Controlling the avian parasitic fly, Philornis downsi


As part of global efforts to protect Galapagos birds from the parasitic fly, Philornis downsi, a second workshop “Searching for solutions to control the parasitic fly, Philornis downsi in theGalapagos " was held on February 9th and 10th, 2015 at the Charles Darwin Research Station.

The workshop was joint hosted by the Charles Darwin Foundation (CDF) and the Galapagos National Park Directorate (GNPD). During the workshop, experts from around the world shared the results of research on the impact of Philornis downsi on Galapagos birds, advances in the understanding of the biology and ecology of this invasive fly, and potential tools for its control. Progress on priority research questions developed during the first Philornis workshop, held in Puerto Ayora in February 2012, was evaluated and new research questions identified. During the first day, rangers and technicians from key institutions in combating introduced species such as the Galapagos Biosecurity Agency (ABG) and GNPD, naturalist guides, volunteers, students, researchers and community members had the opportunity to listen to talks which were open to the public.

At least 16 species of Galapagos birds, including endangered birds such as the mangrove finch and the medium tree finch, are at risk due to the presence of Philornis downsi. The survival of the mangrove finch is of particular concern given that there are only around 80 individuals. In a race against time, and while searching for a suitable control method, the GNPD and CDF have taken steps to raise finches in captivity, to protect juvenile birds being attacked by Philornis. The larvae of this fly cause high mortality of newborn chicks. In addition to direct mortality (up to 100%), studies have confirmed that surviving chicks often have deformed beaks, reduced growth rates and anemia - affecting their ability to survive and reproduce.

Taller Philornis 2015 credito Ismael Ramirez.jpgWorkshop attendees (Photo: Ismael Ramirez)

In order to quickly obtain answers to priority research questions about the reproductive biology and ecology of Philornis,and its control, in 2012 the "Philornis Working Group" was created. This team of experts currently consists of local and international partners from 15 institutions in eight countries (Ecuador, United States, Australia, Austria, Argentina, Israel, Trinidad and Tobago, Panama).

Charlotte Causton, coordinator of the working group and principal investigator on the project says: "It was very pleasing to see how much has been achieved since the first international workshop in 2012. The multi-country and multi-institutional collaboration is key to the success of this project and we are doing everything possible to find a way to reduce the impacts of this very harmful fly species on endangered birds".

Priority actions obtained from the workshop, consist of continuing studies on a specific attractant to catch Philornis in traps; learning more about natural enemies of the invasive fly such as parasitoids which could be used in a biological control program; and developing a method for mass-rearing of Philornis under laboratory conditions. For the latter, advice is being sought from experts in mass rearing the screwworm fly, millions of which are released weekly in a sterile-insect release program to prevent this fly from spreading to neighboring countries. In the coming weeks, several of the participants’ suggestions obtained in consensus at the workshop will be implemented, in order to continue meeting short, medium and long term goals in the search for methods to control Philornis downsi.

Collaborators: Galapagos National Park Directorate; Galapagos Biosecurity Agency (ABG); University of Vienna; St Louis Zoo, Missouri; SUNY-ESF; University Minnesota; Hebrew University (Israel); Lecen - ICIVET COAST (Argentina); Flinders University; COPEG-APHIS-USDA, Panama; University of Utah; University of West Indies; FUNDAR; University of Guayaquil.

The workshop was made possible by the funding support of Galapagos Conservancy, International Community Foundation (with funding from The Leona M. and Harry B. Helmsley Charitable Trust).

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VIDEO | Looking for a solution to Philornis downsi