Male P. J. G. auteur aut IRD Ferdy J. B. auteur aut IRD Leroy Céline auteur aut IRD Roux Olivier auteur aut IRD Lauth J. auteur aut IRD Avilez A. auteur aut IRD Dejean A. auteur aut IRD Quilichini A. auteur aut IRD Orivel J. auteur aut IRD text journalArticle eng text/pdf born digital access The diversion of a host's energy by a symbiont for its own benefit is a major source of instability in horizontally-transmitted mutualisms. This instability can be counter-balanced by the host's retaliation against exploiters. Such responses are crucial to the maintenance of the relationship. We focus on this issue in an obligate ant-plant mutualism in which the ants are known to partially castrate their host plant. We studied plant responses to various levels of castration in terms of (1) global vegetative investment and (2) investment in myrmecophytic traits. Castration led to a higher plant growth rate, signalling a novel case of gigantism induced by parasitic castration. On the other hand, completely castrated plants produced smaller nesting and food resources (i.e. leaf pouches and extra floral nectaries). Since the number of worker larvae is correlated to the volume of the leaf pouches, such a decrease in the investment in myrmecophytic traits demonstrates for the first time the existence of inducible retaliation mechanisms against too virulent castrating ants. Over time, this mechanism promotes an intermediate level of castration and enhances the stability of the mutualistic relationship by providing the ants with more living space while allowing the plant to reproduce. specialized Evolutionary conflict Cheater Overexploitation Mutualism breakdown Allomerus decemarticulatus Hirtella physophora GUYANE FRANCAISE 076 080 020 41 1 22-28 2014 0071-3260 https://www.documentation.ird.fr/hor/PAR00011529 10.1007/s11692-013-9242-7 0071-3260 [F B010061823] https://www.documentation.ird.fr/hor/PAR00011529 https://www.documentation.ird.fr/intranet/publi/2014/03/010061823.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2014-04-02 2017-08-23 PAR00011529 fre