Mating aVects reproductive investment into eggs, but not the timing of oogenesis in the Xesh Xy Sarcophaga crassipalpis

Abstract We examined the eVects of mating on repro-ductive investment and the timing of oogenesis in the Xesh Xy Sarcophaga crassipalpis by exposing females to males or not. All females exposed to males were mated within a few days and we found that mating aVected reproductive investment. Virgin females not exposed to males produced a large clutch of eggs (»91), but females exposed to males and mated produced 10 % more. There was no eVect of mat-ing on egg length or mass. There was also no eVect of mat-ing on the timing of oogenesis. Females in both treatments provisioned their eggs at the same rate with yolk Wrst becoming visible in the oocytes on day three of adulthood and complete provisioning of eggs occurring by the seventh day of adulthood. We examined the biochemical basis of egg provisioning by identifying the yolk proteins and quan-tifying their blood titer during the oogenic period in both, females exposed to males and mated and those not exposed to males. There was no diVerence in the timing of the Wrst appearance, peak titer, or disappearance of yolk proteins in the blood between the two treatments. However, consistent with our observation of greater egg production in mated females, these females contained a greater peak yolk pro-tein titer