Philornis parasitism and nestling survival of the Puerto Rican sharp-shinned hawk

Abstract

Abstract Philornis larvae penetrate the host integument, undergo a period of development and growth, and establish as third instar larvae between the dermis and the body musculature (Fig. 5.l(b),(c)). Movement into this location plus growth and development of the fly larvae, appears to be linked to the ingestion of host tissues including red blood cells, mononuclear cells which infiltrate from focal accumulations adjacent to the lesions, and necrotic cellular debris which accumulate in the lesion (Nielsen 1911; Uhazy and Arendt 1986). The larvae develop just under the skin of the host until they are about 2 cm long and about 4-6 days old. When development is completed, the larvae exit from the skin and drop into the host's nest to pupate (Fig. 5.1(d)). Adult flies emerged from pupae about 2 weeks after pupation (Fig. 5.1(a)). Larvae develop only in living chicks, and when a chick dies they leave its body within a few minutes (Snyder et al. 1987).