Interaction Between the Ants Zacryptocerus maculatus and Azteca trigona: Interspecific Parasitization of Information

Abstract

In mangrove forests on the Atlantic coast of Panama, the arboreal ant Zacryptocerus maculatus was positively associated with territorial ants in the genus Azteca. Systematic sampling showed that this association was not caused by shared preference for the same size or species of tree. Furthermore, Z. maculatus was not forced to live within territories of Azteca by being excluded from the territories of other abundant ants. Instead, the association appeared to be caused by direct interactions between colonies of Azteca and Z. maculatus. When in the presence of A. trigona, colonies of Z. maculatus engaged in an unusual form of social parasitism. Workers followed pheromone trails deposited by scouts of A. trigona in order to locate newly discovered food sources. In effect, Z. maculatus parasitizes the foraging efforts of A. trigona by reading information contained within its recruitment signals. Z. maculatus workers were able to gain access to these resources because of their stealthy approach and unusual body armor. Observations on related ants suggest that this parasitic habit is shared by other species of Zacryptocerus within the subgenus Harnedia.