Nestmate recognition in the absence of a pheromone

Individual recognition cues were manipulated to elucidate the system of nes tmate recognition employed by the introduced European paper wasp, Polistes dominulus. Tests involved exposing P. dominulus individuals to their natal nest material, to which we added a novel hydrocarbon, pentacosanoic acid me thyl ester, or exposing them to the artificial odor alone. Results show tha t II dominulus (1) performs nestmate discrimination, (2) can use artificial exogenous chemicals as recognition odors, and (3) can distinguish single d ifferences in hydrocarbon profiles. Taken individually, these experiments p rovide evidence revealing the nature of the production and action component s of recognition. Taken together, these results establish that recognition takes place outside the classical definition of a pheromone-based system.