Bot fly myiasis of the cottontail rabbit, Sylvilagus floridanus mallurus in Virginia with some biology of the parasite, Cuterebra buccata.

Abstract

Twenty four percent of 2,643 cottontail rabbits (Sylvilagus floridanus) collected in Virginia from 1949-1975 showed evidence of Cuterebra parasitism. Occurrence was seasonal with greatest prevalence from July to November. Some Oryctolagus cuniculus, S. palustris and one S. transitionalis also showed Cuterebra myiasis. Juvenile rabbits had higher infection rates (28%) than did adult rabbits 14.5%, P less than .001). Juveniles had greater numbers of larvae per host than adults, with means of 2.14 and 1.62, respectively. Larval development sites were in the genital region of most hosts. Twenty flies reared from wild cottontails were identified as C. buccata. Duration of induced infections in Oryctalagus was 30-33 days. Minimal generation time for C. buccata is concluded to be 11 weeks, allowing up to four generations of flies to occur annually in the southern and one generation to occur in the northern distributional limits of this bot fly. Peromyscus hosts were refractory to C. buccata infections. C. buccata fecundity averaged 1316 eggs. Field observations of adult flies are described.