Gyne nutrition as a stronger predictor of mating success than nestmateship in Vespula germanica.

Mate choice can optimize resource investment by weighing the benefits of selecting high-quality mates against the costs of rejecting mating opportunities. Female choosiness can be influenced by their own physiological condition as well as nestmate discrimination. In social Hymenoptera, same colony members are usually closely related, and mechanisms allowing nestmate discrimination may reduce the probability of incestuous matings and their associated fitness costs. Here, we examined whether nestmateship and nutritional condition influence mating success in the eusocial wasp Vespula germanica. Through binary-choice olfactory behavioral assays and mating trials, we assessed gyne responses to olfactory cues from nestmate and non-nestmate males and evaluated whether nestmateship and female nutrition influence mating success. Our results indicate that neither gyne preferences nor mating outcomes are affected by nestmateship, whereas female nutrition seems to significantly influence mating success. Gynes showed no preference between nestmate and non-nestmate males and even spent more time in arms containing clean air, suggesting an apparent avoidance of male olfactory cues. Gyne nutrition significantly influenced mating outcomes, as females with higher weight/size ratio exhibited a greater probability of insemination. Overall, our findings suggest that mating outcomes in V. germanica are more strongly associated with female physiological condition than with nestmate avoidance.