Species Fact Profile: Leaf-Cutter Ant (Atta cephalotes)

Leaf-Cutter Ant

Atta cephalotes (Linnaeus, 1758)

Range: Central America, Northern and Central South America
Habitat: Tropical Rainforest
Diet: Fungus cultivated in underground chambers, Nectar, Grubs
Social Grouping: Colonies of several millions of individuals
Reproduction: The queen is the mother of all other ants in the colony, most of which are sterile.  When the time does come for the colony to spread, she lays eggs which develop into fertile males and females, who leave the colony to establish new ones.  Upon breeding, the males die while the females lay millions of eggs to generate the new colony (using sperm stored from the multiple males).  Mature at 40-50 days
Lifespan: Worker - 1-2 years, Queen - up to 20 Years
Conservation Status: Not Evaluated

• Body length about 10 millimeters (queens up to 25 millimeters), dark red in color.  Small spines on the back of the thorax (back section) help them haul leaf fragments
• Worker ants scour the forest by day, using chemical cues to let other members of their colony know when they have found a good source of leaves.  The harvested pieces of leaves are carried back to their colony and chewed up.  The leaves themselves are not eaten - instead, they are used to cultivate fungus, which the ants feed on
• New colonies are established by queens who set off from their natal colony carrying a small piece of fungus.  At the time of her departure she is winged and accompanied by a number of males, also winged.  She looses her wings after settling down and breeding
• Worker ants are divided into castes based on size.  Small workers tend the underground fungus gardens, medium workers go off into the forest to collect leaves, and larger workers serve as colony guards.  An additional caste tends to the rubbish and waste piles, and has a markedly shorter lifespan than the other ants
• Nest sites are positioned so that breezes will come and carry off potentially toxic fumes generated by the fungus gardens
• Considered agricultural pests by some farmers as they will forage in cultivated fields, but also benefit the environment by aerating soil

Zookeeper's Journal: Leaf-cutter ants (of which there are several species) are among the mainstays of zoo invertebrate collections.  They are often displayed through a series of tubes running through a building, with visitors being able to observe the little ants as they trek back and forth to collect plant matter from feeding stations and haul the pieces of greenery back to their colony.  Ants are among the most prolific, abundant, and ecologically important insects in the world, and few species lend themselves better to public display than leaf-cutters.  I mean, they can still be hard to see by themselves, but the big chunks of leaves that they haul around, combined with their constant movement, make them much easier to observe than many other species.  Their impact on the rainforests where they live is enormous, as a colony is capable of stripping a tree's leaves in a day.  Their use of agriculture is also very unique, being one of the most impressive adaptations of any species, vertebrate or invertebrate.  Managing leaf-cutter ants in a zoo outside of their natural range requires permits from APHIS to assure that they will not escape and establish themselves as a pest.