title: Inferring the origin of populations introduced from a genetically structured native range by approximate Bayesian computation: case study of the invasive ladybird Harmonia axyridis.
abstract: Correct identification of the source population of an invasive species is a prerequisite for testing hypotheses concerning the factors responsible for biological invasions. The native area of invasive species may be large, poorly known and/or genetically structured. Because the actual source population may not have been sampled, studies based on molecular markers may generate incorrect conclusions about the origin of introduced populations. In this study, we characterized the genetic structure of the invasive ladybird Harmonia axyridis in its native area using various population genetic statistics and methods. We found that native area of H. axyridis most probably consisted of two geographically distinct genetic clusters located in eastern and western Asia. We then performed approximate Bayesian computation (ABC) analyses on controlled simulated microsatellite data sets to evaluate (i) the risk of selecting incorrect introduction scenarios, including admixture between sources, when the populations of the native area are genetically structured and sampling is incomplete and (ii) the ability of ABC analysis to minimize such risks by explicitly including unsampled populations in the scenarios compared. Finally, we performed additional ABC analyses on real microsatellite data sets to retrace the origin of biocontrol and invasive populations of H. axyridis, taking into account the possibility that the structured native area may have been incompletely sampled. We found that the invasive population in eastern North America, which has served as the bridgehead for worldwide invasion by H. axyridis, was probably formed by an admixture between the eastern and western native clusters. This admixture may have facilitated adaptation of the bridgehead population.
authors: INRA, UMR 1301 IBSV (INRA/Université de Nice Sophia Antipolis/CNRS), 400 Route des Chappes, BP 167-06903 Sophia Antipolis Cedex, France. lombaert@sophia.inra.fr
authors: E
authors: E
authors: Lombaert
authors: T
authors: T
authors: Guillemaud
authors: C E
authors: CE
authors: Thomas
authors: L J
authors: LJ
authors: Lawson Handley
authors: J
authors: J
authors: Li
authors: S
authors: S
authors: Wang
authors: H
authors: H
authors: Pang
authors: I
authors: I
authors: Goryacheva
authors: I A
authors: IA
authors: Zakharov
authors: E
authors: E
authors: Jousselin
authors: R L
authors: RL
authors: Poland
authors: A
authors: A
authors: Migeon
authors: J
authors: J
authors: Van Lenteren
authors: P
authors: P
authors: DE Clercq
authors: N
authors: N
authors: Berkvens
authors: W
authors: W
authors: Jones
authors: A
authors: A
authors: Estoup
mesh_terms: D000818:Animals; D001211:Asia, Western; D001499:Bayes Theorem; D016000:Cluster Analysis; D001517:Coleoptera / Q000235:genetics*; D003198:Computer Simulation; D005202:Asia, Eastern; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D005843:Geography; D058865:Introduced Species; D018895:Microsatellite Repeats; D008957:Models, Genetic; D009656:North America; D010572:Pest Control, Biological