Solenopsis invicta

Stefan Cover (EOL) - The Red Imported Fire Ant (Solenopsis invicta) is a native of tropical and subtropical South America that has achieved international notoriety by becoming an enormously successful invasive ant throughout much of the southern United States. S. invicta is now spreading rapidly in parts of the Caribbean, and new infestations have been detected and exterminated in Arizona, California, Australia, New Zealand, and southern China. The probability of new invasions is therefore quite high and S. invicta must be considered a potential threat worldwide in all areas where climates are suitable.

Invasive populations of Solenopsis invicta are by no means easy to ignore. They have been linked to a multitude of destructive effects, including stinging humans, agricultural and horticultural damages, and substantial negative impacts on native faunas and floras. This has resulted in social and political pressure on governments to "solve" the fire ant problem. Government involvement in fire ant research developed first in the United States, which has an 80 year history of Imported Fire Ant infestation, but other governments have more recently begun research and control efforts of their own.

In the US, federal and state governments have responded primarily by funding research and by developing detection and infestation prevention programs. There have also been expensive and ecologically disasterous attempts to exterminate entire Imported Fire Ant populations. On the brighter side, over the course of fifty years, federal and state funding agencies have underwritten a plethora of research programs that have examined in detail the behavior, ecology, life-history, genetics, and potential controls for Solenopsis invicta. As a result, S. invicta has become in some sense the Drosophila melanogaster of the ant world. We probably know more about its biology than is known for any other species of ant. Despite this, our ability to control large-scale infestations remains limited.

Distribution
Solenopsis invicta is a native of South America, centered on the Pantanal region found at the headwaters of the Paraguay River. This area is comprised of seasonally flooded savannas and wetlands. Solenopsis invicta first became noticed as pest species after its introduction in Mobile, Alabama in the 1930's. This introduction was thought to have its origins from a cargo ship from somewhere in NE Argentina. It is also possible there were numerous introductions. The fire ant is now found throughout the SE United States and California. It has subsequently been introduced and spread to other parts of the world as well (as detailed below).

Distribution based on Regional Taxon Lists
Australasian Region: Australia. Indo-Australian Region: Hawaii. Nearctic Region: United States. Neotropical Region: Anguilla, Antigua and Barbuda, Argentina, Aruba, Brazil, British Virgin Islands, Cayman Islands, Greater Antilles, Mexico, Montserrat, Netherlands Antilles, Paraguay, Puerto Rico, Saint Martin (French part), Trinidad and Tobago, Turks and Caicos Islands, United States Virgin Islands. Palaearctic Region: China.



Nomenclature

 * wagneri. Solenopsis saevissima var. wagneri Santschi, 1916e: 380 (w.) ARGENTINA. Junior synonym of saevissima: Wilson, 1952b: 55. Revived from synonymy, raised to species and senior synonym of invicta: Bolton, 1995b: 391. [Trager, 1991: 173 wrongly gave wagneri as an unavailable name, incorrectly citing its original notation as S. saevissima subsp. electra var. wagneri, and referring its material to invicta. But wagneri is available, with the original notation cited above, and has priority over invicta.] S. invicta conserved over wagneri because of usage, in accord with ICZN (1999): Shattuck, Porter & Wojcik, 1999: 27.
 *  invicta. Solenopsis invicta Buren, 1972: 9, fig. 2 (w.q.m.) BRAZIL. Wheeler, G.C. & Wheeler, J. 1977: 588 (l.). Junior synonym of wagneri: Bolton, 1995b: 388. [Trager, 1991: 173 incorrectly gave wagneri as an unavailable name; the name is available and has priority over invicta, see note under wagneri.] S. invicta conserved over wagneri because of usage, in accord with ICZN (1999): Shattuck, Porter & Wojcik, 1999: 27. See also: Rhoades, 1977: 1; Smith, D.R. 1979: 1386.