1988 年 28 巻 4 号 p. 203-208
The History of the evolutionary study of eusociality in Hymenoptera are briefly reviewed, and simultaneous evolution of sex ratio and worker behavior is studied. The importance of haplodiploid sex determination is corroborated by computer Simulation. It is also found that the sex ratio of the first brood is biassed by their mother towards the sex which has more worker than another sex. This fact suggests that mother control of sex ratio in first brood is important factor responsible for Hymenopteran society having no male worker.