Study On Terpene Of Tritrophic Interaction Among Pinus Tabulaeformis, Dendroctonus Valens And Nature Enemies

This paper mostly studies on terpene of tritrophic interaction among Pinus tabulaeformis, Dendroctonus valens and nature enemies. Firstly the predators of Red turpentine beetle (RTB), Dendroctonus valens were investigated by the method of anatomizing of the pine trunk and rearing choice test. One of predator species of RTB (Prostomis sp.) was found in the larval gallery. Behavioral response of this natural enemy to the volatiles emitted from healthy pines (Pinus tabulaeformis),RBT damaged pines and fecal pellets of RTB were studied with a Y-tube olfactometer. The results showed that natural enemies were attracted to all the volatiles above,especially to that of damaged pines. Volatiles from healthy pines, RBT damaged pines and fecal pellets of RTB can be used by the natural enemies to locate the host habitat and to discriminate the pines damaged from healthy ones. The volatiles emitted from pines are mostly the terpene, including (R)-(+)-α-pinene,(S)-(-)-β-pinene,myrene,(S)-(+)-3- carnene,( + ) - Limonene and so on. The predator of RTB (Prostomis spp.) is more sensitive to (S)-(+)-3-Carene than three other monoterpenes in the lab experiment;. (S)-(-)-β- pinene is more significant than (S)-(-)-α- pinene; (R)-(+)-α- pinene and (S)-(-)-α- pinene is not significant.In the field experiment, RBT and another predator (Carabidae) are more sensitive to (S)-(+)-3-Carene than three other monoterpenes. In the comparison of continuous change of volatiles between health and damaged Pinus tabulaeformis, the relative contents of α-pinene of damaged Pinus tabulaeformis is more than health pines all the time; the relative contents of β-pinene and 3- carnene are both less than the health pines; the relative contents of limonene has two pinnacles; the relative contents of myrene is more than the contrast.