''Philornis downsi'', also known as the avian vampire fly, is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of fly (
Diptera,
Muscidae
Muscidae are a family of flies found in the superfamily Muscoidea.
Muscidae, some of which are commonly known as house flies or stable flies due to their synanthropy, are worldwide in distribution and contain almost 4,000 described species i ...
) that was first recorded in
Trinidad
Trinidad is the larger and more populous of the two major islands of Trinidad and Tobago. The island lies off the northeastern coast of Venezuela and sits on the continental shelf of South America. It is often referred to as the southernmos ...
and
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
in the 1990s. It has been accidentally
introduced to the
Galapagos Islands (
Ecuador
Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ' ...
). Adults of ''P. downsi'' feed on fruit. Eggs are laid in bird nests and hatch into
parasitic
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...
larvae that reside in the nest material and emerge at night to feed both internally and externally on the blood and flesh of developing nestlings. The parasite causes significant mortality in
Darwin's finch
Darwin's finches (also known as the Galápagos finches) are a group of about 18 species of passerine birds. They are well known for their remarkable diversity in beak form and function. They are often classified as the subfamily Geospizinae or t ...
nestlings and threatens the survival of some rarer species such as the
mangrove finch (''Camarhynchus heliobates'') and the
medium tree finch (''C. pauper'').
To protect the threatened finch populations,
insecticide-laced cotton has been supplied as nesting material for the finches, with the results being highly successful in combating ''P. downsi'' infestations at a localized scale.
Currently,
Biological pest control agents, including ''
Conura'' ''annulifera'', are being investigated for their potential safety and efficacy in eradicating ''P. downsi'' on the Galapagos Islands.
References
Further reading
*Dudaniec R Y, Kleindorfer S & Fessl B (2006) Effects of the introduced ectoparasite ''Philornis downsi'' on haemoglobin level and nestling survival in Darwin's small ground finch (''Geospiza fuliginosa''). ''Austral Ecology'', 31, 88–94.
*Fessl B, Couri M. & Tebbich S. (2001) ''Philornis downsi'' Dodge & Aitken, new to the Galápagos Islands, (Diptera, Muscidae). ''Studia Dipterologica'', 8, 317–322.
*Fessl B, Kleindorfer S & Tebbich S. (2006a) An experimental study on the effects of an introduced parasite in Darwin's finches. ''Biological Conservation'', 127, 55–61.
*Fessl B, Sinclair BJ & Kleindorfer S (2006b) The life cycle of ''Philornis downsi'' (Diptera: Muscidae) parasitizing Darwin's finches and its impacts on nestling survival. ''Parasitology'', 133, 739–747.
*Huber S K (2008) Effects of the introduced parasite ''Philornis downsi'' on nestling growth and mortality in the medium ground finch (''Geospiza fortis''). ''Biological Conservation'', 141, 601–609.
*Huber SK, Owen JP, Koop, JAH, King MO, Grant PR, Grant BR, Clayton DH (2010) Ecoimmunity in Darwin's Finches: Invasive Parasites Trigger Acquired Immunity in the Medium Ground Finch (''Geospiza fortis''). ''PLoS One''. 5(1):e8605
* O'Connor JA, Robertson, J, & Kleindorfer, S (2010) Video analysis of host-parasite interactions in Darwin's finch nests. ''Oryx'', 44, 588–594.
External links
Global Invasive Species Database: ''Philornis downsi''
GlSD ''Philornis downsi'' profile
Muscidae
Parasites of birds
Parasitic flies
Ectoparasites
{{Muscidae-stub