A COMPARISON OF FEMALE POSTCOPULATORY BEHAVIOR IN DROSOPHILA-MELANOGASTER AND DROSOPHILA BIARMIPES

The postcopulatory behavior of Drosophila biarmipes and Drosophila mel anogaster females was analyzed and compared. Females from both species were shown to undergo a series of behavioral changes following mating , including significant reductions in both sexual attractiveness and r eceptivity. However, while both attractiveness and receptivity returne d to ''virgin-like'' levels within a few days in D. melanogaster, D. b iarmipes females, which regained their sexual attractiveness within a few days, remained unreceptive to copulation for at least 2 weeks. Wit h respect to fecundity, D. melanogaster females produced more offsprin g when given opportunities to remate, while D. biarmipes females did n ot benefit from remating opportunities. These observations suggest tha t D. biarmipes females may have the ability to store sperm and produce offspring from a single mating ol er longer periods of time than othe r drosophilids.