Elucidation of termite-feeding deterrent action against decayed wood and the possibility to utilize the phenomenon for termite-damage prevention

利用田间腐烂木桩制备的干湿样品，用细纹白蚁进行白蚁取食生物测定。在湿样上明显观察到白蚁的摄食威慑作用，而在干样上则没有。从木桩中分离得到的真菌鉴定为根状纤维poria。在室内规模试验中，对真菌腐烂的日本红松样品也观察到上述现象。抑制白蚁取食的活性物质主要存在于正己烷部分和可能的挥发物中。未来，将进行扩展分馏，以澄清投喂吓阻剂的化学结构。

Wet and dried samples prepared from stakes decayed in the field were subjected to the termite feeding bioassay using Reticulitermes speratus. Termite-feeding deterrence was clearly observed on the wet sample but not on the dried sample. The fungus isolated from the stake was identified as Fibroporia radiculosa. The phenomenon mentioned above was also observed on Japanese red pine wood samples decayed by the fungus in a laboratory scale test. The active substances causing termite-feeding deterrence were contained in n-hexane fraction and possibly volatiles. In future, the extended fractionation will be conducted to clarify chemical structures of the feeding deterrents.