|| 要旨トップ | 目次 |||日本生態学会第62回全国大会 (2015年3月、鹿児島) 講演要旨
一般講演（口頭発表） I1-23 (Oral presentation)
In order to reproduce, males generally compete for access to females. In the male-male competition, males usually display fighting behaviour against rival males. However, they also may display non-fighting tactics such as sneaking and satellite behaviour. Non-fighting tactics are likely displayed by less competitive males, who often lose the male fight and hence make the ‘best of a bad job’ to produce at least a few offspring. However, if the alternative tactics maximize lifetime reproductive success, all males may display non-fighting as well as fighting tactics. Life-history theory predicts that young males avoid fighting or other risky tactics, because the likelihood of future reproduction is high when young. Recently, we found sneaking behaviour as a non-fighting male mating tactic in the two-spotted spider mite, Tetranychus urticae Koch. We also found that the alternative male mating tactics in this mite are not maintained as a genetic polymorphism and that the sneaking behaviour is not associated with morphological differences such as body size and weapon size. Here, we report the flexibility of the male mating tactics and an association of mating tactics with male age.