Home & Garden Tips
Fall is a good time to control fire ants
By Roosevelt McWilliams County Extension Agent

It's appropriate to treat for fire ants anytime that they're active. They're active in warm months.

Fall is an ideal time to control fire ants.

Since it stays warm well into the fall, we should continue to control fire ants. You hear about fall treatments sometimes in light of baiting programs. Many of the baits registered for fire ant control are very slow-acting growth regulators. It may take a half year or more to eliminate the colonies. The thinking is to bait in the fall, and the next spring the ants will not return.

Red imported fire ants first made an appearance in Georgia in the early 1950's. By 1987 they had spread to 143 of 159 counties. Today the entire state is infested, as is much of the East Coast to southern Virginia.

While the basic biology of fire ants hasn't changed, there have been some advances in control techniques and materials. Baits remain the best options for large areas (more than 1 acre or so).

Many brands fall into two basic groups: Those with active ingredients that are toxic to the ants (like Amdro) and those that have as active ingredients insect growth regulators that sterilize the queen and stop development of the immature ants in the colony.

Baits work by taking advantage of the ants' behavior so we can apply a small amount (1 to 1.5 pounds per acre) of material and

let the workers take it back to the mound and feed it to the colony. Applied every six months, they often carry a guarantee of no mounds if applied correctly. Not no ants, but no mounds.

As it happens, it takes about six months for a colony to grow from the founding queen to a size where there are enough workers to build the characteristic mound and the baits are good at breaking the cycle. There will be ants there between applications, just not all that many.

Bait treatments generally cost $20-$30 per acre. For smaller areas, or where you need zero ants, I recommend a broadcast application of a contact insecticide.

The best of these include fipronil products such as Over'nOut for homeowners or those with pyrethroids as active

ingredients. Pyrethroids are active ingredients ending in thrin such as bifenthrin, permethrin, cypermethrin or cyfluthrin.

There are lots of these on the shelves, as they're all off patent now. Fipronil will usually give a season of no ants. The pyrethroids are less long-lasting but will give one to three or even four months of control.

Costs range from less than $50 per acre for pyrethroids to more than $150 per acre for fipronil. This is not expensive if your yard is 5,000 square feet.

A newcomer to the fire ant control market is insoxacarb which is sold as Advion for commercial use and in the Spectracide line for homeowners. It's a bait, but instead of weeks to see a reduction in ants, they start to disappear in a couple of days. It's still a no mounds type, but fast.