Colonization history and factors promoting the success of invading populations of the Asian tiger mosquito Aedes albopictus in Europe

• Main Author: Sherpa, Stéphanie
• Other Authors: Laboratoire d'Ecologie Alpine (LECA ), Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ), Université Grenoble Alpes, Laurence Després, Michaël Blum
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2019
• Subjects: Biological Invasion; Population Genetics; Landscape Genetics; Local Adaptation; Aedes albopictus; Invasion Biologique; Génétique des Populations; Génétique du Paysage; Adaptation Locale; [SDV.BID]Life Sciences [q-bio]/Biodiversity; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.IE]Environmental Sciences/Environmental Engineering; Tigre; Antarc*; Antarctica
• Online Access: https://theses.hal.science/tel-02907540; https://theses.hal.science/tel-02907540/document; https://theses.hal.science/tel-02907540/file/SHERPA_2019_archivage.pdf

The Asian tiger mosquito, Aedes albopictus, is native to Southeast Asia and has colonized all continents but Antarctica in the last decades. However, the factors determining the invasive success of populations at the global scale remain to be elucidated. Focusing on the European invasion, we used a comprehensive framework and multi-source data for distinguishing the role of historical and contemporary processes, both neutral and adaptive, in structuring the genetic variability of invasive populations. Examining the genetic variability of 1,000 individuals from 150 invasive and native populations revealed three independent introduction events in Europe (in Albania, North Italy, and Central Italy), from the United States (previously invaded area) and from China (native range). Primary introduced populations constituted dispersal centers for the colonization of Europe, and migration routes correlate with the geography of human transportation networks. Several admixture events either during introduction or subsequent expansion, as well as high connectivity between invasive populations, promoted the maintenance of high levels of genetic diversity. Pre-existing cold adaptation within the native range of the species and niche conservatism between introduced populations and their sources suggest that these populations were already prepared for establishing under temperate European climate. Nonetheless, shifts in allele frequencies along environmental gradients within Europe suggest post-introduction adaptive changes. The adaptive potential of populations and long-distance human-aided dispersal facilitated the rapid expansion of populations. Although often neglected in the context of biological invasions, natural dispersal at the landscape scale further contributed to range filling in range edge populations. The study of the demo-genetic and environmental characteristics of the European invasion allows a better understanding of processes at play during two key stages of the invasion process: establishment and expansion. ...