Calopteryx atrata has weak sexual dichromism of the wings, and females lack pseudopterostigmata whereas C. cornelia and C. virgo japonica have stronger sexual dichromism, with pseudopterostigmata present in the female. The mating sequence of atrata is described and compared with that of the other two, based on a review of 6 species hitherto studied by several authors. Life span estimates for C. atrata and C. virgo japonica are presented. Their survival curves are somewhat different from each other.