We compared the microbial communities of Megalomyrmex ants (Solenopsidini), containing free-living predatory species and a derived socially parasitic clade, and their fungus-growing ant hosts (Attini) from the genera Sericomyrmex, Trachymyrmex and Cyphomyrmex, to determine whether (i) the bacterial communities of these distantly related ant lineages have convergently evolved in social parasites and hosts or, (ii) their bacterial communities have remained distinct but some bacterial symbionts might be shared.