Evolutionary Applications (2011) 4, 71-88

Benoît Facon, Laurent Crespin, Anne Loiseau, Eric Lombaert, Alexandra Magro and Arnaud Estoup (2011)
Can things get worse when an invasive species hybridizes? The harlequin ladybird Harmonia axyridis in France as a case study
Evolutionary Applications 4 (1), 71-88
Abstract: 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.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Benoît Facon, Alexandra Magro

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Harmonia axyridis (predator)			France