Jack jumper ant
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: for workers, and for males. The queen measures roughly long and is similar in appearance to workers, whereas males are identifiable by their perceptibly smaller mandibles.
Jack jumper ants are primarily active during the day and live in open habitats, nesting in bushland, woodlands, and dry open forests, surrounded by gravel and sandy soil, which can be found in rural areas and are less common in urban areas. They prey on small insects and use their barbless stingers to kill other insects by injecting venom. Other ants and predatory invertebrates prey on the jack jumper ant. The average worker has a life expectancy of over one year. Workers are gamergates, allowing them to reproduce with drones, whether or not a queen is present in the colony. The ant is a part of the Myrmecia pilosula species complex; this ant and other members of the complex are known to have a single pair of chromosomes.
Their sting generally only causes a mild local reaction in humans; however, it is one of the few ant species that can be dangerous to humans, along with other ants in the genus Myrmecia. The ant venom is particularly immunogenic for an insect venom; the venom causes about 90% of Australian ant allergies. In endemic areas, up to 3% of the human population has developed an allergy to the venom and about half of these allergic people can suffer from anaphylactic reactions, which can lead to death on rare occasions. Between 1980 and 2000, four deaths were due to anaphylaxis from jack jumper stings, all of them in Tasmania. Individuals prone to severe allergic reactions caused by the ant's sting can be treated with allergen immunotherapy.
Taxonomy and common names
The specific name derives from the Latin word pilosa, meaning 'covered with soft hair'. The ant was first identified in 1858 by British entomologist Frederick Smith in his Catalogue of hymenopterous insects in the collection of the British Museum part VI, under the binomial name Myrmecia pilosula from specimens he collected in Hobart in Tasmania. There, Smith described the specimens of a worker, queen, and male. The type specimen is located in the British Museum in London. In 1922, American entomologist William Morton Wheeler established the subgenus Halmamyrmecia characterised by its jumping behaviour, of which the jack jumper ant was designated as the type species. However, John Clark later synonymised Halmamyrmecia under the subgenus Promyrmecia in 1927 and placed the ant in the subgenus in 1943. William Brown synonymised Promyrmecia due to the lack of morphological evidence that would make it distinct from Myrmecia and later placed the jack jumper ant in the genus in 1953.One synonym for the species has been published – Ponera ruginoda, described by Smith in the same work, and a male holotype specimen was originally described for this synonym. P. ruginoda was initially placed into the genera Ectatomma and Rhytidoponera, but it was later classified as a junior synonym of the jack jumper ant, after specimens of each were compared. The M. pilosula species complex was first defined by Italian entomologist Carlo Emery. The species complex is a monophyletic group, where the species are closely related to each other, but their actual genetic relationship is distant. Members of this group include M. apicalis, M. chasei, M. chrysogaster, M. croslandi, M. cydista, M. dispar, M. elegans, M. harderi, M. ludlowi, M. michaelseni, M. occidentalis ''M. queenslandica, M. rugosa, and M. varians. Additional species that were described in this group in 2015 include M. banksi, M. haskinsorum, M. imaii, and M. impaternata.
Their characteristic jumping motion when agitated or foraging inspires the common name "jack jumper", a behaviour also shared with other Myrmecia ants, such as M. nigrocincta. This is the most common name for the ant, along with "black jumper," "hopper ant", "jumper ant", "jumping ant", "jumping jack" and "skipper ant". It is also named after the jumping-jack firecracker. The species is a member of the genus Myrmecia'', a part of the subfamily Myrmeciinae.
Description
Like its relatives, the ant possesses a powerful sting and large mandibles. These ants can be black or blackish-red in colour, and may have yellow or orange legs. The ant is medium-sized in comparison to other Myrmecia species, where workers are typically long. Excluding mandibles, jack jumpers measure in length. The ant's antennae, tibiae, tarsi, and mandibles are also yellow or orange. Pubescence on the ant is greyish, short and erect, and is longer and more abundant on their gaster, absent on their antennae, and short and suberect on their legs. The pubescence on the male is grey and long, and abundant throughout the ant's body, but it shortens on the legs. The mandibles are long and slender, and concave around the outer border.The queen has a similar appearance to the workers, but her middle body is more irregular and coarser. The queen is also the largest, measuring in length. Males are either smaller or around the same size as workers, measuring. Males also have much smaller, triangular mandibles than workers and queens. The mandibles on the male contain a large tooth at the centre, among the apex and the base of the inner border. Punctures are noticeable on the head, which are large and shallow, and the thorax and node are also irregularly punctuated. The pubescence on the male's gaster is white and yellowish.
Distribution and habitat
Jack jumper ants are abundant in most of Australia, being among the most common bull ant to be encountered. The ants can be found in the south-western tip of Western Australia, where it has been seen in the sand hills around Albany, Mundaring, Denmark and Esperance. The ant is rarely sighted in the northern regions of Western Australia. In South Australia, it is commonly found in the south-east regions of the state, frequently encountered in Mount Lofty, Normanville, Hallett Cove and Aldgate, but it is not found in north-western regions. There are dense populations on the western seaboard of Kangaroo Island. Jack jumpers are widespread throughout the whole of Victoria, but the species is uncommon in Melbourne. However, populations have been collected from the suburb of Elsternwick, and they are commonly found in the Great Otway Ranges, with many nests observed around Gellibrand. In New South Wales, nests are found throughout the entire state, but dense populations are mostly found in the Snowy Mountains, Blue Mountains and coastal regions. The ants are widespread in the Australian Capital Territory. In Queensland, the ants are only found along the south-eastern coastlines of the state, where populations are frequently encountered in the Bunya Mountains, Fletcher, Stanthorpe, Sunshine Coast, Tamborine Mountain and Millmerran, and have been found as far north as Atherton Tablelands. The ant also resides in all of Tasmania, and their presence in the Northern Territory has not been verified.Jack jumper ants live in open habitats, such as damp areas, forests, pastures, gardens, and lawns, preferring fine gravel and sandy soil. Colonies can also be spotted around light bushland. Their preferred natural habitats include woodlands, dry open forests, grasslands, and rural areas, and less common in urban areas. Their nests are mounds built from finely granular gravel, soil, and pebbles, measuring in diameter and can be as tall as 0.5 m in height. Two types of nests for this species have been described, one being a simple nest with a noticeable shaft inside, the other being a complex structure surrounded by a mound. These ants use the sun's warmth by decorating their nests with dry materials that heat in a quick duration, providing the nest with solar energy traps. They decorate their nests with seeds, soil, charcoal, stones, sticks, and even small invertebrate corpses. They also camouflage their nests by covering them with leaf litter, debris, and long grass. Nests can be found hidden under rocks, where queens most likely form their colonies, or around small piles of gravel, instead. Their range in southern Australia, like other regional ant species, appears like that of a relict ant. Jack jumpers have been found in dry sclerophyll forests, at elevations ranging from, averaging. Rove beetles in the genus Heterothops generally thrive in jack jumper nests and raise their brood within their chambers, and skinks have been found in some nests.
Populations are dense in the higher mountain regions of Tasmania. Widespread throughout the state, their presence is known on King Island, located north-west from Tasmania. The ant prefers rural areas, found in warm, dry, open eucalypt woodlands; the climate provides the ant with isolation and warmth. This environment also produces the ant's food, which includes nectar and invertebrate prey. In suburban areas, this ant is found in native vegetation, and uses rockeries, cracks in concrete walls, dry soil, and grass to build nests. One study found suburbs with voluminous vegetation cover such as Mount Nelson, Fern Tree and West Hobart host jack jumper populations, while the heavily urbanised suburbs of North Hobart and Battery Point, do not.
Pest control of the jack jumper ant is successful in maintaining their populations around suburban habitats. Chemicals such as bendiocarb, chlorpyrifos, diazinon, and permethrin are effective against them. Spraying of Solfac into nests is an effective way of controlling nests if they are in a close range of areas with considerable amounts of congestion and human activity. Pouring carbon disulfide into nest holes and covering entrances up with soil is another method of removing colonies. The Australian National Botanic Gardens have an effective strategy of marking and maintaining jack jumper nests.