Genetic variation in the behavioural mechanisms involved in the response of the egg parasitoid Trissolcus brochymenae to contact chemical cues left by the pest Murgantia histrionica

The ability of parasitoid females to perceive chemical traces left by their hosts is of utmost importance in the host location process. The behaviours involved in such ability have thus most likely been promoted by natural selection in the course of the evolutionary time. For this to happen, however, there must be significant genetic variation in natural populations on which natural selection could act. Using the isofemale line method and motion analysis, we detected significant intra-population genetic variation for several walking behaviour traits of the egg parasitoidTrissolcus brochymenae(Hymenoptera: Scelionidae) females responding to chemical traces left by its hostMurgantia histrionica(Heteroptera: Pentatomidae). Besides opening new avenues of research on the reproductive strategies, behaviour, and biological control potential of parasitoid wasps, these results also have implications for understanding their life-history evolution in general.