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163-420: 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

326-412: A Proto-Indo-European word *morwi- was the root for Sanskrit vamrah , Greek μύρμηξ mýrmēx , Old Church Slavonic mraviji , Old Irish moirb , Old Norse maurr , Dutch mier , Swedish myra , Danish myre , Middle Dutch miere , and Crimean Gothic miera . The family Formicidae belongs to the order Hymenoptera , which also includes sawflies , bees , and wasps . Ants evolved from

489-488: A cosmopolitan distribution . They are found on all continents except Antarctica , and only a few large islands, such as Greenland , Iceland , parts of Polynesia and the Hawaiian Islands lack native ant species. Ants occupy a wide range of ecological niches and exploit many different food resources as direct or indirect herbivores, predators and scavengers. Most ant species are omnivorous generalists , but

652-560: A monophyletic clade . Some of the examined haplotypes form a closer relationship to S. megergates , S. quinquecuspis and S. richteri than they do with other S. invicta haplotypes. The occurrence of a possible paraphyletic grouping suggests that the red imported fire ant and S. quinquecuspis are possible cryptic species groups composed of several species that cannot be distinguished morphologically. Studies show that mitochondrial DNA variation occurs substantially in polygyne societies (nests with multiple queens), but no variation

815-422: A " disturbance specialist"; human disturbance to the environment may be a major factor behind the ants' impact (fire ants tend to favour disturbed areas). This is shown through one experiment, demonstrating that mowing and plowing in studied areas diminished the diversity and abundance of native ant species, whereas red imported fire ants found on undisturbed forest plots had only diminished a couple of species. In

978-442: A 2001 review. Under the present classification, the red imported fire ant is a member of the genus Solenopsis in the tribe Solenopsidini , subfamily Myrmicinae . It is a member of the family Formicidae , belonging to the order Hymenoptera , an order of insects containing ants, bees , and wasps . The red imported fire ant is a member of the S. saevissima species-group. Members can be distinguished by their two-jointed clubs at

1141-436: 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

1304-422: A burning sensation of the skin rather than itchiness. Swelling of the tongue or throat occurs in up to about 20% of cases. Other features may include a runny nose and swelling of the conjunctiva . The skin may also be blue tinged because of lack of oxygen . Respiratory symptoms and signs that may be present include shortness of breath , wheezes , or stridor . The wheezing is typically caused by spasms of

1467-415: A cause for anaphylaxis, and HPV may cause anaphylaxis as well. Many foods can trigger anaphylaxis; this may occur upon the first known ingestion. Common triggering foods vary around the world due to cultural cuisine. In Western cultures, ingestion of or exposure to peanuts , wheat , nuts , certain types of seafood like shellfish , milk , fruit and eggs are the most prevalent causes. Sesame

1630-419: A class of food preservatives and a byproduct in some fermented foods like vinegar; allergies to medications – including some antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) like aspirin; allergy to general anaesthetic (used to make people sleep during surgery); allergy to contrast agents – dyes used in some medical tests to help certain areas of the body show up better on scans; allergy to latex –

1793-400: A conservative estimate of the ants at about 20 × 10 (20 quadrillion). Ants range in size from 0.75 to 52 millimetres (0.030–2.0 in), the largest species being the fossil Titanomyrma giganteum , the queen of which was 6 cm ( 2 + 1 ⁄ 2  in) long with a wingspan of 15 cm (6 in). Ants vary in colour; most ants are yellow to red or brown to black, but

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1956-690: A difference in the current episode of anaphylaxis, but may be used in the hope of decreasing the risk of biphasic anaphylaxis. Their prophylactic effectiveness in these situations is uncertain. Nebulized salbutamol may be effective for bronchospasm that does not resolve with epinephrine. Methylene blue has been used in those not responsive to other measures due to its presumed effect of relaxing smooth muscle. People prone to anaphylaxis are advised to have an allergy action plan. Parents are advised to inform schools of their children's allergies and what to do in case of an anaphylactic emergency. The action plan usually includes use of epinephrine autoinjectors ,

2119-515: A different one or different group of NSAIDs. Other relatively common causes include chemotherapy , vaccines , protamine and herbal preparations. Some medications ( vancomycin , morphine , x-ray contrast among others) cause anaphylaxis by directly triggering mast cell degranulation . The frequency of a reaction to an agent partly depends on the frequency of its use and partly on its intrinsic properties. Anaphylaxis to penicillin or cephalosporins occurs only after it binds to proteins inside

2282-499: A few are specialist feeders. There is considerable variation in ant abundance across habitats, peaking in the moist tropics to nearly six times that found in less suitable habitats. Their ecological dominance has been examined primarily using estimates of their biomass : myrmecologist E. O. Wilson had estimated in 2009 that at any one time the total number of ants was between one and ten quadrillion ( short scale ) (i.e., between 10 and 10 ) and using this estimate he had suggested that

2445-406: A few species are green and some tropical species have a metallic lustre . More than 13,800 species are currently known (with upper estimates of the potential existence of about 22,000; see the article List of ant genera ), with the greatest diversity in the tropics. Taxonomic studies continue to resolve the classification and systematics of ants. Online databases of ant species, including AntWeb and

2608-409: A high resolution image. They also have three small ocelli (simple eyes) on the top of the head that detect light levels and polarization . Compared to vertebrates , ants tend to have blurrier eyesight, particularly in smaller species, and a few subterranean taxa are completely blind . However, some ants, such as Australia's bulldog ant , have excellent vision and are capable of discriminating

2771-401: A higher metabolic O 2 demand. While the metabolic rate is highest at 32 °C, colonies often thrive at slightly cooler temperatures (around 25 °C). The high rate of metabolic activity associated with warmer temperatures is a limiting factor on colony growth because the need for food consumption is also increased. As a result, larger colonies tend to be found in cooler conditions because

2934-538: A history of previous atopic diseases, and of children who die from anaphylaxis, more than 90% have asthma. Those with mastocytosis or of a higher socioeconomic status are at increased risk. Anaphylaxis is a severe allergic reaction of rapid onset affecting many body systems . It is due to the release of inflammatory mediators and cytokines from mast cells and basophils , typically due to an immunologic reaction but sometimes non-immunologic mechanism. Interleukin (IL)–4 and IL-13 are cytokines important in

3097-519: A lineage within the stinging wasps , and a 2013 study suggests that they are a sister group of the Apoidea . However, since Apoidea is a superfamily, ants must be upgraded to the same rank. A more detailed basic taxonomy was proposed in 2020. Three species of the extinct mid- Cretaceous genera Camelomecia and Camelosphecia were placed outside of the Formicidae, in a separate clade within

3260-446: A node-like petiole . The head, mesosoma , and metasoma are the three distinct body segments (formally tagmata ). The petiole forms a narrow waist between their mesosoma ( thorax plus the first abdominal segment, which is fused to it) and gaster (abdomen less the abdominal segments in the petiole). The petiole may be formed by one or two nodes (the second alone, or the second and third abdominal segments). Tergosternal fusion, when

3423-428: A normal blood pressure , and they are not specific for the diagnosis. There are three main classifications of anaphylaxis. Allergy testing may help in determining the trigger. Skin allergy testing is available for certain foods and venoms. Blood testing for specific IgE can be useful to confirm milk, egg, peanut, tree nut and fish allergies. Skin testing is available to confirm penicillin allergies, but

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3586-428: A pipe". It is a compound of two Ancient Greek words, solen , meaning "pipe" or "channel", and opsis , meaning "appearance" or "sight". The ant is commonly known as the "red imported fire ant" (abbreviated as RIFA); the " fire ant " part is because of the burning sensation caused by its sting. Alternative names include "fire ant", "red ant" or "tramp ant". In Brazil, locals call the ant toicinhera , which derives from

3749-403: A protective casing around the body and a point of attachment for muscles, in contrast to the internal skeletons of humans and other vertebrates . Insects do not have lungs ; oxygen and other gases, such as carbon dioxide , pass through their exoskeleton via tiny valves called spiracles . Insects also lack closed blood vessels ; instead, they have a long, thin, perforated tube along the top of

3912-639: A rash, and a panic attack may have flushing but does not have hives. Other conditions that may present similarly include: scrombroidosis and anisakiasis . In a person who died from anaphylaxis, autopsy may show an "empty heart" attributed to reduced venous return from vasodilation and redistribution of intravascular volume from the central to the peripheral compartment. Other signs are laryngeal edema, eosinophilia in lungs, heart and tissues, and evidence of myocardial hypoperfusion. Laboratory findings could detect increased levels of serum tryptase , increase in total and specific IgE serum levels. Avoidance of

4075-479: A result is nomen nudum . In 1995, English myrmecologist Barry Bolton corrected Trager's error, recognising S. wagneri as the valid name and synonymised S. invicta . He states that Trager wrongfully classified S. wagneri as an unavailable name and cites S. saevissima electra wagneri as the original taxon. He concludes that S. wagneri is, in fact, the original name and has priority over S. invicta . In 1999, Steve Shattuck and colleagues proposed conserving

4238-527: A scientific expedition around the French coast of the Atlantic Ocean, specifically to study on the toxin produced by cnidarians (like jellyfish and sea anemones ). Richet and Portier boarded Albert's ship Princesse Alice II for ocean exploration to make collections of the marine animals. Richet and Portier extracted a toxin called hypnotoxin from their collection of jellyfish (but the real source

4401-417: A series of different colours. For example, workers may be much darker, and the gastric spot may be completely absent or appear dark-brown. Queens have a head length of 1.27 to 1.29 mm (0.050 to 0.051 in) and a width of 1.32 to 1.33 mm (0.052 to 0.052 in). The scapes measure 0.95 to 0.98 mm (0.037 to 0.039 in) and the thorax is 2.60 to 2.63 mm (0.102 to 0.104 in). The head

4564-400: A series of tunnels that protrude from the central region. Such protrusions can span up to 25 feet away from the central mound, either straight down in to the ground or, more commonly, sideways from the original mound. Constructed from soil, mounds are oriented so that the long portions of the mound face toward the sun during the early morning and before sunset. Mounds are usually oval-shaped with

4727-431: A single colony. This does not affect colony performance, as polymorphic colonies and nests with small workers produce broods at roughly the same rate, and polymorphism is not an advantage or disadvantage when food sources are not limited. However, polymorphic colonies are more energetically efficient, and under conditions where food is limited, polymorphism may provide a small advantage in brood production, but this depends on

4890-430: A single gene of Solenopsis invicta can decide whether the colony will have single or multiple queens. The Australian jack jumper ant ( Myrmecia pilosula ) has only a single pair of chromosomes (with the males having just one chromosome as they are haploid ), the lowest number known for any animal, making it an interesting subject for studies in the genetics and developmental biology of social insects. Genome size

5053-438: A small portion of the first gastric tergite . The thorax is concolorous, ranging from light reddish-brown to dark-brown. The legs and coxae are usually lightly shaded. The head has a consistent colour pattern in large workers, with the occiput and vertex appearing brown. Other parts of the head, including the front, genae, and the central region of the clypeus , are either yellowish or yellowish brown. The anterior borders of

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5216-444: A strong shagreen with distinct transverse punctostriae. The sides are covered in deep punctures, where they appear smaller but deeper. In S. richteri , the punctures are larger and more shallow. This gives a more opaque appearance to the surface. In some cases, punctostriae may be present around the rear portion. The pilosity appears similar to that of S. richteri . These hairs are erect and vary in length, appearing long on each side of

5379-412: A thick and blunt scale; if observed from behind, it is not as rounded above in contrast to S. richteri , and sometimes it may be subtruncate. The postpetiole is large and broad, and in the larger workers, it is broader than its length. The postpetiole tends to be less broad in front and broader behind. On the rear side of the dorsal surface, a transverse impression is present. In S. richteri , this feature

5542-457: A type of rubber found in some rubber gloves and condoms. Other causes can include physical exercise, and cases may also occur in some people due to escalating reactions to simple throat irritation or may also occur without an obvious reason. The mechanism involves the release of inflammatory mediators in a rapidly escalating cascade from certain types of white blood cells triggered by either immunologic or non-immunologic mechanisms. Diagnosis

5705-1104: A variety of habitats. It can survive the extreme weather of the South American rain forest, and in disturbed areas, nests are seen frequently alongside roads and buildings. The ant has been observed frequently around the floodplains of the Paraguay River. In areas where water is present, they are commonly found around: irrigation channels, lakes, ponds, reservoirs, rivers, streams, riverbanks, and mangrove swamps. Nests are found in agricultural areas, coastlands, wetlands, coastal dune remnants, deserts, forests, grasslands, natural forests, oak woodland, mesic forest , leaf-litter, beach margins , shrublands, alongside rail and roads, and in urban areas. In particular, they are found in cultivated land, managed forests and plantations, disturbed areas, intensive livestock production systems, and greenhouses. Red imported fire ants have been found to invade buildings, including medical facilities. In urban areas, colonies dwell in open areas, especially if

5868-528: A very narrow east–west distribution. The northernmost record of the red imported fire ant is Porto Velho in Brazil, and its southernmost record is Resistencia in Argentina; this is a distance of about 3,000 km (1,900 mi). In comparison, the width of its narrow range is about 350 km (220 mi), and this is most likely narrower into southern Argentina and Paraguay and into the northern areas of

6031-467: A wide variety of crops, and mounds built on farmland may prevent harvesting. They also pose a threat to animals and livestock, capable of inflicting serious injury or killing them, especially young, weak, or sick animals. Despite this, they may be beneficial because they consume common pest insects on crops. Common methods of controlling these ants include baiting and fumigation; other methods may be ineffective or dangerous. Due to its notoriety and importance,

6194-498: Is paraphyletic In 1966, E. O. Wilson and his colleagues identified the fossil remains of an ant ( Sphecomyrma ) that lived in the Cretaceous period. The specimen, trapped in amber dating back to around 92 million years ago, has features found in some wasps, but not found in modern ants. The oldest fossils of ants date to the mid-Cretaceous, around 100 million years ago, which belong to extinct stem-groups such as

6357-431: Is 4–100 per 100,000 persons per year, with a lifetime risk of 0.05–2%. About 30% of affected people get more than one attack. Exercise-induced anaphylaxis affects about 1 in 2000 young people. Rates appear to be increasing: the numbers in the 1980s were approximately 20 per 100,000 per year, while in the 1990s it was 50 per 100,000 per year. The increase appears to be primarily for food-induced anaphylaxis. The risk

6520-589: Is a fundamental characteristic of an organism. Ants have been found to have tiny genomes, with the evolution of genome size suggested to occur through loss and accumulation of non-coding regions, mainly transposable elements , and occasionally by whole genome duplication. This may be related to colonisation processes, but further studies are needed to verify this. Anaphylaxis Common causes include allergies to insect bites and stings, allergies to foods – including nuts, milk, fish, shellfish, eggs and some fresh fruits or dried fruits; allergies to sulfites –

6683-537: Is a host to parasites and to a number of pathogens , nematodes , and viruses , which have been viewed as potential biological control agents. Nuptial flight occurs during the warm seasons, and the alates may mate for as long as 30 minutes. Colony founding can be done by a single queen or a group of queens, which later contest for dominance once the first workers emerge. Workers can live for several months, while queens can live for years; colony numbers can vary from 100,000 to 250,000 individuals. Two forms of society in

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6846-414: Is almost indistinguishable from S. richteri , but the occipital excision is less crease-like and the scapes are considerably shorter. Its petiolar scale is convex and resembles that of S. richteri . The postpetiole has straight sides that never concave, unlike in S. richteri where they concave. The thorax is almost identical, but the clear space between the metapleural striate area and propodeal spiracles

7009-549: Is also influenced by environmental temperature. Peak metabolism occurs at about 32 °C. Metabolism, and therefore respiration rate, increases consistently as temperature increases. DGE stops above 25 °C, although the reason for this is currently unknown. Respiration rate also appears to be influenced significantly by caste. Males show a considerably higher rate of respiration than females and workers, due, in part, to their capability for flight and higher muscle mass. In general, males have more muscle and less fat, resulting in

7172-484: Is also possible for many medications, however it is advised that most people simply avoid the agent in question. In those who react to latex it may be important to avoid cross-reactive foods such as avocados, bananas, and potatoes among others. Anaphylaxis is a medical emergency that may require resuscitation measures such as airway management , supplemental oxygen , large volumes of intravenous fluids , and close monitoring. Passive leg raise may also be helpful in

7335-408: Is also present but much weaker. The sculpture is very similar to S. richteri . The punctures are from where pilosity arises, and these are often elongated on the dorsal and ventral portions of the head. On the thorax, striae are present, but they are less engraved with fewer punctures than in S. richteri . On the petiole, the punctates are located on the sides. The postpetiole, when viewed above, has

7498-429: Is also seen on the propodeum. The colour of the queen is similar to that of a worker: the gaster is dark brown and the legs, scapes, and thorax are light brown with dark streaks on the mesoscutum . The head is yellowish or yellowish-brown around the central regions, the occiput and mandibles are a similar colour to the thorax, and the wing veins range from colourless to pale brown. Males appear similar to S. richteri , but

7661-577: Is available, the prognosis is good. Even if the cause is unknown, if appropriate preventive medication is available, the prognosis is generally good. Usually death occurs due to either respiratory failure (typically involving asphyxia ) or cardiovascular complications, such as cardiovascular shock , with 0.7–20% of cases causing death. There have been cases of death occurring within minutes. Outcomes in those with exercise-induced anaphylaxis are typically good, with fewer and less severe episodes as people get older. The number of people who get anaphylaxis

7824-586: Is based on the presenting symptoms and signs after exposure to a potential allergen or irritant and in some cases, reaction to physical exercise. The primary treatment of anaphylaxis is epinephrine injection into a muscle , intravenous fluids , then placing the person "in a reclining position with feet elevated to help restore normal blood flow". Additional doses of epinephrine may be required. Other measures, such as antihistamines and steroids , are complementary. Carrying an epinephrine autoinjector , commonly called an "epipen", and identification regarding

7987-1014: Is common in the Middle East, while rice and chickpeas are frequently encountered as sources of anaphylaxis in Asia. Severe cases are usually caused by ingesting the allergen, but some people experience a severe reaction upon contact. Children can outgrow their allergies. By age 16, 80% of children with anaphylaxis to milk or eggs and 20% who experience isolated anaphylaxis to peanuts can tolerate these foods. Any type of alcohol, even in small amounts, can trigger anaphylaxis in people with AERD. Any medication may potentially trigger anaphylaxis. The most common are β-lactam antibiotics (such as penicillin ) followed by aspirin and NSAIDs . Other antibiotics are implicated less frequently. Anaphylactic reactions to NSAIDs are either agent specific or occur among those that are structurally similar meaning that those who are allergic to one NSAID can typically tolerate

8150-401: Is defined as a greater than 30% decrease from a person's usual blood pressure. In adults a systolic blood pressure of less than 90 mmHg is often used. During an attack, blood tests for tryptase or histamine (released from mast cells) might be useful in diagnosing anaphylaxis due to insect stings or medications. However these tests are of limited use if the cause is food or if the person has

8313-583: Is detected in monogyne societies (nests with a single queen). Triploidy (a chromosomal abnormality) occurs in red imported fire ants at high rates (as high as 12% in non-reproductive females), which is linked to the high frequency of diploid males. The red imported fire ant is the first species shown to possess a green-beard gene , by which natural selection can favour altruistic behaviour . Workers containing this gene are able to distinguish between queens containing it, and those that do not, apparently by using odour cues. The workers kill queens that do not contain

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8476-405: Is diagnosed on the basis of a person's signs and symptoms. When any one of the following three occurs within minutes or hours of exposure to an allergen there is a high likelihood of anaphylaxis: Skin involvement may include: hives, itchiness or a swollen tongue among others. Respiratory difficulties may include: shortness of breath, stridor , or low oxygen levels among others. Low blood pressure

8639-421: Is either a narrow crease or not present. The side portions of the petiole are punctate. The sides of the postpetiole are opaque with punctures present, but no irregular roughening is seen. The anterior of the dorsum is shagreen , and the middle and rear regions bear transverse puncto-striae. All these regions have erect hairs. The anterior portions of both the petiole and postpetiole have appressed pubescence that

8802-744: Is greatest in young people and females. Anaphylaxis leads to as many as 500–1,000 deaths per year (2.7 per million) in the United States, 20 deaths per year in the United Kingdom (0.33 per million), and 15 deaths per year in Australia (0.64 per million). Another estimate from the United States puts the death rate at 0.7 per million. Mortality rates have decreased between the 1970s and 2000s. In Australia, death from food-induced anaphylaxis occur primarily in women while deaths due to insect bites primarily occur in males. Death from anaphylaxis

8965-444: Is intravenous and up to 2 hours if from eating food. The most common areas affected include: skin (80–90%), respiratory (70%), gastrointestinal (30–45%), heart and vasculature (10–45%), and central nervous system (10–15%) with usually two or more being involved. Symptoms typically include generalized hives , itchiness , flushing , or swelling ( angioedema ) of the affected tissues . Those with angioedema may describe

9128-458: Is longer. Overall, the morphological appearance of a worker changes dramatically when it grows larger. The head exhibits the greatest shape change and the height of the alinotum grows quicker than its length, where a height/length ratio of 0.27 in minor workers and 0.32 in major workers is seen. Due to this, larger workers tend to have a humped-shape and robust alinotum in contrast to smaller workers. No petiole segment exhibits any change in shape as

9291-419: Is most commonly triggered by medications. The conditions of anaphylaxis has been known since ancient times. French physician François Magendie had described how rabbits were killed by repeated injections of egg albumin in 1839. However, the phenomenon was discovered by two French physiologists Charles Richet and Paul Portier . In 1901, Albert I, Prince of Monaco requested Richet and Portier join him on

9454-409: Is not available for other medications. Non-immune forms of anaphylaxis can only be determined by history or exposure to the allergen in question, and not by skin or blood testing. It can sometimes be difficult to distinguish anaphylaxis from asthma , syncope , and panic attacks . Asthma however typically does not entail itching or gastrointestinal symptoms, syncope presents with pallor rather than

9617-874: Is not effective intravenous glucagon can be administered which has a mechanism of action independent of β-receptors . If necessary, it can also be given intravenously using a dilute epinephrine solution. Intravenous epinephrine, however, has been associated both with dysrhythmia and myocardial infarction . Epinephrine autoinjectors used for self-administration typically come in two doses, one for adults or children who weigh more than 25 kg and one for children who weigh 10 to 25 kg. Antihistamines (both H1 and H2 ), while commonly used and assumed effective based on theoretical reasoning, are poorly supported by evidence. A 2007 Cochrane review did not find any good-quality studies upon which to base recommendations and they are not believed to have an effect on airway edema or spasm. Corticosteroids are unlikely to make

9780-442: Is polymorphic with two different castes of workers: minor workers and major workers (soldiers). Like many ants that exhibit polymorphism, young, smaller ants do not forage and tend to the brood instead, while the larger workers go out and forage. In incipient colonies, polymorphism does not exist, but instead they are occupied by monomorphic workers called "minims" or "nanitics". The average head-width in tested colonies increases during

9943-399: Is recommended that an epinephrine solution be given intramuscularly into the mid anterolateral thigh as soon as the diagnosis is suspected. The injection may be repeated every 5 to 15 minutes if there is insufficient response. A second dose is needed in 16–35% of episodes with more than two doses rarely required. The intramuscular route is preferred over subcutaneous administration because

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10106-416: Is removed. Larvae measure 3 mm (0.12 in). They show a similar appearance to S. geminata larvae, but they can be distinguished by the integument with spinules on top of the dorsal portion of the posterior somites. The body hairs measure 0.063 to 0.113 mm (0.0025 to 0.0044 in) with a denticulate tip. The antennae both have two or three sensilla . The labrum is smaller with two hairs on

10269-399: Is strong, but weak or absent in the red imported fire ant. As well as that, S. richteri workers are 15% larger than red imported fire ant workers, are blackish-brown, and have a yellow stripe on the dorsal side of the gaster. Eggs are tiny and oval-shaped, remaining the same size for around a week. After one week, the egg assumes the shape of an embryo and forms as a larva when the egg shell

10432-409: Is weakly convex in S. richteri . Upon examination, the base of the propodeum is elongated and straight in S. richteri , while convex and shorter in the red imported fire ant. It also has a wide postpetiole with either straight or diverging sides. The postpetiole in S. richteri is narrower with converging sides. In S. richteri , the transverse impression on the posterodorsal portion of the postpetiole

10595-463: Is well developed in the queen, while the other glands are larger in workers. The postpharyngeal gland functions as a vacuum to absorb fatty acids and triglycerides , as well as a gastric caecum . The functions of the other glands remain poorly understood. In one study discussing the enzymes of the digestion system of adult ants, lipase activity was found in the mandibular and labial glands, as well as invertase activity. The Dufour's gland found in

10758-700: The Haidomyrmecinae , Sphecomyrminae and Zigrasimeciinae , with modern ant subfamilies appearing towards the end of the Cretaceous around 80–70 million years ago. Ants diversified extensively during the Angiosperm Terrestrial Revolution and assumed ecological dominance around 60 million years ago. Some groups, such as the Leptanillinae and Martialinae , are suggested to have diversified from early primitive ants that were likely to have been predators underneath

10921-810: The Paleogene period . By the Oligocene and Miocene , ants had come to represent 20–40% of all insects found in major fossil deposits. Of the species that lived in the Eocene epoch, around one in 10 genera survive to the present. Genera surviving today comprise 56% of the genera in Baltic amber fossils (early Oligocene), and 92% of the genera in Dominican amber fossils (apparently early Miocene). Termites live in colonies and are sometimes called "white ants", but termites are only distantly related to ants. They are

11084-481: The S. saevissima species complex was examined and, together with nine other species-group names, S. saevissima electra wagneri was synonymised with S. saevissima saevissima . This reclassification was accepted by Australian entomologist George Ettershank in his revision of the genus and in Walter Kempf's 1972 catalogue of Neotropical ants. In 1972, American entomologist William Buren described what he thought

11247-457: The bronchial muscles while stridor is related to upper airway obstruction secondary to swelling. Hoarseness, pain with swallowing, or a cough may also occur. While a fast heart rate caused by low blood pressure is more common, a Bezold–Jarisch reflex has been described in 10% of people, where a slow heart rate is associated with low blood pressure . A drop in blood pressure or shock (either distributive or cardiogenic ) may cause

11410-438: The haplodiploid sex-determination system in ants, workers of a number of species can lay unfertilised eggs that become fully fertile, haploid males. The role of workers may change with their age and in some species, such as honeypot ants , young workers are fed until their gasters are distended, and act as living food storage vessels. These food storage workers are called repletes . For instance, these replete workers develop in

11573-485: The mandibles , used to carry food, manipulate objects, construct nests, and for defence. In some species, a small pocket (infrabuccal chamber) inside the mouth stores food, so it may be passed to other ants or their larvae. Both the legs and wings of the ant are attached to the mesosoma ("thorax"). The legs terminate in a hooked claw which allows them to hook on and climb surfaces. Only reproductive ants ( queens and males) have wings. Queens shed their wings after

11736-423: The myofibril and the slow breakdown of the myofilaments . Such dissolution continues until it reaches the only free Z-line materials, which would also disappear; only the nuclei and lamellar bodies remain. In one study, the amino acids increase in the hemolymph after insemination. The glandular system contains four glands: the mandibular, maxillary, labial, and postpharyngeal glands. The postpharyngeal

11899-457: The nuptial flight , leaving visible stubs, a distinguishing feature of queens. In a few species, wingless queens ( ergatoids ) and males occur. The metasoma (the "abdomen") of the ant houses important internal organs, including those of the reproductive, respiratory (tracheae), and excretory systems. Workers of many species have their egg-laying structures modified into stings that are used for subduing prey and defending their nests. In

12062-454: The pronotum and mesonotum ; on the head, the long hairs are seen in longitudinal rows. Numerous appressed pubescent hairs are on the petiolar scale; this is the opposite in S. richteri , as these hairs are sparse. Workers appear red and somewhat yellowish with a brown or completely black gaster . Gastric spots are sometimes seen in larger workers, where they are not as brightly coloured as those in S. richteri . The gastric spot usually covers

12225-605: The red imported fire ant ( Solenopsis invicta ) of South America, are regarded as invasive species in other parts of the world, establishing themselves in areas where they have been introduced accidentally. The word ant and the archaic word emmet are derived from ante , emete of Middle English , which come from ǣmette of Old English ; these are all related to Low Saxon e(e)mt , empe and varieties ( Old Saxon emeta ) and to German Ameise ( Old High German āmeiza ). All of these words come from West Germanic * ǣmaitjōn , and

12388-408: The 1950s. Since its introduction to the United States, the red imported fire ant has spread throughout the southern states and northeastern Mexico, negatively affecting wildlife and causing economic damage. The expansion of red imported fire ants may be limited since they are almost wiped out during Tennessee winters, thus they may be reaching their northernmost range. However, global warming may allow

12551-549: The 2010s, the rate appeared to be increasing. It occurs most often in young people and females. About 99.7% of people hospitalized with anaphylaxis in the United States survive. The word is derived from Ancient Greek : ἀνά , romanized :  ana , lit.   'up', and Ancient Greek : φύλαξις , romanized :  phylaxis , lit.   'protection'. Anaphylaxis typically presents many different symptoms over minutes or hours with an average onset of 5 to 30 minutes if exposure

12714-537: The Amazon River basin. Most known records of the red imported fire ant are around the Pantanal region of Brazil. However, the interior of this area has not been examined thoroughly, but it is certain that the species occurs in favourable locations around it. The Pantanal region is thought to be the original homeland of the red imported fire ant; hydrochore dispersal via floating ant rafts could easily account for

12877-653: The Bahamas, the British Virgin Islands, Antigua, and the Turks and Caicos Islands. Since then, red imported fire ants have been recorded on more islands and regions, with new populations discovered in: Anguilla , Saint Martin , Barbuda , Montserrat , Saint Kitts , Nevis , Aruba , and Jamaica. The ants recorded from Aruba and Jamaica have only been found on golf courses; these courses import sod from Florida , so such importation may be an important way for

13040-509: The Hymenoptera Name Server, help to keep track of the known and newly described species. The relative ease with which ants may be sampled and studied in ecosystems has made them useful as indicator species in biodiversity studies. Ants are distinct in their morphology from other insects in having geniculate (elbowed) antennae , metapleural glands , and a strong constriction of their second abdominal segment into

13203-813: The Murray Darling Basin. Red imported fire ants have spread beyond North America. The Invasive Species Specialist Group (ISSG) reports the ant inhabiting at least three of the Cayman Islands . However, the sources the ISSG cited give no report about them on the island, but recent collections indicate that they are present. In 2001, red imported fire ants were discovered in New Zealand, but they were successfully eradicated several years later. Red imported fire ants have been reported in India, Malaysia,

13366-758: The North American honeypot ant Myrmecocystus mexicanus . Usually the largest workers in the colony develop into repletes; and, if repletes are removed from the colony, other workers become repletes, demonstrating the flexibility of this particular polymorphism . This polymorphism in morphology and behaviour of workers initially was thought to be determined by environmental factors such as nutrition and hormones that led to different developmental paths ; however, genetic differences between worker castes have been noted in Acromyrmex sp. These polymorphisms are caused by relatively small genetic changes; differences in

13529-581: The Philippines and Singapore. However, these reports were found to be incorrect as the ants collected there were incorrectly identified as the red imported fire ant. In Singapore, the ants were most likely misidentified as well. In India, surveyed ants in Sattur Taluk, India listed the red imported fire ant there in high populations; meanwhile, no reports of the ant were made outside the surveyed area. In 2016, scientists state that despite no presence of

13692-467: The Portuguese word toicinho (pork fat). The red imported fire ant was first described by Swiss entomologist Felix Santschi in a 1916 journal article published by Physis . Originally named Solenopsis saevissima wagneri from a syntype worker collected from Santiago del Estero , Argentina, Santschi believed the ant was a variant of S. saevissima ; the specific epithet, wagneri , derives from

13855-571: The Southern U.S. than in its home range. Red imported fire ants were first discovered in Queensland , Australia, in 2001. The ants were believed to be present in shipping containers arriving at the Port of Brisbane , most likely from North America. Anecdotal evidence suggests fire ants may have been present in Australia for six to eight years prior to formal identification. The potential damage from

14018-430: The United States, the red imported fire ant first arrived in the seaport of Mobile, Alabama , by cargo ship between 1933 and 1945. Arriving with an estimated 9 to 20 unrelated queens, the red imported fire ant was only rare at the time, as entomologists were unable to collect any specimens (with the earliest observations first made in 1942, preceded by a population expansion in 1937); the population of these ants exploded by

14181-1056: The ant acts as a source of trail pheromones , although scientists believed the poison gland was the source of the queen pheromone. The neurohormone pheromone biosynthesis activating neuropeptide is found in the ant that activates the biosynthesis of pheromones from the Dufour's gland. The spermatheca gland is found in queens, which functions in sperm maintenance. Males appear to lack these glands, but those associated with its head are morphologically similar to those found in workers, but these glands may act differently. The ant faces many respiratory challenges due to its highly variable environment, which can cause increased desiccation , hypoxia , and hypercapnia . Hot, humid climates cause an increase in heart rate and respiration which increases energy and water loss. Hypoxia and hypercapnia can result from red imported fire ant colonies living in poorly ventilated thermoregulatory mounds and underground nests. Discontinuous gas exchange (DGE) may allow ants to survive

14344-557: The ant has become one of the most studied insects on the planet, even rivalling the western honey bee ( Apis mellifera ). The specific epithet of the red imported fire ant, invicta , derives from Latin , and means "invincible" or "unconquered". The epithet originates from the phrase Roma invicta ("unconquered Rome"), used as an inspirational quote until the fall of the Western Roman Empire in 476 AD . The generic name, Solenopsis , translates as "appearance of

14507-609: The ant in India, the red imported fire ant will more than likely find suitable habitats within India's ecosystem if given the opportunity. The reports in the Philippines most likely misidentified collected material as the red imported fire ant, as no populations have been found there. It was, however, positively identified in Hong Kong and mainland China in 2004, where they have spread into several provinces as well as Macau and Taiwan. No geographic or climatic barriers prevent these ants from spreading further, thus it may spread throughout

14670-456: The ant is less vulnerable to heat and desiccation stress. Although S. richteri has higher water body content than the red imported fire ant, S. richteri was more vulnerable to desiccation stress. The lower sensitivity to desiccation is due to a lower water loss rate. Colonies living in unshaded and warmer sites tend to have a higher heat tolerance than those living in shaded and cooler sites. Metabolic rate, which indirectly affects respiration,

14833-549: The ant to spread throughout the West Indies. Ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees , belong to the order Hymenoptera . Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22,000 species have been classified. They are easily identified by their geniculate (elbowed) antennae and

14996-645: The anterior surface that are 0.013 mm (0.00051 in). The maxilla has a sclerotised band between the cardo and stipes. The labium also has a small sclerotised band. The tubes of the labial glands are known to produce or secrete a proteinaceous substance that has a rich level of digestive enzymes, which includes proteases and amylases that function as an extraintestinal digestion of solid food. The midgut also contains amylases , roteases and upases. The narrow cells in its reservoir have little to no function in secretion. The pupae resemble adults of any caste, except that their legs and antennae are held tightly against

15159-1167: The ants appear to operate as a unified entity, collectively working together to support the colony. Ants have colonised almost every landmass on Earth . The only places lacking indigenous ants are Antarctica and a few remote or inhospitable islands. Ants thrive in moist tropical ecosystems and may exceed the combined biomass of wild birds and mammals. Their success in so many environments has been attributed to their social organisation and their ability to modify habitats, tap resources, and defend themselves. Their long co-evolution with other species has led to mimetic , commensal , parasitic , and mutualistic relationships. Ant societies have division of labour , communication between individuals, and an ability to solve complex problems . These parallels with human societies have long been an inspiration and subject of study. Many human cultures make use of ants in cuisine, medication, and rites. Some species are valued in their role as biological pest control agents. Their ability to exploit resources may bring ants into conflict with humans, however, as they can damage crops and invade buildings. Some species, such as

15322-614: The area is sunny. This includes: urban gardens, picnic areas, lawns, playgrounds, schoolyards, parks, and golf courses. In some areas, there are on average 200 mounds per acre. During winter, colonies move under pavements or into buildings, and newly mated queens move into pastures. Red imported fire ants are mostly found at altitudes between 5 and 145 m (16 and 476 ft) above sea level. Mounds range from small to large, measuring 10 to 60 cm (3.9 to 23.6 in) in height and 46 cm (18 in) in diameter with no visible entrances. Workers are only able to access their nests through

15485-556: The body (called the "dorsal aorta") that functions like a heart, and pumps haemolymph toward the head, thus driving the circulation of the internal fluids. The nervous system consists of a ventral nerve cord that runs the length of the body, with several ganglia and branches along the way reaching into the extremities of the appendages. An ant's head contains many sensory organs . Like most insects, ants have compound eyes made from numerous tiny lenses attached together. Ant eyes are good for acute movement detection, but do not offer

15648-403: The body doubles. All individual legs of the body are isometric with body length meaning that even when the length of the body doubles, the legs will also double. However, not all of the legs are the same length; the prothoracic portion accounts for 29% of leg length, the mesothoracic 31%, and the metathoracic 41%. The first two pairs of legs are of equal length to one another, whereas the final pair

15811-505: The body with some agents binding more easily than others. Anaphylaxis to penicillin occurs once in every 2,000 to 10,000 courses of treatment, with death occurring in fewer than one in every 50,000 courses of treatment. Anaphylaxis to aspirin and NSAIDs occurs in about one in every 50,000 persons. If someone has a reaction to penicillin, his or her risk of a reaction to cephalosporins is greater but still less than one in 1,000. The old radiocontrast agents caused reactions in 1% of cases, while

15974-720: The body. They appear white, but over time, the pupa turns darker when they are almost ready to mature. Four larval instars have been described based on distinctive morphological characters. The larvae of the minor and major workers are impossible to distinguish before the final instar, when size differences become apparent. Upon pupation a wider head width difference between castes become more evident. Reproductive larvae are larger than worker larvae, and present discrete morphological differences in mouthparts. Fourth-instar larvae of males and queens can be differentiated based on their relative shape and body coloration, and also internal gonopodal imaginal discs can differ. The red imported fire ant

16137-515: The colonies of a few ant species, there are physical castes—workers in distinct size-classes, called minor (micrergates), median, and major ergates (macrergates). Often, the larger ants have disproportionately larger heads, and correspondingly stronger mandibles . Although formally known as dinergates, such individuals are sometimes called "soldier" ants because their stronger mandibles make them more effective in fighting, although they still are workers and their "duties" typically do not vary greatly from

16300-463: The condition is recommended in people with a history of anaphylaxis. Immediately contacting ambulance / EMT services is always strongly recommended, regardless of any on-site treatment. Getting to a doctor or hospital as soon as possible is absolutely required in all cases, even if it appears to be getting better. Worldwide, 0.05–2% of the population is estimated to experience anaphylaxis at some point in life. Globally, as underreporting declined into

16463-404: The contents. In the reproductive system , queens release a pheromone that prevents dealation and oogenesis in virgin females; those tested in colonies without a queen begin oocyte development after dealation and take up the egg-laying role. Flight muscle degeneration is initiated by mating and juvenile hormones, and prevented by corpus allatectomy . Histolysis begins with the dissolution of

16626-637: The continued use of S. invicta and not S. wagneri , as this name has been rarely used; between 1995 and 1998, over 100 papers were published using S. invicta and only three using S. wagneri . They requested that the International Commission on Zoological Nomenclature (ICZN) use plenary powers to suppress S. wagneri for the purpose of the Principle of Priority and not for the Principle of Homonymy . Furthermore, they requested that

16789-591: The contraction of bronchial smooth muscles , trigger vasodilation , increase the leakage of fluid from blood vessels, and cause heart muscle depression. There is also a non-immunologic mechanism that does not rely on IgE, but it is not known if this occurs in humans. Non-immunologic mechanisms involve substances that directly cause the degranulation of mast cells and basophils. These include agents such as contrast medium , opioids , temperature (hot or cold), and vibration. Sulfites may cause reactions by both immunologic and non-immunologic mechanisms. Anaphylaxis

16952-472: The country, and have been recorded in Boquerón , Caaguazú , Canindeyú , Central , Guairá , Ñeembucú , Paraguarí , and Presidente Hayes departments; Trager claims that the ant is distributed in all regions of the country. They are also found in a large portion of northeastern Bolivia and, to a lesser extent, in northwestern Uruguay. The red imported fire ant is able to dominate altered areas and live in

17115-532: The distance and size of objects moving nearly a meter away. Based on experiments conducted to test their ability to differentiate between selected wavelengths of light, some ant species such as Camponotus blandus, Solenopsis invicta, and Formica cunicularia are thought to possess a degree of colour vision. Two antennae ("feelers") are attached to the head; these organs detect chemicals, air currents , and vibrations ; they also are used to transmit and receive signals through touch. The head has two strong jaws,

17278-712: The distinctive node-like structure that forms their slender waists. Ants form colonies that range in size from a few dozen individuals often living in small natural cavities to highly organised colonies that may occupy large territories with sizeable nest that consist of millions of individuals or into the hundreds of millions in super colonies . Typical colonies consist of various castes of sterile, wingless females, most of which are workers (ergates), as well as soldiers (dinergates) and other specialised groups. Nearly all ant colonies also have some fertile males called "drones" and one or more fertile females called " queens " ( gynes ). The colonies are described as superorganisms because

17441-457: The emergency management. Administration of intravenous fluid bolus and epinephrine is the treatment of choice with antihistamines used as adjuncts. A period of in-hospital observation for between 2 and 24 hours is recommended for people once they have returned to normal due to concerns of biphasic anaphylaxis. Epinephrine (adrenaline) (1 in 1,000) is the primary treatment for anaphylaxis with no absolute contraindication to its use. It

17604-776: The end of the funiculus in workers and queens, and the second and third segments of the funiculus are twice as long and broad in larger workers. Polymorphism occurs in all species and the mandibles bear four teeth. The following cladogram shows the position of the red imported fire ant among other members of the S. saevissima species-group: Solenopsis geminata Solenopsis daguerrei Solenopsis quinquecupsis Solenopsis macdonaghi Solenopsis megergates Solenopsis invicta Solenopsis richteri Solenopsis interrupta Solenopsis altipunctata Solenopsis weyrauchi Solenopsis saevissima Solenopsis pythia Solenopsis electra Solenopsis pusillignis Phenotypic and genetic data suggest that

17767-562: The far south populations around the Paraguay and Guaporé Rivers . The western extent of its range is not known exactly, but its abundance there may be limited. It may be extensive in easternmost Bolivia, owing to the presence of the Pantanal region. These ants are native to Argentina, and the red imported fire ant most likely came from here when they first invaded the United States; in particular, populations of these ants have been found in

17930-420: The feeling of lightheadedness or loss of consciousness . Rarely very low blood pressure may be the only sign of anaphylaxis. Coronary artery spasm may occur with subsequent myocardial infarction , dysrhythmia , or cardiac arrest . Those with underlying coronary disease are at greater risk of cardiac effects from anaphylaxis. The coronary spasm is related to the presence of histamine -releasing cells in

18093-451: The first six months of development. In five-year-old colonies, the head width of minor workers decreases, but for major workers, the head-width remains the same. The total weight of a major worker is twice that of a minor worker when they first arrive, and by six months, major workers are four times heavier than minor workers. Once major workers develop, they can make up a large portion of the workforce, with as many as 35% being major workers in

18256-424: The genae and mandibles are dark-brown; they also both appear to share the same coloured shade with the occiput. The scapes and funiculi range from being the same colour as the head or shares the same shade with the occiput. Light-coloured areas of the head in small to medium-sized workers is restricted to only the frontal region, with a dark mark resembling an arrow or rocket being present. On occasion, nests may have

18419-406: The gene. In 2011, scientists announced they had fully sequenced the red imported fire ant genome from a male. Red imported fire ant workers range in size from small to medium, making them polymorphic . Workers measure between 2.4 and 6.0 mm (0.094 and 0.236 in). The head measures 0.66 to 1.41 mm (0.026 to 0.056 in) and is 0.65 to 1.43 mm (0.026 to 0.056 in) wide. In

18582-874: The general superfamily Formicoidea , which, together with Apoidea, forms the higher-ranking group Formicapoidina . Fernández et al. (2021) suggest that the common ancestors of ants and apoids within the Formicapoidina probably existed as early as in the end of the Jurassic period, before divergence in the Cretaceous. Chrysidoidea Vespidae Rhopalosomatidae Pompilidae Mutillidae Tiphiidae Chyphotidae Scolioidea Apoidea Formicidae Myrmicinae Ectatomminae Heteroponerinae Formicinae Dolichoderinae Aneuretinae Pseudomyrmecinae Myrmeciinae Dorylinae‡ Ponerinae Agroecomyrmecinae Paraponerinae Proceratiinae Amblyoponinae Apomyrminae Leptanillinae Martialinae *Cerapachyinae

18745-450: The head tends to have more elliptical sides. The head of small workers is wider out front than it is behind. In the major workers, the pronotum does not have any angular shoulders, nor does it have any sunken posteromedian area. The promesonotum is convex and the propodeum base is rounded and also convex. The base and declivity are of equal length. The suture of the promesonotum is either strong or weak in larger workers. The petiole has

18908-429: The head, thorax, and postpetiole. In S. richteri , the sides of the head are broadly elliptical and the cordate shape seen in the red imported fire ant is absent. The region of the occipital lobes that are situated nearby the midline and occipital excision appear more crease-like in S. richteri than it does in the red imported fire ant. The scapes of S. richteri are longer than they are in the red imported fire ant, and

19071-511: The heart. Gastrointestinal symptoms may include severe crampy abdominal pain , and vomiting. There may be confusion, a loss of bladder control or pelvic pain similar to that of uterine cramps. Dilation of blood vessels around the brain may cause headaches . A feeling of anxiety or of "impending doom" has also been described. Anaphylaxis can occur in response to almost any foreign substance. Common triggers include venom from insect bites or stings , foods, and medication . Foods are

19234-480: The hypercapnic and hypoxic conditions frequently found in their burrows; it is ideal for adapting to these conditions because it allows the ants to increase the period of O 2 intake and CO 2 expulsion independently through spiracle manipulation. The invasion success of the red imported fire ant may possibly be related to its physiological tolerance to abiotic stress , being more heat tolerant and more adaptable to desiccation stress than S. richteri . This means that

19397-433: The ingestion of certain foods or taking an NSAID . In aspirin-exacerbated respiratory disease (AERD), alcohol is a common trigger. During anesthesia , neuromuscular blocking agents , antibiotics , and latex are the most common causes. The cause remains unknown in 32–50% of cases, referred to as " idiopathic anaphylaxis." Six vaccines (MMR, varicella, influenza, hepatitis B, tetanus, meningococcal) are recognized as

19560-414: The initial generation of antibody and inflammatory cell responses to anaphylaxis. In the immunologic mechanism, immunoglobulin E (IgE) binds to the antigen (the foreign material that provokes the allergic reaction). Antigen-bound IgE then activates FcεRI receptors on mast cells and basophils. This leads to the release of inflammatory mediators such as histamine . These mediators subsequently increase

19723-408: The larger workers (as in the major workers), their heads measure 1.35 to 1.40 mm (0.053 to 0.055 in) and 1.39 to 1.42 mm (0.055 to 0.056 in) wide. The antenna scapes measure 0.96 to 1.02 mm (0.038 to 0.040 in) and the thoracic length is 1.70 to 1.73 mm (0.067 to 0.068 in). The head becomes wider behind the eyes with rounded occipital lobes present, and unlike

19886-433: The latter may have delayed absorption. It is recommended that after diagnosis and treatment of anaphylaxis, the patient should be kept under observation in an appropriate clinical setting until symptoms have fully resolved. Minor adverse effects from epinephrine include tremors , anxiety, headaches, and palpitations . People on β-blockers may be resistant to the effects of epinephrine. In this situation if epinephrine

20049-399: The levels of food stress. As worker ants grow to larger sizes, the shape of the head changes, due to the head length growing at the same time as the total body length, and the head width may grow by 20%. The length of the antennae only grows slowly; the antennae may only grow 60% longer by the time the body doubles its length, thus the relative antennal length decreases by 20% as the length of

20212-523: The long axis of the nest orientating itself in a north–south direction. These ants also spend large amounts of energy in nest construction and transporting brood, which is related with thermoregulation . The brood is transported to areas where temperatures are high; workers track temperature patterns of the mound and do not rely on behavioural habits. Inside nests, mounds contain a series of narrow horizontal tunnels, with subterranean shafts and nodes reaching grass roots 10 to 20 cm (3.9 to 7.9 in) below

20375-568: The metabolic demands required to sustain a colony are decreased. Red imported fire ants are native to the tropical areas of central South America, where they have an expansive geographical range that extends from southeastern Peru to central Argentina, and to the south of Brazil. In contrast to its geographical range in North America, its range in South America is significantly different. It has an extremely long north–south range, but

20538-489: The minor or median workers. In a few species, the median workers are absent, creating a sharp divide between the minors and majors. Weaver ants , for example, have a distinct bimodal size distribution. Some other species show continuous variation in the size of workers. The smallest and largest workers in Carebara diversa show nearly a 500-fold difference in their dry weights. Workers cannot mate; however, because of

20701-557: The most common trigger in children and young adults, while medications and insect bites and stings are more common in older adults. Less common causes include: physical factors, biological agents such as semen , latex , hormonal changes, food additives and colors, and topical medications. Physical factors such as exercise (known as exercise-induced anaphylaxis ) or temperature (either hot or cold) may also act as triggers through their direct effects on mast cells . Events caused by exercise are frequently associated with cofactors such as

20864-738: The name S. invicta be added to the Official List of Specific Names in Zoology and that S. wagneri be added to the Official Index of Rejected Invalid Specific Names in Zoology. Upon review, the proposal was voted on by the entomological community and was supported by all but two voters. They note that there is no justification in suppressing S. wagneri ; instead, it would be better to give precedence to S. invicta over S. wagneri whenever an author treated them as conspecific. The ICZN would conserve S. invicta and suppress S. wagneri in

21027-575: The name S. invicta . Since the first description of S. invicta , over 1,800 scientific papers using the name were published discussing a wide range of topics about its ecological behaviour, genetics, chemical communication, economic impacts, methods of control, population, and physiology. They state that the use of S. wagneri is a "threat" to nomenclatural stability towards scientists and non-scientists; taxonomists may have been able to adapt to such name change, but name confusion may arise if such case occurred. Due to this, Shattuck and his colleagues proposed

21190-764: The name fire ant is derived from the burning sensation caused by their sting. More than 14 million people are stung by them in the United States annually, where many are expected to develop allergies to the venom. Most victims experience intense burning and swelling , followed by the formation of sterile pustules , which may remain for several days. However, 0.6% to 6.0% of people may suffer from anaphylaxis , which can be fatal if left untreated. Common symptoms include dizziness , chest pain , nausea , severe sweating , low blood pressure, loss of breath, and slurred speech . More than 80 deaths have been recorded from red imported fire ant attacks. Treatment depends on

21353-786: The nest. These ants exhibit a wide variety of behaviours, such as building rafts when they sense that water levels are rising. They also show necrophoric behaviour , where nestmates discard scraps or dead ants on refuse piles outside the nest. Foraging takes place on warm or hot days, although they may remain outside at night. Workers communicate by a series of semiochemicals and pheromones , which are used for recruitment, foraging, and defence. They are omnivores and eat dead mammals , arthropods , insects , seeds , and sweet substances such as honeydew from hemipteran insects with which they have developed relationships . Predators include arachnids , birds , and many insects including other ants , dragonflies , earwigs , and beetles . The ant

21516-693: The newer lower osmolar agents cause reactions in 0.04% of cases. Venom from stinging or biting insects such as Hymenoptera (ants, bees, and wasps) or Triatominae (kissing bugs) may cause anaphylaxis in susceptible people. Previous reactions that are anything more than a local reaction around the site of the sting, are a risk factor for future anaphylaxis; however, half of fatalities have had no previous systemic reaction. People with atopic diseases such as asthma , eczema , or allergic rhinitis are at high risk of anaphylaxis from food, latex , and radiocontrast agents but not from injectable medications or stings. One study in children found that 60% had

21679-495: The original meaning of the word was "the biter" (from Proto-Germanic * ai- , "off, away" + * mait- "cut"). The family name Formicidae is derived from the Latin formīca ("ant") from which the words in other Romance languages , such as the Portuguese formiga , Italian formica , Spanish hormiga , Romanian furnică , and French fourmi are derived. It has been hypothesised that

21842-466: The original name, erroneously believing that the name S. wagneri was unavailable and used Buren's name S. invicta . Trager previously believed that S. invicta was conspecific with S. saevissima until comparing the material with S. wagneri . Trager notes that though S. wagneri has priority over S. invicta , the name was never used above infrasubspecific rank. The use of the name since Santschi has not been associated with collected specimens, and as

22005-517: The phenomenon and was eventually awarded the Nobel Prize in Physiology or Medicine for his work on anaphylaxis in 1913. There are ongoing efforts to develop sublingual epinephrine to treat anaphylaxis. Trials of sublingual epinephrine, currently called AQST-108 (dipivefrin) and sponsored by Aquestive Therapeutics, are in phase 1 trials as of December 2021. Subcutaneous injection of

22168-559: The posterior portion of the midgut. The anterior and superior cavities are formed by the bases of four Malpighian tubules . The superior cavity opens into the lumen of the small intestine. The rectum is a large but thin-walled sac that occupies the posterior fifth of the larvae. The release of waste is controlled by the rectal valves that lead to the anus. Sometimes, the larvae secrete a liquid that consists of uric acid , water and salts. These contents are often carried outside by workers and ejected, but colonies under water stress may consume

22331-416: The pronotum has strong angulate shoulders. Such character is almost absent in the red imported fire ant. A shallow but sunken area is only known in the larger workers of S. richteri , which is located in the posterior region of the dorsum of the pronotum. This feature is completely absent in larger red imported fire ant workers. The red imported fire ant's promesonotum is strongly convex, whereas this feature

22494-657: The provinces of Chaco , Corrientes , Formosa , Santiago del Estero , Santa Fe , and Tucumán . The northeastern regions of Argentina are the most credible guess where the invading ants originate. In Brazil, they are found in northern Mato Grosso and in Rondônia and in São Paulo state . The red imported fire ant and S. saevissima are parapatric in Brazil, with contact zones known in Mato Grosso do Sul , Paraná state and São Paulo. In Paraguay they are found throughout

22657-410: The recommendation to wear a medical alert bracelet , and counseling on avoidance of triggers. Immunotherapy is available for certain triggers to prevent future episodes of anaphylaxis. A multi-year course of subcutaneous desensitization has been found effective against stinging insects, while oral desensitization is effective for many foods. In those in whom the cause is known and prompt treatment

22820-563: The red imported fire ant and the black imported fire ant ( Solenopsis richteri ) differ from each other, but they do share a close genetic relationship. Hybridisation between the two ants occurs in areas where they make contact, with the hybrid zone located in Mississippi. Such hybridisation has resulted from secondary contact between these two ants several decades ago, when they first encountered each other in southern Alabama . Based on mitochondrial DNA , examined haplotypes do not form

22983-432: The red imported fire ant exist: polygynous colonies (nests with multiple queens) and monogynous colonies (nests with one queen). Venom plays an important role in the ant's life, as it is used to capture prey or for defence. About 95% of the venom consists of water-insoluble piperidine alkaloids known as solenopsins , with the rest comprising a mixture of toxic proteins that can be particularly potent in sensitive humans;

23146-484: The red imported fire ant prompted the Australian government to respond rapidly. A joint state and federal funding of A$ 175 million was granted for a six-year eradication programme. Following years of eradication, eradication rates of greater than 99% from previously infested properties were reported. The program received extended Commonwealth funding of around A$ 10 million for at least another two years to treat

23309-550: The red imported fire ant to expand its geographical range. As of 2004, the ant is found in 13 states and occupies over 128 million hectares of land, and as many as 400 mounds can be found on a single acre of land. The United States Department of Agriculture estimates that they expand 120 miles (193 km) westward per year. Likely due to absence of South American competitors ‍ — and lower numbers of native competitors ‍ —  S. invicta dominates more extrafloral nectaries and hemipteran honeydew sources in

23472-691: The residual infestations found most recently. In December 2014, a nest was identified at Port Botany , Sydney , in New South Wales . The port was quarantined, and a removal operation took place. In September 2015, populations originating from the United States were found at a Brisbane airport. Hundreds of millions of dollars have since been allocated to their eradication. In August 2023, the Invasive Species Council said that without additional funding, fire ants would probably spread into northern New South Wales and west, potentially into

23635-464: 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

23798-423: The same dose, they always developed fatal shock. They also found that the effect was not related to the doses of toxin used, as even small amounts in secondary injections were lethal. Thus, instead of inducing tolerance ( prophylaxis ) which they expected, they discovered effects of the toxin as deadly. In 1902, Richet introduced the term aphylaxis to describe the condition of lack of protection. He later changed

23961-413: The similar-looking S. richteri , the lobes peak further than the midline, but the occipital excision is not as crease-like. The scapes in major workers do not extend beyond occipital peak by one or two scape diameters; this feature is more noticeable in S. richteri . In medium-sized workers, the scapes reach the occipital peaks and exceed the rear border in the smallest workers. In small and medium workers,

24124-532: The size of the body changes. The width of the gaster grows more rapidly than its length, where the width may be 96% of its length but increases to 106%. Like other insects, the red imported fire ant breathes through a system of gas-filled tubes called tracheae connected to the external environment through spiracles. The terminal tracheal branches ( tracheoles ) make direct contact with internal organs and tissue. The transport of oxygen to cells (and carbon dioxide out of cells) occurs through diffusion of gases between

24287-509: The sub-order Isoptera , and together with cockroaches , they form the order Blattodea . Blattodeans are related to mantids , crickets , and other winged insects that do not undergo complete metamorphosis . Like ants, termites are eusocial , with sterile workers, but they differ greatly in the genetics of reproduction. The similarity of their social structure to that of ants is attributed to convergent evolution . Velvet ants look like large ants, but are wingless female wasps . Ants have

24450-532: The surface of the soil. During the Cretaceous period, a few species of primitive ants ranged widely on the Laurasian supercontinent (the Northern Hemisphere ). Their representation in the fossil record is poor, in comparison to the populations of other insects, representing only about 1% of fossil evidence of insects in the era. Ants became dominant after adaptive radiation at the beginning of

24613-405: The surface; these shafts and nodes connect the mound tunnels to the subterranean chambers. These chambers are about 5 cm (0.77 inch) and reach depths of 10 to 80 cm (3.9 to 31.5 in). The mean number of ants in a single subterranean chamber is around 200. Red imported fire ants are among the worst invasive species in the world. Some scientists consider the red imported fire ant to be

24776-678: The surname of E.R. Wagner, who collected the first specimens. The type material is currently housed in Naturhistorisches Museum Basel , Switzerland, but additional type workers are possibly housed in the Muséum national d'histoire naturelle , Paris. In 1930, American myrmecologist William Creighton reviewed the genus Solenopsis and reclassified the taxon as Solenopsis saevissima electra wagneri at infrasubspecific rank, noting that he could not collect any workers that referred to Santschi's original description. In 1952,

24939-853: The symptoms; those who only experience pain and pustule formation require no medical attention, but those who suffer from anaphylaxis are given adrenaline . Whole body extract immunotherapy is used to treat victims and is regarded as highly effective. The ant is viewed as a notorious pest, causing billions of dollars in damage annually and impacting wildlife. The ants thrive in urban areas, so their presence may deter outdoor activities. Nests can be built under structures such as pavements and foundations, which may cause structural problems, or cause them to collapse. Not only can they damage or destroy structures, but red imported fire ants also can damage equipment and infrastructure and impact business, land, and property values. In agriculture, they can damage crops and machinery, and threaten pastures. They are known to invade

25102-464: The tergite and sternite of a segment fuse together, can occur partly or fully on the second, third and fourth abdominal segment and is used in identification. Fourth abdominal tergosternal fusion was formerly used as character that defined the poneromorph subfamilies, Ponerinae and relatives within their clade, but this is no longer considered a synapomorphic character. Like other arthropods, ants have an exoskeleton , an external covering that provides

25265-600: The term to anaphylaxis on grounds of euphony . The term is from the Greek ἀνά- , ana- , meaning "against", and φύλαξις , phylaxis , meaning "protection". On 15 February 1902, Richet and Portier jointly presented their findings before the Societé de Biologie in Paris. The moment is regarded as the birth of allergy (the term invented by Clemens von Pirquet in 1906) study ( allergology ). Richet continued to study on

25428-400: The total biomass of all the ants in the world was approximately equal to the total biomass of the entire human race. More careful estimates made in 2022 which take into account regional variations puts the global ant contribution at 12 megatons of dry carbon, which is about 20% of the total human contribution, but greater than that of the wild birds and mammals combined. This study also puts

25591-491: The tracheoles and the surrounding tissue and is assisted by a discontinuous gas exchange . As with other insects, the direct communication between the tracheal system and tissues eliminates the need for a circulating fluid network to transport O 2 . Thus, red imported fire ants and other arthropods can have a modest circulatory system though they have highly expensive metabolic demands. The excretory system consists of three regions. The basal region has three cells found within

25754-580: The trigger of anaphylaxis is recommended. In cases where this may not be possible, desensitization may be an option. Immunotherapy with Hymenoptera venoms is effective at desensitizing 80–90% of adults and 98% of children against allergies to bees , wasps , hornets , yellowjackets , and fire ants . Oral immunotherapy may be effective at desensitizing some people to certain food including milk, eggs, nuts and peanuts; however, adverse effects are common. For example, many people develop an itchy throat, cough, or lip swelling during immunotherapy. Desensitization

25917-713: The tropical and subtropical regions of Asia. In Europe, a single nest was found in the Netherlands in 2002. For the first time, in 2023, ant colonies have been found in Europe. Around 1980, red imported fire ants began spreading throughout the West Indies , where they were first reported in Puerto Rico and the U.S. Virgin Islands . Between 1991 and 2001, the ant was recorded from Trinidad and Tobago, several areas in

26080-448: The upper borders of the petiolar scales are more concave. In both species, the postpetiole's and petiole's spiracles strongly project. The whole body of the male is concolorous black, but the antennae are whitish. Like the queen, the wing veins are colourless or pale brown. The red imported ant can be misidentified as the similar-looking S. richteri . The two species can be distinguished from each other through morphological examinations of

26243-483: Was a new species, naming it Solenopsis invicta . Buren collected a holotype worker from Cuiabá in Mato Grosso , Brazil, and provided the first official description of the ant in a journal article published by the Georgia Entomological Society. He accidentally misspelled invicta as invica [ sic ] above the description pages of the species, although it was clear that invicta

26406-432: Was later identified as Portuguese man o' war ) and sea anemone ( Actinia sulcata ). In their first experiment on the ship, they injected a dog with the toxin in an attempt to immunise the dog, which instead developed a severe reaction ( hypersensitivity ). In 1902, they repeated the injections in their laboratory and found that dogs normally tolerated the toxin at first injection, but on re-exposure, three weeks later with

26569-464: Was the intended spelling because of the constant use of the name in the article. The type material is currently housed in the National Museum of Natural History , Washington, D.C. In a 1991 review of the species complex, American entomologist James Trager synonymised S. saevissima electra wagneri and S. wagneri together. Trager incorrectly cites Solenopsis saevissima electra wagneri as

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