Variation in copulation duration and the resultant degree of sperm removal inOrthetrum cancellatum (L.) (Libellulidae: Odonata)

Summary Orthetrum cancellatum showed two distinct copulation durations at a study site in the south of France. These different durations are correlated with different degrees of sperm displacement from the female sperm stores; long copulations (894±142 s) resulting in almost 100% sperm removal, and short copulations (21.0±13.5 s) resulting in 10–15% removal. The difference in copulation duration is also related to the site of copulation and to the relative age of the copulating males. At oviposition sites males who gained copulations were relatively young and copulated for long periods. The difference in the duration of copulation and the degree of sperm removal is discussed with reference to the female habit of ovipositing before remating during oviposition episodes, and the possibility of differences in the rate at which males encounter receptive females at the two sites.