An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies.
Most ants are capable of biting, stinging, and spraying irritant chemicals. However, only relatively few species can harm humans; among which some can cause significant injury or, in rare cases, death. Like wasps, individual ants are capable of stinging multiple times as they do not lose their stingers.
Fire ants are several species of ants in the genus Solenopsis, which includes over 200 species. Solenopsis are stinging ants, and most of their common names reflect this, for example, ginger ants and tropical fire ants. Many of the names shared by this genus are often used interchangeably to refer to other species of ant, such as the term red ant, mostly because of their similar coloration despite not being in the genus Solenopsis. Both Myrmica rubra and Pogonomyrmex barbatus are common examples of non-Solenopsis ants being termed red ants.
Solenopsis invicta, the fire ant, or red imported fire ant (RIFA), is a species of ant native to South America. A member of the genus Solenopsis in the subfamily Myrmicinae, it was described by Swiss entomologist Felix Santschi as a variant of S. saevissima in 1916. Its current specific name invicta was given to the ant in 1972 as a separate species. However, the variant and species were the same ant, and the name was preserved due to its wide use. Though South American in origin, the red imported fire ant has been accidentally introduced in Australia, New Zealand, several Asian and Caribbean countries, Europe and the United States. The red imported fire ant is polymorphic, as workers appear in different shapes and sizes. The ant's colours are red and somewhat yellowish with a brown or black gaster, but males are completely black. Red imported fire ants are dominant in altered areas and live in a wide variety of habitats. They can be found in rainforests, disturbed areas, deserts, grasslands, alongside roads and buildings, and in electrical equipment. Colonies form large mounds constructed from soil with no visible entrances because foraging tunnels are built and workers emerge far away from the nest.
The southern fire ant, also known as the Californian fire ant or cotton ant, is a stinging fire ant native to southern parts of the United States. Its behaviour is similar to the red imported fire ant (S. invicta), although its sting is less painful. It has a broad and opportunistic diet, and will store seeds in its nest and eat honeydew collected from other insects.
The jack jumper ant, also known as the jack jumper, jumping jack, hopper ant, or jumper ant, is a species of venomous ant native to Australia. Most frequently found in Tasmania and southeast mainland Australia, it is a member of the genus Myrmecia, subfamily Myrmeciinae, and was formally described and named by British entomologist Frederick Smith in 1858. This species is known for its ability to jump long distances. These ants are large; workers and males are about the same size: 12 to 14 mm for workers, and 11 to 12 mm for males. The queen measures roughly 14 to 16 mm long and is similar in appearance to workers, whereas males are identifiable by their perceptibly smaller mandibles.
Solenopsis daguerrei is a species of parasitic ants native to Argentina and Uruguay . The young queens of the species invade the nests of other species, such as the red imported fire ant (RIFA). This is made possible by the fact that the S. daguerrei queen produces pheromones which are very similar to those produced by the queens of the host species. The young queen finds a queen of the host species and latches onto it, eating the food intended for the host queen and slowly killing it. The S. daguerrei queen then begins laying eggs. These are taken care of by the host ants, sometimes preferentially to their own brood. S. daguerrei only produce winged virgin queens and males. No workers are needed, since these are provided by the host species. The winged ants fly off to mate and invade new colonies.
Insect sting allergy is the term commonly given to the allergic response of an animal in response to the bite or sting of an insect. Typically, insects which generate allergic responses are either stinging insects or biting insects. Stinging insects inject venom into their victims, whilst biting insects normally introduce anti-coagulants into their victims.
Myrmecia forficata, commonly known as the inchman ant, is a species of bull ant that is native to Australia. The ants are recorded in the south eastern part of the country, but are most common in the Australian Alps at elevations above 300m but can be found down to sea level around Melbourne and in Tasmania.
Solenopsin is a lipophilic alkaloid with the molecular formula C17H35N found in the venom of fire ants (Solenopsis). It is considered the primary toxin in the venom and may be the component responsible for the cardiorespiratory failure in people who experience excessive fire ant stings.
Solenopsis geminata or tropical fire ant is a species of fire ants, described by Fabricius in 1804, in the tribe Solenopsidini; it was originally placed in the Atta genus. This species has a pan-tropical distribution.
Ant venom is any of, or a mixture of, irritants and toxins inflicted by ants. Most ants spray or inject a venom, the main constituent of which is formic acid only in the case of subfamily Formicinae.
The Brackenridge Field Laboratory (BFL) is an urban research station owned by the University of Texas at Austin. Established officially in 1967, it contains 82 acres of land and research infrastructure. It is dedicated to studies in biology. The extensive historical data kept about its diverse habitats has been important to the study of biodiversity, ecological succession and ecology. Some of the key studies into the red imported fire ant and potential biocontrol agents such as phorid flies have originated at the field station. It also contains the second largest insect collection in Texas. Since 1973 the Brackenridge Field Laboratory has been a subject of controversy due to the high value of the land.
Solenopsis saevissima, commonly known in Brazil as formiga de fogo, formiga-vermelha, or formiga-lava-pes, is one of more than 185 species in the genus Solenopsis. It, along with 13 other species, is also a member of the Solenopsis saevissima species group which are popularly known as fire ants.
The red imported fire ant, or simply RIFA, is one of over 280 species in the widespread genus Solenopsis. It is native to South America but it has become both a pest and a health hazard in the southern United States as well as a number of other countries.
Kneallhazia solenopsae is a unique pathogenic intracellular microsporidium, that infects two of the fire ant species: the red Solenopsis invicta and the black Solenopsis richteri in North and South America.
The red imported fire ant is an invasive species in Australia originating from South America but imported to Australia, New Zealand, the United States of America and several Asian and Caribbean countries. Fire ants are listed by the International Union for Conservation of Nature (IUCN) as one of the world's most invasive species.
The toxicology of fire ant venom is relatively well studied. The venom plays a central role in the biology of Red imported fire ants, such as in capturing prey, and in defending itself from competitors, assailants, and diseases. Some 14 million people are stung annually in the United States, suffering reactions that vary from mild discomfort, to pustule formation, swelling, and in rare cases, systemic reactions followed by anaphylactic shock. Fire ant venoms are mainly composed (>95%) of a complex mixture of insoluble alkaloids added to a watery solution of toxic proteins. For the Red imported fire ant Solenopsis invicta Buren there are currently 46 described proteins, of which four are well-characterised as potent allergens.
Pseudacteon tricuspis is a parasitic phorid fly that decapitates its host, the imported Solenopsis invicta fire ant. There are over 70 described species within the Pseudacteon genus, which parasitize a variety of ant species. However, P. tricuspis is very specific to its host ant and will not attack other native ant species, making it a good biological control against the fire ant. P. tricuspis was also introduced into the United States for this purpose. Aside from the United States, P. tricuspis has also been found in South America, Europe, and Asia. Female P. tricuspis deposit their eggs directly into the fire ant host. Deposition into the ant host determines the sex of the egg, which grows within the host until adulthood, killing and decapitating the host in the process. Interestingly, P. tricuspis has a male-biased sex ratio, where the males are smaller than the females.
An ant supercolony is an exceptionally large ant colony, consisting of a high number of spatially separated but socially connected nests of a single ant species, spread over a large area without territorial borders. Supercolonies are typically polygynous, containing many egg-laying females. Workers and queens from different nests within the same supercolony can freely move among the nests, and all workers cooperate indiscriminately with each other in collecting food and care of the brood, and show no apparent mutual aggressive behavior.
