Fire Ants

Terry Washington  |  3/31/2005 9:54:12 PM

A typical fire ant mound.

Red imported fire ants are widespread in Louisiana.

They inhabit pastures, fields, playgrounds, lawns, flowerbeds and even potted plants. These ants are called imported because they were accidentally bought here from South America in the early 1930s. In Brazil and Argentina, the ants are held in check by other organisms and environmental factors. In Louisiana, however, there are no natural controls, resulting in an ever-growing population.

Red imported fire ants can cause many problems. If stung, some people suffer allergic reactions, secondary infections and unsightly skin damage. The ants can cause structural damage in houses and industrial buildings. Some infestations lead to damage of waste containers, electronic circuitry, ground-placed industrial lighting and even traffic control lights.

Ants belong to the insect order "hymenoptera," which includes the hornets, wasps and bees. Ants can be recognized by two characteristics: a narrow "waist" (called a pedicel) between the thorax and abdomen and elbowed antennae. Winged reproductives have two pairs of wings, each pair of a different size. Ants also differ from most other insects in that they are social and live in colonies with three castes (workers, queens and males).

Ants can be pests around the home because they are attracted by and feed on human foods.

Biology: The life stages of ants are egg, larva, pupa and adult. Worker ants, sterile females, are seldom winged, often extremely variable in size and appearance. The worker builds, repairs, defends the nest and feeds the immature and adult ants of the colony.

Control: Outdoors – to broadcast fire ant bait over the whole yard. Baits are a product containing a food plus a moderate to slow-acting insecticide. When collected by worker ants, bait particles are carried to the colony and shared with the queen and other ants.

Common insecticides for fire ant control: Award, Logic, Amdro, Distance, Extinguish, Spectracide Fire Ant Bait

Mound Treatment:

Orthene, sevin – Seven to 10 days after broadcasting a bait, treat those problem colonies needing immediate attention using a mound treatment

Granular – products contain an insecticide that is released into the soil, usually when drenched with water. Sprinkle the recommended amount of product around and on the top of mound. When directed on the label, sprinkle one to two gallons of water over the granules with a watering can.

Liquid drenches are pesticides mixed with water first and then applied directly to the mound. As with granules, one to two gallons of water are needed per nest. Always wear chemical-resistant, unlined gloves to protect your skin when handling liquid concentrates, and follow label safety directions.

Dusts are applied as powders to tops of mounds. Acephate (orthene) is an effective dry dust treatment that does not require added water. It’s best to keep pets away from treated mounds until the dust is gone.

Boiling water (about three gallons per mound) can eliminate fire ant colonies; however, this method can be hazardous to the person carrying the hot water because of the potential burns from water and steam when poured. Boiling water poured on grass or over plant roots also can be lethal to the plants.

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