Fire ant is the popular name for ants in the genus Solenopsis. There are over 285 species worldwide. They are stinging ants and most of their common names reflect this, for example, ginger ants and tropical fire ants. Many species also are called red ants because of their light brown colour.
The bodies of fire ants, like all insects' bodies, are divided into three sections: the head, the thorax, and the abdomen, with three pairs of legs and a pair of antennae. Fire ants can be distinguished from other ants by their copper brown head and body with a darker abdomen. The worker ants are blackish to reddish, and their size varies from 2 mm to 6 mm (0.12 in to 0.24 in). These different sizes of the ants can all be present in the same nest.
Many ants bite, and formicine ants can cause irritation by spraying formic acid; myrmecine ants like fire ants have a dedicated venom-injecting sting, which injects an alkaloid venom, as well as mandibles for biting.
A typical fire ant colony produces large mounds in open areas, and feeds mostly on young plants, seeds, and sometimes crickets. Fire ants often attack small animals and can kill them. Unlike many other ants, which bite and then spray acid on the wound, fire ants bite only to get a grip and then sting (from the abdomen) and inject a toxic alkaloid venom called Solenopsin, a compound from the class of piperidines. For humans, this is a painful sting, a sensation similar to what one feels when burned by fire—hence the name fire ant—and the after effects of the sting can be deadly to sensitive people. The liquid is both insecticidal and antibiotic.
Fire ants nest in the soil, often near moist areas, such as river banks, pond shores, watered lawns and highway shoulder. Usually, the nest will not be visible, as it will be built under objects such as timber, logs, rocks, or bricks. If there is no cover for nesting, dome-shaped mounds will be constructed, but these are usually only found in open spaces, such as fields, parks and lawns. These mounds can reach heights of 40 cm (15.7 in), and can also be as deep as a metre and a half (five feet). 
Colonies are founded by small groups of queens or single queens. Even if only one queen survives, within a month or so, the colony can expand to thousands of individuals. Some colonies may be polygynous (having multiple queens per nest).
Fire ant queens, usually the most important ants in their colony, are also generally the largest. Their primary function is reproduction; fire ant queens may live as many as 6 to 7 years and can produce up to 3,500 eggs per day. That adds up to roughly 9 million eggs produced during a single queen's lifetime. Young, virgin fire ant queens have wings (as do male fire ants), but rip them off after mating.
Males mate with the queen. They die immediately after mating.
There are other types of roles in an ant colony like the workers and the soldier ants. The soldier ants are known for their larger and more powerful mandibles while the worker takes care of regular tasks (the main tasks in a colony are caring for the eggs/larvae/pupae, cleaning the nest, and foraging for food).
Although most fire ant species do not bother people and are not invasive, Solenopsis invicta, known in the United States as the red imported fire ant (or RIFA) is an invasive pest in many areas of the world, notably the United States, Australia, the Philippines, China and Taiwan. The RIFA was accidentally introduced into the United States aboard a South American cargo ship that docked at the port of Mobile, Alabama, in the 1930s, and came to infest the majority of the Southern and Southwestern United States.
In the US the FDA estimates that more than US$5 billion is spent annually on medical treatment, damage, and control in RIFA-infested areas. Furthermore, the ants cause approximately $750 million in damage annually to agricultural assets, including veterinarian bills and livestock loss, as well as crop loss. Over 40 million people live in RIFA-infested areas in the southeastern United States. Between 30 and 60% of people living in fire ant-infested areas are stung each year. Since September 2004 Taiwan has been seriously affected by the red fire ant. The US, Taiwan and Australia all have ongoing national programs to control or eradicate the species, but, except for Australia, none have been especially effective. In Australia, an intensive program costing A$175 million had by February 2007 eradicated 99% of fire ants from the sole infestation occurring in south-east Queensland.
Symptoms and treatment
The venom of fire ants is composed of alkaloids derived from piperidine (see Solenopsis saevissima). Some people are allergic to the venom, and as with many allergies, may experience anaphylaxis, which requires emergency treatment. Other problems are concentrated to the site of the sting.
The sting swells into a bump, which can cause much pain and irritation, especially when several stings are in the same place. The bump often forms into a white pustule, which can become infected if scratched, but if left alone will usually flatten within a few days. The pustules are obtrusive and uncomfortable while active and, if they become infected, can cause scarring.
First aid for fire ant stings includes external treatments and oral medicines. There are also many home remedies of varying efficacy, including immediate application of urine or aloe vera gel, the latter of which is also often included in over-the-counter creams that also include medically tested and verified treatments.
External, topical treatments include the anesthetic benzocaine, the antihistamine diphenhydramine, and the corticosteroid hydrocortisone. Antihistamines or topical corticosteroids may help reduce the itching.
Oral medicine include antihistamines.
Severe allergic reactions to fire ant stings, including severe chest pain, nausea, severe sweating, loss of breath, serious swelling, and slurred speech, can be fatal if not treated.
Phorid flies, or Phoridae, are a family of small, hump-backed flies resembling fruit flies; two species in this family (Pseudacteon tricuspis and Pseudacteon curvatus) are parasitoids of the red imported fire ant in its native range in South America. Some 110 species of the genus Pseudacteon, or ant-decapitating flies, have been described. Members of Pseudacteon reproduce by laying eggs in the thorax of the ant. The first instar larvae migrates to the head, then develops by feeding on the hemolymph, muscle tissue, and nervous tissue. After about two weeks, they cause the ant's head to fall off by releasing an enzyme that dissolves the membrane attaching the ant's head to its body. The fly pupates in the detached head capsule, emerging two weeks later.
Pseudacteon flies have been widely introduced throughout the southern United States, starting with Travis, Brazos, and Dallas counties in Texas, as well as Mobile, Alabama, where the ants first entered North America.
The Venus Flytrap, a carnivorous plant, is native to North and South Carolina in the United States. The diet of the Venus Flytrap includes 33% ants, most of any species. They lure their prey to their trap by using a sweet sap. Once the prey has fallen into the trap and touched three "hairs" (that look like teeth) within 30 seconds, the leaf closes around the prey and digests it.
This species list is complete.
- Solenopsis abdita Thompson, 1989
- Solenopsis africana Santschi, 1914
- Solenopsis albidula Emery, 1906
- Solenopsis alecto Santschi, 1934
- Solenopsis altinodis Forel, 1912
- Solenopsis amblychila Wheeler, 1915
- Solenopsis andina Santschi, 1923
- Solenopsis angulata Emery, 1894
- Solenopsis atlantis Santschi, 1934
- Solenopsis aurea Wheeler, 1906
- Solenopsis avia (Bernard, 1978)
- Solenopsis azteca Forel, 1893
- Solenopsis balachowskyi Bernard, 1959
- Solenopsis banyulensis Bernard, 1950
- Solenopsis basalis Forel, 1896
- Solenopsis belisarius Forel, 1907
- Solenopsis blanda (Foerster, 1891)
- Solenopsis brasiliana Santschi, 1925
- Solenopsis brazoensis (Buckley, 1867)
- Solenopsis brevicornis Emery, 1888
- Solenopsis brevipes Emery, 1906
- Solenopsis bruchiella Emery, 1922
- Solenopsis bruesi Creighton, 1930
- Solenopsis bucki Kempf, 1973
- Solenopsis canariensis Forel, 1893
- Solenopsis capensis Mayr, 1866
- Solenopsis carolinensis Forel, 1901
- Solenopsis castor Forel, 1893
- Solenopsis celata (Dlussky & Zabelin, 1985)
- Solenopsis clarki Crawley, 1922
- Solenopsis clytemnestra Emery, 1896
- Solenopsis conjurata Wheeler, 1925
- Solenopsis cooperi Donisthorpe, 1947
- Solenopsis corticalis Forel, 1881
- Solenopsis crivellarii Menozzi, 1936
- Solenopsis daguerrei (Santschi, 1930)
- Solenopsis dalli (Kusnezov, 1969)
- Solenopsis decipiens Emery, 1906
- Solenopsis delta (Bernard, 1978)
- Solenopsis deserticola Ruzsky, 1905
- Solenopsis duboscqui Bernard, 1950
- Solenopsis dysderces Snelling, 1975
- Solenopsis egregia (Kusnezov, 1953)
- Solenopsis electra Forel, 1914
- Solenopsis emeryi Santschi, 1934
- Solenopsis eximia (Kusnezov, 1953)
- Solenopsis fairchildi Wheeler, 1926
- Solenopsis foersteri Theobald, 1937
- Solenopsis franki Forel, 1908
- Solenopsis froggatti Forel, 1913
- Solenopsis fugax (Latreille, 1798)
- Solenopsis fusciventris Clark, 1934
- Solenopsis gallardoi Santschi, 1925
- Solenopsis gallica Santschi, 1934
- Solenopsis gayi (Spinola, 1851)
- Solenopsis geminata (Fabricius, 1804)
- Solenopsis georgica Menozzi, 1942
- Solenopsis germaini Emery, 1895
- Solenopsis globularia (Smith, 1858)
- Solenopsis gnomula Emery, 1915
- Solenopsis goeldii Forel, 1912
- Solenopsis granivora Kusnezov, 1957
- Solenopsis hammari Mayr, 1903
- Solenopsis hayemi Forel, 1908
- Solenopsis helena Emery, 1895
- Solenopsis hostilis (Borgmeier, 1959)
- Solenopsis iheringi Forel, 1908
- Solenopsis ilinei Santschi, 1936
- Solenopsis indagatrix Wheeler, 1928
- Solenopsis insculpta Clark, 1938
- Solenopsis insinuans Santschi, 1933
- Solenopsis insularis (Bernard, 1978)
- Solenopsis interrupta Santschi, 1916
- Solenopsis invicta Buren, 1972
- Solenopsis jacoti Wheeler, 1923
- Solenopsis jalalabadica Pisarski, 1970
- Solenopsis japonica Wheeler, 1928
- Solenopsis joergenseni Santschi, 1919
- Solenopsis juliae (Arakelian, 1991)
- Solenopsis kabylica Santschi, 1934
- Solenopsis knuti Pisarski, 1967
- Solenopsis krockowi Wheeler, 1908
- Solenopsis laeviceps Mayr, 1870
- Solenopsis laevithorax Bernard, 1950
- Solenopsis latastei Emery, 1895
- Solenopsis latro Forel, 1894
- Solenopsis leptanilloides Santschi, 1925
- Solenopsis longiceps Forel, 1907
- Solenopsis loretana Santschi, 1936
- Solenopsis lotophaga Santschi, 1911
- Solenopsis lou Forel, 1902
- Solenopsis lusitanica Emery, 1915
- Solenopsis macdonaghi Santschi, 1916
- Solenopsis macrops Santschi, 1917
- Solenopsis madara Roger, 1863
- Solenopsis major Theobald, 1937
- Solenopsis maligna Santschi, 1910
- Solenopsis mameti Donisthorpe, 1946
- Solenopsis marxi Forel, 1915
- Solenopsis maxillosa Emery, 1900
- Solenopsis maxima (Foerster, 1891)
- Solenopsis megera Santschi, 1934
- Solenopsis megergates Trager, 1991
- Solenopsis metanotalis Emery, 1896
- Solenopsis metatarsalis (Kusnezov, 1957)
- Solenopsis mikeyroxis
- Solenopsis minutissima Emery, 1906
- Solenopsis moesta (Foerster, 1891)
- Solenopsis molesta (Say, 1836)
- Solenopsis monticola Bernard, 1950
- Solenopsis mozabensis (Bernard, 1977)
- Solenopsis nicaeensis Bernard, 1950
- Solenopsis nickersoni Thompson, 1982
- Solenopsis nigella Emery, 1888
- Solenopsis nitens Bingham, 1903
- Solenopsis nitidum (Dlussky & Radchenko, 1994)
- Solenopsis normandi Santschi, 1934
- Solenopsis novemmaculata Wheeler, 1925
- Solenopsis occipitalis Santschi, 1911
- Solenopsis oculata Santschi, 1925
- Solenopsis oraniensis Forel, 1894
- Solenopsis orbula Emery, 1875
- Solenopsis orbuloides Andre, 1890
- Solenopsis overbecki Viehmeyer, 1916
- Solenopsis pachycera (Forel, 1915)
- Solenopsis papuana Emery, 1900
- Solenopsis parabiotica Weber, 1943
- Solenopsis parva Mayr, 1868
- Solenopsis patagonica Emery, 1906
- Solenopsis pawaensis Mann, 1919
- Solenopsis pergandei Forel, 1901
- Solenopsis photophila Santschi, 1923
- Solenopsis picea Emery, 1896
- Solenopsis picquarti Forel, 1899
- Solenopsis picta Emery, 1895
- Solenopsis pilosa (Bernard, 1978)
- Solenopsis pilosula Wheeler, 1908
- Solenopsis pollux Forel, 1893
- Solenopsis privata (Foerster, 1891)
- Solenopsis provincialis Bernard, 1950
- Solenopsis punctaticeps Mayr, 1865
- Solenopsis puncticeps MacKay & Vinson, 1989
- Solenopsis pusillignis Trager, 1991
- Solenopsis pygmaea Forel, 1901
- Solenopsis pythia Santschi, 1934
- Solenopsis quinquecuspis Forel, 1913
- Solenopsis reichenspergeri Santschi, 1923
- Solenopsis richardi Bernard, 1950
- Solenopsis richteri Forel, 1909
- Solenopsis robusta Bernard, 1950
- Solenopsis rugiceps Mayr, 1870
- Solenopsis rugosa Bernard, 1950
- Solenopsis sabeana (Buckley, 1867)
- Solenopsis saevissima (Smith, 1855)
- Solenopsis salina Wheeler, 1908
- Solenopsis santschii Forel, 1905
- Solenopsis schilleri Santschi, 1923
- Solenopsis schmalzi Forel, 1901
- Solenopsis scipio Santschi, 1911
- Solenopsis sea (Kusnezov, 1953)
- Solenopsis seychellensis Forel, 1909
- Solenopsis silvestrii Emery, 1906
- Solenopsis solenopsidis (Kusnezov, 1953)
- Solenopsis soochowensis Wheeler, 1921
- Solenopsis spei Forel, 1912
- Solenopsis stricta Emery, 1896
- Solenopsis substituta Santschi, 1925
- Solenopsis subterranea MacKay & Vinson, 1989
- Solenopsis subtilis Emery, 1896
- Solenopsis succinea Emery, 1890
- Solenopsis sulfurea (Roger, 1862)
- Solenopsis superba (Foerster, 1891)
- Solenopsis targuia Bernard, 1953
- Solenopsis tennesseensis Smith, 1951
- Solenopsis tenuis Mayr, 1878
- Solenopsis terricola Menozzi, 1931
- Solenopsis tertialis Ettershank, 1966
- Solenopsis tetracantha Emery, 1906
- Solenopsis texana Emery, 1895
- Solenopsis tipuna Forel, 1912
- Solenopsis tonsa Thompson, 1989
- Solenopsis tridens Forel, 1911
- Solenopsis trihasta Santschi, 1923
- Solenopsis truncorum Forel, 1901
- Solenopsis ugandensis Santschi, 1933
- Solenopsis valida (Foerster, 1891)
- Solenopsis virulens (Smith, 1858)
- Solenopsis vorax Santschi, 1934
- Solenopsis wagneri Santschi, 1916
- Solenopsis wasmannii Emery, 1894
- Solenopsis weiseri Forel, 1914
- Solenopsis westwoodi Forel, 1894
- Solenopsis weyrauchi Trager, 1991
- Solenopsis wolfi Emery, 1915
- Solenopsis xyloni McCook, 1879
- Solenopsis zambesiae Arnold, 1926
- Solenopsis zeteki Wheeler, 1942
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- Bastiaan M. Drees, Professor and Extension Entomologist (2002-12). "Medical Problems And Treatment Considerations For The Red Imported Fire Ant". Texas A&M University. p. 4. Retrieved 2012-12-11.
- "Insects and Scorpions". The National Institute for Occupational Safety and Health. 2008-10-22. Retrieved 2008-11-04.
- Rachel Ehrenberg. "Ant Venom Attracts Decapitating Flies", Science News, September 20, 2009
- Bert Hölldobler and Edward O. Wilson (1990). The Ants. Cambridge: Belknap Press of Harvard University Press. ISBN 3-540-52092-9.
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- Areawide suppression of Fire Ants using baits and Biological Control (PDF). USDA. 2003. Retrieved 2006-10-25. Details use of Phorid flies
- ITIS: Solenopsis species list (2001)
- Treatment of Fire Ant Bites
- Medical Treatment of Fire Ant Bites
|Wikimedia Commons has media related to Solenopsis.|
|Wikispecies has information related to: Solenopsis|
- Biology, Control, and Management of Imported Fire Ants at www.extension.org brought to you by the Imported Fire Ant eXtension Community of Practice
- New Mexico State University Arthropod Museum Fire ant specimens for qualified researchers may be accessed via the Southwest Collections of Arthropods
- The Alabama Fire Ant Management Program
- The UT Austin Fire Ant Research Program
- Queensland Government – Department of Primary Industries Fire Ants Homepage
- Fire Ant Gene Sequence database
- Fireants building a lifeboat to save the queen – Video
- Fire Ants provided by Local Pest Control Services