The invasive avian vampire fly, Philornis downsi (Diptera: Muscidae), poses a significant threat to Darwin's Finches and other endemic bird species in the Galapagos Islands, and the importation of specialized natural enemies is a promising strategy for its long-term control. The parasitoid Conura annulifera (Hymenoptera: Chalcididae) has received the most attention as a potential biological control agent thus far, including st...

The Avian Vampire Fly, Philornis downsi , has invaded the Galapagos Islands, where it causes high mortality of endemic and native landbird species, including most species of Darwin’s finches. Control methods are under development, but key information is missing about the reproductive biology of P. downsi and the behavior of flies in and near nests of their hosts. We used external and internal nest cameras to record the behavio...