Costs to females and benefits to males from forced copulations in fruit flies

► We quantified the costs to females and the benefits to males from forced copulations in fruit flies. ► Forcibly mated females had fewer progeny, shorter life spans and more wing damage than consensually mated females. ► Forcibly mated females also showed higher remating frequencies. ► Forcibly mated males sired significantly fewer progeny than did consensually mated males. ► Males may force-copulate despite low reproductive gain because of the scarcity of sexually receptive females.