Atta is a genus of New World ants of the subfamily Myrmicinae. It contains at least 17 known species.
Leafcutter ants, a non-generic name, are any of 47 species of leaf-chewing ants belonging to the two genera Atta and Acromyrmex, within the tribe Attini. These species of tropical, fungus-growing ants are all endemic to South and Central America, Mexico, and parts of the southern United States. Leafcutter ants can carry twenty times their body weight and cut and process fresh vegetation to serve as the nutritional substrate for their fungal cultivates.
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.
Ant–fungus mutualism is a symbiosis seen between certain ant and fungal species, in which ants actively cultivate fungus much like humans farm crops as a food source. There is only evidence of two instances in which this form of agriculture evolved in ants resulting in a dependence on fungi for food. These instances were the attine ants and some ants that are part of the Megalomyrmex genus. In some species, the ants and fungi are dependent on each other for survival. This type of codependency is prevalent among herbivores who rely on plant material for nutrition. The fungus’ ability to convert the plant material into a food source accessible to their host makes them the ideal partner. The leafcutter ant is a well-known example of this symbiosis. Leafcutter ants species can be found in southern South America up to the United States. However, ants are not the only ground-dwelling arthropods which have developed symbioses with fungi. A similar mutualism with fungi is also noted in termites within the subfamily Macrotermitinae which are widely distributed throughout the Old World tropics with the highest diversity in Africa.
Megalomyrmex is a genus of ant in the subfamily Myrmicinae. The genus is known only from the Neotropics, where some of the species are specialized parasites or predators of Attini.
Sericomyrmex is a genus of fungus-growing ants in the subfamily Myrmicinae.
Acropyga is a genus of small formicine ants. Some species can be indirect pests. A. acutiventris, which is found from India to Australia, tends subterranean, root-feeding mealybugs of the species Xenococcus annandalei. Living, gravid females are carried in the jaws of A. acutiventris queens during their nuptial flight, to establish the symbiotic association in founding colonies. Other Acropyga species have relationships with different species of mealybugs, and it could be a trait common to the whole genus.
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.
Trachymyrmex is a genus of fungus-growing ants in the subfamily Myrmicinae. The genus is mainly tropical in distribution, with most species being found in Central and South America.
Cyphomyrmex is a genus of fungus-growing ants found primarily in South and Central America. However, some species do come up to the southern portion of North America. They grow a variety of fungi in the tribe Leucocoprineae. Most fungal gardens are grown in small nodules, some species to cultivate entire mycelium, though. Colonies are monogynous and are relatively small with about 100 workers on average.
Apterostigma is a genus of New World ants of the subfamily Myrmicinae. Two species have been described from fossils preserved in Dominican amber, while the others are extant. They are fungus-growing ants, though, unlike the majority of other species in Attini who grow Lepiotaceae, some species have begun cultivating Tricholomataceae.
Azteca is a strictly Neotropical genus of ants in the subfamily Dolichoderinae. The genus is very diverse and contains around 84 extant species and two fossil species. They are essentially arboreal and many species have mutualistic associations with particular plant species, where the genus Cecropia presents the most conspicuous association. In the Brazilian Amazonia, Azteca species are associated with species of Codonanthopsis.
Cyatta is a genus of ant in the subfamily Myrmicinae containing the single species Cyatta abscondita. It is considered the most recent ancestor of all fungus-farming ants and a living fossil.
Mycocepurus castrator is a species of parasitic ant, in the genus Mycocepurus, native to Brazil. Described in 2010, the species is a workerless and obligate parasite of the related ant Mycocepurus goeldii. It is known only from Rio Claro, Brazil, and has only been found in nests of M. goeldii.
Mycocepurus goeldii is a species of ant in the genus Mycocepurus.
Escovopsis is a genus of seven formally acknowledged parasitic microfungus species that rely on other fungi to be their hosts. This genus formally circumscribed with a single identified species in 1990; in 2013 three other species were added.
Escovopsis aspergilloides is a species of fungus that was rediscovered in 1995 by mycologists Keith A. Seifert, Robert A. Samson and Ignacio Chapela. Escovopsis aspergilloides co-exist in a symbiotic relationship with attini ants - fungus-growing ants. The highly evolved, ancient ant-fungus mutualism has become a model system in the study of symbiosis. In spite of this, the genus Escovopsis was not proposed until 1990 and the first two species were not formally described until the 1990s: E. weberi by Muchovej and Della Lucia in 1990 E. aspergilloides by Seifert, Samson and Chapela in 1995.
Mycetomoellerius turrifex is a species of fungus farming ant in the myrmicine genus Mycetomoellerius. The species was formerly placed in the genus Trachymyrmex, but was moved to the newly erected genus Mycetomoellerius by Solomon et al (2019) based on molecular phylogenetic analysis.
Leucocoprinus gongylophorus is a fungus in the family Agaricaceae which is cultivated by certain leafcutter ants. Like other species of fungi cultivated by ants, L. gongylophorus produces gongylidia, nutrient-rich hyphal swellings upon which the ants feed. Production of mushrooms occurs only once ants abandon the nest. L. gongylophorus is farmed by leaf cutter ant species belonging to the genera Atta and Acromyrmex, amongst others.
