Fire ant


 * This page is about stinging ants in the genus Solenopsis. For the aggressive red weaver ants sometimes called "fire ants" in theast Asia please see Oecophylla smaragdina. For the Little Fire Ant, Wasmannia auropunctata, see Electric ant. 

Fire ants are a variety of stinging ants with over 280 species worldwide. They have several common names including ginger ants and tropical fire ants (English), hormigas bravas or hormigas coloradas (Spanish), fourmis de feu (French), Feuerameisen (German), mod-kun-fai (Thai), Pulang Langgam(Filipino), and aka-hi-ari or aka-kami-ari (Japanese).

Appearance
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 2mm to 6 mm (0.12 in to 0.24 in). These different sizes of the ants can all exist in the same nest.

Solenopsis sp. ants can be identified with three body features — a pedicel with two nodes, an unarmed propodeum, and antennae with 10 segments and a two segmented club.

Behavior
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 individuals. The venom is both insecticidal and antibiotic. Researchers have proposed that ant nurse workers will spray their brood to protect them from microorganisms.

Fire ants nest in the soil, often near moist areas, such as river banks, pond edges, watered lawns and highway edges. Usually the nest will not be visible as it will be built under objects such as timber, logs, rocks, pavers, bricks, etc. If there is no cover for nesting, dome-shaped mounds will be constructed, but this is usually only found in open spaces such as fields, parks and lawns. These mounds can reach heights of 40 cm (15.7 in). The mounds that the fire ants live in can also be as deep as 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).

Queen
A queen is generally the largest individual in the colony. The primary function of the queen is reproduction; she may live for 6 to 7 years and produce up to 1,500 eggs per day. Many fire ant colonies will have more than one queen.

An established nest can have up to 8 inactive sub-queens that will flee the nest if threatened, which is why poisoning a nest may not completely rid a property of the ants.

Males / Drones
Males mate with the queen for the sole purpose of producing offspring. Their lifespan is approximately four days.

Workers
The workers are sterile females who build and repair the nest, care for the young, defend the nest, and feed both young and adult ants. The worker ants also go find supplies to build up the colony.

Introduced species
Although most fire ant species do not bother people and are not invasive due to biological factors, 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, but now infests 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 US$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 the 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 efforts to control or eradicate the species, but, other than Australia, none have been especially effective. In Australia an intensive program costing A$175 million has, at February 2007, eradicated 99% of fire ants from the sole infestation occurring in South East Queensland.

In just 70 years, according to a new study, lizards in parts of the United States have developed longer legs and new behaviors to escape the ants, which can kill the lizard in under a minute.

Symptoms and first aid
The venom of fire ants is composed of alkaloids such as piperidine (see Solenopsis saevissima), and the sting swells into a bump. This can cause much pain and irritation at times, especially when stung repeatedly by several ants. The bump often forms into a white pustule, which is at risk of becoming infected if scratched; however, if left alone, it will usually flatten within a few days. The pustules are obtrusive and uncomfortable while active and, if the sting sites become infected, can turn into scars. Additionally, some people are allergic to the venom and as with many allergies, may experience anaphylaxis, which requires emergency treatment. An antihistamine or topical corticosteroids may help reduce the itching.

First aid for fire ant bites includes external treatments and oral medicines.
 * External treatments: a topical steroid cream (hydrocortisone), or one containing aloe vera.
 * Oral medicines: antihistamines.

Victims who experience severe or life threatening allergic reactions to fire ant insect stings should visit a doctor or hospital immediately upon contact as these reactions can result in death. These more severe reactions include severe chest pain, nausea, severe sweating, loss of breath, serious swelling, or slurred speech.

Other names
In Spanish, fire ants are known as hormiga colorada/roja (red ant) or hormiga brava (fierce ant). In the Dominican Republic they are known as Hormiga Caribe. In Portuguese, they are called formiga de fogo (fire ant) and formiga lava-pé (wash foot ant).

Natural predators
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, requiring a further two weeks before emerging.

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.

Species
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