“…Other terpenes found in beetle hindguts or collected from living beetles, such as verbenone, myrtenol, pinocarvone, and pino-carveol Lirrionenc r e l e~, e d b j the Scoljtid beetle Dendroctotziis pseudotsugae 1974), are considered to be oxidation products of host-produced alpha-and beta-pinene. However, some of the same oxygenated terpenes are found in the wood of various pine species and Douglas-fir (SUMIMOTO et al 1974(SUMIMOTO et al , 1975SAKAI and SAIKAI 1972), and the question arises whether they are separately biosynthesized by both the host tree and the beetle, or they are passed on by the beetle from the host tree, or perhaps both processes occur.…”