Most ants are capable of biting, stinging, and spraying irritant chemicals. [1] 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. [2]
The fire ants are a group of 20 species of New World ants which are reputed after their aggressiveness and painful stings. Four species are considered of relevant medical importance: Solenopsis invicta , Solenopsis richteri , Solenopsis geminata , and Solenopsis saevissima . The Red Imported Fire Ant S. invicta is the best studied among them, and reputed as the most dangerous species. S. invicta is expanding in range around the world and thus it is most often involved in medical emergencies. A person typically encounters problems with fire ants by inadvertently stepping onto one of their mounds, which causes the ants to swarm up the person's legs, attacking en masse. The ants quickly respond to alarm pheromones that are released by the first disturbed ants, causing a swarm followed by aggressive stinging. Fire ant stings are typically accompanied by burning and urticaria, followed by a welt formation. The welts often develop into white pustules that should not be scratched, as to avoid secondary infections. A few individuals are sensitive to the venom, and can, on rare occasions, die of anaphylaxis. [3] In a survey of 29,300 physicians in the United States of America (in 1989), reports of 83 fatalities were obtained. [4] Some fire ant attacks on humans confined to beds have also been noted; in some locations, fire ants can be a particular threat in medical facilities since they can have nesting colonies inside human habitations. [5]
It has been demonstrated that, whilst the burning sensation and pustule formation is an effect of the sting injecting insoluble venom alkaloids, the more serious allergic reactions are caused by venom protein allergens. [6]
Apart from Solenopsis invicta and Solenopsis richteri , serious allergic reactions are known from ants belonging to 6 different subfamilies (Formicinae, Myrmeciinae, Ponerinae, Ectatomminae, Myrmicinae, and Pseudomyrmecinae) and 10 genera ( Solenopsis , Formica , Myrmecia , Tetramorium , Pogonomyrmex , Pachycondyla , Odontomachus , Rhytidoponera , Pseudomyrmex , and Hypoponera ). [7]
The Argentine ant, Linepithema humile is found in Argentina, Southern Europe, Southern US and California. They are small and are found in human habitations. They often kill other ant species. [8] They have been noted as having the potential to carry pathogens in hospital environments. [9]
The pharaoh ant, Monomorium pharaonis is found around the world. It is not known for its sting, but has been involved in respiratory allergies [10]
Bulldog ants, from the genus Myrmecia, are native to Australia, with all but one of the ninety or so species found on the continent. Belonging to the ant subfamily Myrmeciinae, they are among the most primitive extant ants in the world. This species is known to cause some fatalities in sensitive humans. [11]
Bullet ants, from the genus Paraponera, are found from Nicaragua southward to the Amazon Basin. They are and close relatives of the genus Dinoponera , which are New World ponerines known for their painful stings. [12]
Driver ants, from the genus Dorylus , are found in the Old World, especially West Africa and the Congo Basin. Unlike the army ants of the New World, Old World army ants have a functional sting but rarely use it, preferring their razor-sharp, falcate mandibles for defense instead. Dorylus spp. colonies also reach larger sizes than Eciton .
The Pogonomyrmex maricopa , found in Western US, are bright red myrmicine ants whose venom is the most potent of any ant species. [13]
Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, sneezing, coughing, a runny nose, shortness of breath, or swelling. Note that food intolerances and food poisoning are separate conditions.
Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of the use of emergency medication on site. It typically causes more than one of the following: an itchy rash, throat closing due to swelling that can obstruct or stop breathing; severe tongue swelling that can also interfere with or stop breathing; shortness of breath, vomiting, lightheadedness, loss of consciousness, low blood pressure, and medical shock. These symptoms typically start in minutes to hours and then increase very rapidly to life-threatening levels. Urgent medical treatment is required to prevent serious harm and death, even if the patient has used an epipen or has taken other medications in response, and even if symptoms appear to be improving.
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 black imported fire ant, or simply BIFA, is a species of ant in the genus Solenopsis. It was long thought to either be a subspecies or a color variation of Solenopsis invicta, but is now recognized as its own species with a demonstratively different range and living habits. BIFA seem to be more tolerant of cold and a less dominant species than RIFA. Due to the BIFA higher body content of water than the RIFA conclusions demonstrate the certain factor plays a role in their differences of living regions.
Myrmecia is a genus of ants first established by Danish zoologist Johan Christian Fabricius in 1804. The genus is a member of the subfamily Myrmeciinae of the family Formicidae. Myrmecia is a large genus of ants, comprising at least 93 species that are found throughout Australia and its coastal islands, while a single species is only known from New Caledonia. One species has been introduced out of its natural distribution and was found in New Zealand in 1940, but the ant was last seen in 1981. These ants are commonly known as bull ants, bulldog ants or jack jumper ants, and are also associated with many other common names. They are characterized by their extreme aggressiveness, ferocity, and painful stings. Some species are known for the jumping behavior they exhibit when agitated.
Dicistroviridae is a family of viruses in the order Picornavirales. Invertebrates, including aphids, leafhoppers, flies, bees, ants, and silkworms, serve as natural hosts. There are 15 species in this family, assigned to three genera. Diseases associated with this family include: DCV: increased reproductive potential. extremely pathogenic when injected with high associated mortality. CrPV: paralysis and death.
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.
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.
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.
Monomorium is a genus of ants in the subfamily Myrmicinae. As of 2013 it contains about 396 species. It is distributed around the world, with many species native to the Old World tropics. It is considered to be "one of the more important groups of ants," considering its widespread distribution, its diversity, and its variety of morphological and biological characteristics. It also includes several familiar pest species, such as the pharaoh ant and the flower ant.
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.
Pogonomyrmex maricopa, the Maricopa harvester ant, is one of the most common species of harvester ant found in the U.S. state of Arizona, but it is also known from California, Colorado, New Mexico, Nevada, Texas and Utah, and the Mexican states of Baja California, Chihuahua, Sinaloa and Sonora. Its venom is believed to be the most toxic insect venom in the world.
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.
Many species of arthropods can bite or sting human beings. These bites and stings generally occur as a defense mechanism or during normal arthropod feeding. While most cases cause self-limited irritation, medically relevant complications include envenomation, allergic reactions, and transmission of vector-borne diseases.
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.
Pogonomyrmex badius, or the Florida harvester ant, is a species of harvester ant in the genus Pogonomyrmex. It is the only Pogonomyrmex species found on the east coast of the United States and the only one in North America known to be polymorphic. The Florida Harvester ant is commonly found in Florida scrub and other similar habitats within the Atlantic coastal plain.
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.
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.