Invasive success of two alien insects at the Kerguelen Islands: role of morphological and ecophysiological adjustments to the novel environmental conditions

• Main Author: Laparie, Mathieu
• Other Authors: Paysage, Changements Climatiques, Biodiversité, Ecosystèmes, biodiversité, évolution Rennes (ECOBIO), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Station Biologique de Paimpont CNRS UMR 6653 (OSUR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES), Université Rennes 1, David Renault, Yves Frénot([e-mail])
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2011
• Subjects: ecophysiology; sub-Antarctic island; biological invasion; morphometrics; phenotypic plasticity; Calliphora vicina; écophysiologie; évolution; île subantarctique; invasion biologique; Merizodus soledadinus; morphométrie; plasticité phénotypique; [SDE]Environmental Sciences; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Antarctic; Îles Kerguelen; Kerguelen; Kerguelen Islands; Antarc*
• Online Access: https://tel.archives-ouvertes.fr/tel-00670533; https://tel.archives-ouvertes.fr/tel-00670533/document; https://tel.archives-ouvertes.fr/tel-00670533/file/These_Mathieu_Laparie_2011.pdf

The success of invasive species depends on the adequacy between their life history traits and the environmental characteristics (biotic and abiotic) of their new habitats. The invasive success may then rely on pre-adaptation, be triggered by the release of some selection pressures, perturbations, or quick responses of the organism to the new selection pressures. Phenotypic plasticity and evolutionary processes are then prime components in biological invasions, so that invasive species can be considered as key models for monitoring ecological and evolutionary processes in real time. We thus investigated morphological and ecophysiological responses produced in time and space during the invasion of the sub-Antarctic Kerguelen Islands by the predatory ground beetle Merizodus soledadinus and the saprophagous blowfly Calliphora vicina, which possess contrasted life strategies. We show morphological differentiation among populations of M. soledadinus depending on their residence time, as well as rapid changes of the C. vicina's wing morphology in these islands where flightlessness is the rule. The invasion of M. soledadinus was studied with special emphasis on the role played by phenotypic plasticity in colonizing habitats that differ from native ones (physiological plasticity to salinity) and maintaining durable populations despite the negative feedback of this predator on the availability of its own prey (trophic plasticity). As they spread and encounter novel selection regimes, these adjustments at different timescales are of paramount importance in the invasive success of both these insect species. Le succès des espèces invasives dépend de l'adéquation entre leurs traits d'histoire de vie et les caractéristiques environnementales (biotiques et abiotiques) de leurs nouveaux habitats. Le succès invasif d'une espèce peut donc reposer sur sa pré-adaptation, être déclenché par la levée de certaines pressions sélectives, les perturbations, ou encore la réponse rapide de l'organisme aux nouvelles contraintes sélectives. ...