%0 Journal Article
%T Discrimination of the Social Parasite Ectatomma parasiticum by Its Host Sibling Species (E. tuberculatum)
%A Ren¨¦e F¨¦n¨¦ron
%A Chantal Poteaux
%A Marie Boil¨¨ve
%A Jorge Valenzuela
%A Fabrice Savarit
%J Psyche
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/573541
%X Among social parasites, workerless inquilines entirely depend on their host for survival and reproduction. They are usually close phylogenetic relatives of their host, which raises important questions about their evolutionary history and mechanisms of speciation at play. Here we present new findings on Ectatomma parasiticum, the only inquiline ant described in the Ectatomminae subfamily. Field data confirmed its rarity and local distribution in a facultative polygynous population of E. tuberculatum in Mexico. Genetic analyses demonstrated that the parasite is a sibling species of its host, from which it may have diverged recently. Polygyny is suggested to have favored the evolution of social parasite by sympatric speciation. Nevertheless, host workers from this population were able to discriminate parasites from their conspecifics. They treated the parasitic queens either as individuals of interest or as intruders, depending on their colonial origin, probably because of the peculiar chemical profile of the parasites and/or their reproductive status. We suggest that E. parasiticum could have conserved from its host sibling species the queen-specific substances that produce attracting and settling effect on workers, which, in return, would increase the probability to be detected. This hypothesis could explain the imperfect social integration of the parasite into host colonies. 1. Introduction Parasitism is found at all levels of biological organization from genes to societies. Social parasites are specialized in exploiting the social living conditions of one or several species [1]. They have evolved manifold in social Hymenoptera, especially in ants where they occur with a huge diversity [1¨C3]. Parasitic ants can take advantage of the host-colony resources only during the phase of colony founding (temporary social parasitism) or throughout their life cycle, either by raiding host brood and then enslaving workers (slave-making) or by cohabiting in the nest alongside the host queens (inquilinism) [1¨C3]. In the most derived form, inquilines have developed a set of adaptations such as the loss of the worker caste and a reduced body size (the ¡°inquiline syndrome¡± [4]). Typically, social parasites and their respective hosts are close phylogenetic relatives. This trend has been formalized as Emery¡¯s rule and generalized in two versions [5, 6]. In the strict version, the parasite is a sibling species of its host; in the loose version, the parasite and the host are nonsiblings but belong to the same or a closely related genus. Some empirical studies support the
%U http://www.hindawi.com/journals/psyche/2013/573541/