Study on sexal-selection and mating success of a subsocial spider mite.

1999年，对具有亚社会生活的miscanthi Saito Schizotetranychus进行了行为学和形态学观察。首先建立了不同装螨方式下，反映螨体大小的几个形态特征。然后，我对雄性在巢穴中的分布模式进行了实地调查，以了解在实验条件下观察到的雄性攻击行为如何真正反映了雄性在野外的行为。结果表明，雄性-雄性攻击行为与田间每巢雄性聚集模式吻合较好。结果表明，具有不同雄性攻击水平的两类米氏蝽是性隔离的，可以认为它们是不同的亚种或种。2000年：在不同地区采集了拟雄（刚蜕皮前）和实雄（成虫），并对其形态进行了观察。在本州岛和九州岛的大多数种群中，雄性腿长呈单峰分布，但在频率分布上呈双峰分布，表明了种群雄性交配策略的划分。在实验条件下，通过控制食物条件，我可以得到大小不一的成虫。然后对不同体型的雄性和雌性的交配成功率进行了评价。结果表明，在24小时的交配期内，各组合间差异不显著。但是，为了知道更精确的结果，我应该在未来通过缩短交配周期来继续这个实验。

1999 : I conducted behavioral and morphological observations on Schizotetranychus miscanthi Saito which has subsocial life. I first established several morphological characters of S.miscanthi which reflect mite body size regardless of mounting methods. Then I conducted field surveys on male distribution patters over nests in order to know how the male-male aggressions observed under experimental conditions really reflect male behavior in fields. The result showed that the male-male aggression in S.miscanthi well correspond to the male aggregation pattern per nest in fields. Furthermore, it was revealed that the two groups of S.miscanthi having different levels of male aggression are sexually isolated and they are considered to be different sub-species or species.2000 : The potential males (just before molting) and actual males (adult) of S.miscanthi were collected in various districts and inspected their morphology. The male leg I length of Iriomote population showed bimodal frequency distribution, though it showed uni-modal distribution in most populations of Honshu and Kyushu Islands, seggesting division of male mating tactic in Iriomote population. Under experimental conditions, I could get small and large adults by controlling food conditions. Then the mating success of males and females having different body size was evaluated. The result showed that there is no significant difference among all combinations during 24 hr mating period. However, in order to know more precise result, I should continue this experiment by shortening the mating period in the future.