Parasite exploitation involves a sequential chain of stages that begins with finding the host, initiating the attack, followed by appraisal of the resource, and then regulation of the host to maximize fitness gains. Parasites face challenges to their success at each stage due to coevolving hosts, yet over 70% of insects meet these challenges and lead a parasitic lifestyle. Social parasites (one social organism parasitizing another), also referred to as “behavioral” parasites, have evolved multiple times in ants. Three Megalomyrmex parasite types (thief ants, agro-predator raiders, guest ants) use a combination of physical and chemical-based dominance behaviors against fungus-growing host ant colonies, consuming host brood and fungus garden. Ant lineages have converged on exploitation strategies defined by the level of integration into the host nest. Thief ants also known as lestobionts, live just outside the nest, stealing food or preying on brood. Agro-predator raiders specialize on fungus-growing ant hosts and usurp the nest consuming all brood and fungus-garden left behind by the farmers. Guest ants or xenobionts, move freely inside the host nest but keep their brood separated from the host’s. I will compare convergent traits relating to parasite exploitation among thief ant, agro-predator raider ant, and guest ant species and highlight the evolution of social parasitism in the genus Megalomyrmex.
