Imported fire ants are not native to the United States. Therefore, even though I usually don't recommend killing insects, these firey, pain-inflicting, biting critters are one of a few, such as the Japanese beetle, that make my 'extermination list'.
Fire ants first entered the country around 1918 near Mobile, Alabama, and have since spread throughout most of the southeastern United States. Their distinctive dome-shaped mounds in our lawns and gardens are unsightly and interfere with mowing and other activities, but it’s their painful stings that cause the most problems.
Some stinging or biting native insects, such as wasps and bees, serve a much needed purpose: they pollinate our gardens and crops, and without their work, we'd all be long gone from starvation. But fire ants don't seem to do much...well, maybe they naturally till the soil? What would happen, though, if we didn't take steps to control fire ants? Would our land and gardens in the South become nothing more than one never-ending fire ant bed?
Actually, when not controlled, mound densities can reach 50 to more than 200 mounds per acre!
Fire ants don’t intentionally go looking for people or pets to attack, but disturb their mound and they will defend it aggressively. Even one sting hurts but, more often than not, you'll get lots of stings.
Fortunately, there are effective treatments to control fire ants that are relatively inexpensive and easy to apply, but successful fire ant control has to be a preventive, ongoing effort. Fire ant control recommendations vary slightly, depending on the particular situation. Be sure to choose products that are labeled for the particular site where you plan to apply them.
Methods for Fire Ant Control
Can you ever eliminate all the fire ants on your property? Yes, and no. Yes, you can kill every fire ant on your property when a treatment or combination of treatments are properly applied, however, even if you kill every fire ant on your property, new queens will soon be landing after their mating flights and starting new colonies. Fire ants are persistent. But if you treat regularly and/or preventively, you can keep most of these new colonies from surviving to become big mounds.
Keep in mind that your location: urban or rural, and the size of your property may determine the method(s) you use for controlling fire ants.
Got a pet anteater? If not...
There are three main ways to control fire ants:
- Individual mound treatments
- Broadcast insecticide treatments
- Granular baits
Individual Mound Treatment
Treating mounds individually may be all that is necessary for small properties or any property where only a few mounds show up from time to time. Insecticidal powders/dusts, such as products that contain 75% acephate, are the most effective and economical to get the job done one mound at a time.
Individual mound application instructions: When applying acephate dust do so only on dry mounds in the late afternoon when the temperatures are cooler and the ants are more active. Do not disturb the mound and do not water in. A teaspoon or two of acephate dust spread atop and in a line around the mound will kill all the ants in that mound, overnight. Always make sure to follow instructions on the product label for application rates and personal protection.Note: Granular insecticides that have to be transported and fed to the queens deep inside the mound are not as effective as acephate dust that attaches to the bodies of the ants and is spread through simple bodily contact with other ants and the queen in the mound.
Granular Baits
Fire ant baits are granular products that contain some type of food that is attractive to fire ants and very small amounts of slow-acting insecticides or insect growth regulators. Baits have a lot of advantages. They are inexpensive, easy to apply, safe to pets and wildlife, and they work! The only negative about baits is they are slow-acting. Depending on which bait you use, it takes from two to eight weeks to see the benefit of a fire ant bait treatment.
Granular bait application instructions: Most fire ant baits are applied at very low rates, around one to two pounds per acre. That’s less than 1/2 ounce per 1000 square feet. Don’t try to use a lawn fertilizer spreader to apply fire ant bait; it will put out way too much! Use a smaller hand-held spreader that has micro settings designed for applying fire ant baits.
How granualar fire ant baits work: Fire ant baits are designed to work slowly; this is one of the keys to their success. Adult fire ants can't swallow solid food. They have to carry the bait granules back to the mound and feed them to their young. The larvae convert this solid food into liquid, which is then spread from ant to ant throughout the colony. The slow-acting insecticides and growth disruptors used in fire ant baits get spread throughout the colony before they start killing ants. If granular baits contained quick-killing contact insecticides, they would kill the foraging workers before they were able to carry the granule back to the mound.
Because they are so slow-acting, baits are best used as preventive treatments. If you don’t want to have large fire ant mounds in your yard, you have to treat before you have large fire ant mounds in your yard. The goal with baits is to eliminate small colonies that are just getting started before they grow large enough to be noticed. In rural areas, where fire ant numbers are high, this can mean treating as many as three times per year. In more urban areas, one or two bait treatments per year may be enough. Use the holidays, Easter, Independence Day, and Labor Day, to help remind you when it is time to apply fire ant bait. Don’t under estimate the value of that fall treatment. You may not see much benefit before winter, but you will have a lot fewer mounds next spring.
Some baits work faster than others, but the slower-acting baits tend to provide longer control. Baits that contain slow-acting insecticides that kill adult fire ants usually give maximum control within a few weeks. Baits that contain insect growth regulators that interfere with the development of eggs and/or immature ants may take two months or longer to reach their peak level of control. There are a few baits that contain both types of active ingredients.
Broadcast Insecticide Treatments
The broadcast insecticide treatments most commonly used by homeowners to control fire ants are granular products, but don’t confuse them with baits. They do not contain food or attractant and the ants do not collect the granules and carry them back to the mound. These products contain long-lasting contact insecticides and work by killing ants that contact treated soil.
Broadcast insecticide application instructions: Use a lawn broadcast spreader to broadcast the granules over lawn areas and a hand-held or shoulder type bag spreader in landscape beds and islands. Be sure to read the label and apply the appropriate rate. Rates for broadcast insecticide treatments are usually much higher than the rates for baits.
How broadcast insecticides work: Foraging workers will be controlled when they contact the treated soil, as will young queens trying to colonize the area. Most broadcast insecticide treatments will control fire ants for four to eight weeks, but some products promise season-long control with a single application.
Because these products can be somewhat costly, many homeowners use them only in certain areas areas of their property, places where they really don’t want to have any fire ant mounds, and use baits or individual mound treatments on the rest of the property. By combining all three approaches you will get as close as possible to complete fire ant control.