MULTIPLE MATING, LIFETIME FECUNDITY AND FEMALE MORTALITY OF THE BRUCHID BEETLE, CALLOSOBRUCHUS-MACULATUS (COLEOPTERA, BRUCHIDAE)

1. Females of most insect species mate frequently. Many hypotheses have been proposed to account for the evolution of multiple mating in female insects. In this paper, I test the hypothesis that females of the bruchid beetle, Callosobruchus maculatus, mate frequently to replenish depleting sperm supplies. I also test the hypothesis that females obtain a nutritional contribution from males during copulation, and that this has a positive effect on the female's life history. 2. For C. maculatus, there is no difference in lifetime fecundity between females that mate one time and females that are confined with males throughout life. However, when females are mated at 48-h intervals, but are not confined with males, they lay more eggs than females which have mated only once. 3. When females were maintained under starvation conditions, multiple mating increased female longevity. However, when females had unlimited access to yeast and sugar-water, this influence disappeared. These results support the hypothesis that ejaculate-derived nutrients contribute to female somatic maintenance, but are only detectable when females are nutrient stressed.