Controlling, minimizing the impact of fire ants

Fire ants can present a real problem for home owners. Almost every yard in our area has fire ants. Although they do not cause damage to the turf or other plant material, they can inflict painful stings.

When their mounds are disturbed, the ants become aggressive and will attack anything that disturbs their mounds. An unsuspecting victim can be quickly covered with ants. The stings are usually just irritating and painful. However, some people are highly allergic and can become very ill with just one sting.

Fire ants were accidentally introduced into the United States from South America through the port of Mobile, Ala., in the 1930s and they arrived into Georgia in the 1950s. At present, the ants are present in all counties except for some in the mountains.

Human activity has helped spread the ants through shipments of ant infested nursery stock, soil, sod or other such material. They do not do as well in colder climates, which have slowed their spread northward. States in the western part of the country are trying to control the spread of fire ants through inspections of incoming agricultural products from infested areas and quarantines.

The total elimination of fire ants from an area is not feasible. However, temporary measures can be initiated to control fire ant infestations. But the controls must be used continuously or the ants will return. Many situations exist that do not require the treatment of fire ants, like areas were little or no human activity occurs. However, in high traffic areas, such as lawns and garden areas, control of fire ants is a must.

Killing the queen is very important in controlling fire ants. The queen stays in the mound and continues to reproduce while other ants build the mound and forage for food to feed the colony. Killing the foraging ants without killing the queen will not destroy the mound.

There are basically three methods of treating fire ants. The first way is to broadcast fire ant bait such as Amdro, Logic, and several other brands on and around the mound while the ants are foraging. The ants think the bait is food when it actually is a poison. It goes down to the queen and gets rid of the colony over time.

The second method is to treat the individual mounds with an insecticide drench, such as acephate, carbaryl (Sevin) and several others. The mound drenches use a small amount of the active poison ingredient mixed with water and poured upon the mound.

Some times the "two step" method is used. The fire ants are treated with bait broadcasted into the area and then, seven days later, the mounds are drenched with the appropriate insecticide.

A third method is broadcast applications of granular insecticides. The products are not baits. The products, such as fipronil (Over 'n Out, Chipco, TopChoice), can reduce the fire ant population substantially over time. However, these products only work where they have been directly applied to. Remember, when using chemical pesticides follow all label directions and safety precautions.

One home method is to use boiling hot water. A couple of applications can kill a fire ant mound. However, each mound has to be treated individually and there is the risk of the applicator being scalded by the water. Never use gasoline to try to burn mounds. Besides the risk of setting yourself and the surrounding property on fire, the gasoline will kill the turf and can sterilize the soil. Some "home made remedies" such as grits, are totally useless in controlling fire ants.

Fire ants are a big problem and will continue to be so. But they can be brought under controlled and should in areas of high usage due to their potential danger to human health.

Timothy Daly is an agricultural and natural resource agent with the Gwinnett County Extension Service. He can be reached at 678-377-4010 or tdaly@uga.edu.