Controlling Stable Flies That Pester Zoo Animals

By Sandra Avant
February 13, 2015

U.S. Department of Agriculture (USDA) scientists and their collaborators at the Smithsonian's National Zoo in Washington, D.C., are setting traps to find out which ones are more effective at capturing and killing stable flies that annoy zoo animals.

Stable flies are typically considered farm animal pests, but their bite and blood feeding also cause painful open wounds on zoo animals such as tigers and foxes. Entomologists Gregory Ose, at the Smithsonian, and Jerome Hogsette, at the Agricultural Research Service's (ARS) Center for Medical, Agricultural, and Veterinary Entomology in Gainesville, Florida, are looking at ways to reduce the number of flies at zoos. ARS is USDA's principal intramural scientific research agency.

According to Hogsette and Ose, stable flies are not reproducing at zoos, which are very clean. These pests prefer habitats of decaying fibrous plant materials like silage and hay, so they are likely being carried to zoos on prevailing winds from miles away.

In one study, researchers compared blue-black cloth targets modified to act like sticky traps with Alsynite fiberglass adhesive traps that are traditionally used to capture and monitor stable fly populations. Traps were placed at different sites for nearly 4 months at a zoological park in Reston, Virginia. Fewer stable flies were captured with the modified traps than with the Alsynite traps.

Findings suggest that by modifying the blue-black cloth target surface, which scientists believe are similar to natural forest edges used by stable flies for flight navigation, traps become less attractive and ineffective. However, this research did provide valuable stable fly distribution and seasonality data that can be used to help manage stable flies at zoos by predicting the best times to put out traps.

Read more about this research in the February 2015 issue of Agricultural Research magazine.