Eggs are laid in bird nests and hatch into parasitic 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.

[5][6][7][8] 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.

[9] 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.

[10] Global Invasive Species Database: Philornis downsi

This article related to members of the fly family Muscidae is a stub.