日光の歴史的建造物における木材害虫・シバンムシ類の効果的な捕獲方法の検討

摘要

In the extensive insect trapping surveys in 2009 and 2010, several wood-boring Anobiids were captured in historic buildings in Nikko World Heritage area. Among them, Priobium cylindricum was the major and the severest deteriogen of Sambutsu-do of Rinnohji temple, and Trichodesma japonicum was the major wood-boring insect affecting Nitenmon of the temple. Together with insect monitoring using adhesive tapes, this year (2011) effects of lightening and pyrethroid vapor were tested. Regarding Priobium cylindricum, the adult beetles were strongly attracted to the adhesive tapes lit up with LED lights or by sun light. Also, adult beetles of Trichodesma japonicum were captured or found around the area where slight beams of sunlight came in from outside through gaps on doors. Therefore, adult beetles of these species are thought to be effectively captured by light attraction. Vaporized pyrethroid (profluthrin) was applied at Nitenmon and the circumstance was compared with the one at another building (Ro-mon of Takino-o-jinja of Futarasan-jinja) where no chemical was applied. In a laboratory observation, pyrethroid vapor was effective on an adult beetle of Trichodesma japonicum; the beetle was knocked down in a glass jar containing a small piece of pyrethroid-impregnated paper. But there were not very obvious knock-down effects on insects on site, probably because of the high ventilation rate of the wooden historic building.%本報告において，現時点でシバンムシ類が棲息し，被害が大きいと考えられる輪王寺三仏堂， 大敵院二天門などにおいて，ひきつづきシバンムシ類の発生状況をモニタリングを実施するな かで，オオナガシバンムシ，タロトサカシバンムシなど，木造建造物に顕著な被害を与える大 型のシバンムシの成虫が，自然光やLEDライトなどの光に強く誘引されることが明らかと なった。このことから，今後光を利用した何らかの方法でこれらのシバンムシの成虫を効果的 に捕獲できる可能性が示唆された。