A few phorid flies in Florida will have Georgians cheering them on in their natural
work, chopping off fire ants’ heads.

But don’t get too excited.

"The fact that it’s a biological control agent indicates this fly won’t totally eliminate
fire ants," said Beverly Sparks, a University of Georgia entomologist.

The U.S. Department of Agriculture released some Brazilian phorid flies July 9 to
begin field tests near its Gainesville, Fla., lab. But Sparks said biological control
agents won’t banish fire ants from U.S. soil.

"We tend to think of fire ants in terms of eradication," Sparks said. "Phorid flies and
other biological controls will stress colonies. They’ll suppress them. But they won’t
totally get rid of them."

Sparks, a research and extension scientist in the UGA College of Agricultural and
Environmental Sciences, focuses her own research on controlling fire ant populations.

"We’re developing control programs," she said. "We’re studying learning how to best
use the control programs we already have. And we’re finding more environmentally
friendly ways to control fire ants."

The technology to eliminate fire ants hasn’t arrived, she said. But for most people,
controlling them is another matter.

"We know how to control fire ants and do it economically in urban settings," Sparks
said. "We haven’t found an affordable way to control them in open rural areas, such as
pastures."

With current products, effective fire ant control costs $20 to $25 per acre per year, she
said. In home lawns, school yards and recreational fields, that’s reasonable.

Sparks’ research shows the best fire ant control is a simple two-step process.
"Broadcasting a bait twice a year will reduce fire ant populations by 90 percent," she
said. "Then supplement the bait by treating problem mounds that survive with a contact
pesticide."

But zapping fire ants is an every-year commitment. "If you treat them only one year,"
she said, "you’ll be worse off than if you didn’t treat them at all."

Fire ants compete intensely with each other, she explained. Untreated, their population
will level off at 20 to 40 mounds per acre.

"If you get rid of them one year and don’t treat the next," she said, "they’ll be the first
things to come back. But they’ll become established in higher numbers, because they
won’t have larger mounds to compete with. Instead of 20 to 40 mounds, you’ll have
hundreds."

Having to treat fire ants year after year is far too costly to be practical in farm-size
areas.

"We can get them out and keep them at levels that are acceptable in urban settings,"
Sparks said. "But if you have 300-400 acres of pastures, it’s no longer cost-effective."

So scientists look for new ways to control them. Another UGA researcher, Ken Ross,
is studying fire ant genetics.

Specifically, Ross is trying to find why fire ants go from single-queen to
multiple-queen colonies. In the latter, worker ants sometimes destroy egg-laying
queens. If he can find the genetic trigger that causes that, he may be able to cause
single-queen mounds, in effect, to commit suicide.

The prospect is fascinating, as is the ant-beheading 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.

But don’t expect the tiny flies to decapitate Georgia fire ants soon.

"I don’t anticipate that phorid flies will be released in Georgia for fire ant control until
scientists at the Gainesville laboratory have studied them for many years," Sparks said.

Scientists are working on other biological controls, too. For now, though, everything
they know about killing fire ants won’t get rid of them. "All we can do now is control
them," Sparks said.