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Rapid increase in dispersal during range expansion in the invasive ladybird Harmonia axyridis
Author(s) -
Lombaert E.,
Estoup A.,
Facon B.,
Joubard B.,
Grégoire J.C.,
Jannin A.,
Blin A.,
Guillemaud T.
Publication year - 2014
Publication title -
journal of evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.289
H-Index - 128
eISSN - 1420-9101
pISSN - 1010-061X
DOI - 10.1111/jeb.12316
Subject(s) - harmonia axyridis , biology , biological dispersal , range (aeronautics) , invasive species , ecology , coccinellidae , zoology , predation , predator , demography , population , materials science , composite material , sociology
The evolutionary trajectories associated with demographic, genetic and spatial disequilibrium have become an issue of growing interest in population biology. Invasive species provide unique opportunities to explore the impact of recent range expansion on life‐history traits, making it possible to test for a spatial arrangement of dispersal abilities along the expanding range, in particular. We carried out controlled experiments in laboratory conditions to test the hypothesis of an increase in dispersal capacity with range expansion in Harmonia axyridis , a ladybird that has been invading Europe since 2001. We found a marked increase in the flight speed of the insects from the core to the front of the invasion range in two independent sampling transects. By contrast, we found that two other traits associated with dispersal (endurance and motivation to fly off) did not follow the same spatial gradient. Our results provide a striking illustration of the way in which predictable directional genetic changes may occur rapidly for some traits associated with dispersal during biological invasions. We discuss the consequences of our results for invasion dynamics and the evolutionary outcomes of spatially expanding populations.