title: Agroecosystems shape population genetic structure of the greenhouse whitefly in Northern and Southern Europe.
abstract: BACKGROUND
  To predict further invasions of pests it is important to understand what factors contribute to the genetic structure of their populations. Cosmopolitan pest species are ideal for studying how different agroecosystems affect population genetic structure within a species at different climatic extremes. We undertook the first population genetic study of the greenhouse whitefly (Trialeurodes vaporariorum), a cosmopolitan invasive herbivore, and examined the genetic structure of this species in Northern and Southern Europe. In Finland, cold temperatures limit whiteflies to greenhouses and prevent them from overwintering in nature, and in Greece, milder temperatures allow whiteflies to inhabit both fields and greenhouses year round, providing a greater potential for connectivity among populations. Using nine microsatellite markers, we genotyped 1274 T. vaporariorum females collected from 18 greenhouses in Finland and eight greenhouses as well as eight fields in Greece.
  
  
  RESULTS
  Populations from Finland were less diverse than those from Greece, suggesting that Greek populations are larger and subjected to fewer bottlenecks. Moreover, there was significant population genetic structure in both countries that was explained by different factors. Habitat (field vs. greenhouse) together with longitude explained genetic structure in Greece, whereas in Finland, genetic structure was explained by host plant species. Furthermore, there was no temporal genetic structure among populations in Finland, suggesting that year-round populations are able to persist in greenhouses.
  
  
  CONCLUSIONS
  Taken together our results show that greenhouse agroecosystems can limit gene flow among populations in both climate zones. Fragmented populations in greenhouses could allow for efficient pest management. However, pest persistence in both climate zones, coupled with increasing opportunities for naturalization in temperate latitudes due to climate change, highlight challenges for the management of cosmopolitan pests in Northern and Southern Europe.
authors.forename: Irina
authors.initials: I
authors.lastname: Ovčarenko
authors.forename: Despoina Evripidis
authors.initials: DE
authors.lastname: Kapantaidaki
authors.forename: Leena
authors.initials: L
authors.lastname: Lindström
authors.forename: Nathalie
authors.initials: N
authors.lastname: Gauthier
authors.forename: Anastasia
authors.initials: A
authors.lastname: Tsagkarakou
authors.forename: Karelyn Emily
authors.initials: KE
authors.lastname: Knott
authors.forename: Irene
authors.initials: I
authors.lastname: Vänninen
mesh_terms: D000818:Animals; D057231:Climate Change; D017753:Ecosystem; D005260:Female; D005387:Finland; D051456:Gene Flow; D005828:Genetics, Population; D006115:Greece; D006430:Hemiptera / Q000145:classification / Q000235:genetics*; D018895:Microsatellite Repeats