Breeding Blood-Sucking Maggots to Save Galapagos Finches

     You would think that breeding and raising blood-sucking maggots might not be the best way to preserve an acutely endangered species, but a group of scientists working for the Charles Darwin Foundation in Ecuador are looking to do just that to preserve the rapidly vanishing Mangrove Finch, one of the many species of finch found on the Galapagos Islands.

     Philornis downsi is a species of parasitic flies that became a major threat to Mangrove Finches after arriving on Isabela Island, and the larvae of invasive species can kill an entire nest of chicks when they infest.  The flies deposit their eggs in the unsuspecting birds’ nests, and when the larvae emerge, they crawl into the nostrils and ears of newly hatched chicks and proceed to tear at the chick’s tissue using specialized hooks and draining them of their blood.  This gruesome scenario is commonplace in the world of parasites, but researchers have a solution to curb the appetite of these insects.

     The most effective strategy to bring down the numbers of P. downsi found thus far is breeding infertile males in a laboratory and releasing them into the environment; females will then attempt to unsuccessfully breed with them, causing a decrease in the number of maggots in the next generation, effectively reducing the number of predators the finch chicks have to deal with.  This “sterile insect technique” has been effective in depleting populations of other dangerous parasites and should be able to save the finches as well as other species of birds being affected once it is put into place.


Larva and Pupa of P. Downsi (Jody O Connor, 2016)
Larva and Pupa of P. Downsi (Jody O Connor, 2016)


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