Diapause in Ornithomya biloba Dufour (Diptera: Hippoboscidae) parasitic on fairy martins in South Australia.

A pupal diapause in Ornithomya biloba gives the parasite a life cycle that is well adapted to the migratory life cycle of its host, Petrochelidon ariel (Gould). The fairy martins breed in colonial mud nests to which they return each spring and abandon when they migrate during late summer and autumn. The parasites spend the summer as diapausing puparia in the abandoned nests. Diapause development is completed during winter and the adult flies emerge during August about the time that the martins return. In the laboratory diapause development was completed most rapidly at about 11 C. The parasites complete at least one nondiapausing generation during spring and early summer but diapausing puparaia begin to appear in the nests about the time of the summer solstice. It is not known whether the facultative diapause is induced by photoperiod or food.