Reduced Mating Success of Female Tortricid Moths Following Intense Pheromone Auto-Exposure Varies with Sophistication of Mating System

Mating disruption is a valuable tool for the management of pest lepidopteran species in many agricultural crops. Many studies have addressed the effect of female pheromone on the ability of males to find calling females but, so far, fewer have addressed the effect of pheromone on the mating behavior of females. We hypothesized that mating of female moth species may be adversely affected following sex pheromone auto-exposure, due to abnormal behavioral activity and/or antennal sensitivity. Our results indicate that, for Grapholita molesta and Pandemis pyrusana females, copulation, but not calling, was reduced following pre-exposure to sex pheromone. In contrast, for Cydia pomonella and Choristoneura rosaceana, sex pheromone pre-exposure did not affect either calling or copulation propensity. Adaptation of female moth antennae to their own sex pheromone, following sex pheromone auto-exposure, as measured by electro-antennograms, occurred in a species for which identical exposure reduced mating success (G. molesta) and in a species for which such exposure did not affect mating success (C. rosaceana). These results suggest that pre-exposure of female moths of certain species to sex pheromone may further contribute to the success of pheromone-based mating disruption. Therefore, we conclude that, in some species, mating disruption may include a secondary mechanism that affects the mating behavior of female moths, in addition to that of males.