Breaking the acoustical code of ants: The social parasite’s pathway

Ant colonies represent a well-protected and stable environment (temperature, humidity) where essential resources are stored (e.g., the ants themselves, their brood, stored food). To maintain their social organization, ants use a variety of communication channels, such as the exchange of chemical and tactile signals, as well as caste specific stridulations (Casacci et al. 2013 Current Biology 23, 323–327). By intercepting and manipulating their host’s communication code, about 10,000 arthropod species live as parasites and exploit ant nests. Here, we review results of our studies on Maculinea butterflies, a group of social parasites which mimic the stridulations produced by their host ants to promote (i) their retrieval into the colony (adoption: Sala et al. 2014, PLoS ONE 9(4), e94341), (ii) their survival inside the nest/brood chambers (integration: Barbero et al. 2009 J. Exp. Biol. 218, 4084–4090), or (iii) their achievement of the highest possible social status within the colony’s hierarchy (full integration: Barbero et al. 2009, Science 323, 782–785). We strongly believe that the study of acoustic communication in ants will bring about significant advances in our understanding of the complex mechanisms underlying the origin, evolution, and stabilization of many host–parasite relationships.