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Animal and Plant Health Inspection Service
U.S. Department of Agriculture
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Imported Fire Ant

The Imported Fire Ant threatens America’s farms/crop plants.

Imported fire ants (Solenopsis invicta Buren, S. richteri Forel) will feed on the buds and fruits of numerous crop plants, especially corn, soybean, okra, and citrus. They can also girdle young trees. Large nests located in fields interfere with and damage equipment during cultivation and harvesting. Imported fire ants respond rapidly and aggressively to disturbances, and ant attacks inhibit field-worker activities. A single fire ant can sting its target repeatedly. Young and newborn animals are especially susceptible to the stings’ venom. These pests can damage the environment by displacing native ant species and reducing food sources for wildlife.

  • Alabama, Arkansas, California, Florida, Georgia, Louisiana, Mississippi, New Mexico, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia and Puerto Rico.

  • See Pest Tracker for details
  • Corn
  • Soybean
  • Okra
  • Citrus
  • Humans
  • Young and newborn animals
  • Agricultural equipment
  • Two species of imported fire ants were unintentionally introduced from South America into the port of Mobile, Alabama, almost 100 years ago. The black imported fire ant arrived around 1918 and the red fire ant in the late 1930s. Both species probably came in soil used as ballast in cargo ships.
  • They commonly move to new, non-infested areas either by naturally colonies spreading or by hitchhiking on agricultural commodities, including baled hay.
  • Visible imported fire ants. Ants are 1/8” to 1/4” long and reddish-brown or black in color.

  • Ants that respond rapidly and aggressively when disturbed.

  • They clamp onto their victims with powerful jaws and sting repeatedly while injecting painful venom.

  • The stings cause a burning sensation and itching blisters that can become infected. Although very uncommon, in severe cases, the stings can produce shock or cause death.

  • Hard, mound-shaped nests that can get quite large, posing risks to field workers and farm equipment.

  • Know the restrictions on baled hay, soil, plants, soil-moving equipment, and other items moving out of Imported Fire Ant quarantine areas. Visit the USDA's fire ant page for this information.

  • Report any sightings of this pest to your local Extension office.


What's at Risk from the Imported Fire Ant:

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