Mating strategy of spider mite, Tetranychus urticae (Acari : Tetranychidae) males: postcopulatory guarding to assure paternity

Precopulatory guarding behavior in males of Tetranychus urticae occurs beca use only the first mating is effective for females. Sufficient copulation d uration to fertilize females in the laboratory is shorter than it is in nat ure. This finding leads to the hypothesis that the copulation duration of T : urticae is prolonged by postcopulatory guarding which prevents the female from remating with other males. To test this hypothesis, we manipulated th e interval between the first and second copulations of a female. A signific ant positive correlation was detected between the mating interval and the p roportion of daughters fathered by the first male of each brood. Males usin g postcopulatory guarding are successful when other males disturb the matin g pair to take over from the mating male. These results demonstrate that ma les gain from prolonged copulation that prevents a female from remating unt il their sperm precedence is assured. Thus, males of T. urticae increase th eir paternity not only by precopulatory guarding but also by the postcopula tory guarding.