Termites’ Symbiosis with Fungi

When most people think about termites, they think of little white insects that eat wood. It is easy to forget that for the termites, eating wood is a real challenge.

Termites get their nutrition from cellulose. Cellulose is a very common substance. It is the basic ingredient of wood and most other plant material. Cellulose is found in grass, shrubs, and trees. Cellulose is found in many fibers, including cotton.

Cellulose is very difficult to digest. When many animals, like cows and goats, eat grass, they have to chew it for a very long time in order to digest it.

Many termites digest cellulose by means of tiny one-celled animals in their digestive tract. These tiny animals, called protozoans, actually digest the cellulose. The protozoans break the cellulose down into sugar and then the termites use the sugar for nutrition.

Termites in Africa have a different way of digesting cellulose. They raise fungi in a system that benefits both the termites and the fungi. In this system, the termites and the fungi actually need each other in order to survive.

The African termites, members of the genus Macrotermes, build giant mounds above their nests. The termite workers gather grass, twigs, and other wood debris. They chew up the woody material and bring it back to the nest.

In the nest, the workers deposit the chewed-up woody material onto a pile called a comb. The termite workers place spores of a special fungus called Termitomyces on the woody material in the comb.

The fungus grows on the comb by digesting the cellulose and lignin in the chewed-up wood and grass. The fungi convert the cellulose and lignin into sugars and nitrogen as by-products of digesting woody pulp.

The termites eat the sugary material that is left after the fungi have finished digesting the wood. In this process, the fungus gardens in the termite mounds actually benefit both the fungi and the termites.

Each year, during the rainy season, the fungus gardens inside the termite mounds sprout large mushrooms. The mushrooms grow out through the sides of the mounds. People who live near the termite mounds collect the mushrooms. They prize them as a delicacy.