Tuesday, August 21, 2007

Leafcutter ants are social insects found in warmer regions of Central and South America. These unique ants have evolved an advanced agricultural system based on ant-fungus mutualism. They feed on special structures called gongylidia produced by a specialized fungus that grows only in the underground chambers of the ants' nest. Different species of leafcutter ants use different species of fungus, but all of the fungi the ants use are members of the Lepiotaceae family. The ants actively cultivate their fungus, feeding it with freshly-cut plant material and maintaining it free from pests and molds. This symbiotic relationship is further augmented by another symbiotic partner, a bacterium that grows on the ants and secretes chemicals, or secondary metabolites, which protect the fungus from molds that would feed on the fungus - essentially the ants use portable antimicrobials. Leaf cutter ants are sensitive enough to adapt to the fungi's reaction to different plant material, apparantly detecting chemical signals from the fungus. If a particular type of leaf is toxic to the fungus the colony will no longer collect it.

No comments: