Which term describes ants farming fungi underground on chewed leaves?
Leaf-cutting ants and their cultivated fungus form a resource-based mutualism built on reciprocal nutrition. Workers cut vegetation, clean it, inoculate it with fungal mycelium, remove contaminants, and maintain suitable temperature and humidity in underground gardens. The fungus enzymatically breaks down plant material and produces nutrient-rich structures eaten by ant larvae and adults. Ants thus obtain digestible food from substrates they cannot efficiently use directly, while the fungus receives a protected, continuously supplied growth environment and dispersal to new nests by founding queens. Antibiotic-producing actinobacteria associated with some ants add defense against garden pathogens, showing that the system can involve several mutualists. Mycorrhiza specifically describes fungi associated with plant roots, not an ant agricultural garden. Defensive mutualism captures only disease protection, whereas the primary ant–fungus exchange is substrate and cultivation for food. Commensalism is excluded because both partners gain and many leaf-cutter lineages and cultivars have become highly dependent on one another through long coevolution.
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 8-13