Patricia A. Beckley, Pollet, Dale K.
This is the first issue of a newsletter intended to communicate new information and recommendations for fire ant management and other ant problems in Louisiana. This issue focuses on current methods for community-wide fire ant control. Future issues will address new findings for fire ant management over larger areas and the status of the Argentine ant problem.
Why are fire ants so hard to control?
The red imported fire ant has no natural enemies in the United States, so it remains uncontrolled by any balance of nature. LSU AgCenter researchers are working on natural diseases, predators and parasites that are specific to this insect. Their work is not expected to eradicate the fire ant, but rather to bring populations down to manageable levels.
We cannot eliminate this insect, but we can reduce the numbers of colonies in areas where they are not welcome. The fire ant is an excellent predator and actually benefits some farmers by helping to control other insect pests.
What is the best method for controlling fire ants?
There are different methods, depending on the setting. In an active setting such as a school or highly visited park, where stinging ants cannot be allowed, control is costly and requires repeated efforts. A regular broadcast of contact insecticide, along with regular mound treatments or a growth regulator bait application, is necessary. For a community or neighborhood, the most efficient and least costly control method is to broadcast fire ant bait (contact or growth regulator) throughout the area. The best times are spring (April) and fall (mid October), when the ants are actively foraging.
In spring check to see that ants are foraging by placing something oily like hotdogs, potato chips or sardines in a few places in the yard and checking them in an hour. If the ants are actively foraging, the foods will be covered with ants and the ants will be more likely to pick up the baits. The fall treatment is done before the onset of cool weather, which reduces foraging. Troublesome areas (playgrounds, pet areas and flower beds) within that community may need regular maintenance initially until the baits take affect. Once the bait has reduced the major colonies in the area, the high maintenance or troublesome areas will be managed as well.
What is bait?
Bait smells and tastes like food for the fire ants. Most bait is composed of processed corn cob grits soaked in a mixture of soybean oil and an active insecticide. The bait is broadcast in the yards as you would broadcast granular fertilizer (but do not mix with fertilizer). The ants find the bait immediately and bring it back to the colony where the insecticidal bait is fed to the other ants, killing them. The growth regulator baits cause the colony to become sterilized (including the queen). The worker ants die naturally without replacements. The remainder of the colony dies from starvation.
What is the active ingredient?
Active ingredient (or A.I.) is listed on the label of all pesticides. The A.I. is the chemical that causes the effect you are expecting. If the active ingredient is a poison, you expect the fire ants to die. If the A.I. is a growth regulator, you expect the ant reproduction to be interrupted and the colony gradually dies.
What baits can I use for fire ants?
How do baits work?
The foraging ants pick up the bait as food and feed it to the queen and the rest of the colony. If the bait is an insect growth regulator (IGR), the queen begins to lay infertile eggs or the young ants never develop into adults. The foraging ants live only for three to six weeks and die. As the workers die, the colony gradually dwindles and the reproductives starve. The process requires six to eight weeks before a noticeable effect takes place. Growth regulator baits must be applied during a dry period for the greatest effect. Twenty-four hours of dry weather before application and 48 hours after application are best. The IGR will break down after 48 hours and is no longer functional or an environmental problem. Growth regulators bait is also broken down by high moisture.
The other type of bait is a slow-acting poison that is fed to the entire colony by foraging ants. The poison kills all ants. Results may occur in two to four days or a long as 10 days after application. These are also best applied during dry weather.
Where do I get bait?
Any bait can be ordered in bulk through a pesticide distributor* or through a feed store, co-op, nursery or hardware store that carries pesticides. Check the Internet to find the distributor in your area.
How much do I order?
Order only the amount you will use for one application, and then reorder for the next application. Most bait has a very short life once opened and applied.
If the entire neighborhood is unable to cooperate, then several neighbors could share cost of a package that contains enough bait for their yards, but remember: the larger the area treated, the more effective the management of the ants becomes.
*Helena, BWI, Lesco, Vopak and Oldham Chemicals are a few of the distributors carrying fire ant bait.