Pathogenesis associated with philornid myiasis (Diptera: Muscidae) on nestling Pearly-eyed Thrashers (Aves: Mimidae) in the Luquillo Rain Forest, Puerto Rico

Abstract

Pathogenesis of myiasis due to the muscid fly Philornis decepttous in nestling pearlyeyed thrashers (Margurops fuscatus) in the Luquillo Rain Forest, Puerto Rico was investigated. Philornid larvae penetrated the host integument, underwent a period of development and growth, and established, as third instar larvae, between the dermis and the body musculature. Movement into this location plus growth and development of the fly larva appeared to be linked to the ingestion of host tissues including red blood cells, mononuclear cells which infiltrated from focal accumulations adjacent to the lesion, and necrotic cellular debris which accumulated in the lesion. The resultant increase in size of the larvae greatly displaced the host integument. Following the evacuation of the larvae for the purpose of pupation, repair of the cavernous lesion was initiated with the production of an intense organized fibrinous exudate. Macrophages and plasma cells predominated with vascular congestion in surrounding tissues. Over the 21-day nest period, nestlings were subject to successive infestations of large numbers of larvae and host responses to these appeared to signibcantly debit an energy budget responsible for nestling development and growth. Nestling mortality and post fledging survivorship appeared linked to the impact of these energy demands.

Citation

Uhazy, Leslie S.; Arendt, Wayne J. 1986. Pathogenesis associated with philornid myiasis (Diptera: Muscidae) on nestling Pearly-eyed Thrashers (Aves: Mimidae) in the Luquillo Rain Forest, Puerto Rico. Journal of Wildlife Diseases 22:224–237.