Is Multiple Mating by Female Promethea Moths (Callosamia promethea) (Drury) (Lepidoptera: Saturniidae) Fertility Insurance?

Abstract

Multiple mating is apparently rare in female saturniids but male and female Callosamia promethea (Drury) (promethea moth) mate multiple times. Previous study showed that polyandrous females laid significantly more eggs than monandrous females, suggesting the hypothesis that yoke proteins from male ejaculates enhanced fecundity. However, multiple mating by females could arise if a single mating with a previously-mated male results in low fertility. To test this, I compared females mated once to either a virgin male or a male that had copulated the previous day. No differences were found in fecundity or fertility in females mated to virgin males vs. nonvirgin males, showing that multiple mating by female promethea moths is not related to lower fertility when mating with nonvirgin males. I discuss this finding with respect to known cases of polyandry in saturniids and suggest a hypothesis to explain the evolution of polyandry in this group.