Male larval nutrition affects adult reproductive success in wild European grapevine moth (Lobesia botrana)

In Lepidoptera, males transfer a spermatophore to females containing sperm and accessory gland secretions that are reinvested into female reproduction, providing a fitness gain to females. One of the key factors shaping male spermatophore size is certainly the resources that males have acquired as larvae. In this study, we investigate how male larval food contributes to shaping the spermatophore quantity and quality and how it affects female reproduction in the European grapevine moth (Lobesia botrana). Specifically, we examined the effect of male origin (cultivar or geographical site) on their mating success by scoring individual motivation to mate, male spermatophore size and amount of sperm, and finally female fecundity and fertility. A strong effect of larval cultivar was found on spermatophore size and amount of fertilizing sperm produced by males. These male characteristics had important repercussions on female reproductive output. Females mating with males producing the biggest spermatophore and more fertilizing sperm were the most fecund and fertile. Finally, females were able to recognize males of different quality during the precopulatory phase and changed their mating behavior accordingly. The present results suggest that male nutritional quality could have an important implication for population dynamics.