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 the distinctive node-like structure that forms their slender waists.
Atta is a genus of New World ants of the subfamily Myrmicinae. It contains at least 17 known species.
Leafcutter ants are fungus-growing ants that share the behaviour of cutting leaves which they carry back to their nests to farm fungus. Next to humans, leafcutter ants form some of the largest and most complex animal societies on Earth. In a few years, the central mound of their underground nests can grow to more than 30 m (98 ft) across, with smaller radiating mounds extending out to a radius of 80 m (260 ft), taking up 30 to 600 m2 and containing eight million individuals.
Fungus-growing ants comprise all the known fungus-growing ant species participating in ant–fungus mutualism. They are known for cutting grasses and leaves, carrying them to their colonies' nests, and using them to grow fungus on which they later feed.
Weaver ants or green ants are eusocial insects of the Hymenoptera family Formicidae belonging to the tribe Oecophyllini. Weaver ants live in trees and are known for their unique nest building behaviour where workers construct nests by weaving together leaves using larval silk. Colonies can be extremely large consisting of more than a hundred nests spanning numerous trees and containing more than half a million workers. Like many other ant species, weaver ants prey on small insects and supplement their diet with carbohydrate-rich honeydew excreted by scale insects (Hemiptera). Weaver ant workers exhibit a clear bimodal size distribution, with almost no overlap between the size of the minor and major workers. The major workers are approximately 8–10 mm (0.31–0.39 in) in length and the minors approximately half the length of the majors. Major workers forage, defend, maintain, and expand the colony whereas minor workers tend to stay within the nests where they care for the brood and 'milk' scale insects in or close to the nests.
Carpenter ants are large ants indigenous to many forested parts of the world.
The pharaoh ant is a small (2 mm) yellow or light brown, almost transparent ant notorious for being a major indoor nuisance pest, especially in hospitals. A cryptogenic species, it has now been introduced to virtually every area of the world, including Europe, the Americas, Australasia and Southeast Asia. It is a major pest in the United States, Australia, and Europe. The ant's common name is possibly derived from the mistaken belief that it was one of the Egyptian (pharaonic) plagues.
The name army ant (or legionary ant or marabunta) is applied to over 200 ant species in different lineages. Because of their aggressive predatory foraging groups, known as "raids", a huge number of ants forage simultaneously over a limited area.
Atta sexdens is a species of leafcutter ant belonging to the tribe Attini, native to America, from the southern United States (Texas) to northern Argentina. They are absent from Chile. They cut leaves to provide a substrate for the fungus farms which are their principal source of food. Their societies are among the most complex found in social insects. A. sexdens is an ecologically important species, but also an agricultural pest. Other Atta species, such as Atta texana, Atta cephalotes and others, have similar behavior and ecology.
The banded sugar ant, also known as the sugar ant, is a species of ant native to Australia. A member of the genus Camponotus in the subfamily Formicinae, it was described by German entomologist Wilhelm Ferdinand Erichson in 1842. Its common name refers to the ant's liking for sugar and sweet food, as well as the distinctive orange-brown band that wraps around its gaster.
Nothomyrmecia, also known as the dinosaur ant or dawn ant, is an extremely rare genus of ants consisting of a single species, Nothomyrmecia macrops. These ants live in South Australia, nesting in old-growth mallee woodland and Eucalyptus woodland. The full distribution of Nothomyrmecia has never been assessed, and it is unknown how widespread the species truly is; its potential range may be wider if it does favour old-growth mallee woodland. Possible threats to its survival include habitat destruction and climate change. Nothomyrmecia is most active when it is cold because workers encounter fewer competitors and predators such as Camponotus and Iridomyrmex, and it also increases hunting success. Thus, the increase of temperature may prevent them from foraging and very few areas would be suitable for the ant to live in. As a result, the IUCN lists the ant as Critically Endangered.
The meat ant, also known as the gravel ant or southern meat ant, is a species of ant endemic to Australia. A member of the genus Iridomyrmex in the subfamily Dolichoderinae, it was described by British entomologist Frederick Smith in 1858. The meat ant is associated with many common names due to its appearance, nest-building behaviour and abundance, of which its specific name, purpureus, refers to its coloured appearance. It is among the best-known species of ant found throughout Australia; it occurs in almost all states and territories except for Tasmania. Its enormous distribution, aggression and ecological importance have made this ant a dominant species.
Acromyrmex is a genus of New World ants of the subfamily Myrmicinae. This genus is found in South America and parts of Central America, México and the Caribbean Islands, and contains 33 known species. Commonly known as "leafcutter ants" they comprise one of the two genera of advanced attines within the tribe Attini, along with Atta.
Mycocepurus smithii is a species of fungus-growing ant from Latin America. This species is widely distributed geographically and can be found from Mexico in the north to Argentina in the south, as well as on some Caribbean Islands. It lives in a variety of forested habitats and associated open areas. Two studies published in 2009 demonstrated that some populations of the species consist exclusively of females which reproduce via thelytokous parthenogenesis. A detailed study found evidence of sexual reproduction in some populations in the Brazilian Amazon. Accordingly, M. smithii consists of a mosaic of sexually and asexually reproducing populations. In asexual populations all ants in a single colony are female clones of the queen. Inside the colony, the ants cultivate a garden of fungus grown with pieces of dead vegetable matter, dead insects, and insect droppings.
The green-head ant is a species of ant that is endemic to Australia. It was described by British entomologist Frederick Smith in 1858 as a member of the genus Rhytidoponera in the subfamily Ectatomminae. These ants measure between 5 and 7 mm. The queens and workers look similar, differing only in size, with the males being the smallest. They are well known for their distinctive metallic appearance, which varies from green to purple or even reddish-violet. Among the most widespread of all insects in Australia, green-head ants are found in almost every Australian state, but are absent in Tasmania. They have also been introduced in New Zealand, where several populations have been established.
Atta colombica is one of 47 species of leafcutter ants. This species is part of the Attini tribe.
Atta mexicana is a species of leaf-cutter ant, a New World ant of the subfamily Myrmicinae of the genus Atta. This species is from one of the two genera of advanced attines within the tribe Attini.
Acromyrmex insinuator is a social parasite of the closely related Acromyrmex echinatior. This specific parasite is of particular interest as it is an opportunity to study the development of social parasitism in the Attini tribe, and provides further evidence for Emery's rule, which theorizes social parasites among insects tend to be parasites of species or genera to which they are closely related to.
Amoimyrmex striatus is a species of leafcutter ant found in the Neotropics.
Attaphila is a genus of cockroaches that live as myrmecophiles in the nests of leaf-cutting ants. They have been suggested to feed on the fungus their host ants farm, or on the cuticular lipids of ant workers. Attaphila are not attacked by host workers because they blend into the colony by mimicking the odour of their hosts ants. Female Attaphila are wingless and males have reduced wings. The cockroaches are phoretic and can disperse to new host colonies by riding on virgin host queens departing on their mating flight and by hitchhiking on leaves carried by leaf-cutter ant foragers returning to their nests, or by following leaf-cutter ant pheromone trails
