Biocontrol of leaf-cutting ants using the fungus Escovopsis

Abstract

Leaf-cutting ants (Atta and Acromyrmex) make up the largest group among the derived fungus-growing ants, being considered the most important herbivores in the Neotropics. They live in an obligatory mutualism with the fungus Leucoagaricus gongylophorus (Basidiomycota: Agaricales), providing fresh plant parts as substrate for it, which is their main food source. In turn, ants promote the fungus dispersion and provide protection against alien microorganisms through mechanical and chemical strategies of cleaning. Despite these precautions, a wide variety of microbial groups (yeasts, filamentous bacteria, microfungi) may live inside the nests as well as on their body surface. One of these microorganisms is the fungus of the genus Escovopsis considered a potent antagonist of the symbiosis. Escovopsis has a large distribution among Attini ants group (except for the genus Cyphomyrmex) and can hardly affect infected nests. In this work we aim to develop a method of biocontrol of the leaf-cutting ants through the interaction of the mutualistic fungus and selected strains of the parasite Escovopsis.