Phorid Fly Squadrons Still Battling Fire
February 16, 1998
The offspring of thousands of Brazilian parasitic flies, released
last summer to wage war on fire ants, have survived the first generation. Many
field-reared flies have been found attacking ants and laying eggs to start a
second generation. Agricultural Research
Service scientists released the pinhead-sized flies
last July through
October as part of an environmentally friendly effort to control imported fire
ants. Fire ants infest millions of acres in the southern United States.
Because the Brazilian flies are natural enemies of fire ants in
South America, ARS scientists brought the flies to this country. The scientists
are hoping the flies will lower currently high fire ant densities to the levels
normally found in South America.
The flies swoop down on the ants and pierce their outer cuticle,
depositing an egg inside the ant. The egg hatches into a larva within a day
or two. The larva moves into the ant's head--used as a protective
case--where it completes its development. Once mature, the cycle repeats.
Researchers at ARS' Center for Medical,
Agricultural and Veterinary Entomology released the flies at three
locations near Gainesville, Florida: Kanapaha Gardens, the University
of Florida Dairy Farm, and along Hogtown Creek. When scientists last checked
in January, they discovered flies still attacking fire ant mounds. ARS
research entomologist Sanford Porter says this is a good sign, showing
the flies can survive and may have permanently established themselves.
It will take about another year or two to determine
how effectively the flies are controlling fire ant populations at test sites in
Florida. The scientists plan to release more flies in several other states
later this year.
Scientific contact: Sanford Porter, Center
for Medical, Agricultural and Veterinary Entomology, Imported Fire
Ant and Household Insects Research Unit, Gainesville, Fla., phone
(352) 374-5914, fax (352) 374-5818, firstname.lastname@example.org.