Virgin male age and mating success in Ostrinia nubilalis (Lepidoptera: Crambidae)

It is generally assumed that age is potentially an important aspect affecting the mating biology of insects. Some theoretical models correlate mating success with male age, and predict female preference for either older males, as they have proven viability, or younger partners, to avoid age-related fitness costs. Differences in mating success of males in relation to age have been observed in Lepidoptera. We investigated the mating success of males in relation to their age, controlling for mating experience, and the fitness of their female mates in the European corn borer, Ostrinia nubilalis. In a laboratory experiment we examined mating success in relation to age and the consequences of male age for female fitness parameters. Male age had no significant influence on mating success for O. nubilalis males: 0-day-old virgin males were as likely to mate as 3-, 6- and 9-day-old males. Testes size decreased and spermatophore size increased with virgin male age. Lifetime fecundity was highest for females that mated with 3-day-old virgin males, which was related to their greater longevity. There was no trade-off between daily fecundity and longevity for females mating with different-aged males. These results suggest that direct benefits from males are insufficient to account for the observed female mating preferences for different-aged males.