为了利用被害材,必须杀死被害材中的松斑天牛的幼虫,笔者曾用池水浸泡枯损木的方法,调查幼虫全部死掉所需的日期。下面报告调查的结果。做为予备性的试验,昭和52年8月(即1977年),把可能的松斑天牛幼虫生息的松材切成长15～20公分,直径10～20公分的木园片,然后钉在木板上浸入水中并固定起 In order to use the victim, we must kill the larvae of the pine needles in the victim’s material. The author used the method of immersing the withered wood in pool water to investigate the dates required for all the larvae to die. The results of the investigation are reported below. As a preliminary test, in August, 1982 (ie, 1977), the pine wood of the larvae of the platanus californicum was cut into wooden garden pieces of 15 to 20 cm long and 10 to 20 cm in diameter, Immersed in water and fixed on wooden boards