When people talk about fire ants, they're often referring to a non-native species, the red imported fire ant, Solenopsis invicta. In the 1930's, red imported fire ants made their way to the U.S. from Argentina, via the port of Mobile, Alabama. Red imported fire ants will defend their nest aggressively, emerging en masse and stinging the offending perpetrator. Solenopsis invicta is now established throughout the southeastern states. Isolated populations also exist in California and the southwest.
Entomologically speaking, fire ants is the common name given to about 20 species of ants belonging to the genus Solenopsis. Fire ants sting. Their toxic venom causes a burning sensation, hence the name fire ants.
In the U.S., we have four native species of fire ants:
- Solenopsis xyloni - southern fire ants
- Solenopsis aurea - desert fire ants
- Solenopsis amblychila - desert fire ants
- Solenopsis geminata - tropical fire ants
Another exotic species, the black import fire ant (Solenopsis richteri) arrived in the U.S. around 1918. Red imported fire ants displaced their less aggressive cousin a few decades later. Black imported fire ants still exist in limited populations in parts of Texas, Alabama, and Mississippi.