title: How to be a dioecious fig: Chemical mimicry between sexes matters only when both sexes flower synchronously.
abstract: In nursery pollination mutualisms, which are usually obligate interactions, olfactory attraction of pollinators by floral volatile organic compounds (VOCs) is the main step in guaranteeing partner encounter. However, mechanisms ensuring the evolutionary stability of dioecious fig-pollinator mutualisms, in which female fig trees engage in pollination by deceit resulting in zero reproductive success of pollinators that visit them, are poorly understood. In dioecious figs, individuals of each sex should be selected to produce odours that their pollinating wasps cannot distinguish, especially since pollinators have usually only one choice of a nursery during their lifetime. To test the hypothesis of intersexual chemical mimicry, VOCs emitted by pollen-receptive figs of seven dioecious species were compared using headspace collection and gas chromatography-mass spectrometry analysis. First, fig-flower scents varied significantly among species, allowing host-species recognition. Second, in species in which male and female figs are synchronous, intersexual VOC variation was not significant. However, in species where figs of both sexes flower asynchronously, intersexual variation of VOCs was detectable. Finally, with one exception, there was no sexual dimorphism in scent quantity. We show that there are two ways to use scent to be a dioecious fig based on differences in flowering synchrony between the sexes.
authors.affiliation: Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175, CNRS-Université de Montpellier-Université Paul Valéry Montpellier-EPHE, 1919 route de Mende, 34293 Montpellier, France.
authors.forename: M
authors.initials: M
authors.lastname: Hossaert-McKey
authors.affiliation: Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175, CNRS-Université de Montpellier-Université Paul Valéry Montpellier-EPHE, 1919 route de Mende, 34293 Montpellier, France.
authors.forename: M
authors.initials: M
authors.lastname: Proffit
authors.affiliation: Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175, CNRS-Université de Montpellier-Université Paul Valéry Montpellier-EPHE, 1919 route de Mende, 34293 Montpellier, France.
authors.forename: C C L
authors.initials: CC
authors.lastname: Soler
authors.affiliation: Xishuangbanna Tropical Botanical Garden (XTBG); National Chinese Academy of Sciences; Menglun, Yunnan China;
authors.forename: C
authors.initials: C
authors.lastname: Chen
authors.affiliation: Laboratoire de Chimie Appliquée, Ecole Nationale Supérieure de Chimie de Montpellier, 8 rue de l'Ecole Normale, 34296 Montpellier Cedex 5, France.
authors.forename: J-M
authors.initials: JM
authors.lastname: Bessière
authors.affiliation: Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175, CNRS-Université de Montpellier-Université Paul Valéry Montpellier-EPHE, 1919 route de Mende, 34293 Montpellier, France.
authors.forename: B
authors.initials: B
authors.lastname: Schatz
authors.affiliation: Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560 012, India.
authors.forename: R M
authors.initials: RM
authors.lastname: Borges
mesh_terms: D000818:Animals; D005075:Biological Evolution; D000067558:Biological Mimicry / Q000502:physiology*; D030681:Ficus / Q000378:metabolism*; D035264:Flowers / Q000378:metabolism*; D054817:Pollination / Q000502:physiology*; D055549:Volatile Organic Compounds / Q000378:metabolism*; D014863:Wasps
chemical_list: D055549:Volatile Organic Compounds