© 1972 by The Society for Integrative and Comparative Biology
The Fungus-culturing Behavior of Ants
Biology Department, Swarthmore College Swarthmore, Pennsylvania 19081
A colony of attine ants begins with a recently fecundated female carrying hyphae from the parental garden in a pellet in an infrabuccal pocket. All future food of the colony will be derived from this nucleus. She digs a cavity in the ground, ejects this pellet and manures it with her liquid excrement. As the hyphae proliferate, eggs are laid on them and the colony is launched. She continually licks both the hyphae and the brood. Thus, both salivary and anal excretions play a vital role in the beginning of a colony and this pattern is repeated by the resulting workers. About 60–65% of them in Atta are the minima and these are intimately involved in brood and fungus care. Their excretions are disproportionately large. About 1/3 of the workers in Atta are 4–6 mm media and these cut and prepare the substrate. The 7–9 mm maxima sizes and the soldiers (over 9 mm) are less directly involved in culturing the fungus.
The effectiveness of fungus culturing is shown by the rapid build-up of gardens. The ants maintain their garden despite surrounding contamination after a fragment with ants is introduced to a plate of sterile nutrient agar.