Hope for Eradicating Red Fire Ants

Red fire ants were accidentally introduced into the United States in 1929 from South America. Each year they spread farther north from their foothold in the Southeast, often overtaking native ants along the way to become the dominant species. The pest, officially Solenopsis invicta, now resides in 14 states.

Red ants are known for their sting, which brings painful meaning to the phrase ants in your pants.

A new discovery could help get rid of them.

About 40 percent of people in area infested by the fire ants are stung each year, according to the U.S. Department of Agriculture. Fire ants dramatically reduce populations of native ants, other insects, and ground-nesting wildlife. They also damage crops and even electrical equipment. The USDA estimates damage and control costs at more than $6 billion a year.

The fire ants thrive here -- becoming a higher percentage of the ant population than in South America -- because in the north they lack natural enemies, scientists say.

In 1986, scientists found a natural enemy of the fire ant, a pathogen called Vairimorpha invictae. Now USDA scientists have figured out how to inject the pathogen into otherwise uninfected populations of fire ants.

"The ability to efficiently initiate field infections of V. invictae could result in faster declines in fire ant populations and provide a new, self sustaining tactic to suppress fire ant populations," the researchers write in a paper that's been submitted to the Journal Of Invertebrate Pathology.

-- Robert Roy Britt

Photo credit: USDA/ Scott Bauer