Nestmate recognition behaviors and chemical cue diversity of the co-habitating ants Camponotus femoratus and Crematogaster levior in French Guiana

Parabiosis is the only ant-ant nesting symbiosis to be considered as a mutualism. This unique nesting relationship involves shared nest space and foraging trails between two social insect species, usually of different subfamilies. We examined the nestmate recognition behaviors of two reputedly obligate parabiotic partners; Camponotus femoratus and Crematogaster levior. These two ants occur in the ant-gardens of Amazonia, and we studied their intra and interspecific behavior towards nestmate and non-nestmates during March and July 2010. We also examined the cuticular hydrocarbon cue diversity of the population under study. We found there was no significantly increased aggression towards non-nestmates of the different species, but that ants were aggressive to non-nestmates of the same species. These results may indicate that the close mutualistic nesting relationship does not result in colony-level distinguishing of the other species. The lack of shared cuticular cues may be one reason that ants have low recognition towards their nest partners. Understanding this shared nesting relationship will lead to a greater understanding of social colony function, and of the evolution of mutualisms.