“Controlling Fire Ants,  Pests that Seems to Always be Present”

When it comes to insect pests, fire ants would probably top everyone’s list! Red and black imported fire ants are invasive species and their painful bites can injure or kill livestock, wildlife, domestic animals, and humans. Their mounds (as many as 300 per acre) are unsightly and can often damage mowers and other equipment. Fire ants also infest buildings and can damage electrical equipment by chewing on wire insulation.

Fire ants cost Americans on average over a million dollars a year, including the cost of insecticides. There are methods and other approaches described here that can lower that cost while reducing environmental damage and improving fire ant control. Knowing your options will allow you to make better choices to protect your family, pets, and property.

Identifying Fire Ants

There are hundreds of ant species in the southern United States, including some native fire ant species, and most of them are considered beneficial insects. Collectively, ants till more earth than earthworms and some prey on other insect pests to help to reduce their numbers. Fire ants will build their mounds almost anywhere—in the open or next to a building, tree, sidewalk or electrical box. A fire ant mound does not have a central opening. Fire ants emerge quickly and begin biting and stinging when the mound is disturbed. They will even run up vertical surfaces.

Worker fire ants are dark reddish-brown with shiny black abdomens and are about 1/16- to about 1/4-inch long. Fire ants are similar in appearance to many other ants, so make sure you have correctly identified the species before attempting to solve your ant problem.

If you are uncertain about the species, call your local Extension office.

Control Products

Biological control: Government and university researchers have imported and tested natural enemies of fire ants, such as parasitic phorid flies from South America. These natural enemies have been successful in areas where they have been released but they are not available to the general public. However, ongoing release programs in all infested states are making phorid flies more prevalent in the environment. Biological control agents available on the retail market, such as parasitic nematodes, do not sustain themselves or spread on their own once they are released. Home remedies: Many home remedies have been devised to control fire ants. Drenching a mound with two to three gallons of almost boiling water eliminates ant colonies about 60 percent of the time, but it will also kill plants the water contacts. This method is labor intensive and the hot water must be handled carefully.

Some home remedies, such as applying instant grits, molasses, or aspartame to ant mounds, do not work. Pouring gasoline or diesel fuel on mounds can contaminate the soil and groundwater, is dangerous, and is strongly discouraged.

Organic products: A few products are certified as organic. These include ingredients such as d-limonene, an extract from citrus oil, or spinosad, a chemical complex produced by a soil microbe. Chemical control: The use of insecticides for fire ant control is regulated by the Environmental Protection Agency. Approved products must be used according to label directions. Read the label carefully! An approved product is one that has directions for fire ant control on the label. Be sure it is appropriate for where you intend to use it, particularly if you will be treating a vegetable garden or other food production site. Products for use in electrical utility boxes and indoors may not be available at retail stores and some products are for use only by professional pest control operators.ice.

Most active ingredients are marketed under more than one brand or trade name. This article refers to the generic names of the active ingredients in insecticides, which you should see on the product labels. Some sample trade names are given as well. Products are formulated as dusts, granules, liquid drenches or baits. They are applied either to individual ant mounds or across the surface of the ground (broadcast). The various active ingredients affect ants in different ways.

Most active ingredients are contact insecticides that affect the nervous system of ants. Contact insecticides includeproduct), pyrethrins, pyrethroids (bifenthrin, beta-cyfluthin, cyfluthrin, cypermethrin, deltamethrin, gammacyhalothrin, lambda-cyhalothrin, permethrin, esfenvalerate, tefluthrin, tralomethrin, or zeta-cypermethrin), and liquid fipronil or spinosad formulations. These ingredients vary in how quickly they kill ants and how long they remain in the environment. Natural pyrethrins and synthetic pyrethroid ingredients kill ants in minutes. Acephate and carbaryl take about one day, while granular fipronil may take four to six weeks to eliminate colonies. Hot water, pyrethrins, and d-limonene treatments have little or no lasting effect. Carbaryl, spinosad, and acephate break down in a matter of days to weeks. Pyrethroids can remain in the environment for weeks to months, while fipronil can persist as long as a year.

Baits contain active ingredients dissolved in a substance ants eat or drink. Some bait ingredients affect the nervous system. These include abamectin (Ascend®), indoxacarb (Advion®, Spectracide® Fire Ant Bait Once and Done!, and Over ‘N Out® Mound Treatment), spinosad, and fipronil. Some affect the digestive system (boric acid) or metabolism (hydramethylnon or Amdro®). Other bait ingredients interfere with reproduction or growth. These include fenoxycarb (Award®), methoprene (Extinguish®), and pyriproxyfen (Distance® or Esteem®). A relatively new type of bait combines two active ingredients, hydramethylnon, and methoprene (AMDRO FireStrike® or Extinguish Plus®).

To be effective, baits must be fresh and applied when ants are actively foraging. To determine if the time is right for treatment, place a small amount of bait in the area to be treated and see if foraging ants remove it within an hour. Because ants collect bait and return it to the colony, very little insecticide is needed. Baits are ruined by water, so do not water baits after application or apply them when rain is expected.

Make a Management Plan

Chemical control lasts only as long as the effects of the insecticide used, or until new ant colonies move in from untreated areas. You can expect an ant infestation to return to its original level eventually. Thus, keeping fire ants in check requires a commitment of time and money. To reduce the cost and make control easier, consider making a map of your property. Divide the property into treatment areas and designate the most appropriate treatment approach for each area. Make and maintain a schedule for first treatment and any necessary re-treatments.

For more information please contact, Dalton Dockery, County Extension Director, at 910-640-6605. Also I would like to thank the following authors for providing information to this column, Bastiaan M. Drees, Professor and Extension Entomologist; Kimberly Schofield, Elizabeth “Wizzie” Brown, Paul Nester, and Molly Keck, Extension Program Specialists; The Texas A&M System. Kathy Flanders, Alabama Cooperative Extension System.

North Carolina A&T State University and NC State University are committed to positive action to insure secure equal opportunity regardless of race, color, creed, national origin, religion, sex, age, veteran status, or disability. In addition, the two Universities welcome all persons without regard to sexual orientation. Also N.C. Cooperative Extension does not recommend one chemical treatment over another we try to provide a list of all available resources.