Fire ants don’t just cause pain to humans. They cause damage
to public and personal property and to Georgia crops.
“Fire ants appear to be attracted to electricity,”
said Beverly Sparks, an Extension Service entomologist with the
University of Georgia College of Agricultural and Environmental
Sciences. “They can enter electrical boxes and cause damage
to traffic lights, air-conditioning units and electrical
conduits.”
Sparks’ research focuses on fighting the fire ant battle in
Georgia. She and UGA research coordinator Stan Diffie have the
envious job of killing fire ants for a living.
“Stan has killed more fire ants than anyone else in
Georgia,”
Sparks said.
Besides the damage fire ants cause inside electrical boxes,
their mounds damage landscape and farming equipment.
“Fire ant mounds sit out in the open and dry to the
consistency
of concrete,” Sparks said. “When lawn mowers and hay
balers hit these mounds, they can cause significant damage to
the equipment.”
Fire ants were once a problem only for people in central and
southern Georgia. “Now we’ve found fire ants in every
county,”
she said, “even in mountainous areas we first thought were
too cold in the winter for them to survive.”
Spreading Across the
U.S.
Until recently, fire ants in the United States were a southern
problem. But they’re spreading out. Fire ants are now reported
in southern states as far west as Texas and in five California
counties.
In Texas, fire ants damage pecans, Sparks said, by entering
cracks in the soft-shelled nuts and eating the nutmeats.
“They can damage agricultural crops and harm wildlife,
including birds, deer and cattle,” she said.
If you’re battling a few fire ant mounds yourself, Sparks
recommends
not disturbing the mounds.
What You Can Do
“If you can tolerate a few mounds, it’s better to leave
them alone,” she said. “This keeps new mounds from
popping
up.
The fire ant mounds you see are actually only one-third of
the entire mound. To kill the ants, you have to reach the whole
thing.
“With fire ant baits, you can enlist the assistance of
the ants to help you deliver the insecticide to every member of
the colony,” Sparks said. “The secret is to get the
worker ants to carry your pesticide into the mounds and share
it with others, especially the queen.”
Broadcast a bait first, she said. Then come back two to three
days later and treat any large mounds. “It’s important to
do this twice a year, in the spring and fall,” she said.
Having tested most of the baits on the market, Sparks says
those containing hydramethylnon, sold under the trade names of
Amdro and Siege, work the fastest.
“All the baits basically look the same. They’re made of
corncob grit and soybean oil, which attracts the ants,” she
said. “It’s the toxicants inside that are
different.”
Looking For New
Controls
Sparks and other UGA entomologists are studying new and
unconventional
ways to fight fire ants. One new technique is to introduce one
of the ant’s natural enemies, the Brazilian phorid fly.
The tiny fly lays its egg inside a fire ant’s body. The egg
hatches into a larva, which moves into the ant’s head and causes
it to fall off. The fly completes its development inside the
fallen
head.
“Phorid flies and other biological controls will stress
colonies,” Sparks said. “They’ll suppress them. But
they won’t totally get rid of them.”
Another promising biological control agent is a microsporidium
called thelohania solenopsae.
“This seems to have a lot of promise,” Sparks said.
“It gives the colony a disease which weakens it.” On
the down side, the microsporidium is hard to apply.
Since fire ants arrived in the 1950s, Georgians have learned
how to coexist with them.
“I worry more about visitors,” Sparks said.
“Visitors
come to Georgia, stay in our hotels and play on our golf courses.
If they don’t know what fire ants are, they’re in for a big
surprise.”