title: Synergistic effect of heartwood extractives and quaternary ammonium compounds on termite resistance of treated wood.
abstract: This study evaluates the synergistic effect of wood extractives and quaternary ammonium compounds (QACs) on the resistance to termites of several treated wood species. Wood specimens from different natural durability classes were extracted with either hot water alone or hot water + ethanol/benzene. The extracted and unextracted wood specimens were treated with either didecyldimethylammonium tetrafluoroborate (DBF) or commercial didecyldimethylammonium chloride (DDAC) solutions and then exposed to subterranean termites, Coptotermes formosanus Shiraki, for 3 weeks under laboratory conditions. The results showed that extractives of the heartwood portions of the wood species contributed to increased resistance against termite attack in the presence of either DBF or DDAC wood preservatives. The synergistic effect of wood extractives and DBF was much clearer with Pseudotsuga menziesii (Mirbel) Franco and Tsuga heterophylla Sarg wood samples. Further studies are needed for a better understanding of the synergism between wood extractives and either DBF or DDAC using both the sapwood and heartwood portions of the same wood species.
authors.affiliation: Research Institute for Sustainable Humanosphere (RISH), Kyoto University, Uji 611-0011, Kyoto, Japan. wjhwang@rish.kyoto-u.ac.jp
authors.forename: Won-Joung
authors.initials: WJ
authors.lastname: Hwang
authors.forename: S Nami
authors.initials: SN
authors.lastname: Kartal
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yoshimura
authors.forename: Yuji
authors.initials: Y
authors.lastname: Imamura
mesh_terms: D000818:Animals; D029780:Chamaecyparis; D032485:Cryptomeria; D004357:Drug Synergism; D020049:Isoptera; D028221:Larix; D010936:Plant Extracts; D028224:Pseudotsuga; D000644:Quaternary Ammonium Compounds; D064028:Tracheophyta; D028225:Tsuga; D014934:Wood
chemical_list: D010936:Plant Extracts; D000644:Quaternary Ammonium Compounds; C027118:didecyldimethylammonium