Disease management in two sympatric fungus-growing ants for controlling the parasitic fungus .

Antagonistic interactions between host and parasites are often embedded in networks of interacting species, in which hosts may be attacked by competing parasites species, and parasites may infect more than one host species. To better understand the evolution of host defenses and parasite counterdefenses in the context of a multihost, multiparasite system, we studied two sympatric species, of congeneric fungus-growing ants (Attini) species and their symbiotic fungal cultivars, which are attacked by multiple morphotypes of parasitic fungi in the genus, . To assess whether closely related ant species and their cultured fungi are evolving defenses against the same or different parasitic strains, we characterized that were isolated from colonies of sympatric and . . We assessed in vitro and in vivo interactions of these parasites with their hosts. While the ant cultivars are parasitized by similar spp., the frequency of infection by these pathogens differs between the two ant species. The ability of the host fungi to suppress growth, as well as ant defensive responses toward the parasites, differs depending on the parasite strain and on the host ant species.