Control of reproduction and a survival cost to mating in female Bicyclus nynana butterflies

1. Given that sexual conflict is all pervasive, investigating potential costs to mating and the control of female reproduction are important issues. 2. Here, female reproductive output and longevity are investigated in relation to mating status (virgin vs. once-mated females) and host-plant availability in the tropical butterfly Bicyclus anynana. 3. Both factors significantly affected realised fecundity in a manner demonstrating that female reproduction is not entirely under control of the female herself, but is rather subject to additive contributions of the female, her male partner, and intrinsic physiological processes. As evident from the deposition of significant egg numbers by virgin, host-deprived females, B. anynana is effectively unable to completely inhibit oogenesis. 4. Mated females suffered a reduction in adult life span, which cannot be explained as a side-effect of variation in egg size, lifetime, or early fecundity. 5. Such detrimental effects of mating per se are indicative of the cooperation-conflict balance between sexes being shifted towards conflict in B. anynana.