As the weather warms up, and Spring showers come in, there seems that everyone has at least one thing on their mind… Fire Ants! It’s inevitable that at some point you will see fire ants in your yard, but with good planning and control you can limit the numbers you have. Extension has developed what they call the “Texas 2-Step Method” when dealing with fire ants which does very well here in East Texas.
1) The first step is to broadcast a fire ant bait (a product containing a food plus an insecticide) over the whole yard. When collected by worker ants, bait particles are carried to the colony and shared with the queen and other ants. Less pesticide is needed with baits because this kind of delivery is so efficient. Baits work best when scattered lightly over the whole yard. Hand-held seed spreaders are ideal for applying fire ant baits. Set the spreader on the smallest opening and make one pass over the area to be treated. This should apply the recommended rate (1 to 11 /2 pounds per acre for most products). Push type fertilizer spreaders put out most baits too quickly, so it is recommended you use a hand-held spreader.
Be patient. Baits work slowly. Products containing hydramethylnon or spinosad work the fastest, controlling ants within 2 to 4 weeks. Insect growth regulator baits (like fenoxycarb, pyriproxifen and methoprene) usually require 2 to 6 months. The advantage of growth regulators is that they need to be reapplied less often when treating areas larger than an acre. Some products like Amdro and Extinguish will have both.
As critical as choosing the right bait the time you apply has a large impact on its efficacy. Baits are effective only when fire ants are actively searching for food. Ants remove baits from the soil surface within a few hours if baits are applied during peak foraging times. Fire ants forage when the soil surface temperature is between 70 and 90 degrees, May to September, in most of Texas. I also personally recommend that you wait till after rains pass to apply fire ant baits, this ensures that ants are out and about as they build and keeps the bait from being washed away.
2) The second step is to treat problem ant colonies—those needing immediate attention— using a mound treatment. Mound treatment is the fastest way to get rid of individual colonies. It’s not necessary to treat all fire ant colonies with mound treatments after applying a bait. Limit Step Two treatments to mounds located next to house foundations, in high-traffic areas or other trouble spots.
Granular products contain an insecticide that releases into the soil, usually when drenched with water. Sprinkle the recommended amount of product around and on top of the mound. When directed on the label, sprinkle 1 to 2 gallons of water over the granules with a watering can. Sprinkle gently to avoid disturbing the colony and washing the granules off the mound.
Liquid drenches are pesticides mixed with water first and then applied directly to the mound. As with granules, 1 to 2 gallons of water is needed per nest. Always wear chemical resistant, unlined gloves to protect your skin when handling liquid concentrates and follow label safety directions.
The chemical Acephate is an effective dry dust treatment that does not require added water. You will know if it is Acephate by its distinctive rotten egg smell. Sprinkle lightly and evenly over the entire mound. Avoid disturbing the colony during application. This can cause the ants to vacate a mound. It’s best to keep pets away from treated mounds until the dust is gone. Dust can be easily dispersed with water after the colony is killed.
If you are wanting to control individual ant mounds organically, there are a few options. Pouring roughly 3 gallons of boiling water on each mound can be used but this poses a threat to you, pets, and desired nearby plants. You can shovel the ant mounds out of where you do not want them but be sure to wear gloves and cover them with talcum powder to prevent them from climbing on you. Pine oil and citrus oil can be mixed with water and sprayed on individually mounds, results may vary, and reapplication may be necessary.
Apply baits when ants are foraging. To see if ants are active, place a small amount of bait or suitable food (hot dog or potato chip) next to a mound. If ants begin removing the food within 30 minutes, it’s a good time to treat.
In summer, apply baits in the evening. During the cool of evening, ants will quickly discover and carry off baits. If applied during the day, in extreme heat, baits quickly lose their effectiveness. Also, ants do not forage during the day.
This article was adapted from The Texas 2-Step Method.
For more information on fire ants, contact the Texas A&M AgriLife Extension Service of Nacogdoches County at (936) 560-7711, or visit our website at http://nacogdoches.agrilife.org.