Leafcutter Ant Colony

General Information

Leafcutter ant development has four life cycle stages, each of which is different from the other stages. The four stages are: egg, larval, pupal and adult. These ants live in Central and South America in large colonies that may number into the millions of individuals. Leafcutter ants cut leaves and other plant parts, which is where they get their name. Instead of eating the plants they collect, leafcutter ants take the plant materials back to their nests to grow a fungus garden. This fungus is their only known source of food. Some of the plant materials the Texas leafcutter ant (Atta texana) damages include grasses, crops, fruit trees, ornamental plants and even weeds.

Leafcutter Ant Colony

Leafcutter ant queens are the reproductive females within the colony. New colonies start when queens mate with males during mating flights. In Texas, Atta texana mating flights occur at night during the months of April through June. After mating, the male dies and the queen loses her wings. The queen leaves the nest that she was raised in, carrying a fungal part known as the mycelium. The mycelium is carried in a special pocket located in her mouth. The wingless queen digs a small tunnel where she begins laying eggs and culturing her fungus garden using the mycelium she brought with her. Since fungus growth is scarce in the beginning of the new nest, the queen will get nourishment by eating many of her own eggs. However, in time the eggs from her first brood will become adult ants that will begin searching for and collecting foliage used to develop the fungal gardens. As subsequent broods develop, more and more workers forage for plant material to provide a substrate to grow fungus and expand the colony.

Most adult ants in the colony are sterile, female workers. These workers are divided into various forms (castes) of mature workers. Each worker is a different size and has a different role within the colony. The largest workers are soldiers (majors) who guard the nest entrances. The smaller workers (minors) protect the foraging ants and the forage trails from intruders. The medium-sized (mediae) workers cut and carry pieces of leaves and other plant materials back to the nest. Smaller workers (minims) take the plant material from the mediae workers, cut the material into smaller pieces and give it to other specialist ants. The job of these highly specialized ants is to further chew and soften these plant bits into a pulp-like material, then introduce and cultivate fungus to create the fungus gardens within the nest. These workers maintain the nest environment that enables the fungus gardens to grow, plus they will care for the queens and their broods. As the queen’s eggs hatch, the minims care for the larvae which feed on the fungus that provides energy for both the adult and larval ant’s diet.

Four to five queens may inhabit one colony, and they may survive for many years. A mature colony will have many ant mounds that are interconnected by underground tunnels.