THE PRECOPULATORY FUNCTION OF MALE GENITAL SPINES IN DROSOPHILA ANANASSAE[DOLESCHALL] (DIPTERA: DROSOPHILIDAE) REVEALED BY LASER SURGERY

That male genital morphology evolves via postcopulatory sexual selection is a widely held view. In contrast, the precopulatory sexual selection hypothesis for genital evolution has received less attention. Here, we test the hypothesis that male genital spines of Drosophila ananassae promote competitive male copulation success. Using laser surgery to manipulate trait size, we demonstrate that incremental reductions of spine length progressively...