Philornis downsi
Encyclopedia
Philornis downsi is a species
of fly (Diptera
, Muscidae
) that was first recorded in Trinidad
and Brazil
. It has been accidentally introduced
to the Galapagos Islands
(Ecuador
). Adult P. downsi feed on fruit. Eggs are laid in bird nests and hatch into parasitic larvae which 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 is causing significant mortality in Darwin's finch nestlings and threaten the survival of some rarer species such as the Mangrove Finch
(Camarhynchus heliobates) and the Medium Tree Finch (C. pauper).
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of fly (Diptera
Diptera
Diptera , or true flies, is the order of insects possessing only a single pair of wings on the mesothorax; the metathorax bears a pair of drumstick like structures called the halteres, the remnants of the hind wings. It is a large order, containing an estimated 240,000 species, although under half...
, Muscidae
Muscidae
Muscidae are a family of flies found in the superfamily Muscoidea. The apical segment of the antennae of Muscidae are plumose, and the basal portion is smooth....
) that was first recorded in Trinidad
Trinidad
Trinidad is the larger and more populous of the two major islands and numerous landforms which make up the island nation of Trinidad and Tobago. It is the southernmost island in the Caribbean and lies just off the northeastern coast of Venezuela. With an area of it is also the fifth largest in...
and Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
. It has been accidentally introduced
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
to the Galapagos Islands
Galápagos Islands
The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...
(Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
). Adult P. downsi feed on fruit. Eggs are laid in bird nests and hatch into parasitic larvae which 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 is causing significant mortality in Darwin's finch nestlings and threaten the survival of some rarer species such as the Mangrove Finch
Mangrove Finch
The Mangrove Finch, Camarhynchus heliobates, is a species of bird in the Darwin's finch group of the tanager family Thraupidae. It is endemic to the Galápagos Islands. It was found on the islands of Fernandina and Isabela, but recent surveys have failed to record the species on Fernandina...
(Camarhynchus heliobates) and the Medium Tree Finch (C. pauper).