attine

Attine ants, or Attini, are a tribe of fungus-farming ants within the subfamily Myrmicinae. They are best known for their obligate mutualism with cultivars of fungi that they cultivate in subterranean gardens. The ants harvest plant material, including leaves, stems, and other vegetative matter, which serves as substrate for the fungus. In return, the fungus provides all the nutritional needs of the colony. The symbiosis is highly specialized and is thought to have originated in the Neotropics around 50–60 million years ago, with early lineages tending to more general fungi and later lineages (the higher attines, including leaf-cutters in the genera Atta and Acromyrmex) maintaining highly specialized Leucoagaricus cultivars.

Attine nests are complex, with dedicated fungus chambers and waste disposal areas. The colony structure is caste-diverse, including workers of various sizes, males and queens. Reproduction occurs by winged queens during nuptial flights. Leaf-cutting ants (Atta and Acromyrmex) are among the most prominent attines and are notable for harvesting fresh foliar material to feed their fungal gardens; other attines may use different plant substrates and collections.

The fungal cultivar and its bacterial symbionts shape the ecology of attine nests. Ants host actinobacteria such as Pseudonocardia on their cuticle; these bacteria produce antibiotics that suppress specialized fungal pathogens like Escovopsis and help stabilize the garden. Attine ants play an important role in tropical ecosystems by influencing decomposition and nutrient cycles.

In summary, attine ants are a key example of insect agriculture, representing one of the most elaborate symbioses between insects and microbes in nature.