Texas Landscape Project: Map of the Spread of the Red Imported Fire Ant, 1958-2013

Red Imported Fire Ants

Red imported fire ants (Solepnosis invicta Buren) are hardy and harmful invasive creatures that hail from South America and first appeared on American shores in the 1930s, likely in Mobile, Alabama. By the early 1950s, the ant had entered the southeastern corner of Texas.

Over the next 60 years, this small creature, just 1/6 of an inch long, had moved over 490 miles westward in Texas.In its wake, the red imported fire ant displaced many harvester, leafcutter, carpenter and other native ants, and threatened game (bobwhite quail), rare species (the Houston toad), and even large mammals (young calves and white-tailed deer).

The ant proved resistant to powerful insecticides such as heptachlor and mirex, but may eventually meet its match in biocontrols, such as introduced fungi, viruses, nematodes, wasps, and even a parasitic ant.


Please hear Bill Oliver sing about the exploits of the red imported fire ant:

Map source:

Code of Federal Regulations, Title 7, Chapter III, Section 301.81-11, January 1, 2013

Selected reference:

Callcott, Anne-Marie A. and Homer L. Collins. 1996. Invasion and Range Expansion of Imported Fire Ants (Hymenoptera: Formicidae) in North America from 1918-1995, in The Florida Entomologist, Vol. 79, No. 2 (Jun., 1996), pp. 240-251.