Lack of fungal cultivar fidelity and low virulence of Escovopsis trichodermoides

Abstract

Fungus-growing ants (the attines) are a paramount example of symbiosis, practicing fungiculture for food. Fungi in the genus Escovopsis (Ascomycota: Hypocreales) threaten the ant fungal cultivars and show patterns of specificity towards them. Escovopsis trichodermoides was described from colonies of the lower attine Mycocepurus goeldii, however, its ecological role is still unknown. Here we provide clues of the generalist nature of E. trichodermoides, with lack of fidelity to fungal cultivars from different attine ant species and low infection in ant colonies of M. goeldii. Inhibitory soluble compounds are produced by E. trichodermoides towards different fungal cultivars, as a mechanism of interference competition. Interestingly this generalist lifestyle is not a common trait of Escovopsis species, which usually show partner fidelity. Our study indicates that Escovopsis has more lifestyles than previously thought, prompting further investigations on its evolution in the attine ant-fungal symbiosis.