Male size and sequential mate preference in the cricket Gryllus bimaculatus

In crickets, females show preferences for male traits such as body size and either reject outright, take longer to mate with, or remove the spermatophores of nonfavoured males sooner, interrupting sperm transfer. In most mate choice studies, however, empirical tests so far have concentrated on choice between simultaneously presented males, which may not reflect the natural situation. We exposed sequentially to potential mates females that ranged from completely naive (virgin) to twice mated. Naive females did not remove the spermatophores of smaller males sooner, but tended (nonsignificant) to reject small males outright. With increasing experience, there was a general decline in spermatophore retention time, but large males were favoured: females either increased retention time when large males succeeded small males or maintained it for the same duration. There were more rejections when small males succeeded large or small males, but fewer when large males succeeded small males. Females appeared to 'bet hedge' at the first copulation, rather than be unable to judge male size/quality; but with increasing experience, their spermatophore retention and rejection behaviour clearly indicated a favouring of large males and an active discrimination against small males. There was a first-male advantage in terms of sperm transfer, but subsequent female behaviour compromised any advantage gained by a small first mate. (C) 2001 The Association for the Study of Animal Behaviour.