Nuptial gifts fail to resolve a sexual conflict in an insect
1 Centre for Ecology and Conservation, School of Biosciences, University of Exeter, Cornwall Campus, Penryn, TR10 9EZ, UK
2 Centre for Evolutionary Biology, School of Animal Biology (M092), The University of Western Australia, Crawley, WA 6009, Australia
BMC Evolutionary Biology 2008, 8:204 doi:10.1186/1471-2148-8-204Published: 15 July 2008
Because of the potential benefits to individuals of saving investment for future mating opportunities, there is conflict between mates over most aspects of reproduction. Males of many species transfer compounds in the ejaculate that manipulate female reproductive physiology to increase male reproductive success. These seminal compounds are often associated with direct and/or indirect costs to females. In contrast, in some species ejaculates also contain nutrients used by females for somatic maintenance and increased reproductive output. In general, the extent to which male seminal components are detrimental or beneficial to females is poorly understood, and interactions between seminal compounds with different effects have been almost completely neglected. Here we examine the impact of male receptivity-suppressing factors and nutrient donations on female longevity and lifetime reproductive output in the bushcricket Requena verticalis.
We show that receiving multiple ejaculates reduces longevity in female R. verticalis, indicating a cost of male derived receptivity-suppressing compounds. Consumption of male nutrient donations does not appear to ameliorate this longevity cost, and there was no effect of nutrient provisioning on female lifetime fecundity.
These results indicate that nutrient provisioning does not provide a resolution to sexual conflict over female receptivity in this bushcricket species.