Attina

Fungus-growing Ants

Genus Guides

Acromyrmex(leafcutter ants)
Atta(Atta Leaf-cutter Ants)
Cyphomyrmex(fungus-growing ants)
Mycetomoellerius(fungus-farming ants)
Mycetosoritis
Trachymyrmex

Attina is a subtribe of fungus-growing ants within the Myrmicinae, comprising all known that participate in obligate ant-fungus mutualism. These ants cultivate fungi as their sole food source, with leafcutter ants ( Atta and Acromyrmex) being the most well-known members. The subtribe is sister to Dacetina and represents one of only two known groups of organisms (along with humans) that practice agriculture. Attina ants are native to the New World tropics and subtropics, where they play significant roles in nutrient cycling and soil modification.

Pheidole crassicornis by (c) Luke Padon, some rights reserved (CC BY), uploaded by Luke Padon. Used under a CC-BY license.

Cyphomyrmex by (c) Toby, some rights reserved (CC BY), uploaded by Toby. Used under a CC-BY license.

Cyphomyrmex by no rights reserved, uploaded by Philipp Hoenle. Used under a CC0 license.

Pronunciation

How to pronounce Attina: /ˈætɪnə/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Habitat

Diverse across the New World tropics and subtropics, ranging from tropical rainforests to semi-open sandy areas. Specific habitat preferences vary by : leafcutter ants (Atta, Acromyrmex) occur in tropical forests, while some genera such as Mycetosoritis are restricted to sun-exposed sandy soils. Nests are typically subterranean with specialized chambers for fungal .

Distribution

New World distribution from the southern United States (Louisiana, Texas) through Central America and South America, extending to at least Honduras and Rica. Some have more restricted ranges; Mycetosoritis hartmanni ranges from Louisiana and Texas across eastern Mexico to at least Honduras.

Diet

Obligate fungal cultivators; all cultivate fungi in underground gardens as their sole food source. Leaves, flowers, and other plant material serve as substrate for fungal growth rather than direct food. Specialized fungal structures called gongylidia are harvested and distributed throughout the colony to feed larvae, , and queens.

Life Cycle

Colonies are typically monogynous (single ) with ranging from fewer than 100 in some to several million in large leafcutter colonies. activity cycles vary by latitude: in temperate regions, reduced activity occurs November–February with laying resuming in April, worker pupae developing by June, and reproductives reared July–August. Mating occur late June through August. Established nests of smaller species average 1.9–2.5 years lifespan (maximum 6 years observed). Males usually die soon after mating; in some species, males aggregate hundreds of meters above ground for mating flights, while in others they remain near ground level waiting for female calling signals.

Behavior

Agricultural includes foraging for plant material, processing it into substrate, and meticulously tending fungal gardens. detect and remove fungi and garden . Trail- coordinate foraging. Leafcutter ants exhibit with specialized roles: major workers cut and carry vegetation, intermediate workers transport materials, and minima workers hitchhike on leaves to defend against and parasitic flies. Soldiers with powerful jaws defend colonies. Some construct characteristic nest structures: Mycetosoritis builds steep turriform mounds of excavated sand 3–8 cm in diameter and 2–4 cm high.

Ecological Role

Major herbivores and nutrient cyclers in tropical . Leafcutter ants harvest more than 10% of leaf production in tropical forests and can remove over 500 dry weight pounds of vegetation annually from large colonies. They enrich and cultivate tropical soils through decomposition and soil modification. Locally abundant in suitable ; some appear relatively unaffected by fire ants.

Human Relevance

Agricultural pests when nests occur near orchards or crops, capable of stripping trees and vegetables overnight. Historical and ongoing conflict with farmers, often resulting in colony destruction. Subject of extensive scientific research due to their unique agricultural mutualism. The subtribe has been cited in legal contexts regarding Eighth Amendment interpretation (Cannaday v. State, 1984, though this case involved a human defendant and is unrelated to the group).

Similar Taxa

DacetinaSister subtribe to Attina within tribe Attini; distinguished by predatory rather than fungivorous habits, with typically possessing elongated for capturing small prey rather than cutting vegetation

More Details

Chemical ecology

Male ants produce tyramides, a class of compound found only in males of the Myrmicinae . These compounds are transferred to female during mating and may be converted to tyramine to trigger rapid reproductive development, though this function has been experimentally demonstrated only in fire ants (Solenopsis invicta) and remains to be confirmed in Attina.

Cytogenetics

Attina exhibits remarkable karyotype diversity with GC-rich heterochromatin present across multiple , supporting a hypothesis of common origin for this characteristic. Chromosomal numbers range from 2n=18 in some Cyphomyrmex to 2n=48 in Sericomyrmex maravalhas.

Taxonomic research challenges

complexes exist within the subtribe, as demonstrated by the recent description of Mycetomoellerius mikromelanos as distinct from M. zeteki based on integrative taxonomic approaches combining , chemical profiles, molecular markers, and . Previous studies frequently misidentified these , with most reports of 'M. zeteki' or 'M. cf. zeteki' actually referring to M. mikromelanos, including at least one study.