Coevolution Between Slavemaking Ants and Their Hosts

Ohio State University Research Foundation -Do Not Use, Columbus OH

Investigators

Abstract

Coevolution between slavemaking ants and their hosts Joan M. Herbers Slavemaking ants are "social parasites" that can survive only by capturing worker pupae from another species. Those captured workers hatch out in the slavemaker nest and start to forage, clean, feed the larvae, and so on. The slavemaker ants do virtually nothing except find other colonies of host species. When the slavemakers find a host colony, they stage a "slave raid" in which they enter the host nest, injure or maim those defending their nest, and remove pupae to return to their own slavemaking nest. We have uncovered geographic variation in how these two species interact: in a site near Albany, New York, slavemakers are extremely fierce and hosts resist raids strongly. By contrast, the interaction in a site in mountainous West Virginia is more benign; slavemakers kill few hosts during a raid, and the hosts themselves offer little resistance. In a third site near Burlington, Vermont, the ants show characteristics intermediate between these two extremes. The powerful tools of molecular ecology will be used uncover how often slave raids end in death of the host, how many slave raids a given slavemaker nest mounts in a year, and what the impact on their host population is. Second, mounting slave raids between ants parasites and hosts collected from the same site versus different sites will offer insight to how localized interactions can be. Finally, the genetic, ecological, and behavioral will be analyzed in terms of the "coevolutionary arms race" metaphor that has proven useful in studies of other parasite-host relationships.