The 190 species of leaf-cutter ants live mostly in Latin America. In Belize, they’ve been known to spirit away entire vegetable gardens in a night, carrying the leaves down the holes of the nest and chewing them to a soft pulp. The ants then pluck a tuft of fungus from another part of their farm and plant it on the new leaf. They eat the fungal shoots. The first leaf cutters probably got their starter fungi from the wild. But today, when queens leave the nest to found a new colony, they take along starter pellets.
Fungi in the nests of highly evolved leaf cutters in Brazil, Trinidad, Costa Rica, Nicaragua and three states in the United States, the scientists find, are clones of each other; that is, they are apparently genetically identical. Using DNA analysis, the scientists calculate that the clone has been around for 23 million years, says Cornell’s Ulrich Mueller. Which raises a question: if ants have had so long to farm, why do they always show up at our picnics?
