Fire ant

Taxobox

---

image_caption = "Solenopsis" queens and workers
image_width = 250px
regnum = Animalia
phylum = Arthropoda
classis = Insecta
ordo = Hymenoptera
subordo = Apocrita
familia = Formicidae
subfamilia = Myrmicinae
tribus = Solenopsidini
genus = "Solenopsis"
genus_authority = Westwood, 1840
diversity_link = > 280 species + subspecies
range_

range_map_width = 250px
subdivision_ranks = Species
subdivision = "S. conjurata"
"S. daguerrei"
"S. fugax"
"S. invicta"
"S. molesta"
"S. richteri"
"S. solenopsidis"
"S. wagneri"
"S. xyloni"
many more, see text

Fire ants, (referred to as red ants in the U.K.), are stinging ants with over 280 species worldwide. They have several common names including Ginger Ants and Tropical Fire Ants (English), aka-kami-ari (Japanese), and Feuerameise (German).

Appearance

The bodies of fire ants, like all insects' bodies, are broken up 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.

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 only bite 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 aftereffects of the sting can be deadly to sensitive individuals. Although fire ants do not typically seek out and attack the face, they are as likely to attack an exposed and vulnerable face as any other body part. The venom is both insecticidal and antibiotic. Researchers have proposed that nurse workers will spray their blood 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).

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) [ [http://www.bioone.org/perlserv/?request=get-document&issn=0015-4040&volume=086&issue=03&page=0381 Colonies in Florida dissected and observed with greater than 5 queens] ] .

Roles

Queens

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

Males

Mate with the queen ant in order to produce eggs.

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.

Introduced species

Although most fire ant species do not bother people and are not invasive due to biological factors, "Solenopsis invicta", commonly known 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 due to a South American cargo ship coming to an Alabama port in 1918, 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. [cite journal | quotes=no |last=McDonald | first=Maggie | title=Reds Under Your Feet (interview with Robert Vander Meer) | journal=New Scientist | volume=189 | issue=2538 | year=2006 | month=February | pages=50 | url=http://www.newscientist.com/channel/opinion/mg18925381.700-interview-extinguishing-red-fire-ants.html ] 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.

Symptoms and First aid

The venom of a fire ant sting causes stinging and swells into a bump. This can cause much pain and irritation at times, especially when stung repeatedly by several at once. The bump often forms into a white pustule, which is at risk of becoming infected if scratched, however if left alone usually go down within a few days. The pustules are unattractive 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. [cite journal |author=deShazo RD, Butcher BT, Banks WA |title=Reactions to the stings of the imported fire ant |journal=N. Engl. J. Med. |volume=323 |issue=7 |pages=462–6 |year=1990 |pmid=2197555 |doi=] 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

Patients 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.

Other names

In Spanish, fire ants are known as "hormiga colorada/roja" (red ant) or "hormiga brava" (fierce ant). In Puerto Rico there is a native, very small and slow-moving kind of fire ant called abayarde. In Portuguese, they are called "formiga de fogo" (fire ant) and "formiga lava-pé" (wash foot ant).

pecies

This species list is incomplete.

References

* cite book
author = Bert Hölldobler and Edward O. Wilson
title = The Ants
publisher = Belknap Press of Harvard University Press
location = Cambridge
year = 1990
id = ISBN 3-540-52092-9
* cite paper
publisher = USDA
title = Areawide suppression of Fire Ants using baits and Biological Control
date = 2003
url = http://www.ars.usda.gov/fireant/publications/brochure_2003.pdf
format = PDF
accessdate = 2006-10-25 Details use of Phorid flies
* ITIS: [http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=154237 "Solenopsis" species list] (2001)

External links

* [http://www.fireant.net Non-Chemical Natural Control, Bite Home Remedies, Mounds, Colonies, Information]
* [http://www.extension.org/fire+ants Biology, Control, and Management of Imported Fire Ants in North America at www.eXtension.org]
* [http://www.ag.auburn.edu/enpl/fireants The Alabama Fire Ant Management Program]
* [http://www2.dpi.qld.gov.au/fireants/ Queensland Government Department of Primary Industries Fire Ants Homepage]