By Sharon Omahen
University of Georgia
If you decide to take a hike through the Georgia wilderness, you may have to fight off ticks and chiggers along the way. But a recent University of Georgia study shows you shouldn't have to worry about fire ants.
Reid Ipser, an entomology graduate student with the UGA College of Agricultural and Environmental Sciences, recently completed a study of ant habitats. For a year, he scouted sites in Georgia's Indian Springs and High Falls state parks.
"The state parks were the perfect locations for this study as they contain both open fields and undisturbed wooded areas," Ipser said.
He collected ant species for a year and was surprised to find that he never caught a red imported fire ant in a wooded test site. Yet he collected native ants in abundance in the wooded test sites.
In the open-field test sites, Ipser collected many more fire ants than native ants.
Fire ants like open areas
So does this explain why fire ant mounds are commonly seen in open areas like pastures?
"When the environment is simplified, like in clear-cut, open fields, there are fewer species due to fewer available niches," Ipser said. "Native ants don't thrive in that kind of environment, and fire ants do."
Fire ants naturally thrive in open environments because there's less competition from native ants that prefer wooded environments, he said.
In wooded areas, fire ants have to fight against other ant species when foraging for food and establishing nesting sites, Ipser said.
"When fire ants were first found in the United States, everyone thought they were going to wipe out all other ant species because their natural enemies were back home in South America," he said.
Competition keeps population down
That hasn't been the case. Ipser has found that native ant species actually help keep down fire ant populations by competing with them.
UGA entomologists now plan to compare chemical pesticide treatments to determine how they affect both native ant and fire ant populations.
"People need to realize that killing all ants isn't the best method from an environmental or an economical standpoint," Ipser said. "Conserving forests is one of several variables that will help control fire ants, too. Overall, management of pests needs to be more biologically than chemically based."
When buying pesticides to kill ants or any other insects, he said, select a product that's been formulated for that insect.
"For fire ants, make sure the pesticide is targeted for exotic ants," he said.
Don't kill all ants
If you have ants in your lawn that aren't fire ants and aren't coming indoors, Ipser suggests leaving them alone.
"If the circumference of the ant bed is the size of a quarter or a silver dollar, they aren't pest ants," he said. "These don't cause ecological damage. They don't sting. But they do compete with exotic ants like fire ants and Argentine ants."
Like the red imported fire ant, the Argentine ant is an exotic ant. But it doesn't sting.
"If you find little black ants in your dishwasher, they are most likely Argentine ants," Ipser said. Argentine ants typically nest near the trunks of trees and don't create high mounds.
(Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)