The potential use of a fungal treatment is the result of a 15-year study of leaf-cutter ants in both North and South America, and the sharing of data between the several academic instituting: Rice University, São Paulo State University in Rio Claro, Brazil, and the University of Texas at Austin. The ants are considered pests because they damage crops and trees (particularly fruit trees).
Over this period research groups narrowed down to a particular fungus called Escovopsis. The genus has been recovered from dozens of colonies of leaf-cutter ants and related ant species. The fungus attacks the ants’ food sources and under certain conditions can wipe out the source completely, leading to colony collapse.
Leaf-cutter ants are hard to kill with conventional insecticides because they grow their own food, using fungi. This is through a type of symbiotic or mutualistic relationship.
The process flows by worker ants going out from the nest, cutting and gathering leaves, and then bringing the leaves back to deep underground chambers. The chambers contain fungal gardens. Chambers can be 60 feet deep and several hundred feet wider, containing millions of ants. The fungus-growing ants actively propagate, nurture and defend the basidiomycete fungus.
By exploiting this leaf-fungus factory, researchers have experimented with introducing a parasitic fungus into the mix: Escovopsis. The fungus can destroy the food supply by out-competing the beneficial fungus.
The research outcomes are published in the journal Royal Society Open Science. The paper is called “Shared Escovopsis parasites between leaf-cutting and non-leaf-cutting ants in the higher at tine fungus-growing ant symbiosis.”
