CONFLICTS-OF-INTEREST BETWEEN THE SEXES - A STUDY OF MATING INTERACTIONS IN A SEMIAQUATIC BUG

Mating behaviour can be expected to reflect a compromise between the c onflicting interests of the two sexes. Adults of the water strider, Aq uarius remigis, mate many times over a period of several months, and m ales often remain mounted for several hours following sperm transfer. Conflict between the sexes is indicated by both pre-mating and post-ma ting struggles. To determine the relative influence of males and femal es on the frequency and duration of mating, 548 mating interactions we re videotaped in the laboratory and an additional 140 interactions wer e observed under more natural, field conditions. Mating attempts were initiated by males, but most of these attempts were resisted by female s. The duration of pre-mating struggles initially increased and then d eclined as the number of mating attempts increased, suggesting possibl e mate assessment by females at low levels of harassment, but convenie nce polyandry at higher levels. Long pre-mating struggles were associa ted with unsuccessful matings. Matings that were long enough to allow sperm transfer were characterized by short pre-mating struggles and lo ng post-mating struggles. Post-mating struggles invariably resulted in the male being dislodged. Depriving males of mates for 7 days prior t o the trials increased the number of mating attempts and the durations of the pre- and post-mating struggles, but did not significantly infl uence the frequency or duration of mating. These results confirm male incentive to increase the frequency and duration of mating, but indica te that female resistance effectively limits both parameters.