Abstract

Conflicts of interest between the sexes are considered strong forces in shaping mating systems. Thus an understanding of the behaviour of both sexes is essential. The waterstrider Aquarius remigis has been used in several studies investigating sexual conflict. However, little is known about oviposition behaviour or how it affects male/female interactions. In this study, I observed and quantified oviposition behaviour, tested whether the absence of males affected the temporal pattern of oviposition, and looked for relationships between oviposition behaviour and male/female interactions. Females oviposited under water in a manner not previously described for waterstriders. A daily rhythm in oviposition occurred in the absence of temperature cues. Oviposition rates were below average in the early morning, peaked in the evening just prior to 'lights out' or dusk and continued above average for the first few hours of darkness. The absence of males affected the temporal pattern of oviposition, but not the overall daily rate of oviposition. In the absence of males, oviposition rates were above average in the early morning, increased slightly at dusk, and were below average during darkness. Delayed oviposition in the presence of males was not due to prolonged copulation since females initiated oviposition around the same time regardless of their copulation history. Females were much more reluctant to mate before oviposition than after oviposition. The daily rhythm of oviposition and the effect of oviposition on female reluctance alter the intensity of sexual conflict and sexual selection over the course of the day.