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

Sexual Differences in Life History Traits ofPhilornis seguyi(Diptera: Muscidae) Parasitizing House Wrens (Troglodytes aedon)

“…Most Philomis species (82%, are subcutaneous parasites. Each larva feeds on serous fluids, tissue debris, and blood of the host, and breathes through a small aperture it cuts in the host's integument (Skidmore 1985, Uhazy and Arendt 1986, Young 1993. In some species, larval development is completed in a 4-8-d period (Teixeira 1999) in which the larvae grow up to 1 cm or more in length and pass through three larval instars (Fraga 1984, Arendt 1985a, Skidmore 1985, Delannoy and Cruz 1991, Spalding et al 2002.…”

Avian studies and research opportunities in the Luquillo Experimental Forest: A tropical rain forest in Puerto Rico

“…Within their avian hosts, larval philornid botflies live subcutaneously within furuncles where they feed on their host's erythrocytes and other tissues before pupating (Arendt, 1985a(Arendt, ,b, 2000. Infesting larvae significantly reduce the energy available for nestling growth and development (Uhazy and Arendt, 1986) and with high infestation rates cause nestling mortality. Given the prevalence of botfly parasitism in the LEF nestling mortality rates can be high.…”

Lethal and Sublethal Effects of Botfly (Philornis seguyi) Parasitism on House Wren Nestlings

“…Larvae of most species of botflies live subcutaneously on altricial nestlings, feeding on serous fluids, tissue debris, and blood cells (Uhazy andArendt 1986, Teixeira 1999). Larvae complete growth in 4-8 days, after passing through three instars (Fraga 1984), dropping then from the host to the base of the nest, where they pupate for approximately 2 weeks (Teixeira 1999).…”