Sperm Strategies: Partner's Mating Status as a Driver of Last Male Success in Ladybirds

Abstract

In the present study, we examined the last male sperm precedence based on the mating status of males and females (virgin, once-mated, or multiply-mated) of a coccinellid beetle, Menochilus sexmaculatus (Fabricius). Results revealed that, in comparison to virgin females, once- and multiply-mated females significantly affected the process of last male sperm precedence. While virgin females either showed the last male sperm precedence effect or produced equal numbers of offspring with phenotypes similar to both male partners. The latter result was obtained when: (i) the virgin female mated with an unmated typical male followed by a multiply-mated intermediate male, or (ii) the virgin female mated with a once-mated typical male followed by a multiply-mated intermediate male. However, once- and multiply-mated females showed the first male precedence in all mating treatments, and their offspring had phenotypes similar to the first male partner. Present empirical studies suggest that the process of the last male sperm precedence is not ubiquitous in M. sexmaculatus. Rather, it changes with the mating status of the partners, and the effects of female mating status on the last male sperm precedence are more prominent than the male mating status.