Escovopsis trichodermoides as a parasite in the lower-attine ant fungiculture

Abstract

An interesting example of symbiotic association is the mutualism between ants in the tribe Attini and fungi they grow for food. Fungi in the genus Escovopsis are parasites of the fungal partner cultivated by these insects. The parasite is specialized to certain mutualistic fungi, although occasional host switches occurred during the evolution of this association. Recently, our research group described Escovopsis trichodermoides from lower attine ant colonies. There is a lack of knowledge regarding its specificity and parasitic mechanisms towards the mutualistic fungi cultivated by lower attine ants. In this study we will attempt to answer the question: Does E. trichodermoides present similar parasite-host specificity that naturally occurs in other Escovopsis species? In vitro dual-culture assays will be performed to evaluate whether these strains inhibit the growth of the mutualistic fungi. In addition, experiments will be carried out to evaluate the preference of E. trichodermoides strains to different mutualistic fungi of lower attine ants. Then, we will also verify the possible mechanisms used by E. trichodermoides to affect their host. In this case, we will perform growth assays of the mutualistic fungi against the metabolites produced by E. trichodermoides, in addition to scanning electron microscopy experiments to investigate the physical interaction with its host. Our results will determine whether E. trichodermoides is in fact a parasite of the fungi cultivated by lower attine ants. Moreover, our results will demonstrate the generalist or specialist behavior of this parasite against its host. Therefore, this project will contribute to the understanding of the evolution process of Escovopsis parasitism associated with lower attine ants, describing the role of E. trichodermoides in colonies of these insects. (AU)