If you're starting a fall "to do" list for your home garden and landscape, add "treat for fire ants" to your list.
"Overcast days when the ants are actively foraging are excellent times to apply treatments," said Beverly Sparks, an Extension Service entomologist with the University of Georgia College of Agricultural and Environmental Sciences.
"The temperature should be between 65 and 90 degrees," she said, "so spring and fall are the best application times."
Don't Treat if Rain is Forecasted
Treat for fire ants on a day when rain isn't in the forecast. "It needs to be dry for at least 24 hours after you apply your treatment," Sparks said.
To effectively fight the fire ant battle, neighbors should join forces. "If you treat and your neighbors don't, the fire ants can rapidly reinfest your yard," said Sparks. "Neighbors have to work together and treat at the same time. And you can't just treat once and expect to get rid of them."
Sparks said you have to begin a treatment program or you won't be effective.
When you apply a fire ant bait, it's best broadcast the product over the infested area.
"Broadcasting is much more effective and cost-efficient than spot treating mounds with contact insecticides," Sparks said. "If you want quick results, use Amdro. It works in four to six weeks, while other bait treatments may take several months to control the mounds."
New Control Makes Fire Ants Sick
Sparks and a team of UGA entomologists are testing a new control method for fire ants. And they're finding it effective.
"We have released a microsporidian into fire ant colonies in south Georgia," Sparks said. "This is a biological control agent that weakens the fire ant colonies and allows other ant species to be more competitive with them."
The control agent is introduced into the colony by infested larvae, which then spread it through the entire colony.
"The challenges we face in using this technology include mass production of the microsporidian and dispersal of the control agent from colony to colony," said Sparks.
Entomologists are also searching for other biological controls in the ants' homeland.
Native to South America, the ants were first recorded in the United States in Alabama in the 1920s. The red imported fire ant quickly earned a top spot on Americans' most hated pests list.
The ants can sting repeatedly, and the result is a burning, itching area that often develops a white pustule.
Some Farmers Like Fire Ants
Most people hate them, but fire ants can be an asset to cotton and sugar cane farmers.
"We've found that cotton and sugar cane fields that contain fire ant mounds, also contain less crop pests," Sparks said. "The fire ants eat the pests."
Almost 300 million acres in the southern United States are infested with fire ants. "The most recent infestations are in New Mexico, Nevada and California," said Sparks.
Here in Georgia, losses and control costs for fire ants exceed $52 million per year.
Fire Ants Hate Cold Weather
"Fire ants aren't a problem in states like Missouri and Michigan because they can't survive the cold," Sparks said. "They can't survive freezing soil temperatures for more than a week.
"We first thought they couldn't survive in the Georgia and Tennessee mountains either," she said. "But with mild winters and behavioral adaptations, they've managed to spread and survive in these cooler regions."
Fire ants can also move into walls of homes or other protected areas to survive the winter.
Sparks spends her days searching for ways to control fire ants. But she doesn't think we'll ever eliminate them.
"With the technology we have today, we aren't going to eradicate them, she said. "We are going to have to learn to live with them and control them in an effective, safe manner around our homes and recreational areas."
(Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)