Non-native fire ants are proliferating in North America, due to
a lack of natural predators
(CNN) -- Researchers
at the University of Texas are breeding flies to control the population
of imported fire ants that has rapidly spread from California
to Florida, leaving substantial damage along the way.
Last year,
southern U.S. states spent millions of dollars on fire ant-related
damage. The venomous ants have killed livestock and pets, diminished
crops and caused serious electrical fires by invading circuit
boxes. A more extreme case occurred last spring, when a woman
in a Florida nursing home died after fire ants attacked her in
bed.
Two kinds of fire ants inhabit the United States: those that are
native and kept in check by North American predators and those
that were inadvertently imported from Brazil or possibly northern
Argentina in the 1920s.
Now researchers
are attempting to control the ants by importing one of their native
predators: phorid flies.
Larry Gilbert,
an ecologist at the University of Texas, says the flies are the
key to controlling the population of imported ants. Thanks to
funding from the state of Texas, Gilbert has established an imported
phorid fly breeding farm in Austin. "We can't find many negatives
about the fly except that it might not work," Gilbert said.
The flies
actually invade the bodies of fire ants and lay their eggs there.
As the larval stages of the fly develop inside the body, they
pupate in the fire ant's head. The head of the ant then falls
off.
Researchers
believe it takes about 3,000 flies to make a serious assault on
a fire ant colony. So far, Gilbert and his team have released
100,000 flies in Texas. Additional phorids are being released
throughout Florida and other southeastern states.
While the
flies have yet to make a substantial dent in the imported fire
ant population, researchers are cautiously optimistic.
Naysayers
worry that releasing non-native insects to control non-native
ants could create further ecological problems, but Gilbert says
the flies are host-specific. They only interact with and kill
the imported fire ants.
What's more,
Gilbert says, the flies are more environmentally sound than chemical
pesticides.
"People
shouldn't forget that there's never been a successful biological
control of a social insect," Gilbert said. "You can't
expect a solution to come overnight."
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