title: Effects of Decompression Treatment for Controlling the Powderpost Beetle, Lyctus africanus Lesne, (Coleoptera: Lyctinae).
abstract: The efficacy of decompression treatment as a non-destructive method to control larvae of the powderpost beetle, Lyctus africanus Lesne, was evaluated in the laboratory using various combinations of two pressure levels, 1.1 kPa and 40 kPa, and three temperature levels, 20, 25, and 40 °C. Larval mortality generally depended on weight reduction while decreases in the oxygen level had relatively little effect. The lower pressure, 1.1 kPa, significantly affected mortality, and no larvae survived after 12 h of this pressure treatment, at 25 °C. The average body weight was reduced with treatment time and temperature, and the reduction rate at 25 °C was higher than that at the lower temperature, 20 °C. Effects on larvae of the higher pressure treatment, 40 kPa, with a CO₂ gas purge, were tested to determine the feasibility of decompression treatment in the manufacturing process. Although higher pressure resulted in low mortality, the body weight was dramatically decreased using the CO₂ purge. These results present important information on the possibility of using decompression treatment for wood products.
authors.affiliation: Production Engineering and Procurement Department, Yamaha Corporation, 283 Aoya-cho, Minami-ku, Hamamatsu 435-8567, Japan. kazushi.nakai@music.yamaha.com.
authors.forename: Kazushi
authors.initials: K
authors.lastname: Nakai
authors.affiliation: Production Engineering and Procurement Department, Yamaha Corporation, 283 Aoya-cho, Minami-ku, Hamamatsu 435-8567, Japan. tatsuya.hiraku@music.yamaha.com.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Hiraku
authors.affiliation: Research Institute for Sustainable Humanosphere, Kyoto University, Uji Campus, Kyoto 611-0011, Japan. izumi_fujimoto@rish.kyoto-u.ac.jp.
authors.forename: Izumi
authors.initials: I
authors.lastname: Fujimoto
authors.affiliation: Research Institute for Sustainable Humanosphere, Kyoto University, Uji Campus, Kyoto 611-0011, Japan. tsuyoshi@rish.kyoto-u.ac.jp.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yoshimura
keywords: CO2 purge; L. africanus; decompression treatment; powderpost beetle