title: Intraspecific variability in the parasitoid wasp Trichogramma chilonis: can we predict the outcome of hybridization?
abstract: In the framework of biological control, the selection of effective natural enemies determines the final pest control. Thus, the genetic improvement of biocontrol agents could enhance the efficiency of biocontrol programs. Although promising, this approach has rarely been applied in this field. At the intraspecific level, hybridization between divergent populations of biocontrol agents is expected to promote hybrid vigor (heterosis), but it is not clear to what extent. An even more difficult task is the ability to predict the fitness of hybrids from the biological characteristics of their parents. We investigated these general questions by crossing seven populations of the parasitoid wasp Trichogramma chilonis (Hymenoptera: Trichogrammatidae). Our results show different levels of mating compatibilities among populations, including asymmetric or almost complete reproductive isolation. Hybrids' performance (fitness of the F(1) generation) ranges from inbreeding depression to heterosis. It was possible, to some extent, to predict hybrid fitness from pairwise genetic and phenotypic distances among parents, in accordance with the 'dominance' hypothesis. This may provide general guidelines for the genetic improvement of biological control agents.
authors.forename: Chiara
authors.initials: C
authors.lastname: Benvenuto
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Tabone
authors.forename: Elodie
authors.initials: E
authors.lastname: Vercken
authors.forename: Nathalie
authors.initials: N
authors.lastname: Sorbier
authors.forename: Etty
authors.initials: E
authors.lastname: Colombel
authors.forename: Sylvie
authors.initials: S
authors.lastname: Warot
authors.forename: Xavier
authors.initials: X
authors.lastname: Fauvergue
authors.forename: Nicolas
authors.initials: N
authors.lastname: Ris