Because this rabbit flea has been previously re- 
corded in print from only one Illinois locality (Kohls 
1940), additional records are marked on the accompany- 
ing map, fig. 1], to demonstrate its state-wide occur- 
rence on rabbits. 
Spangler a 
. ° ! i 
eye atin tI A 
\e ote ye 
J B | 
f\ | @ t 
ee ee 
ae be i ! 
Ke Spe 2 es ina 
q eel ay hiiccaccael 
‘alisha ! "ial ij 
Po Aitp alece. et =; =4 e 
ot eee bei | . 
g I | Pe t ] ise =f 
B | 9 De | t—— 
[eee ey [Fees 
f ma! / 
ee poe eap ek esi! 
t ee ee eet Nea 
ee ee fae j aa a ot 
> ty j@ @. 
Fig. 11.—Cediopsylla simplex distribution in Illinois, 
based on Illinois Natural History Survey records. 
Odontopsyllus multispinosus (Baker); giant eastern 
rabbit flea; fig. 12. - The giant eastern rabbit flea is 
primarily an ectoparasite of cottontails. Here in Illinois 
and seemingly elsewhere, this insect is usually less 
numerous on rabbits than the smaller-sized common 
eastern rabbit flea. Nowhere throughout its range, from 
the east coast to about the 100th meridian, has the 
giant rabbit flea been found to be common. Shaftesbury 
(1934), in speaking of the North Carolina fauna, stated, 
“this latter species [O. multispinosus ] might be rela- 
tively more abundant on some other kind of rabbit in 
some other locality.’? So far, no one has discovered 
this other kind of rabbit or this other locality. Rather, 
this flea appears to be the minor rabbit flea of eastern 
North America and may be scarce to rare on its rabbit 
host fn all regions. 
In Lee County, this flea was observed only on the 
backs of rabbits, and most of the specimens were from 
the lower backs. Apparently the two rabbit fleas divide 
their rabbit host into territories; that is, the common 
eastern rabbit flea occupies the front region, head and 
ears, whereas the giant eastern rabbit flea occupies 
the hind region. 
14 
The giant eastern rabbit flea was taken in Lee 
County during every season of the year. Ninety-six adult 
specimens were obtained from ]2 rabbits. Inasmuch as 
more than 700 rabbits were examined, the 12 rabbits 
infested by this flea represent less than 2 per cent of 
the population studied. To our knowledge, and as 
measured by relative abundance, this flea is of little 
consequence as a rabbit ectoparasite, except perhaps 
on rare occasions. Once, in late February, 1953, we 
found a rabbit harboring 74 specimens. Usually each 
infested rabbit had only one, two, or three individuals 
of this flea. 
In the collection of the Illinois Natural History 
Survey, specimens have been preserved from rabbits at 
Carbondale, Charleston, Cobden, Elkville, Starved Rock 
State Park, Urbana, and Vandalia, as well as in Lee 
County. The records given herein, fig. 13, constitute 
the first published records for Illinois. 
Opisocrostis bruneri (Baker). — Single specimens 
of this ground squirrel flea were taken from rabbits in 
Lee County on September 22, 1952, and on July 24, 
October 8, October 11, November 3, and November 8, 
1953. This flea was once found on a cottontail in cen- 
tral Illinois in early April (INHS collection). 
Ctenophthalmus pseudagyrtes (Baker). — Although 
this flea is usually found on moles (Fox 1940), it in- 
fests many other small mammals, including cottontails. 
We collected this flea twice from cottontails in lee 
County, once on January 2, 1954, and again on October 
26, 1954. 
Orchopeas howardii (Baker). — Ordinarily, this flea 
occurs on tree squirrels. We have two records of it from 
rabbits, one from Lee County on February 14, 1953, and 
the other from central Illinois on May 5, 1948. 
Epitedia wenmanni (Rothschild). — This mouse 
flea was taken in Lee County from a cottontail on 
November 9, 1954. 
BOT FLIES 
Cuterebra spp.; bot fly; fig. 14. — Bot fly larvae 
were occasionally noticed in open ruptures of the skin 
of rabbits, particularly in midsummer. In Lee County 
all but 1 of our 11 records of bot fly larvae were taken 
from rabbits in July; the exception, a large larva, was 
found on November 5, 1952. In summer both medium- 
sized and large larvae were found, even on the same 
day and on the same host. 
Cuterebra buccata (Fabricius). — Six of the bot fly 
larvae collected from rabbits in Lee County were pro- 
visionally determined as Cuterebra buccata by Dr. C. 
Sabrosky of the United States National Museum. One 
larva, of large size, collected from a rabbit in Lee 
County on July 9, 1953, pupated in soil provided for it 
