Get 'Two Steps' Ahead Of Fire Ants With Organic Control

When the ground temperature stays above 65 degrees for several days, fire ants begin to build up mounds, produce young and forage for food. That is one of the best times to manage populations, according to Kimberly Engler, Texas Cooperative Extension program specialist for urban Integrated Pest Management.

"The best way to control the red imported fire ant is the 'Texas Two-Step' Method, which now incorporates organic products into the overall management plan," Engler said. "This plan follows an IPM approach that involves minimal risk to people, pets and the overall environment."

The first step is to let them eat bait.

"Apply a broadcast bait, which is a product containing a food source and an insecticide. The bait should be broadcast over the entire yard in the fall and spring," Engler said. "The bait is carried by the workers to the rest of the colony, where it becomes a shared food source. This product kills the whole fire ant colony, which prevents new mounds from forming and treats unseen mounds."

Some of the organic baits on the market that are listed by the Organic Materials Review Institute are Safer Brand Fire Ant Bait and Green Light Fire Ant Control with Conserve. These products contain the active ingredient spinosad.

"Spinosad is a product formed from a common bacteria found in nature," Engler said. "Once ingested by the fire ant, spinosad attacks the nervous system causing paralysis and death."

Engler warned that to work correctly, baits must be applied at the right time and used with patience. Baits are only effective when the fire ants are searching for food.

"Fire ants will forage when the soil surface temperature is between 70 and 90 degrees, which is usually between May and September," Engler said. "To see if fire ants are actively foraging, place a small amount of bait or food, such as a hot dog or potato chips, by the mound. Also, only fresh bait products should be used. Fire ants will not pick up the bait if it smells rancid."

The second step is to treat the individual mounds.

"The mound treatment is the fastest way to get rid of the fire ant mounds. Apply a mound drench to provide immediate control of large mounds," said Engler. "However, step two should be limited to those mounds found around the foundation and in high traffic areas."

Some organic individual mound drenches that are listed by Organic Materials Review Institute are Safer Brand Fire Ant Mound Drench and Citrex Fire Ant Killer, both containing the active ingredient d-limonene.

D-limonene is an extract of orange oil released from crushed or grated orange peels. When the citrus fruits are juiced the oil is pressed out of the rind. D-limonene is the oil left behind and collected.

"D-Limonene destroys the wax coating of the insect's respiratory system," Engler said. "When applied directly, the insect suffocates."

Fire ants came into the United States from South America, probably in soil used for ships' ballast. They were accidentally introduced in the 1930s and have been spreading ever since.

For more information on the organic two-step method, visit http://fireant.tamu.edu/materials/factssheets/fapfs039_2002rev.pdf.