Abstract
The life cycles of two bamboo scale insects, Unachionaspis bambusae and Nikkoaspis shiranensis, which are parasitic on the dwarf bamboo, Sasa nipponica, were investigated on Mt. Ohdaigahara, central Japan. U. bambusae and N. shiranensis overwintered as adults. U. bambusae laid eggs from May to July and N. shiranensis from May to August. They had eggs and larvae under their scales and the larvae were found on current leaves in July, suggesting that dispersal occurs from June to July. Consequently, the number of U. bambusae and N. shiranensis per 50 leaves of S. nipponica decreased dramatically from June to July. U. bambusae and N. shiranensis had no eggs under their scales in autumn. These results suggest that U. bambusae and N. shiranensis have one generation a year in Mt. Ohdaigahara.
