Fire ants can be costly on farms

Schultz Bruce, Fontenot, Keith A., Pollet, Dale K.

News Release Distributed 03/18/09

Fire ants can be an aggravation around the house, but they can be a costly pest on the farm, too.

Dale Pollet, LSU AgCenter entomologist, met with homeowners and farmers in Evangeline Parish on March 17 to tell them how to control fire ants. He said the best months to start a control program are April and October.

Keith Fontenot, LSU AgCenter county agent in Evangeline Parish, said even producers of rabbits and pigeons complain about fire ants killing young animals.

Pollet said ants are attracted to electrical fields, causing them to nest in electrical components, including pump motors, junction boxes and air conditioning units. They’ve also been known to nest in light sockets on airport runways, causing a damaging short circuit.

He said investing in growth regulators to control fire ants can save an agricultural producer money in the long run. For example, a north Louisiana hay producer has saved money that would have been spent on equipment repairs by treating fire ants.

Pollet said fire ants are now found as far east as Maryland and westward into California.

Some people can suffer serious effects from just one sting, he said. And just because someone is not allergic to the sting of fire ants now doesn’t mean that will always be the case, Pollet said.

“As your system changes, your resistance can change,” Pollet said.

Fire ants can be controlled quickly with contact chemicals Orthene or Over and Out with Indoxicarb.

Baits, such as Amdro, are perceived to be food by ants, but they contain an insecticide. Application must be made when ants are looking for food, he said. That can be determined by placing an oily food item, such as a potato chip or a hot dog chunk, on the ground for about 30 minutes. If a large number of ants are found, a broadcast application can be made.

“But the bait won’t work if it becomes wet,” he cautioned.

Growth regulators such as Extinguish and Esteem are also baits, but they sterilize the ants, he said. Growth regulators take several weeks to become effective but result in the death of a nest. They pose no risk to pets or other animals, and they don’t have to be applied to an entire yard or field to be effective. Because of the foraging activity of the ants, the growth regulators can be applied in strips.

LSU AgCenter extension offices in several parishes, including Evangeline, have mechanical spreaders that can be borrowed to apply growth regulators.

Some control can be obtained from using liquid soap at the ratio of 1 cup per gallon of water per mound, Pollet said. The soap prevents ants from maintaining the proper body temperature, he said.

Researchers have introduced the phorid fly, a natural enemy of the fire ant, in areas of Louisiana, he said. But these predators only lower the populations because the queen is unaffected.

Even when chemical controls work, they probably will have to be applied in the future because queens can fly to new locations and start a colony after each rain.

“In no system are you going to eliminate fire ants completely,” he said.

An organized approach is the best way to control ants in a neighborhood, Pollet said. A subdivision association can buy growth regulators in bulk and apply them in a coordinated effort to manage populations and prevent ants from just relocating.

Pollet said always read the label before purchasing to make sure it is what you want and before applying to make sure it is applied at the proper rate, proper method and time. When questions arise, contact your local extension agent for advice.

For more information you can go to and search for Fire Ants.

Bruce Schultz

3/19/2009 1:49:51 AM
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