Articles

Fungus Farmers

By Trevor Major

Leafcutting ants grow and eat fungus. To accomplish this tremendous feat, the ant colonies divide the work among classes. The biggest ants have powerful jaws to cut leaves, flower pedals, and blades of grass. They bring these big pieces back to the nest where slightly smaller workers cut and dice the plant material into tiny lumps. The smallest workers chew these up into “spit balls” and add bits of fungus. The ant “spit” contains ingredients that help the fungus break down the plant material, and kills harmful bacteria and other fungi.

Small workers also strip off wax and other parts of the plants that the fungus cannot use. They dump this trash into special waste chambers. There are other classes, too, like the soldiers who protect the nest from invaders. Some types of leafcutting ants have small hitchhikers that help the big workers. Then there is the queen. She starts out with wings, and flies away with a piece of the fungus to establish a new colony. Every worker born in that colony, no matter what class it belongs, will be her daughter.

As you can tell, the fungus gets a good deal. The ants feed it, protect it, and spread it from place to place. In return, the fungus grows a clump of special hyphae. Each lump is like an instant three-course meal. The smallest workers feed these to the larvae, but the adults get most of their food from nectar and plant juices.

The leafcutter ants and its fungus have come to depend on each other. You will never find the ants without their fungus. And most of the time, the fungus grows nowhere else, except in the special gardens of the leafcutter ants. No one knows how nature could have come up with such a complicated arrangement. That God designed these ants to be fungus farmers is a much better explanation.

Discovery April 1999 pg. 29