Solenopsis invicta
Buren, 1972 (Red Imported Fire Ant ) |
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Class: Insecta Order: Hymenoptera Family: Formicidae Synonym(s): Solenopsis wagneri (Santschi, 1916) |
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Adult Description: Well known to most Texans, red imported fire ants (Solenopsis invicta) are small ants that live in colonies and consist of several types of adults: winged males, reproductives and worker ants. Workers are sterile females ranging in size from 3-6mm in length. Winged males, or "reproductives" live in the colony until their mating flight where they fly with the queen to establish a new colony, then die. Queens can attain greater sizes (9mm), especially when they are mature and producing eggs. Queens, winged males, and workers are reddish-brown in appearance, and look very similar to other Solenopsis species, including the Ginger ant Solenopsis geminata (native) and the Black Imported Fire ant Solenopsis richteri (invasive). Red Imported Fire ants are also notorious for their sting for which they are named. The stinger is obvious on the abdomen under close examination. Larva Description: The larval stage typically lasts 6 to 12 days, and the pupal stage for 9 to 16 days. The larvae and pupae are small and a non-descript white color. Host Plant: None History: The red imported fire ant was introduced around the 1930's and has spread to infest more than 260 million acres of land in 9 southeastern states, including all or portions of Florida, Georgia, South Carolina, Tennessee, Alabama, Mississippi, Arkansas, Texas, and Oklahoma. This species has become very abundant, displacing many native ant species when abundant. It has the potential of spreading west and surviving in southern Arizona and along the Pacific coast north to Washington. Biology: Red imported fire ants are prolific breeders and aggressive feeders, which makes them a successful invader. Mounds can be hundreds of thousands of individuals strong, and multiple queen colonies exist whose individuals can move between mounds freely which ultimately leads to an increase in the number of mounds that may be found within an area. Thus, Red Imported Fire ants are able to take over an area rather quickly by turning fields into homogeneous, desolate wastelands comprised of dozens of Red Imported Fire ants mounds. Most Texans have observed this phenomenon, possibly in their own backyard. Ecological Threat: Any Texan who has walked through a field and seen dozens of red fire ant mounds knows the destructive power of the red imported fire ant. Not only are the mounds unaesthetic, but they can ruin lawns, and more ecologically important, they can displace native ants from their habitat. These native ants, including the Texas leaf-cutter ant, the harvester ant, as well as the carpenter ant are out-competed and even face hostility from red imported fire ants. This has led to a reduction in population numbers of all indigenous ants. US Habitat: In infested areas, colonies are common in lawns, gardens, school yards, parks, roadsides, and golf courses. Nests generally occur in sunny, open areas and are especially common in disturbed and irrigated soil. Red Imported Fire ant mounds are 4 to 24 inches tall and have no visible surface entrance. Mounds are accessed through subterranean tunnels that spoke out from the central mound. Non-Red Imported Fire ant mounds rarely exceed an inch or 2 in height. Red Imported Fire ant mounds have a fresh-tilled appearance, especially after a rain. Distribution
Resembles: Red Imported Fire ants look very similar to other Solenopsis species, including the tropical fire ant, S. geminata (native), and the black imported fire ant, S. richteri (invasive). Management: Managing the Red Imported Fire ant has proven difficult, as the ants are hearty and tough to eradicate. Presently, insecticides seem to be the best and most-recommended option. Spraying mounds, injecting mounds, bait-traps, colony poisons, pouring boiling water onto the mounds, or igniting mounds have all been tried with varying results. Text References
Data Source Last Updated: 2011-09-21 by Amber Bartelt - Sam Houston State University |
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