Effects of heat treatments of wood on the feeding behaviour of two subterranean termites

This paper deals with the results of choice feeding tests of two termite species, Coptotermes formosanus Shiraki and Reticulitermes speratus (Kolbe), with steam-treated and dry-heated samples of Japanese commercial woods. Some steam-treated species were heavily attacked by C. formosanus and R. speratus while all dry-heated samples were attacked not more than unheated controls except for the combination Japanese larch-R. speratus. The steam treatment in some wood species produced feeding attractants which were removed by hot water extraction. Termite species showed some differences in the susceptibility to these substances. Attraction of the termites to steam-treated Japanese beech was different from that to the steam-treated softwoods. These phenomena were discussed with references to heat treatment of wood as well as to termite attractive factors.