Abstract Abstract. Mating behaviour can be expected to reflect a compromise between the conflicting interests of the two sexes. Adults of the water strider, Aquarius remigis, mate many times over a period of several months, and males often remain mounted for several hours following sperm transfer. Conflict between the sexes is indicated by both pre-mating and post-mating struggles. To determine the relative influence of males and females on the frequency and duration of mating, 548 mating interactions were videotaped in the laboratory and an additional 140 interactions were observed under more natural, field conditions. Mating attempts were initiated by males, but most of these attempts were resisted by females. The duration of pre-mating struggles initially increased and then declined as the number of mating attempts increased, suggesting possible mate assessment by females at low levels of harassment, but convenience polyandry at higher levels. Long pre-mating struggles were associated with unsuccessful matings. Matings that were long enough to allow sperm transfer were characterized by short pre-mating struggles and long post-mating struggles. Post-mating struggles invariably resulted in the male being dislodged. Depriving males of mates for 7 days prior to the trials increased the number of mating attempts and the durations of the pre- and post-mating struggles, but did not significantly influence the frequency or duration of mating. These results confirm male incentive to increase the frequency and duration of mating, but indicate that female resistance effectively limits both parameters.