I This studies due to investigatjon and observation in Tokyo, Yamanashi, Sizuoka Drefecture, 1948 April-1949 March. II a. Period of overwintering ; November-March (Exception; November January). b. Place of overwintering; twigs, under parts of trunk, and stamps. c. Characteristic shape of overwintering tunnels; 4-5 branched, filled in these tunnels saw dust like powder. d. Relations between the season for cutdown and overwintering; August-October, the most. e. Number of insects burrowed into one stamp for overwintering; 5-100 f. Relations between sunbeams and overwintering ; out side of forest, the most. g. Relations between volume of pin-resin filled upon the surf acc of stamp and number of insects those are overwintering; It seems that, the more volume of pine-resin, the more number of insects. III The best season of control: December-February.