Dumping on House Flies
By Sean Adams
March 24, 1997
House flies are in short supply in the poultry houses at Zephyr Egg near
Tampa, Fla. Thats because scientists with USDAs Agricultural Research Service teamed up
with University of Florida cooperators to
release a predatory fly--the black dump fly--that gobbles up house fly larvae
that live in poultry manure.
Each week for a year, the scientists released 70,000 black dump flies into
the poultry houses at Zephyr. The company is one of the largest egg producers
in Florida, with two million chickens that can produce up to 300 tons of wet
manure a day--heaven for house flies that breed in the manure.
But a single dump fly larva can kill up to 20 house fly larvae a day. Soon
after releasing the dump flies, the house flies had virtually disappeared. This
meant Zephyr no longer had to spray an estimated $12,000 a year in chemical
pesticides to control the pests. Also, organic farmers are now interested in
buying the chemical-free manure.
The black dump fly, native to the United States, will kill more house fly
larvae than it can eat, making it an excellent biocontrol insect. Another plus:
Dump flies wont bother people.
Black dump fly larvae will also eat the larvae of stable flies and other
pests. Black dump flies are sold commercially in the United States, Canada and
Europe, and have been used predominantly in the midwestern United States. But
this is the first time the flies have been used as far south as Florida to
control house flies in a commercial poultry house.
ARS scientists are now working with a Florida poultry farm that wants to
breed the flies in an on-the-farm insectary. The scientists also are also
testing the dump flies for controlling pest flies in manure at dairy farms.
Scientific contact: Jerry Hogsette,
USDA-ARS Center for Medical, Agricultural
and Veterinary Entomology, Gainesville, FL; telephone (352) 374-5912;