基金The authors are thankful to T. Miyata, T. Tanaka, and T. Itioka （Nagoya University） fbr their help throughout the research work. The authors also extend their thanks to Ishihara Sangyo Kaisha, Tokyo, Japan, for supplying chlorfluazuron, and K. Ohba （Shionogi Pharmaceutical, Koga-Shiga Prefecture, Japan） for providing the eggs of S. litura that were needed to establish the laboratory population. This work was supported partly by a Grant-in-Aid for Scientific Research （B） No. 11460020 and （C） No. 05806006 from the Ministry of Education, Science, Sports and Culture of Japan.