and incidences of

67

occurfince of mites. (5) The procedure of examination of bees
must be standardized to be certain each species of bee and
each locality collected is uniformly treated. (4) All vials,
bees and slides must be labeled with a minimum of date,
locality and sample number for future reference. (5) All
specimens must be stored in a manner that will insure con-
tinuing preservation of the data. (6) All bumble bee nests
should be examined in a consistent manner.

It is not always possible to meet the objectives listed
above. The following paragraphs describe the several proce-
dures attempted and the ones presently used.

COLLECTION PROCEDURE

Although museum specimens were examined and utilized,
many of the bumble bees were caught and examined immediately
upon return to the laboratory. Bees were caught at flower
with an insect net, transferred to a killing jar and pinned
and labeled in the laboratory. The net used throughout this
study was rarely used for species other than Bombinae. If a
considerable number were caught at a considerable distance
from the laboratory, several days elapsed before examining
for mites. Museum specimens that were dried for several
years were placed in a humidifying jar before being examined.

Several killing agents, collecting techniques and pre-
servation techniques were employed. Most of the specimens
collected in 1965 and 1964 were killed with cyanide. Chloro-
form was used to kill the bees taken from one nest in 1965.

The cyanide in jars tends to dissipate and become a less

68
effective killing agent after a few weeks of continuous use

of the jar. Most of the specimens in 1965 and 1966 were
killed with carbon tetrachloride although ethyl acetate was
used for several samples. Carbon tetrachloride is now used
exclusively. It is very easy to handle and is less volatile
than ether or chloroform. An extra bottle may be transported
into the field. It kills rapidly and does not dissolve the
plastic in the lid of some jars as ethyl acetate does. On
one trip in 1964, cigar smoke was used to asphyxiate bees
when all killing jars were full.

Some bees were captured by placing a small screw top
vial over them while on the flower. While this is not always
effective, bees trapped in this manner are least likely to be
contaminated with mites that may have been knocked off other
bees in a common collecting net. Most of the bees collected
were collected in a common net, transferred to a killing jar
for a few minutes and then removed to a l" x 2%" screw top
vial. Upon return to the laboratory, most of the bottles
were emptied and examined for mites. The bees were pinned,
labeled and examined for mites. In some instances the bottles
containing bees were refrigerated temporarily or frozen for
extended periods of time. In a few instances bottles con-
taining bees were filled with 70% alcohol.

The plastic suction collecting device utilized by some
entomologists at Cornell University was not evaluated but

looks promising for future work in this area.

PROCEDURE FOR BEE EXAMINATION

When examinations of bees began early in 1965, as much
as 50 minutes was utilized per bee. As handling techniques
became more familiar, the time spent per bee gradually de-
creased. It now takes from one to two minutes depending upmi
the condition of the specimen. A 10X and 50X binocular dis-
secting microscope is utilized. In 1965, nearly all the bees
collected were examined within two hours after capture. It
is much easier to move the parts if freshly caught bees are
examined. In 1965, I noted that mites found on bees killed
in one weak cyanide dilling jar were still alive and a few
were noted crawling down the insect pin. Bee specimens left
over four days are usually not satisfactory for examination
for internal mites although these mites have been identified
in specimens pinned for a month. These soft bodied mites
are barely recognizable after this period of time.

The dorsal aspect of the bee is examined first. The bee
is held in one hand while manipulating the hairs of the thorax
and abdomen with an insect minuten at the end of a matchstick.
The abdomen is depressed and the area between the thorax and
abdomen is examined. Grooves between the scutellum and pro-
podium are probed and the area between the head and thorax
is examined.

An examination of the front and side of the head is made.
The region between the head and neck as well as the mouth parts
on the ventral aspect of the head are inspected. Next, the
area near the pronotal spiracular lobe and the various inter-

69

7O
segmental grooves are probed. The tegulae and the wings
are examined. The area of the propodeal spiracle is probed.
An examination around the coxae and thoracic sternites fol-
lows. Finally, the abdominal sternites and lateral aspect
of the abdomen are examined.

Throughout the 1965 collecting season, freshly caught
bees were examined for internal mites as well as external
mites. The first internal mites were found and techniques
were developed in 1964. After the routine examination above,
the bee is grasped between abdominal sternite one and two
with fine forceps. With a second pair of fine forceps, an
incision is made between the two sternites and enlarged by
grasping abdominal sternite one and pulling sternites one
and two apart. This reveals the ventral aspect of the crop
(honey sac) and the anterior portions of the paired air sacs.
If the crop is distended with nectar, it may be removed by
grasping the narrow anterior portion and pulling it. The
crop separates from the remainder of the digestive tract at
the junction of the ventriculus and proventriculus in most
cases. If care is taken the crOp will not burst. It it
does, tissue paper is used to absorb the nectar. If the
nectar is spilled into the air sacs, which are examined next,
it is very difficult to find and remove internal mites. The
air sacs are punctured with the sharp tips of the forceps.
Releasing the closed forceps widens the initial Opening and
widens the posterior abdominal air sacs as internal inspecthx1

continues. After inspection and removal of mites to slides

71
or to 70% alcohol, the abdomen falls back to its nornal posi-

tion as the dorsal aspect is still continuously connected.
The bee may be pinned and labeled before or after examination.
In larger bees, the weight of the pin is helpful in holding
open the inspection cavity.
BEE IABELING AND STORAGE PROCEDURE

In most instances, bees were individually labeled immedi-
ately upon return from the field. All of the bees were re-
examined for determination of the bee species and identifi-
cation labels were affixed in 1966. Sufficient supplies of
moth crystals (paradichlorobenzene) were maintained in each
box to discourage dermestid beetles and other pests. Unfor-
tunately, the nests were not all sufficiently protected after
examination and are now contaminated with dermestid remains
and probably other species. Most of the nests are now pre-
served in insect trays and are satisfactory for possible
studies of nest construction but are not suitable for micro-
examination for mites or other arthropods which.may have been
a part of the nest fauna at the time the nest was inhabited
by bees.

FOR REMOVAL OF ACARINA FROM BOMBINAE

The method of mite extraction from bee nests by utili-
zation of a funnel apparatus has been described earlier in
this report and will not be repeated. The chloropicrin
method is very effective. It is a little difficult to use
unless a good breeze is blowing outside or an adequate venti-

lation hood is present indoors as chlorOpicrin is a lacrymal

72

agent.

The mites are removed from the bees with an insect
minuten placed in the end of a matchstick. Internal mites
are sometimes removed by taking out a piece of the air sac
wall. No problem is encountered with fresh specimens.

The mite is placed ventral aspect up on a drop of Hoyer's
mounting medium on a 25mm x 75mm slide, positioned and air
bubbles are removed before placing an 8 - 12mm cover slip
over the mite. The slide is placed in a drying oven at
approximately 45°C until a hard surface is formed at the
edge of the cover slip. After cooling, a ring of laquer is
placed around the edge of the cover slip to help seal the
surface of the mounting medium. The mounting medium is 50 ml.
distilled water, 200 grams chloral hydrate, 50 grams gum
arabic and 4 ml. glycerine.

PROCEDURE FOR PRESERVATION AND LABELING OF ACARINA

Mite specimens removed from dry bees are difficult to
mount prOperly as air bubbles are trapped within the mite and
the legs break easily. If the mites are stored in 70% alcohol
for a few weeks, they are usually quite pliable and the air
bubbles are replaced with alcohol. An eye dropper is used a:
transfer mites from vial to the slide. After the alcohol
partially evaporates, a drop of Hoyer's is placed on the mite
and the procedure described above is followed. In a few in-
stances, heavily sclerotized mites are placed in 80% lactic
acid until cleared sufficiently or are stored in Hoyer's

mounting medium for a day or two at 50°C before mounting on

75
a slide. Mites stored in alcohol are inside cottenstoppered,

9 x 50mm, % dram, short shell vials which in turn are inside
neOprene-stoppered, 17 x 60mm, 2 dram, patent lip vials.
labels which contain the same information that is found on
the insect pin are in each vial.

After several labeling schemes were investigated the fol-
lowing one is now consistently used. The date is given first
followed by a sequence number. If 10 bumble bees were col-
lected on July 10, 1965, the labels would appear as 10 July
1965-1, 10 July 1965-2 and so on through 10 July 1965-10.

In the past two years, only bees with mites were given se-
quence numbers. The sequence number appears in the vials, on
the slides and on the bees. It is a simple matter to find a
specimen. The next information is the state and county of
collection. Below this appears the tier, range and section
or other more specific locality information. The last infor-
mation is the collector's name. Most of the vials do not
contain the species of Bombinae from which the mites were
obtained as the species were determined after the vials were
prepared. Nearly all of the slides have the genus and spe-
cies of Bombus sp. as well as other collection information

on the left label. The right label on the side contains in-
formation on the identity of the mite. The specimens stored
in alcohol are available through Dr. Roland Fischer, Direcfln?
of the Museum of Entomology, Michigan State University, East
Lansing, Michigan. Most of the slide collection is retained

by R. W. Husband for future work in this area. Information

74
on disposition of type specimens is found after the descrip-

tion of the species.
IDENTIFICATION OF ACARINA

The literature upon which some identifications were
based appears in the discussion of the various groups. The
following authorities contributed to determinations varying
from species to families:

E. W. Baker - Acaridei (genera, species)

J. Camin - Uropodid and other Mesostigmata (genera)

E. A. Cross - Scutacaridae (genera, species)

P. E. Hunter-Pneumolaelaps (species)

D. Johnson - Oribatei

E. Lindquist-—Proctolaelaps (species Haemolaelaps,

 

Cosmolaelaps (genera)

Unpublished keys provided as a part of a summer session of
the Institute of Acarology at Ohio State University and
Guide to the Families of Mites (Baker et a1” 1958) were also
used.

A phase contrast A0 microstar microscope was used for
identifications, drawings and photographs. Low power photo-
graphy of bees with mites was accomplished by a Nikkormat FT

camera with assistance from Mr. Wayne Lancaster.

THE BIOLOGY, DISTRIBUTION AND NEW COMBINATION OF

Locustacarus (Bombacarus) buchneri (Stammer) 1951

 

The generic taxon Bombacarus was erected as a monotypic

 

genus (Podapolipodidae) by Stammer in 1951 with Bombacarus

 

buchneri as the type species. The first two internal mite
species of this family were described from Locustidae by

Ewing. Locustacarus trachealis Ewing (1924) was described

 

from trachea of Hippicus apiculatus (Harris) and Arphia

 

carinata; Iocustacarus locustae Ewing (1952) from the African

 

 

 

 

Locusts migratorioides. Stammer found Bgmbacargg buchneri
in several species of European bumble bees in Germany. It
has also been found in England (Cumber 1949), Austria
(Postner 1952), Denmark (Skou, Holm and Haas 1965) and Sweden
(Hasselrot 1960). A search of the literature has revealed
three species of internal mites in this family and several
external species associated with beetles and grasshoppers.
Stammer characterizes the genus as follows: "Both sexes
with three pairs of legs without pseudostigmatic organs. All
tarsi with two claws and a large empodium somewhat narrowed
at the base. A large median pair of setae on the posterior
margin of the propodosoma. Oviparous. The adults develop

directly from the eggs. The genus is near Locustacarus sp.

 

It differs in the markedly varying physiology and the strik-
ing median pair of setae on the propodosoma."

A review of specimens of Locustacarus spp. and Ewing's

 

description of the genus has been made. Both Locustacarug sp.

 

and Bombacarus sp. are tracheal parasites of insects. The

 

75

76
body chaetotaxy differs somewhat in position and relative

length of setae but not in number of setae from Locustacarus

 

trachealis Ewing (1924) and Locustacarus locustae Ewing (1952).

 

 

The last pair of propodosomal setae are longer than the other

propodosomal setae in both Locustacarus sp. and Bombacarus sp.

 

 

On the basis of similar but not identical chaetotaxy and sim-

ilar physiology, Bombacarus is considered to be a synonym of

 

Locustacarus.

 

Differences between the drawings of Locustacarus buchneri

 

(Stammer) and specimens of Michigan B. buchneri have been
noted. European specimens of this species have not yet been
examined. 0n the basis of many observations and a lengthy
discussion with Dr. Edward Baker of the U. S. Department of
Agriculture, a description of this species based on Michigan
.B. buchneri is offered.

Locustacarus buchneri (Stammer) 1951, New Combination

 

Newly developed female (figures 51 and 52). Body oval,
length 181p, greatest diameter 107”, tail setae 122p.

Gnathosoma follows Stammer's description for Iocustacanm

 

buchneri.

Dorsal aspect (figure 51): The long pair of prodosomal
setae are approximately 5/4 of the body length as given for
.B. buchneri. The opisthosoma differs in that the small pair
of sub-median setae are found on a nearly square sclerite.
The long pair of tail setae are about the same length as the

setae in B. buchneri.

'76

 

Figure 52. Locustacarus buchneri, ventral aspect, young female

 

79
Ventral aspect (figure 52): The three pair of sternal

grooves are the same as B. buchneri.

Appendages: The three pair of legs are similar to B.
buchneri but differ in chaetotaxy (table 2). The underlined
numbers represent numbers which differ from numbers given by
Stammer for this species.

Table 2. Iocustacarus buchneri, female, leg chaetotaxy

 

Trochanter Femur Genu Tibia Tarsus

Leg 1 0 2 1 2(1) Ԥ(l) [B sensory setae
leg 2 0 0 l .§(l) 2(2) '1 sensory seta
leg 5 0 0 1 5(1) 2(1) “B sensory setae

All tarsi have two claws and an empodium. The claws and
empodium are reduced on tarsus 1. As in_B. buchneri, the
ambulacral apparatus of the first tarsus is scarcely narrowed.
The ambulacral apparatus of tarsi two and three are well de-
veloped and markedly narrowed proximally.

Developing females: The develOping female resembles B.
buchneri. The eggs are oval l77-l9lpilong and 117-129yiwide.
The eggs are thus somewhat longer and the range in width is
less than that described for EA buchneri.

Males (figures 55 and 54): Slightly smaller than the
young females. Length 145 '15OH9 width 99-1029.

Gnathosoma: Chelicera as described by Stammer. Palpi
with an empodium-like lateral membranous projection with
three small stiff chitinous supports.

Dorsal aspect (figure 55): Three pair of setae on the

anterior margin of the pr0podosomal shield. Metapodosoma

80

 

 

 

 

 

 

 

 

 

Figure 55. Locustacarus buchneri, dorsal aspect, male

82

nearly rectangular, elevated and folded posteriorly. Meta-
podosomal setae more developed than in the female. Opistho-
some cone-shaped without the long paired setae that appear
in the female.

The penis originates at the anterior margin of the meta-

podosoma and closely resembles European Locustacarus buchneri

 

and otter Locustacarus spp.

 

Ventral aspect (figure 54): The ventral aspect differs

little from locustacarus buchneri.

 

Appendages: The leg chaetotaxy differs from the female.
The underlined numbers represent differences from numbers
given by Stammer for the male (table 5).

Table 5. Locustacarus buchneri, male, leg chaetotaxy

Trochanter Femur Genu Tibia Tarsus

leg 1 0 4 1 4(1) B(l) ‘B sensory setae
leg 2 0 0 1 5(1) 'B(l) 'B sensory setae
Leg 5 0 0 1 5(1) _B($) ‘B sensory setae

The tarsal spines, setae and sensory setae differ
markedly from those given for B. buchneri.

Occurrence: In the airsacs of Bombus bimaculatus in

 

Kansas, Missouri and Michigan, in one male Psithyrus

 

laboriosus and one male Bombus vagans. Sinha (personal com-

 

 

munication) reports Lomistacarus sp. from Bombus terricola

 

 

in Canada. In several European Bombinae.
locustacarus buchneri develops directly from egg to
adult. The mites are nearly mature when the eggs leave the

female. Judging from the positions of mites upon removal

85
from the bee air sacs, copulation takes place very soon

after the mites break out of the eggs. Stammer (1951) ob-
served that the mature females were usually found to con-
tain 2x5 large eggs although as many as 50-60 may be found
stuck together around the female.

Most of the observations made of Iocustacarus buchneri

 

in Michigan Bombinae agree with Stammer's detailed descrip-
tion of the biology of this species in Germany. The follow—
ing differences were noted. Whereas B. buchneri in Germany
was observed to be less numerous in the short lived species

Bombus_p§atorum than in long lived species, B. buchneri in

 

Michigan seems to be primarily associated with the short

lived species Bombus bimaculatus. Throughout 1965, many spe-

 

cies were methodically examined for internal mites. Internal

mites were very common in Bombus bimaculatus in Michigan and

 

Missouri and had been found by D. Dies in Kansas in 1960.

However, only one male Psithyrus sp. and one Bombug vagans

 

male had internal mites. Sinha has found Locustacarus sp.in

 

Bombus terricola.in Canada but I am not aware of the com-

 

plete details of this record as Sinha is in Japan while his
records are in Canada.
.9. buchneri was found in bees from two nests of Bombus

bLmaculatus. On 4 August 1965, a declining nest was found

 

at the W. K. KelIOgg Biological Station in Kalamazoo County,
Michigan. The few remaining worker and male bees were ob-
served in place for several days. On 5 August, two bees were

observed crawling on top of the nest. large mesostigmatid

84
mites were crawling on both'bees. One bee was removed with

forceps and placed in a covered Petri dish. The bee was not
very active and died the following day. About an hour after

it died, two living young female Locustacarus buchneri were

 

noted on the posterior lateral aSpect of the thorax and a
third on the lateral margin of abdominal tergite I. They
were removed and placed on slides. A fourth.mite was removed
from the left thorax and a fifth and sixth were found on the
glass near the bee. Several hours later one had died. The
other was moving slowly. Both were put on slides. No other
.B. buchneri were noted in the dish or on the bee. The bee
was dissected and living males, young females and a mature
female were removed from the abdominal air sacs and placed on
slides. The air sacs were dark brown as described by Stammer.
This is the first recorded instance of this mite outside the
air sacs and trachea.

A second bee was removed on 6 August and died on 9 Aug-
ust. No.9. buchneri were observed on the bee but three dead
ones were found on the glass near the bee on 9 August. This
bee had many acarid hypopi on both corbicula. On 9 August,
no mites were on the corbicula. Hypopi were crawling on the
~bee and dish. On 11 August mesostigmatid mites and acarid
hypopi were found externally and male and female B. buchneri
were found internally.

A third bee was picked up with forceps. It had diarrhea
and was killed and examined. Several male and female mites

were removed from the abdominal air sacs. As in the other

85
cases, the airsacs were dark brown. This is the first time

that a bee was noted to have diarrhea and gives further
evidence to the claim by Skou, HOlm and Haas (1965) that the
consequences Of infestation with B. buchneri can be serious.

The nest was placed in an open glass funnel on 11
August and no internal mites were observed in the nest or
collected in the alcohol below.

A second nest was of Bombus bimaculatus and obtained on

 

7 July 1966. The nest was at its peak of activity. Males
and newly emerged queens were present. This nest has been
described earlier in this report. Males, queens and workers
had internal mites. One of two pupal queens had mites in
an abdominal air sac. This is the first record of an inter-
nal mite in a pupa and suggests that the young female mites
may enter the cells Of larvae as they are few by workers.
Hobbs (personal communication) states that openings are
made in cells by worker bees in feeding larvae and are Open
long enough for mites to enter the cell. Medler (1959)
noted other kinds Of mites are also found Occasionally in
closed cells. Over half (60.7%) Of the worker bees had in-
ternal mites and 54.8% Of the males had B. buchneri in the
abdominal air sacs. Forty-six percent (15 of 28) Of the

queens had internal mites.

In summary, locustacarus (Bombacarus) buchner;_(StammerL

 

 

new combination, is justified on the basis Of similar mor-
phology and physiology. .B. buchneri is redescribed with

changes in leg chaetotaxy and the addition Of an opisthosmnal

86

plate. Living female L. buchneri were noted outside Of a

Bombus bimaculatus worker and inside a pupal queen.

 

RELATIVE ABUNDANCE OF MITE-INFESTED BOMBINAE
The relative abundance of Bombinae with mites has been
recorded for a few European species. Stammer (1951) reported

on Locustacarus buchneri (Stammer) in Bombinae in Germany.

 

He found this mite in 12 species Of Bombinae. The incidences
of infestation were from less than 1% to 58% for the various
species. Stammer states that infestation with this species
is probably not significant as numbers Of mites per bee are
usually low.

Skou, HOlm and Haas (1955) report Parasitus fucorum de

 

Geer, Kuzinia (Tyrophagus) laevis Dujardin and Locustacarus

 

 

buchneri Stammer in Bombus spp. in Denmark and state that the
former two are important disease vectors in Bombus spp.

They found a Bombus sp. queen so weak that she ceased nesting
activity. Dissection revealed a large number Of L. buchneri
and the insides "almost entirely wasted away".

Loomis (1956) has studied the relative abundance of chig—
ger larvae in Eastern Kansas during various months and a few
other studies Of vertebrate mites Of this type are in the
literature. However, studies Of relative abundance of mites
Of hymenOptera are not common. A search Of the literature
has revealed no study which gives the relative numbers Of
Bombinae with mites throughOut the year.

Between 1965 and 1966, several thousand pinned and

freshly caught bees were examined for mites by methods

87

described previously. Records were not compiled for all Of
the museum specimens examined nor were all daily collections
recorded. However, detailed records from 27 April 1965 to
24 October 1965 and supplemental records to 10 September 1966
include 5,477 Bombinae collected throughout the state of
Michigan (Table 4). The following Observations are based up-
on this sample. The mites are lumped together in this study
to give an estimate Of the total number Of bees with mites.
By far the most common mite is the deutonymph of Kuzinia
laevis (Dujardin). The various other mites found will be
discussed later. The figures in tables 4, 5 and 6 are rounded
to the nearest whole percent.
Table 4. The seasonal Occurrence Of Acarina on Michigan
Bombinae (Numbers in parentheses indicate nest:data)

Months 1965-66 No. Of Bombinae Total Number % of Bombinae

With Mites of Bombinae With Mites
April 7 7 100%
May 196 401 49%
June 41 125 63%
July 151 (72) 565 (99) 27% (76%)
August 204 (7) 886 (155) 26% (06;)
September 209 (196) 1468 (1427) 14% (14%)
October 20 27 74%
TOTAL 828 (275) 5477 (1659) 24% (17%)

The figures in table 4 include bees taken from nests
at night. It is possible that mites may be found more or

less frequently on nest bees than on bees taken at flower.

88
The figures in parentheses indicate that considerable dif-

ferences may occur between the number of bees with.mites
from flowers and those from nests. One factor which.might
bias the results is interference with nest activity by man.
One nest was doused with gasolene the day before it was col-
lected. Another was in a ball Of twine which may have been
treated with fungicide and a third nest may have been sprayed
with insecticide as the property Owner was attempting to
reclaim the dog house in which the nest was located. NO
mites were found on the bees in these nests and very few
mites were retrieved from the nests.

The data in table 1 tend to suggest that the highest
overall incidence Of mites on bees is in April, May and Octo-
ber. Seven queens form the May sample and 27 bees consti-
tute the October sample. Two queens collected in logs and
18 males collected at flower in October had mites.

Thirteen Of forty-one bees (52%) collected at flower in
September support the possibility Of an increase in number
Of mite-infested bees outside the nest in September. This
figure is lower in table 1 by the large number of nest bees
without mites. The reduction in numbers of nest bees with
mites in September may be a natural tendency but this is
doubtful. A more detailed analysis of two nests which were
known to be relatively undisturbed will be presented later
in this report to support this conclusion.

The overall tendencies for occurrences Of mites on

Michigan Bombinae is highest in the spring and late fall and

89

lowest in July, August and September.

The frequency of mite-infested bees collected at flower
in the lower peninsula of Michigan was compared to the numba?
Of bees with mites in the upper peninsula during May and
August of 1964 and 1965 (table 5).

Table 5. Frequency of mite-infested Bombinae collected

at flower in 1964 and 1965

Month Area Of NO. Of Bombinae Total NO. % Bombinae
Collection With Mites Bogginae With Mites

May Lower Peninsula 77 165 47%
Upper Peninsula 119 256 51%

August lower Peninsula 156 546 25%
Upper Peninsula 61 207 29%

Slight differences Occurred in relative abundance of
Bombinae with mites in broad areas Of the state during the
period covered in this study.

The number of Psithyrus spp. which had mites compared

 

to the number Of mite-infested Bombus spp. appear to be more
significant. In five days Of collecting from different areas

of Michigan's upper peninsula, 54 Of 74 Psithyrus spp. collaflr

 

ed had mites (table 6). The number Of Bombus spp collected
the same day are in parentheses.

The large numbers of Psithyrus spp. collected on May 51

 

were from seven sites in three counties and could not have
come from one nest area. The remaining seven specimens were
collected from widely separated areas but do not constitute

a sufficient sample. However, the trend for a greater

90

infestation Of upper peninsula Psithyrus spp. is supported

 

by these data.
Table 6. Frequency Of upper peninsula, mite-

infested Psithyrus spp.

 

NO. of Bombinae Total No. % Bombinae

 

 

 

 

With Mites Bomglnae With Mites
29 May Psithyrus spp. 2 (7) 2 (27) 100% (26%)
60 May Psithyrus spp. 1 (56) 1 (64) 100% (56%)
51 May Psithyrus spp. 47 (55) 66 (99) 71% (64%)
26 Aug.Psithyrus spp. 2 (8) 6 (47) 67% (17%)
28 Aug.Psithyrus spp. 2 (l7) 2 (42) 100% (40%)

 

In summary, the relative numbers Of Bombinae with.mites
is highest in April and steadily decreases until August. The
relative numbers with mites then increase until October.
Relative abundance Of Bombinae with.mites throughout the stems
appear to be nearly the same if the records Of the same month

are compared. The relative numbers Of Psithyrus spp. with

 

mites was higher than Bombus spp. collected on the same days.

THE REIATIVE ABUNDANCE 0F MITE-INFESTED
BOMBINAE IN TWO SELECTED NESTS
Two nests Of the 27 nests examined were selected for
analysis as both were relatively undisturbed. The nest Of

Bombus bimaculatus reaches a climax with the production Of

 

males in early July in southern Michigan. The nest Of

Bombus pennsylvanicus reaches a clbnax with the production

 

Of males in late August. Both nests were collected near the
climax of the nest activity.

The first nest presented is that of Bombus pennsyflvanicus

 

collected on 5 September 1965. It was collected in Kalamazoo
County, T55, R11W, S26, from the ground underneath a pile Of
boards. It was composed Of leaf litter and a small amount Of
glass wool. The Berlese sample included Araneae, Pseudo-
scorpiones, ChilOpOda, Acarina, Isopoda, Collembola, Siphono-
ptera, Diptera, Coleoptera, lepidoptera and Hymenoptera.

Thirty of 61 (97%) males, 16 of 21 (66%) queens and 49
Of 101 (49%) workers had mites on them. The total number of
bees with.mites is 97 of 170 (67%) bees. The numbers of
mites which occurred on these bees will be covered in the
next section Of this report. All Of the mites collected frmn
the Berlese sample were not separated from the debris. Repre—
sentative mites were selected and put on slides. The remain-
ing mites cover a volume approximately 50mm in diameter to a
depth Of 2 mm.

The second nest is that Of Bombus bimaculatus collected

 

7 July 1966 in lenawee County T68, R5E, S54. It was located

91

92
under a cement slab porch. Very little Of the outer nest

material was recovered as the nest was difficult to reach.
Twentyseven of 28 queens, 10 Of 11 males and 54 of 56 workers
had mites on them (table 7).

Table 7. Incidence Of mite-infested Bombus bimaculatus

 

Queens Workers Males Total

Acarid hypopi only 14 0 ' 4 18
Acarid hypopi and

internal mites 12 O 5 15
Internal mites only 2 (1 pupa) 54 5 59
*Internal, Acarid

and mesostigmatid 5 0 0 5
NO mites l (pupa) 21 l 25

*also tabulated with acarid hypopi and internal mites.

Of the 95 bees, 72 (76%) had mites. The incidence of
infestation was: internal mites - 57%, acarid hypopi -
55% and mesostigmatid - 5%.

In this particular nest, it is interesting to note that
all but three (including 2 pupae) queen bees had acarid
hypopi. Seven of the 11 males had acarid hypopi. Most of
the males and queens appeared to have recently emerged. Some
had only pollen in the crop. It is possible that acarid
deutonymphs are attracted to newly emerged bees in preference
to the older workers.

Nest bees from relatively undisturbed nests had a much
higher percent of infestation than the monthly average for

all Bombinae which was presented in the previous section.

95
Part of this may be due to the time of collection. However,

workers had a much lower rate Of infestation than either males
or queens.

In summary, nest bees, particularly queens and males,
have a higher percent of infestation than bees collected at
flower in the same months. Acarid hypopi may be attracted to
newly emerged bees in preference to Older workers.

POSITION AND NUMBERS OF MITES ON VARIOUS
ANATOMICAL PARTS OF MICHIGAN BOMBINAE

Zakhvatkin (1941) states that large numbers Of acarid

hypopi occur On all species Of Palearctic Bombus spp. Skou,

Holm and Haas (1965) found 106 nymphs Of Parasitus fucorum

 

on a hibernating queen. In order to get an indication of
where mites occur on Michigan Bombinae and how many mites
occur in each area, counts Of incidences of infestation were
made from bees collected and recorded in 1965. An incidence
is defined as the finding Of one or more mites on a particu-
lar anatomical part.

The sample collected will not agree with.the total num-
ber of bees with mites in the previous section due to the 10m;
of some mites and lack Of appropriate data for all specimens.
This is due in part to a technique which did not work. Some
Of the bees caught in 1965 were stored in individual vials in
the refrigerator and freezer after they had been examined
alive through the glass wall of their closed containers. In
some instances the mites moved Off the bee. In other instancea,

the bee and mites decayed before all could be examined.

94

Incidences are recorded throughout the season from April
through October and it is believed an adequate and repre—
sentative sample was Obtained.

The categories chosen, arbitrarily, are head, thorax,
abdomen, wings and legs. These are further subdivided
(table 8). Many instances such as intersegmental groove III
of the thorax, propodeal spiracle, scutellum and pr0podeum
are lumped together tO give a workable basis for comparison
of general areas of the bee. living mites have been Observed
crawling on all external structures Of bees in nests. The
more common areas are illustrated in figures 55, 56 and 57.
In some instances, mites remain alive after the bee has been
killed and have been Observed spreading to various parts Of
the bee and to the insect pin Of pinned bees. An attempt was
made to control this through use Of potent killing jars.
Mites found on the head, abdominal segment I and tibia III
of the same bee appear as three separate incidences (tableEB).
All mites are lumped together in this study.

The most common site of mite infestation is the propo-
deum with 181 instances of infestation. Skou, Holm and Haas
(1965) suggest that only after the pr0podeum and anterior
portion of abdominal tergite I are occupied will hypopi be
found on other parts of the body. The techniques used in
this study are not adequate to test this statement. Since
56% of the incidences Of infestation occur on this area Of
the bee, the hypothesis by Skou, Holm and Haas may be correct.

However, bees which had numerous hypopi on the abdominal

95

     

THORAX

 

Figure 55. Position of mesostig'xatid mites on Michigan Bombinae

THORAX

   

THORAX

 

TH ORAK

MITES

WING

 

ABDOMEN

Figure 56. Acarid hypopi on thorax, wing and
abdominal tergite I of Michigan Bombinae

97

 

Figure 57. Acarid hypopi on abdominal tergites
of Michigan Bombinae

98
Table 8. Position Of mites on Michigan Bombinae collected

in 1965
At Flower In Nest Total
Head 4 2 6
Thorax 250
Prothorax 1 7
Propodeum 57 124
Other (ventral, lateral, dorsal) 15 15
Between thorax and abdomen 10 21
Wings 8 45 55
Legs 56
Coxae 7 l4
Femur III 5 1
Tibia l6 2
Tarsus III 1 1
Between legs and thorax 1 4
Between\legs and abdomen 1 5
Abdomen . 161
Segment I 19 69
Segment II 17 5
Segment III 14 5
Segment IV 12 0
Segment V 6 0
Segment VI . 4 0
Segment VII 1 0
Other (segment not recorded) 10 5

Total 209 517 526

99
tergites and not on the propodeum.or anterior aspect Of the

abdomen were not unusual.
large numbers of mites have been found on Bombinae.

One queen Bombus vagans collected in Kalamazoo County, Michi-

 

gan on 27 April 1965 had 57 Scutacarus acarorum on the region

 

of coxae II and III and 802 Kuzinia laevis hypOpi on the

 

thorax and abdomen. This is a partial count since two slides
of scutacarids and two slides Of B. laevis had been made
from collections from the thorax and were not available at
the time Of this report. Of the 859 mites, 408 were removed
from abdominal tergite II for counting while the remaining
ones were counted lg_§323. This is difficult and the count
is thought to be slightly lower than it would be if all mites
were removed and counted. Although many hypopi are found on
bees, this is one Of the most heavily infested ones that was
found.

To estimate how many mites may occur on various parts

of male, female and worker bees, 170 Bombus pennsylvanicus

 

from the nest previously discussed were examined for mites
(tables 9, 10, 11, 12). When first examined, 67% Of the bees
had mites. later, no mites could be found on four Of these.
The sample consists Of 16 queens, 29 males and 48 workers.
Fifteen mesostigmatid mites occurred on 14 bees. Both acarid
hypopi and mesostigmatid mites occurred on the same bees.
Approximately 2646 acarid hypopi were found on 207 anatomical
parts of the 95 bees. The average number is approximately

28 mites per bee and 12.8 mites per anatomical part.

100
Table 9. Number Of mites per body part for 29

male Bombus pennsylvanicus

 

Body Region Hypopi HypOpi Average Mesostig-

matid
Head 1(1) 1.0 0
Thorax
Prothorax 6(5) 2.0 0
Propodeum 1062(29) 56.6 1(1)
Other (lateral) 59(1) 59.0 0
Between the thorax
and abdomen 57(5) 7.4 2(2)
Wings 15(4) 5.8
Legs
Coxae 1(1) 1.0 1(1)
Between legs and thorax 5(1) 5.0 1(1)
Between legs and abdomen 0 0 1(1)
Abdomen
Segment I 149(14) 10.6 0
Remaining segments 20(2) 10.0 0
Unknown (drOpped from bee) O 0 1(1)
Total 1525(61) 21.7 7(7)

Of the bees in this nest, the highest numbers of mites
per bee part occurred in the males (table 9) followed by the
workers (table 11) and queens (table 10) in that order. Why
males carried more hypOpi per anatomical part Of the bee in
this study is unknown. The activity patterns Of the male in

the nest vary from those of both workers and females but

insufficient evidence exists to suggest this as a reason for

101

increased average numbers Of mites.
The queens and males carried all but one Of the fifteen
mesostigmatid mites found. This pattern may be characteris—

tic Of the mites involved. large numbers of Parasitus

 

fucorum.nymphs have been reported previously on a Bombus sp.
queen (Skou, Holm and Haas 1965).
Table 10. Number of mites per body part for 17 queen

Bombus pennsylvanicus

 

Body Region Hypopi Hypopi Average Mesostigmatid
Head 0 0 0
Thorax
Prothorax O O O
Propodeum 50(7) 7.1 2(1)
Other (lateral) 1(1) 1.0

Between thorax

and abdomen 1(1) 1.0 2(2)
Wings 4(6) 1.6 0
Legs

Tibia II 1(1) 1.0 0

Between legs

and thorax 0 0 1(1)
Abdomen
Segment I 12(2) 6.0 2(2)

Total 68(15) 4.5 7(6)

102
Table 11. Number of mites per body part Of 48 worker

Bombus pennsylvanicus

 

Body Region Hypopi HypOpi Average Mesostigmatid
Head 1(1) 1.0 0
Thorax
Prothorax 2(2) 1.0 0
Propodeum 526(45) 7.6 1(1)
Other 5(5) 1.0 0

Between thorax

and abdomen 24(4) 6.0 0
Wings 245(55) 7.4 0
Legs 1(1) 1.0 0
Abdomen

Segment I 665(42) 15.8 0
Segment ll 5(2) 1.5 0
Total 1267(151) 9.7 1(1)

The data for the bees in this nest suggest that not only
are mites more likely to be found on the pr0podeum and ab-
dominal segment I but that the largest numbers Of mites will
be found in this area (table 12). The order of magnitude
from the highest to lowest numbers Of mites per body part is
pr0podeum, abdominal segment I, wings, thorax (other than
pr0podeum), abdomen (other than segment I), legs and head.
The 29 males carried half (1525) of the 2646 acarid hypopi

counted on 95 Bombus americanorgm.males, queens and workers.

 

 

The average numbers of hypopi per bee was (1) males, 21.7

(2) workers, 9.7 and (5) queens, 4.5.

105
Table 12. Summary of number of mites for 95

Bombus pennsylvanicus

 

Body Region Hypopi Hypopi Average Mesostigmatid

Head 2(2) 1.0 O
Thorax
Propodeum 1458(79) 18.2 4(5)
Other 115(20) 5.7 4(4)
Wings 264(40) 6.6
Legs 5(5) 1.0 1(1)

Between legs
and thorax 5(1) 5.0 2(2)

Between legs

and abdomen 0 0 1(1)

Unknown 0 0 1(1)
Abdomen

Segment I 824(58) 14.2 2(2)

Other 23(4) 5.8 0

Total 2646(207) 12.8 15(14)

CHECK LIST OF MITES ASSOCIATED WITH

Phylum Arthropoda
Subphylum Chelicerata
Class Arachnida
Subclass Acarina
Order Mesostigmata
Cohort Uropodina

Family Uropodidae

MICHIGAN BOMBINAE

Genus Fuscuropoda sp.

 

UroEoda sp.
Family Urodinychidae

Genus Leiodinychus sp.

 

Cohort Gamasina
Family Parasitidae

Genus Parasitus sp.

 

Family Phytoseiidae

Genus Typhlodromus sp.

 

Family Blattisociidae

Genus Proctolaelaps

 

Proctolaelagg

sp.

longanalis

 

Proctolaelaps

Proctolaelaps

longisetosus

ornatus

 

Family Laelaptidae

Genus Pneumolaelaps

 

Pneumolaelaps
Pneumolaelaps

Pneumolaelaps

sp.
mistigilus Hunter 1966
longipilus Hunter 1966

longanalis new species

104

105
Family Iaelaptidae (cont'd)

Genus Pneumolaelaps new species

 

Pneumolaelaps new species

 

Pneumolaelaps new species

 

Pneumolaelaps new species

 

Cosmolaelaps sp.

 

Androlaelaps sp.

 

Family Veigaiaidae
Order Prostigmata
Family Podapolipodidae

Genus Locustacarus sp.

 

Locustacarus (Bombacarus)

A
B
C
D

buchneri

 

Family Pyemotidae
Family Scutacaridae

Genus Scutacarus sp.

 

Scutacarus acarorum

 

Family Tarsonemidae
Family Tydeidae

Genus Tydeus sp.
Family Cunaxidae

Genus Cunaxa sp.
Family Stigmaeidae
Family Anystidae
Family Cheyletidae

Genus Cheyletus sp.

 

Family Smarididae

106
Family Trombidiidae

Genus Eutrombidium sp.

 

Order Astigmata
Family Acaridae
Genus Kuzinia sp.

Kuzinia laevis

 

Tyrophagus sp.
Tyrophagus_putrescentiae
Ca loglyphus s p.

 

Rhizoglyphus sp.

 

Family SaprOglyphidae
Genus 1.19.39. sp.
Calvolia sp.
Family Glyciphagidae

Ge nus C tenoglyphus s p .

 

Ctenoglyphus robustus
Family Anoetidae

Genus Histiostoma sp.

 

Family Epidermoptidae

Genus Dermatophagoides sp.

 

Order Cryptostigmata
Family Nothridae

Genus Nothrus sp.
Family Phthiracaridae

MITES ASSOCIATED WITH MICHIGAN BOMBINAE IN NESTS

Species of Bombinae

Bombus affinig

 

Bombus bimaculatus

 

Bombus fervidus

 

Acarina

Pneumolaelaps mistipilus

 

Pneumolaelaps sp.

 

Kuzinia laevis

 

Tyrophagus putrescentigg

 

Parasitidae
Stigmaeidae

Scutacarus acarorum

 

Pneumolaelaps mistipilus

 

Pneumolaelaps longanalis

 

Proctolaelaps longisetosus

 

Kuzinia laevis

 

Tyrophagus putrescentidae

 

Ctenoglyphus robustus

 

Parasitidae
Anystidae
Smarididae
Cunaxa sp.

Pneumolaelaps longipilus

 

 

Pneumolaelaps longanalis

Pneumolaelaps sp.

 

gTerQhagus putrescentiae

Ctenoglyphus sp.

 

Scutacarus acarorum

Tydeus sp.
107

County
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo,
Allegan
Kalamazoo
Kalamazoo
Allegan

Kalamazoo

108
MITES ASSOCIATED WITH MICHIGAN BOMBINAE IN NESTS (cont'd)

 

 

 

 

Species of Bombinae Acarina County

B: fervidus (contd) leiodynchus sp. Kalamazoo
Parasitidae Kalamazoo
Uropodidae Kalamazoo
Pthiracaridae Kalamazoo

Bombus griseocollis Kuzinia laevis Kalamazoo
Cheyletus sp. Kalamazoo
Parasitidae Kalamazoo
Phytoseidae Kalamazoo
Pneumolaelaps sp. Kalamazoo

 

Bombus pennsylvanicus Pneumolaelapg mistipilus Kalamazoo

 

 

Pneumolaelaps longipilus Kalamazoo

 

Pneumolaelapg sp. Kalamazoo,

 

Allegan
Proctolaelaps longisetosus Kalamazoo

Cosmolaelapg sp. Kalamazoo

 

Androlaelaps_glasgowi(?) Kalamazoo

 

 

 

 

Parasitus sp. Allegan,
Kalamazoo
Uroooda sp. Kalamazoo
FUScuropoda sp. Kalamazoo
Ieiodinychus sp. Kalamazoo
Cheyletidae Kalamazoo
Stigmaeidae Kalamazoo
Kuzinia laevis Kalamazoo

 

Ctenoglyphus sp. Kalamazoo

 

109
MITES ASSOCIATED WITH HICHIGAN HCMBINAE IN NESTS (oont'd)

 

 

 

 

Species of Bombinae Acarina County

.§._pennsylvaniggs (cont'd) Histiostoma sp. Kalamazoo
Tarsonemidae Kalamazoo
Nothrus sp. Kalamazoo
Scutacarus acarorum Kalamazoo

Bombus gagags Pneumolaelaps sp. Kalamazoo
Parasitidae Barry

Ctenoglyphus sp. Kalamazoo

 

MITES ASSOCIATED WITH MICHIGAN BOMBINAE AT FLOWER

Species of Bombinae

Bombus affinis

 

Bombus bimaculatus

 

Acarina
Pneumolaelaps mistipilus
Androlaelaps casalis

Pneumolaelapg sp.

Proctolaelaps longisetosus

Proctolaelgps longanalig

 

Kuzinia laevis

CtenOglyphus sp.
Vidia sp.
Parasitidae

Scutacarus acarorum

Kuzinia laevis

 

Scutacarus acarorum

 

Parasitidae

Locustacarus buchneri

 

Proctolaelaps longanalis

Pneumolaelaps longanalis

 

110

County
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo,
Alpena,
Geneaee
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo,
Ingham,

lenawee

Allegan,
Ingham,
Kalamazoo,
Oceana
Kalamazoo
Kalamazoo,
Oceana
Allegan,
Kalamazoo
Kalamazoo

Kalamazoo

111

MITES ASSOCIATED WITH MICHIGAN BOMBINAE AT FLOWER (contfifi

Species of Bombinae

Bombus borealis

 

Bombus fervidus

 

Bombus_griseocollis

Acarina

Kuzinia laevis

 

Pneumolaelaps mistipilus

 

Pneumolaelaps longipilus

 

Pneumolaelaps sp.

 

Proctolaelapg longisetosus

 

Proctolaelapg ornatus

 

Parasitidae

Dermatophaggides sp.

 

Kuzinia laevis

 

Calvolia sp.

Scutacarus acarorum

 

Rhizoglyphus sp.

 

 

Oribatei

Pneumolaelaps mistipilus

 

Pneumolaelagg longanalis

 

Pneumolaelaps sp.

 

Kuzinia laevis

 

County
Delta
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Luce,
Kalamazoo
Luce
Delta,
Ingham,
Kalamazoo,
Iuce
Allegan
Kalamazoo,
Allegan,
Alger
Luce
Allegan,
Kalamazoo
Kalamazoo
Huron
Kalamazoo
Kalamazoo

Kalamazoo

1.1.2

MITES ASSOCIATED WITH MICHIGAN BCMBINAE AT FLOWER (cont'd)

Species of Bombinae

Acarina

§._griseocollis (cont'd)Caloglyphus sp.

 

Bombus impatiens

 

Bombus nevadensis

 

Bombus pennsylvanicus

 

 

Scutacarus acarorum

 

Parasitidae

 

Pneumolaelaps mistipilus

Proctolaelaps longisetosus

 

Kuzinia laevis

Parasitidae

Scutacarus acarorum

 

Pneumolaelaps mistipilus

 

Pneumolaelaps sp.

 

Proctolaelaps longisetosus

 

Scutacarus acarorum

 

Kuzinia laevis

 

Parasitidae

Pneumolaelaps longipilus

Pneumolaelaps longanalis

Proctolaelapg longanalis

County
Cheboygan
Branch,
Huron,
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo,
Ingham
Kalamazoo
Lenawee,
Barry
Kalamazoo
Allegan
Kalamazoo
Kalamazoo,
Missaukee
Kalamazoo
Kalamazoo
Berrien,
Clinton,
Iapeer,
Oceana

St. Joseph

Kalamazoo

115

MITES ASSOCIATED WITH MICHIGAN BOMBINAE AT FLOWER (cont'd)

Species of Bombinae Acarina

.B. pennsylvanicus (cont'd) Proctolaelaps sp.

 

 

Proctolaelapg longisetosus

 

Proctolaelapg‘grnatug

 

 

 

 

 

 

figginia laevis
Scutacarus acarorum
Parasitidae
Bombus rufocinctus Kuzinia laevis
Bombus ternariug Kuzinia laevis

Scutacarus acarorum

 

(in killing jar) Eutrombidiug sp.

 

County

St. Joseph
Kalamazoo
Kalamazoo
Genesee,
Kalamazoo,
Kent

Bay,
Kalamazoo,
Ingham,
Oceana
Barry,
Kalamazoo,
Ke nt

Alger
Alger,
Alpena,
Delta,
Houghton,
Marquette,
Schoolcraft
Houghton,
Alger,
Delta,
SChoolcraft

Delta

114

MITES ASSOCIATED WITH MICHIGAN BOMBINAE AT FLOWER (cont'd)

Species of Bombinae
.8. ternagigg (cont'd)

Bombus tegricola

(In killing jar)

Acarina

Pneumolaelapg sp.

 

Kuzinia laevis

 

Scutacarus acarorum

Pneumolaelaps sp.

Ca loglyphus s p .

 

Parasitidae
Eutrombidium sp.

Typhlodromus sp.

County
Delta
Alger,
Alpena,
Baraga,
Delta,
Houghton,
Ingham,
Macinac,
Marquette,
Missaukee,
Ontonagon,
Schoolcra ft
Delta,
Baraga,
Houghton,
Ontonagon,
Schoolcraft
Alpena,
Baraga
Ontonagon
Alpena
Delta

Luce

115

MITES ASSOCIATED WITH MICHIGAN BOMBINAE AT FLOWER (cont'd)

Species of Bombinae

Bombus vagans

 

Psithyrus ashtoni

Acarina

Kuzinia laevis

 

 

Scutacarus acarorum

 

Parasitidae

Ca log lyphus s p .

 

Vidia sp.

Pneumolaelapg longanalis

 

Locustacarug buchneri
Pyemotidae

Kuzinia laevis

 

Scutacaridae

Pneumolaelaps longanalis

 

Rhizoglyphus sp.

 

County
Alger,
Allegan,
Barry,
Delta,
Ienawee,
Marquette,
Ontonagon,
Kalamazoo,
Oceana,
Keweenaw
lenawee,
Kalamazoo,
Alpena,
Alger
Lenawee
Alger
Kalamazoo
Kalamazoo
Kalamazoo
Kalamazoo
Ontonagon,
Alger,
Keweenaw
Alger
Ontonagon

Alpena

116
MITES ASSOCIATED WITH MICHIGAN BOMBINAE AT FLOWER (cont'd)

 

 

Species of Bombinae Acarina County
Psithyrus laboriosus Iocustacarus buchnegi Kalamazoo
Scutacarug acarorum Barry,

 

 

Kalamazoo

Kuzinia laevis Kalamazoo

 

Psithyrus fernaldae _Kuzinia laevis Keweenaw

 

 

THE DISTRIBUTION OF PNEUMOLAEIAPS spp. IN NORTH AMERICA

 

WITH DESCRIPTIONS OF A NEW SPECIES (ACARINA: LAELAPTIDAE)
Both Hunter (1966) and Evans and Till (1966) recently

reviewed the status of Pneumolaelapg spp. Hunter published

 

a complete list of synonymy. In this present report, new
host and distribution records of the three North American
species described by Hunter are given. A new species of

Pneumolaelaps is described and illustrated.

 

Pneumolaelaps mistipilus Hunter 1966 has been reported

 

from Georgia and from Kalamazoo County, Michigan. Collections

were made from the following Bombinae: B. bimaculatus, B.

 

 

 

 

fervidus, B. griseocollis and B. nevadensis. Distribution

records are given in table 15.

 

Pneumolaelaps aequalipilus Hunter 1966 has been reported

from Georgia. Collections were made from Bombus impatiens

 

and B. pennsylvanicus. Distribution records are listed in

 

table 14.

Pneumolaelaps longipilus Hunter 1966 has been reported

 

from Bombus pennsylvanicus in Georgia. Distribution records

 

 

are listed in table 15.
0f the three species known from North America, Pneumo-

laelaps aequalipilus appears to be southern in distribution

 

while both 2. longipilus and 2. mistipilus appear to be more

 

 

cosmopolitan in distribution throughout the eastern United
States. The latter two species have longer body setae than

3. aequalipilus. It might be hypothesized that the shorter

 

body setae may have some connection with the northern limits

117

118

Table 15. Distribution of Pneumolaelaps mistipilus Ihunmr

 

 

 

1966
Species of Bombinae State
g. affinis Michigan (Kalamazoo Co.)
‘B. bimaculatus Michigan (Kalamazoo Co.)
Missouri
‘B. fervidus Michigan(Kalamazoo Co.)

 

Ԥ.'ggiseocollis Michigan (Kalamazoo Co.)

 

Michigan (Huron Co.)

'B. impatiens Michigan (Kalamazoo Co.)

 

Illinois
Kansas
Louisiana
Georgia

‘8. nevadensis Michigan (Kalamazoo Co.)

 

Illinois
Missouri

§._pennsylvanicus Michigan (Kalamazoo Co.)

 

Arkansas
Kansas

Georgia

Month Collected
Apr., July, Aug.
Apr., May
April

May

May, Aug.

May

August

April

unknown

March

Ange, OCtO

May, July, Aug.

April

Apr. , Aug., Sept.
May, Aug.

Sept.

July, Sept.

Apr . , June

119

Table 14. Distribution of Pneumolaelapg aequalipilus

 

Species of Bombinae State

Bombus impatiens Georgia

 

B. pennsylvanicus Alabama

 

Florida
Georgia
Illinois
Kansas
Louisiana
Missouri
South Carolina

Texas

Month Collected
April

April

no date

May, June

May

June, Aug.
Mar., Sept., Oct.
June

May

July

Table 15. Distribution of Pneumolaelaps longipilus

 

 

Species of Bombinae State
Bombus fervidus Michigan (Kalamazoo Co.)
‘B. nevadensis Indiana

 

B. pennsylvanicus Georgia

 

Iowa
Kansas
Minnesota

Micthan

Month Collected
Aug., Sept.
Sept.

Apr. , May, July
Aug., Oct.
unknown

May

April

May, June, Ju ly

of this species. However, the new species which is described

in this report has short body setae and is northern in dis-

tribution.

120
Pneumolaelapg longanalis new species

This species may be separated from all known species by
the follwoing combination of characters. Dorsal plate com-
pletely covers the dorsum. Dorsal setae short, not extend-
ing beyond the base of the next posterior row of setae.
First pair of sternal setae do not reach the bases of the
third pair. Anal plate longer than wide. Distinct stria-
tions on the presternal, sternal and genitoventral plates.

Female: Body oval; 572rilong, 572,,wide. Dorsum: Dor—
sal plate covering all of dorsum (figure 58); no integument
laterad of plate. Setae short, up to 52,ilong, except for
11 (setal notations following Costa 1961), not overlapping
the base of the next posterior row, a row of heavier setae
along margin of body; setae il thickest. Entire surface of
dorsal plate marked by scale like striations. Ventrum: Pre-
sternal plate with several striations (figure 59). Sternal
plate 80rilong on midline, 140,;at narrowest width between
coxae II; anterolateral corner extends in a T-shape between
and laterad of coxae I and II, striations of plate extend to
third pair of sternal setae but are less obvious along the
posterior border and posterio-mesal portions of the sternal
plate. Sternal setae heavy, thick at base, first pair not
reaching the base of the third pair, relative lengths as
shown in figure 59. Metasternal plates weakly sclerotized
mesially, metasternal setae about the same size as the ster-
nal setae. Genito-ventral plate slightly overlapping sternal,

5llrnlong on midline, 161“ at greatest width, rounded

121

b. Chelicera

 

a. Dorsal shield

Figure 58. Pneumolaelaps logganalis n. sp.,
dorsal aspect, female

 

 

a- ~
3 ' 122

     

sp.

Figure 59. Pneumolaelaps longanalis n.
,fema e

ventral aspec ,

 

123
posteriorly, slightly expanded beyond genital setae; genital

setae shorter than metasternal setae, extending approximately
one half the distances from their bases to the posterior mar-
gin of plate. Striations are pronounced and form a vase-like
pattern mesially. Anal plate pear-shaped, 105rilong, 96.x
wide, tapering to 22riat the posterior border; narrowed and
bluntly rounded posteriorly with striations on the posterior
border; striations diminishing posteriorly (figure 59). One
large metapodal plate, with a smaller plate anterior to it
and two rod like plates at base of first ventral plate setae.
Peritremal plate large extending to dorsal plate in area of
setae rl; extending posterior of stigmata, two small pores hi
posterior tip of plate; peritreme wide, extending to area of
coxa I but not to dorsal surface; stigmatal opening large.
Ventral body setae short, most about as long as distance be-
tween setal rows; two pairs between genito-ventral and anal
plates; on lateral margins setae extend anterior to stigmatal
opening; pores in integument as shown. Legs; Legs II
heaviest; relative length and thickness of setae as indicated.
Dorsal leg setae short. All tarsi with claws and caruncle.
Chaetotaxy (following Evans 1965) given in Table 15.
Gnathosoma: Deuterostomal groove with six rows of teeth,
first three anterior rows each with 1-2 large and 5-4 smaller
teeth, three posterior rows with one large and 2-5 smaller
teeth. Internal posterior rostral setae distinctly longer
than other setae on the gnathosoma. Corniculi short, well

sclerotized. Palps moderately heavy. Chelicerae chelate,

124

both fixed and movable digits with two teeth (figure 58).

 

Table 16. Pneumolaelaps longgnalis, female,
leg Trochanter Femur Genu
2 5 55
--- 2 --- 2 2 ----
I l 5 O 4 21
0 5 52
--- l 2 --- 2 ----
II 1 5 5 11
0 5 22
III 1 -3- l l -1" l 2 ’11-
IV 1 -9- 1 1 -—_ 2 -§--
5 11
Ma le: Body ova l; 6 l2 ,1 long , 580 ,1 wide .

Tibia

55

21
22

leg chaetotaxy

2

---- 2

ll

Dorsum:

Dor-

sal plate covering all of dorsum (figure 40); no integument

visible laterad of plate.

Setae short, up to 269 long ex-

cept for 31 (setal notations following Costa 1961), not

overlapping the base of the next row; setae i1 thickest.

Entire surface of dorsal plate marked by scale like stria-

tions. Ventrum:

No presternal plate (figure 41).

Ventral

plates coalesced to form holoventral plate; expanded posterhx'

to coxae IV; 472ralong, llOPawide between coxae II, 76,.wide

between coxae IV, plate widest behind coxae IV - 260pi;

anterolateral corner extends between coxae I and II, stria-

tions on entire holoventral plate; striations more prominant

along the margins of plate.

Sternal setae heavy, thick at

base, not extending to anal setae, behind the genital setae

as indicated (figure 40).

to dorsal surface in area of setae rl;

Peritremal plate large extending

extending posterior

of stigmata, two small pores in posterior tip of plate; peri-

treme wide, extending to area of coxa I but not to dorsal

 

 

 

Figure 40. Pneumolaelaps longanalis n. sp.,
dorsal aspect, male

 

 

7 \Figure 41. Pneumolaelaps longanalis n. sp.,
’1 t, ma e

ventral aspec

127

surface; stigmatal opening large. Ventral body setae short,
most shorter than distance between setal rows; on lateral
margins setae extend anterior to stigmatal opening; pores in
integument as shown.

legs: Legs II heaviest; relative length and thickness
of setae as indicated. Dorsal leg setae short. All tarsi
with claws and caruncle. Femur II with a thick ventral seta..
All legs with ventral setae thicker than in female. Deutero-
stomal groove with six rows of teeth, first three anterior
rows with eight teeth, three posterior rows with 5-6 teeth.
Internal rostral setae distinctly longer than the other setae
on the gnathosoma. Corniculi short well sclerotized. Palps
moderately heavy. Chelicerae chelate.

Holotype (femalg): Gull Lake Biological Station, Kala-

 

mazoo County, Michigan, 10 August 1964-4; collector R. W.

Husband; from petiole region of_Bgmbus griseocollis (DeGeer)

 

female.

 

Allotype (male): Farm meadow, Macdonald College, Pro-
vince of Quebec, Canada, 15 August 1965; collector G. Jamie-
son; from nest of Bombus sp.

Paratypes: All were collected in Kalamazoo County,

 

Michigan by R. W. Husband unless otherwise noted. Four miles

west of Kalamazoo, 11 August 1965-2, on Bombus ggiseocollis

 

female: 1 female. Four miles west of Kalamazoo, 5 August

1965-5, on Bombus griseocollis female: 1 female. Five miles

 

west of Kalamazoo, 11 September 196505, from petiole region

of Bombus vagans male: 1 female. West side Kalamazoo,

 

128
26 July 1965-7, from Bombus bimaculatus: 1 female. Gull

 

lake Biological Station, 12 August 1965, from nest of Bombus

bimaculatus: 1 female. Gull lake Biological Station,

 

5 August 1965-2, from Bombus bimaculatus female in nest:

 

1 female. Four miles west of Kalamazoo, 7 August 1965,

on Bombus griseocollis female: 1 female. Gull lake Bio-

 

 

logical Station, 5 August 1965, from nest of Bombus

bimaculatus: 1 female, 2 nymphs. Gull Lake Biological

 

Station, 11 August 1965, from nest of Bombus bimaculatus:

 

6 females. Gull Lake Biological Station, 15 August 1965,

from nest of Bombus bimaculatus: 2 females, 1 nymph.

 

Northwest Kalamazoo, 4 September 1965, from nest of Bombus
fervidus: 2 females. Nottawa, St. Joseph County, 51 August

1955, collector C. Sabrosky, from Bombus pennsylvanicus:

 

1 female. Creve Coeur lake, St. Louis County, Missouri,

2 September 1956, collector E. P. Meiners, from Bombus
pennsylvanicus: 1 female. logan, Utah, 27 June 1956, col-
1ectors G. E. Bohart, A. locker, E. Cross, from nest of
Bombus morrisoni: 1 female. T42N, R2lW, Sl9, Delta County,
Michigan, 28 August 1965, collector T. W. Porter, from
sealed collecting vial with Bombus ternarius and Bombus

terricola: 5 females. TSlN, R42W, 814, Ontonagon County,

 

Michigan, 28 August 1965, collector T. W. Porter in a

sealed collecting vial with Bombus terricola, B. vagans and

 

Psithyrus ashtoni: 1 female. Farm meadow, Macdonald Col-

 

lege, Province of Quebec, Canada, 15 August 1965, collector

G. Jamieson; from nest of Bombus sp.: 2 females (2 slides).

129

The holotype and four paratypes will be deposited with

the U. S. National Museum, Washington D. C.

Paratypes will

be deposited with the Institute of Acarology, Wooster,

Ohio; Bishop Museum, Honolulu; British Museum (Natural Histo-

ry); and the Entomology Museum, Michigan State University,

East lensing, Michigan. The distribution is northern United

States and Southern Canada (table 17).

Table 17. Distribution of Pneumolaelaps longanalis n.sp.

 

Species of Bombinae State

Bombus bimaculatus Michigan (Kalamazoo Co.)

 

‘2. fervidus Michigan (Kalamazoo Co.)

B. griseocollis Michigan (Kalamazoo Co.)

 

B. morrisoni Utah, Logan

 

g. pennsylvanicus Michigan (St.Joseph Co.)

 

‘8. ternarius and

 

B. terricola Michigan (Delta Co.)

 

B. terricola,

 

B. vagans and
Psithyrus ashtoni Michigan (Ontonagon Co.)

 

 

Bombus vagans Michigan (Kalamazoo Co.)
Bombus sp. Quebec, Canada

.8. _pennsylvanicus Missouri (St. Louis Co.)

 

Month Co lle cted
July, Augus t
September
August

June

August

August

August
September
August

September

RElATIONSHIPS BETWEEN ACARINA AND BOMBINAE

This section is concerned with distribution, nest coloni-
zation and food habits of Michigan Acarina found in or on
Michigan Bombinae or in their nests.

The literature on distribution and food habits of var-
ious genera and species of mites, although incomplete, is
very extensive. In this study, the works of Baker and
Wharton (1952), Zakhvatkin (1941) and Hughes (1961) are the
main sources of information on world wide distribution and
food habits for various genera and species. The latter two
references are mainly concerned with mites of stored pro-

ducts.

DISTRIBUTION OF MICHIGAN ACARINA ASSOCIATED WITH BOMBINAE
A majority of the investigations were conducted in Kala-
mazoo County. large numbers of Bombinae from this county
have yielded 11 families of mites in addition to 12 families
which were listed by Homann (1955) from hives of Apgg

mellifica in Germany. On the basis of incomplete infor—

 

mation for many genera and species, distribution patterns
for mites are difficult to discern. Four common species
are illustrated in figures 42 and 45.

Kuzinia laevis has been collected throughout the state

 

from Isle Royale to the southern counties (figure 42). It

has been collected from 15 species of Bombinae in Michigan.

 

Additional K. laevis have been obtained from Wisconsin,
Minnesota and Illinois Bombinae. Thorp (personal communi-

cation 1965) found K. laevis on California Bombinae.

150

 

Figure 42. Scutacarus acarorum (Goeze),

 

Kuzinia laevis (Dujardin)
and Pneumolaelaps mistipilus Hunter

 

 

Figure 45. Locustacarus buchneri (Stammer)

 

| (I ll Ill .I. I

’i\u O < ‘. f 1!.

135
Zakhvatkin (1941) states that K. laevis is found as far

north as Greenland and may be found wherever Bombinae are
found. The species is found throughout Europe and northern
Asia. The southern limits have not been established.

Scutacarus acarorum was found in seventeen counties

 

throughout the state on twelve species of Bombinae at

flower and on Bombus affinis, B. fervidus and B. pennsy -

 

vanicus in nests (figure 42). Bees in an underground B.
affinis nest were particularly heavily infested. This
species has been taken from Bombinae collected in Georgia,
Illinois, Kansas, Missouri, New York and Tennessee. é,
acarorum is associated with.Bombinae in Europe. Cross
(personal communication 1966) recently saw a specimen of
'B. acarorum collected in Mongolia.

The genus Pneumolaelaps has a wide distribution pattern

 

in Michigan and Eastern United States. Present records in-

 

dicate that B. aequalipilus is found in the southeastern

United States and that B. longipilus and B. mistipilus are

 

 

found throughout the eastern United States. Thus far, the
genus has been found in three upper peninsula counties as
well as several counties in lower Michigan. The nestzof

all seven species of bees for which nests were collected con-

tained Bombus sp. bearing Pneumolaelaps sp. Four additional

 

species of Bombinae caught at flower also carried Pneumolae-

 

laps spp. (figure 42).
Both nymph and adult male and female Parasitidae were

found in nests of six species of Bombinae from Allegan,

lull4.|l.‘ ll {I‘i‘llf' 'I‘ III'I'I "l‘ 4" ‘I (a < I

154
Barry and Kalamazoo Counties. Only nymphs were taken from

nine species of Bombinae in seven counties from Luce County
in the upper peninsula to Kalamazoo and lenawee Counties in

the south. Parasitus fucorum was reported by Banks (1919)

 

from Bombus sp. in northern Canada. Frison (1926) found

Parasitus sp. in Illinois. Plath (1954) found Parasitus

 

 

fucorum in the eastern United States. Thorp (personal
communication 1965) found Parasitidae on California Bombinae.
Parasitidae associated with Bombinae have been reported by
several authorities in Europe (Vitzthum 1945, Skou, Holm

and Haas 1965).

Proctolaelaps spp. were found on six species of Bom—

 

binae in Kalamazoo and St. Joseph counties. Lindquist (per-

sonal communication 1966) reports Proctolaelaps bombophilus

 

from North American Bombinae. Proctolaelaps longisetosus

 

was found in the nests of two species of Bombus spp.

Proctolaelaps sp. may eventually be found throughout the

 

state but are less common on bees than Pneumolaelaps sp.

 

and Parasitidae.

locustacarus buchnepi was collected in three Bombinae

 

in Allegan, Kalamazoo and Lenawee counties (figure 45).

Sinha (personal communication 1966) found locustacarus sp.

 

in Bombus terricolg in Canada. This species may be found

 

throughout the state. On the basis of present data, this
seems to be the only mite which is relatively host specific.

Only one male Psithyrus laboriosus and one male Bombus vagans

 

 

have been found to bear this mite. These species of Bombinae

155
occasionally are found in Bombus bimaculatus nests.

 

Records of mites found on Psithyrus sp. tend to follow

 

the pattern of mites found on Bombus sp. with the exception
that none of the predaceous mesostigmatids have been collectui
from them.

No distribution or association patterns are evident for
the remaining species of mites. More data are needed for
these species.

NEST COLONIZATION BY ACARINA

Norberg (1956) and Woodruffe (1955) have studied mites
and insects in bird nests and have several explanations for
the ways by which arthropods could colonize bird nests.

With some modification the same possibilities for coloni-
zation of Bombinae nests by Acarina exist. A discussion of
these possibilities will be presented later in this report.

Bombinae nests are usually constructed in the nests of
rodents and would be expected to have at least some of the
fauna characteristically associated with the previous occu-
pants. Sixteen of the families of Acarina found by Drummond
(1957) in rodent nests have also been found on Michigan Bom—
binae or in their nests. Eleven genera are common to both.
Problems in identification of larval and nymph stages and in
getting species opinions have prevented the making of many

species comparisons. Haemolaelaps_glasgowi which is so com-

 

mon in nests and on rodents throughout the United States was
found in a Bombinae nest. The specimen is in poor condition

and was identified by Lindquist as "Androlaelaps (Haemolaehfim)

 

 

156
near glasgowi". Some of the parasitic insects such as

Siphonaptera have been found in nests of Bombinae and rodenti
Many of the predaceous and detritus feeding mites are common
to both Bombinae and rodent nests. Few species of host
specific vertebrate parasites are found in Bombinae nests.
Mites could enter nests by (1) transportation on nest
material at the time the vertebrate constructed the nest
(2) transportation on the vertebrate animal (usually rodent)
(d) transportation on the species of Bombinae queens, males
or workers indiginous to the nest (4) transportation on in-

vading Psithyrus sp. queens and other Bombus spp. (5) trans-

 

portation on lepidoptera, Diptera, Coleoptera, Hymenoptera or
other arthropods such as isopods, spiders, millipedes and
centipedes which invade the nest (7) transportation on
Mollusca, Annelida or other invertebrates (8) transportation
on other acarina (Scutacaridae on Parasitidae) and (9) de-
liberate entrance.

Norberg (1956) studied experimentally the means by
which arthropods enter bird nests and concluded that some
arthropods search for nests actively but no mites were ob-
served to do this. The colonization of the nest by mites
can be adequately explained by transportation upon nest
material, upon the vertebrate which constructed the nest,

upon Bombinae and a host of invertebrate invaders of the nest.

FOOD HABITS OF MICHIGAN ACARINA ASSOCIATED WITH BOMBINAE

A number of acarologists have discussed various types
of associations between insects and mites (Vitzthum 1941,
Tragfirdh 1945, Evans, Sheals and Macfarlane 1961). The four
major categories usually suggested are (1) commensal (2)
phoretic (5) predaceous and (4) parasitic. A fifth category
no close relationship, could be utilized for such mites as
the Phthiracaridae which is reported to feed upon decaying
leaves and wood. The categories used by Drummond (1957)
for mites found in mouse nests is a simplified form of the
categories above. He utilized the categories (1) predaceous
(2) parasitic and (5) miscellaneous. The miscellaneous
category included such feeding habits as phytophagous, sapro—
phagous, fungivorous, COprophagous and other non-predaceous
and non-parasitic feeding habits. Drummond's system is the
one that will be utilized in this report.

Evans, Sheals and Macfarlane (1961) indicate the food
habits of some mites vary depending upon the availability
of food. The use of such categories as predaceous and
phytophagous cannot be interpreted in an exclusive sense as
some mites may be predaceous at one time and phytophagous at
another. The feeding habits in this report are the primary

feeding habits of the mites when abundant food is available.

157

FOOD HABITS OF ACARINA ASSOCIATED WITH MICHIGAN BOMBINAE
Acarina Parasitic-Predaceous-Miscellaneous
Mesostigmata

Uropodidae
Uropoda sp. X

Fuscuropoda sp. X

 

Urodinychidae

Ieiodipychus sp. X

 

Parasitidae

Parasitus sp. X

 

Phytoseiidae

Typhlodromus sp. X

 

Blattisociidae

Proctolaelaps sp. X

 

Laelaptidae

Pneumolaelaps sp. X

 

Cosmolaelaps sp. X

 

Androlaelaps sp. X X

 

Prostigmata
Podapolipodidae

Iocustacarus sp.

 

Pyemotidae X
Scutacaridae

Scutacarus sp. X

 

Tarsonemidae X
Tydeidae

Cunaxidae X

158

159
Prostigmata (cont'd) Parasitic-Predaceous-Miscellaneous

Stigmaeidae X
Anystidae X
Cheyletidae X
Smarididae X
Trombidiidae X
Astigmata
Acaridae
Kuzinia sp.

Tyrophagus sp.

 

Caloglyphus sp.

 

>4><><><

Rhizoglyphus sp.

 

Saproglyphidae

>4

Vida sp.
Calvolia sp. X
Glyciphagidae

Ctenoglyphug sp. X

 

Anoetidae

Histiostoma sp. X

 

Epidermoptidae

 

Dermatophagoides sp. X
Cryptostigmata I
Nothridae X

Phthiracaridae X

140
Some biological relationships have been discussed in

considering lecustacarus buchneri and the relative abundance

 

of Kuzinia laevis on Bombus spp. The feeding habits of

 

Kuzinia laevis are not definitely known but may be myceto-

 

phagous. No success was experienced in attempts to rear
this species. The hypopi (deutonymphs) are phoretic and
have non-functional mouth parts. Although the hypopi do

not feed upon the bees, when present in sufficient numbers,
they may cause the queen to abandon nest construction and
cease foraging in a similar pattern to what occurs with high

infestations of Parasitus sp. nymphs (Skou, Holm and Haa31965fi.

 

In moderate numbers, Kuzinia laevis probably has a commensal

 

relationship to Bombinae and a few other bees (Xylocopa and
Osmia) and may not be harmful.

A mesostigmatid mite, possibly Pneumolaelaps longanalis,

 

entered the abdominal airsac of a female Bombus bimaculatus

 

that was being inspected for internal mites. The mite
appeared to insert chelicerae into the ventral abdominal

sinus through the wall of the airsac. Fluid could be observed
to course into the relatively transparent mite. The mite be-
(came swollen after nine minutes of intermittent feeding. In
the following seven minutes it crawled in and out of the air
sac, under the intestine and was noted to rub its hind legs
together. It was transferred to a cotton steppered vial and

was subsequently lost when the vial was knocked to the floor.

141

There is very little direct evidence for parasitism of
Bombinae by mesostigmatid mites. If the feeding habits de-
scribed above are an indication of the feeding habits of
some mites on Bombinae, feeding probably takes place in the
nest when the bee is less active and feeding is rapid and
intermittent. Feeding may be lynited to immature bees.

Many of the mesostigmatid mites are predaceous on other
insects in the nest. Others have a wide range of feeding

habits. Androlaelaps (Haemolaelapg) casalis, found in rodent

 

nests and in a kill jar with Michigan Bombus affinis, is not

 

parasitic but may feed on blood exuding from abrasions, eggs
of other mites, farinaceous materials or may be predaceous
depending upon the availability of food.

Female locustacarus buchneri were observed with chel-

 

icerae inserted into abdominal air sacs. A few mature fe-
males have been put on slides with a piece of the air sac
to Which they are attached. The males were not observed
feeding.

Some Scutacaridae and Pyemotidae are insect parasites
but no direct evidence of feeding activity was noted in this

study. Two instances of pseudoparasitism of Scutacarus

 

acarorum were noted. One was on Pneumolaelaps sp. and the

 

other upon a veigaiid mesostigmatid.

142

In summary, many of the mite families, genera and
species appear to occur throughout the state of Michigan in
a non-obligatory relationship to Bombinae. Relationships

vary from the nearly host specific parasitic Locustacarus

 

buchneri found in Bombus bimaculatus to the cosmopolitan,

 

phoretic hypopi of Kuzinia laevis found on nearly every

 

species of Michigan Bombinae throughout the state. The
closeness and nature of the relationships of many species

of mites has not yet been determined.

SUMMARY

Locality data for more than 15,000 Michigan Bombinae
was used in determining the distribution of the sub-family
Bombinae in Michigan. The systematics of Michigan Bombinae
were reviewed and keys to species were presented. Seventeen
of 19 species discussed had ranges that terminated at lati-
tudes within Michigan or at the borders. Bombinae distri-
bution appeared to be most closely related to rodent distri-
bution, the 70°F July isotherm, rainfall, vegetation, ter-
rain elevation and host distribution for Psithyrus spp.
Studies of nests of Bombinae indicated that Acarina were
common to all but one of the 27 nests examined. Coleoptera,
Lepidoptera, Collembola, Diptera, Hymenoptera and Psocoptera
were found in 9 to 18 of the 27 nests. Most of the nests
may have been former rodent nests.

Techniques for examining bees for mites were developed
and are presented. The techniques for examining bees for
internal mites are unique. The help of several authorities
(E. W. Baker, J. Camin, E. A. Cross, P. E. Hunter, D. Johnston
and E. Lindquist) in determinations of mites is acknowledged

Locustacarus (Bombacarus) buchneri (Stammer) 1951, new com-

 

bination, is redescribed and discussed in detail. This spe-
cies has not been previously described from North America.
New biological observations on B. buchneri are presented.
The relative abundance of Bombinae with mites is highest in
April, steadily decreases until August and reaches a second

high peak in October. Queens and males in nests were cmeerved
145

144

to have a higher percent of infestation with hypopi. This
supports the hypothesis that acarid hypOpi may be attracted
to newly emerged bees in preference to older worker bees in
the nest. Additional evidence to support this hypothesis is
presented. Queens and males in one nest studied carried 14
of the 15 mesostigmatid mites found on all bees in this nest.

One queen Bombus vagans caught at flower had over 859 mites

 

(Scutacarus acarorum and Kuzinia laevis) on the thorax and

 

 

abdomen. The average numbers of hypopi per anatomical part
of 95 nest bees were (1) males, 21.7 (2) workers, 12.8 and
(5) queens, 4.5 in one nest studied. The pr0podeum and
abdominal segment I were demonstrated to be the most likely
area for occurrence of mites and the area most likely to
bear the highest numbers of mites. A check list of twenty-
five families of mites found with Bombinae is provided.
Distribution records and species associations of mites and
bumble bees collected at flower and in nests are presented.

The distribution of Pneumolaelaps spp. in North America is

 

discussed and Pneumolaelgps longanalis n.sp. (Acarina: Lae-

 

laptidae) is described. The distribution and association
patterns of the mites found most commonly on Michigan Bom-

binae are discussed. Kuzinia laevis and Scutacarus acarorum

 

 

were found on most Bombinae throughout Michigan. Pneumolae»

 

laps spp., Parasitus sp. and Broctolaelaps spp. occurred

 

 

 

with less frequency. locustacarus buchneri is relatively

 

host specific and is found primarily in air sacs of Bombus

bimaculatus. The colonization of nests by mites can be

145

adequately explained by transportation upon nest material,
upon the vertebrate which constructed the nest, upon Bom-
binae and upon a host of invertebrate invaders of the nest.
Michigan mites found with Bombinae range from mites which
feed upon decaying leaves in the nest to fungivorous,

omnivorous, predaceous and parasitic mites.

MAJOR FINDINGS OF THE STUDY OF ACARINA
ASSOCIATED WITH MICHIGAN BOMBINAE

l. Seventeen of 19 species of Bombinae discussed were found
to have ranges that terminate at latitudes within Michigan

or at the borders.

2. Bombinae distribution appeared to be most closely related
to rodent distribution, the 700F July isotherm, rainfall,
vegetation, terrain elevation and host distribution for

Psithyrus spp.

 

5. Acarina were common to 26 of 27 Bombinae nests studied.
4. Techniques for examining Bombinae for internal mites are
unique.

5. Locustacarus (Bombacarus) buchneri (Stammer) 1951 is

 

redescribed and discussed in detail. This species has not
been reported from North America. New biological observa-
tions on B. buchneri are presented.

6. The relative abundance of Bombinae with mites is highest
in April, steadily decreases until August and reaches a secomi
peak in October.

7. Evidence for the hypothesis that acarid hypopi may be
attracted to newly emerged bees in preference to older
workers is presented.

8. The pr0podeum and abdominal segment I were demonstrated
to be the most likely areasfor occurrence of mites and the
areas most likely to bear the most mites.

9. Twenty-five families of mites were found with Michigan

Bombinae.

146

147
10. Distribution records and species associations of mites

and Bombinae collected at flower and in nests are presented.

11. The distribution of Pneumolaelaps spp. in North.America

 

is discussed.

l2. Pneumolaelaps longanalis n.sp. (Acarina: Laelaptidae)

 

is described.

15. Kuzinia laevis (Dujardin) and Scutacarus acarorum (80628)

 

 

were found on most Bombinae throughout Michigan.

14. Pneumolaelaps spp., Parasitus sp., Proctolaelaps spp.

 

 

 

and Iocustacarus buchneri occurred with less frequency than

 

'K. laevis or B. acarorum.
15. Michigan Acarina found with Bombinae range from mites
which feed upon decaying leaves in the nests to fungivorous,

omnivorous, predaceous and parasitic mites.

APPENDIX

NESTS OF MICHIGAN BOMBINAE

Bombus affinis Cresson

 

A.

Collected 29 August 1965 in Kalamazoo County, T23, RllW,
8165. The nest was removed from a stack of shingles in
a garage, and transferred to a rearing box for 17 days.
Mold was taking over the nest so it was placed in a
modified Berlese apparatus. Thirty-seven bees were re-
moved. Over 200 mites, ll Diptera, 27 LepidOptera, 7
Hymenoptera, 5 Coleoptera, 2 PSOCOptera and l Collembola
came into the alcohol. Maple seed wings and sunflower
seeds were found in the nest. It is thought to be for-
merly occupied by mice.

Collected 10 September 1965 in Kalamazoo County, T53,
RllW, S52. The nest was removed by digging two feet
down and six feet laterally in a lawn. It was put into
a modified Berlese funnel within an hour after removal.
Two hundred and twenty-seven bees were removed. Hundrab
of mites, larval Diptera and Coleoptera were collected
along with several adult beetles. Many decayed acorns
and white oak leaves were found. It is thought that

this nest was formerly occupied by a ground squirrel.

Bombus bimaculatus Cresson

A.

Collected 4 August 1965 in Kalamazoo County, TlS, Rlow,
S52. The nest was removed from a site in a field where
bee behavior was being studied. The original site was

in a stack of crates four feet above the ground. The

148

149

nest was removed from the field and placed in an
extraction funnel. Tear gas (chloropicrin) was applied
to cotton at the top of the covered funnel to drive the
arthropods into an alcohol containing bottle below the
funnel. Collembola, Psocoptera, Orthoptera (Blattidae),
Hymenoptera (ants), lepidoptera, millipedes, centipede,
Isopoda and many mites were found in the sample. Only
a small sample of bees was obtained.

Collected 11 August 1965 in Kalamazoo County, T13, R9W,
S7. The nest was observed in place 5 August to 11 Aug-
ust, then placed in an Open top glass funnel balanced
on an open jar containing alcohol. No living bees re-
mained in the nest although a male had been flying near
the nest earlier on the day the nest was removed. The
nest was on the ground under a thin piece of cement. It
was two feet from a vine covered, five feet tall cement
and stone wall. Spiders, isopods, centipedes, a milli-
pede, pseudoscorpions, a snail, an oligochaete, Homo-
ptera, Thysanoptera, Hymenoptera, Orthoptera, Coleo-
ptera and hundreds of mites were found in the nest.
Only a small sample of bees was obtained. No queens
remained in the nest.

Collected 7 July 1966 in Lenawee County, T68, R5E, S54.
The nest was removed from beneath a cement slab porch
and placed in a modified Berlese funnel. Ninety-five

bees were removed. The queen-worker-male ratio was

150
28-56-11. Only Diptera larvae and mites were found.

very little of the outer covering of the nest was

obtained due to the difficulty of reaching the nest.

Bombus fervidus (Fabricius)

 

A.

Collected 1 September 1965 in Kalamazoo County, T28,
RlOW, S21. The nest was removed from the boarded eaves
of a toolshed six feet above the ground and placedin
rearing box for 7 days before transfer to a modified

Berlese funnal. Two dead mice (Peromyscus sp.) were

 

found in the nest. Forty four bees were found. Eighty
two LepidOptera larvae, 85 Diptera, 55 Coleoptera, four
Siphonaptera, two Collembola, Psocoptera and over 2000
mites were found in the Berlese sample.

Collected 4 September 1965 in Kalamazoo County, T23,
R12W, $1. The nest was removed from the ground where

it was located in the circle of a tire under a bale of
hay and placed in a rearing box for 27 days. One hundnmi
and forty-six bees were found. Ten Collembola were re-
moved. A few Lepidoptera, many Diptera, Hymenoptera

and mites were found in the Berlese sample.

Collected 6 September 1965 in Kalamazoo County, TlS,
R9W, S29. The nest was removed from the roof of an
abandoned dog house and placed in a modified Berlese
funnel. The dog house had been tipped over two days be-
fore. Nest material included a lot of leaf litter. One
hundred and twenty-six bees were found. Many Lepido-

ptera larvae and mites were found in the Berlese sample

151

in addition to Siphonaptera, Coleoptera and Hymeno-
ptera.

Collected 11 September 1965 in Allegan County, TlN,
R15W, S54. The nest was removed from a roll of fence
wire two feet above the ground and placed in a modified

Berlese funnel. Feathers, hair, leaves and a Peromyscus

 

sp. skeleton indicate this was a former mouse nest.
Thirty seven bees were found. Collembola (5), Diptera,

Coleoptera, Lepidoptera and many mites were found.

Bombus griseocollis (DeGeer)

 

A.

Collected 4 September 1965 in Kalamazoo County, T4S,
Rllw, S24. The nest was removed from a burlap bag hang~
ing from a wall in a barn and put in a modified Berlese
funnel. Twenty three bees were removed. The small nest
was constructed entirely of burlap. Several Psocoptera,
Coleoptera and mites were found in the Berlese sample.
Collected 11 September 1965 in Allegan County, TlN,
R15N, S27. The nest was collected on the ground in tall
grass three feet from a barn and placed in a modified
Berlese funnel. Twenty two bees were found. Psocoptena
(21), Hymenoptera, lepidoptera and mites were found.
Collected 7 August 1965 in lenawee County, T7S, R5E, S5.
The nest was removed from a ball of twine on a shelf

six feet above the floor in a garage and put in a modi-
fied Berlese funnel. Eleven bees were removed from the

nest. Several PSOCOptera and many Lepidoptera were found.

152

Bombus pennsylvanicus (deGeer)

 

A.

Collected 50 August 1965 in Kalamazoo County, TlS,

Rllw, $18. The nest was removed from a hubcap in an
abandoned chicken coop and put into a rearing box for
58 days. The nest became contaminated with ants. No
Berlese sample was taken. One hundred and twenty bees
were removed. A few mites were removed from bees which
were killed on August 51.

Collected 2 September 1965 in Barry County, TlN, R10W,
S28. The nest was removed from a haymow in a barn and
put in a rearing box for 50 days. Red ants indigenous
to the new site set up a colony in the nest. Ants,
Psocoptera and.larval Lepidoptera were found in the Ber—
lese sample. Forty-six bees were removed. One mite was
removed from a bee which was removed from the nest on
50 September.

Collected 5 September 1965 in Kalamazoo County, T18,
R12W, S52. The nest was removed from the seat of an
abandoned truck and put into a rearing box for 48 days
before transfer to a modified Berlese apparatus. The
nest was constructed of cotton, tissue paper and grass.
It may be a former mouse nest. The nest contained 25
bees, some with.mites. Many Lepidoptera larvae, Diptera
and ColeOptera were found in the Berlese sample.
Collected 5 September 1965 in Kalamazoo County, T53,
RlOW, S7. The nest was removed from the empty loft of

a barn and transferred to a modified Berlese funnel.

155
The nest was constructed with cotton and a small amount

of paper. It is thought to be a former mouse nest.
Eighty one bees were collected. Many Lepidoptera and
Coleoptera larvae were found in the Berlese sample.

Two Collembola and many mites were found.

Collected 4 September 1965 in Allegan County, TlN,
R11W, S56. The nest was removed from a roll of glass
wool insulating material found in a shed and transfer-
red to a modified Berlese funnel. The small nest con-
tained 42 bees. Many Coleoptera and mites were found
in the Berlese sample.

Collected 5 September 1965 in Kalamazoo County, T4S,
RllW, S2. The nest was removed from beneath glass wool
insulating material and transferred to a modified Ber-
lese funnel. The nest was composed of glass wool and a
small amount of leaf litter. Many full huney pots were
present but only 50 bees were found. Coleoptera, Lepido-
ptera, isopods, seventy three Collembola (5 species)
and over a hundred mites were found in the Berlese
sample.

Collected 5 September 1965 in Kalamazoo County, T53,
RllW, S26. The nest was removed from the ground under-
neath a pile of boards near a corral. The nest was com-
posed of leaf litter (pin oak) and a small amount of
glass wool. One hundred and seventy bees were found.
The Berlese sample included spiders, Pseudoscorpiones,

Chilopoda, many Acarina, Isopoda, 256 Collembola,

J.

154

Siphonaptera, Diptera, Coleoptera, lepidoptera and
Hymenoptera (ants).

Collected 6 September 1965 in Kalamazoo County, T1S,
Rllw, 821. A partial nest was removed from an old car
Seat in an unused barn and placed in a modified Ber-
lese funnel. A few mites and Lepidoptera larvae were
found. Forty seven bees were collected. The nest
material was cotton with a small amount of burlap.
Collected 7 September 1965 in Kalamazoo County, TlS,
RlOW, S8. The nest was removed from beneath floor
boards in a barn and put in a modified Berlese funnel.
Ninety three bees were removed. Coleoptera, Pseudo-
scorpiones, lepidoptera and several mites were found
in the Berlese sample.

Collected 9 September 1965 in Kalamazoo County, TlS,
Rllw, $19. The nest was removed from a rock pile at
the edge of a field and placed in a modified Berlese
funnel. Sixty three bees were removed. The nest could
have been a second year nest as the nest cases below
the active ones looked older than one year. The nest
was constructed of a very soft plant material. Grass-
hopper remains and a dead wasp were found in the nest.
The Berlese sample contained many diptera larvae (Bagpga
canicularis Linnaus), Coleoptera, some lepidoptera

larvae, a pseudoscorpion and many mites.

M.

155
Collected 9 September 1965 in Kalamazoo County, T4S,

R12W, 815. The nest was inaccessable but eighty one
bees were obtained. Two bees had mites on them.
Collected 11 September 1965 in Kalamazoo County, TlS,
R12W, 817. The nest was removed from its location
about two feet above ground in a wood pile and placed
in a modified Berlese funnel. Fifteen bees were found.
Many lepidoptera larvae, 158 Collembola, several Coleo-
ptera and mites were found in the Berlese sample.
Collected 12 September 1965 in Kalamazoo County, T13,
RllW, S52. The nest was removed from a drill base on
the floor of a garage and placed in a modified Berlese
funnel. Eighty three bees were removed from the nest.
Ten Collembola, many Coleoptera, a few Diptera, isopods,
a centipede and mites were found in the Berlese sample.
Collected 5 August 1965, Kalamazoo County. The nest
was originally obtained from a crevice in a rock wall
in south Kalamazoo by R. Macomber. He transferred it
to a site 9 miles northeast for behavioral experiments.
A flat dish of alcohol and glycerine was placed below
the open screen under the nest. Several mites and

three Collembola were found.

Bombus vaggns F. Smith

 

A.

Collected 7 July 1965 in Barry County, T2N, R8W, S52.
The nest was removed from a junked washing machine and
placed in an extraction funnel. Tear gas was applied

to cotton at the top of the covered funnel to drive

156
nest inhabitants into a jar of alcohol below. The

nest had been disturbed in the days preceding its
collection and only one bee remained. Several Diptera.
larvae, Coleoptera and mites were found in the sample.
Many Diptera larvae and hundreds of nematodes were
found in the gallon jar in which the nest was trans-
ported to the laboratory. After the nest was placed in
the funnel, the inside of the jar was washed with
alcohol and the jar was closed.

Collected 7 July 1965 in Barry County, T2N, RBW, S52.
The nest was removed from the air duct of an abandoned
car and placed in an extraction funnel. Tear gas was
applied to cotton at the top of the covered funnel.

The nest had been disturbed in the days preceding its
collection. Gasolene had been thrown on one edge of
the nest. Three bees were collected. Coleoptera,

Psocoptera and mites were found in the sample.

LITERATURE CITED

Baker, E. W., J. H. Camin, F. Cunliffe, T. A. Woolley and
C. E. Yunker, 1958. Guide to the Families of Mites.
Institute of Acarology. University of Maryland, Col-
1ege Park. 242 p.

Baker, E. W. and G. W. Wharton. 1952. An Introduction to
Acarology. The Macmillan Co, New York. 465 p.
Banks, N. 1919. Report of the Canadian Arctic Expedition

A l9l5-18.‘ Vol. III : Insects. Part 15H.

Burt, W. H. 1957. Mammals of the Great lakes Region. The
University of Michigan Press, Ann Arbor. 246 p.

Chandler, L. 1950. The Bombidae of Indiana. Indiana
Academy of Science Proc. 60:166-177.

Cockerell, T. D. A. 1916. Bees from the Northern Peninsula
of Michigan. Occasional Papers of the Museum of Zoo-
logy, University of Michigan. No. 25.

Costa, M. 1961. Mites Associated with Rodents in Israel.
Bull. Brit. Mus. (Nat. Hist.) Zool. 8:1-70.

Cumber, R. A. 1949. Humble bee parasites and commensals
found within a thirty mile radius of Tendon. Proc.
Roy. Ent. Soc. London. Ser. A 24:119-127.

Curtis, J. T. 1959. The Vegetation of Wisconsin. U. of
Wisconsin Press, Madison.

Dice, L. R. 1945. The Biotic Provinces of North America.

University of Michigan Press, Ann Arbor. 78 p.

157

158

Drummond, R. O. 1957. Observations on the fluctuations of
acarine populations from nests of Peromyscus leucopus.
Ecol. Monographs. 27:157-152.

Evans, G. O. 1965. Observations on the chaetotaxy of the

legs in the free living Gamasina (Acari: Mesostigmata).
Bull. Brit. Museum (Nat. Hist.) ZoolOgy lO(5):277-505.

Evans, G. O., J. G. Sheals and D. Macfarlane. 1961. The

Terrestrial Acari of the British Isles. British
Museum, London. 219 p.

Evans, G. O. and W. M. T111. 1966. Studies on British

Dermanyssidae (Acari: Mesostigmata). Bull. Brit.

Museum (Nat. Hist.) Zoology l4(5):8-570.

Franklin, H. J. 1915. The Bombidae of the New World.

Trans. Amer. Ent. Soc. 58:177-486.

Frison, T. H. 1926. Contribution to the Knowledge of the

Interrelations of the Bumblebees of Illinois with Their

Animate Environment. Ann. Entomol. Soc. of Amer.

19:225.

Hasselrot, T. B. 1960. Studies on Swedish bumble-bees

Genus Bombus latr.) Opu Sc. Ent. Suppl. 17:1-192.

Homann, H. 1955. Die Milben in gesunden Bienensthken.

Zeitschr. fur Parasitenkunde Berlin.
415.

V0. 6, NO. 33550“

Hughes, A. M. 1961. The Mites of Stored Food. Her

Magesty's Stationery Office. 287 p.

159
Hunter, P. E. 1966. The Genus Pneumolaelaps with Descrip-

 

tions of Three New Species (Acarina: Laelaptidae).
J. Kansas Entomol. Soc. 59:557-569.

Loomis, R. B. 1956. The Chigger Mites of Kansas (Acarina:
Trombiculidae). Univ. of Kansas Sci. Bull. 57(19):
1195-1445.

Lutz, F. E. and T. D. A. Cockerell. 1920. Notes on the dis-
tribution and bibliography of North American Bees of the
families Apidae, Meliponidae, Bombidae, Englossidae and
Anthophoridae. Bull. Am. Mus. Nat. Hist. 42:491-461.

Medler, J. T. 1959. A nest of Bombus huntii Greene (Hymen-

 

optera: Apidae). Ent. News 70(7):l79-l82.

Medler, J. T. and D. W. Carney. 1965. Bumblebees of Wiscon-
sin (Hymenoptera: Apidae). Research Bulletin 240.

Univ. of Wisconsin. 47 p.

Merriam, C. H., V. Bailey, E. H. Nelson and E. A. Preble.
1910. Zone map of North America. Biol. Surv., U. S.
Dept. of Agriculture, Washington, D. C.

McNeel, W., Jr. and F. G. Goff. 1961. Manual of Resource
Conservation. Central Michigan Univ., Mt. Pleasant.2141x

Michigan State University Agricultural Experiment Station.
1965. Michigan Freeze Bulletin. Mich. State Univ. Agr.
Exp. Stn. Research Rep. 26, 40 p.

Milliron, H. E. 1959. The taxonomy and distribution of
Michigan Bombidae, with keys. Papers of the Mich.

Acad. 801., Arts and Letters. 24:167-82.

160
Milliron, H. E. 1961. Revised classification of the bumble

bees - a synopsis (Hymenoptera: Apidae). Jour.
Kansas Ent. Soc. 54(2):49-61.

Mitchell, T. B. 1962. Bees of the eastern United States.
North Carolina Agric. Exp. Sta. Tech. Bull. 152:1—557.

Neave, F. 1955. The Bremidae of Manitoba. Canadian Jour-
nal of Res. 8:62-72.

Norberg. S. 1956. Biologish-bkologische Untersuchungen
uber die Vogelnidicolen. Acta 2001. Fennica 21:1-168.

Plath, 0. E. 1954. Bumblebees and Their Ways. Macmillan
Co. 201 p.

Postner, M. 1952. Biologisch-bkologische Untersuchungen
and Hummeln und ihren Nestern. Verbff. Ubersee Museum,
Bremen Reihe A 2:45-86.

Putnam, F. W. 1864. Notes on the habits of some species
of humble-bees. Proc. Essex Inst., Salem, Mass.
14:98-105.

Senninger, E. J. 1965. Atlas of Michigan. Flint Geo-
graphical Press, Flint. 61 p.

kou, J. P., S. V. Holm and H. Haas. 1965. Preliminary
investigations on diseases in bumble-bees. Royal Vet.
and Ag. College Yearbook. pp. 27-41.

Snodgrass, R. E. 1956. Anatomy of the Honey Bee, Comstock

Publishing Associates. 667 p.

Stammer, H. J.. 1951. Eine neue Tracheenmilbe, Bombacarus

 

buchneri n. g. n. sp. (Acar., Podapolipodidae).
Zool. Anzeiger 146:157-150.

161

Tr§g§rdh, I. 1945. Die Milben und ihre bkologischen
Bezeihungen zu den Insekten. Arb. physiol. angew.
Ent. Berl. 10:124-156.

U. S. Dept. of Agriculture. 1941. Climate and Man, Year-
book of Agriculture. U. S. Govt. Printing Office,
Washington. 1248 p.

Vitzthum, H. G. 1950. Die Bombus Parasitiden. Der
"Acarologischen Beobachtungen" 15 Riehe Zool. Jahrb.,
Syst. 60:1-45.

Vitzthum, H. G. 1945. Acarina in Bron's, Klassen und
Ordnungen des Tierreichs. 5 Band, 1 V Abt. 5. Buch,
leipZig, 1011 p.

Woodruffe, G. E. 1955. An ecological study of the insects
and mites in the nests of certain birds in Britain.
Bull. Ent. Res. 44:729-772.

Zakhvatkin, A. A. 1941. Arachnoidea, Acariens, Tyrogly-
phoides faune de 1' U. R. S. S. 6. 1. Inst. 2001.

Acad. Sci. ioscow, N. w. No. 28, 475 p.