Which fungus is cultivated by leafcutter ants as their main food crop?

The fungus most commonly associated with leafcutter ants’ cultivated food crop is Leucoagaricus gongylophorus.

Leafcutter ants do not primarily eat the fresh leaves they carry. Workers cut plant material, bring it underground, chew it into a substrate, and tend a fungus garden. The fungus breaks down difficult plant carbohydrates and converts the leaf mulch into nutritious tissue that the colony can use. This makes the ants farmers rather than simple leaf-eaters.

The fungus produces swollen hyphal tips called gongylidia, often clustered into structures known as staphylae. These nutrient-rich swellings are especially important food for the larvae, while workers also obtain nutrients from the garden and its products. The best-known farming ants belong to the higher attine groups, including Atta and Acromyrmex.

The partnership is a tightly managed mutualism. Ant workers weed unwanted molds, remove contaminated garden material, and can carry antibiotic-producing bacteria that help suppress pathogens such as Escovopsis. Different fungus-growing ants may cultivate different fungal lineages, so this species is not the only fungus used by all attine ants. However, L. gongylophorus is the classic and most commonly documented crop of leafcutter ants.