Choice in Varroa jacobsoni Oud. between honey bee drone or workerbrood cells for reproduction

Summary The effect of variation in copulation duration on sperm precedence (P₂) of the last male was investigated in a non-territorial libellulid using irradiated-male techniques and observations in a large field enclosure. Copulation duration varied between 6 min and more than 1 h (X = 23.19 min ± 12.74). In the clutch deposited immediately after the copulation, most copulation durations resulted in high sperm precedence for the last male. Several experimentally interrupted short matings still resulted in 100% precedence. However, most interrupted copulations of 10 min or less resulted in a low P₂. After long, uninterrupted copulations, P₂ remained high in clutches that were collected up to 9 days after the mating. After interrupted short copulations, P₂ fluctuated or remained at a low level from the first clutch onwards. This indicates that sperm mixing probably starts within 24 h and that after a long copulation virtually no rival sperm is left in the female's sperm storage organs. As most natural copulations are long, complete removal of rival sperm seems to be common in S. danae. Only 3 f 17 variables investigated explained a significant amount of the variation in copulation duration. Copulations shortened with increasing temperature and for each additional mating of the male. The strongest effect however, was due to time of day: early morning copulations lasted longer than midday copulations. Adjustment of the copulation duration to the decreasing chance of obtaining additional matings was found to be the most likely of five explanatory hypotheses that were evaluated.