Fig. 14.—Cuterebra sp., bot fly larva, dorsolateral view. Actual size about 1-1/4 inches. 
present, however, in leaf mold, even before cold weather 
set in. 
Larvae of this tick apparently suffered high losses 
during winter, and few were found in spring. In mid- 
summer, larvae of the new generation hatched and then 
reached the peak of their abundance on rabbits in Au- 
gust and September. 
Nymphs of the new generation reached their peak 
of abundance on rabbits in September and Qctober. Un- 
like larvae, nymphs commonly survived the winter and 
reappeared fairly abundantly on rabbits in early spring. 
The proportion of rabbits infested with the conti- 
nental rabbit tick, in any stage, varied with the season. 
Ninety per cent of the rabbits examined harbored this 
tick in August and September, 0 per cent in midwinter, 
75 per cent in spring, and 50 per cent in early summer. 
The variable wood tick, Dermacentor variabilis, the 
principal vector in Illinois of Rocky Mountain spotted 
fever, was found principally in spring, and even then 
not commonly. Possibly because of the behavior pat- 
terns of this tick and the rabbit, only larvae and nymphs 
were found feeding on cottontails in Lee County. 
The eastern rabbit tick, [xodes dentatus, although 
almost exclusively restricted to rabbits, was found to 
he rare on cottontails in Lee County. 
The common eastern rabbit flea, Cediopsylla sim- 
plex, was the flea most often collected. It was found 
primarily around the head and neck region of rabbits. 
This flea infested cottontails throughout the year; it 
was most abundant in early spring and least abundant 
in late summer. It was observed to have a sex ratio of 
about 2 females to 1 male. The largest number of fleas 
of this species found on one rabbit was 101; the aver- 
age per rabbit examined was approximately 4. On a few 
rabbits no fleas were found. 
The giant eastern rabbit flea, Odontopsyllus multi- 
spinosus, which seemed to prefer to feed on the hind 
regions of cottontails, was taken occasionally at all 
seasons. It was not found to be abundant except in 
rare instances. 
Fleas of four additional species normally found on 
other mammals were taken several times on cottontails 
in the Lee County study area. These specimens had 
probably strayed to rabbits accidentally. 
Cuterebra buccata was the principal bot fly ob- 
tained from cottontails in Lee County. Larvae were 
found, mostly during the summer, in open ruptures of 
the skin of rabbits. One of the large unidentified larvae 
may prove to be cuniculi or horripilum. 
No chiggers were found on the rabbits examined. 
