Open AccessCan things get worse when an invasive species hybridizes? The harlequin ladybird Harmonia axyridis in France as a case study
Author(s) -
Facon Benoît,
Crespin Laurent,
Loiseau Anne,
Lombaert Eric,
Magro Alexandra,
Estoup Arnaud
Publication year - 2011
Publication title -
evolutionary applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.776
H-Index - 68
ISSN - 1752-4571
DOI - 10.1111/j.1752-4571.2010.00134.x
Subject(s) - harmonia axyridis , biology , invasive species , population , biological pest control , introduced species , coccinellidae , hybrid , ecology , zoology , phenotypic plasticity , effective population size , genetic variation , evolutionary biology , genetics , botany , predation , demography , predator , gene , sociology
So far, only a few studies have explicitly investigated the consequences of admixture for the adaptative potential of invasive populations. We addressed this question in the invasive ladybird Harmonia axyridis . After decades of use as a biological control agent against aphids in Europe and North America, H. axyridis recently became invasive in four continents and has now spread widely in Europe. Despite this invasion, a flightless strain is still sold as a biological control agent in Europe. However, crosses between flightless and invasive individuals yield individuals able to fly, as the flightless phenotype is caused by a single recessive mutation. We investigated the potential consequences of admixture between invasive and flightless biological control individuals on the invasion in France. We used three complementary approaches: (i) population genetics, (ii) a mate‐choice experiment, and (iii) a quantitative genetics experiment. The invasive French population and the biological control strain showed substantial genetic differentiation, but there are no reproductive barriers between the two. Hybrids displayed a shorter development time, a larger size and a higher genetic variance for survival in starvation conditions than invasive individuals. We discuss the potential consequences of our results with respect to the invasion of H. axyridis in Europe.