Comparison of host volatiles under different physiological states and electroantennogram responses of Semanotus bifasciatus （Motschulsky） to these volatiles

Based on an analytical TCT-GC/MS method, volatile compounds of branches of Platycladus orientalis under three physiological states （healthy, weak and baited trees） were analyzed. The results showed that α-pinene, β-phellandrene, 3-careen, limonene and thujopsene were released under all three physiological states. There were other kinds of volatiles released from branches of weak P. orientalis trees, such as camphene, γ-terpinene, （＋）-4-carene and cedrene, but these four volatiles compounds were not released from the branches of healthy P. orientalis. Volatile components from the physically damaged branches of P. orientalis had changed. β-terpinene, mycrene, isocaryophillene and caryophyllene were identified in both healthy and weak branches of P. orientalis. Only cedrene was identified in the baited wood. Electroantennogram （EAG） tests were conducted with nine volatile compounds from the branches of P. orientalis. Antennnae of male and female Semanotus bifasciatus （Motschulsky） were highly sensitive to these nine volatile compounds. Cedrene elicited the strongest response, whereas β-terpinene the lowest. Males and females showed no signifi-cant difference in their EAG responses to the nine volatile compounds.

Comparison of host volatiles under different physiological states and electroantennogram responses of Semanotus bifasciatus (Motschulsky) to these volatiles

Based on an analytical TCT-GC/MS method, volatile compounds of branches of Platycladus orientalis under three physiological states (healthy, weak and baited trees) were analyzed. The results showed that α-pinene, β-phellandrene, 3-careen, limonene and thujopsane were released under all three physiological states. There were other kinds of volatiles released from branches of weak P. orientalis trees, such as camphene, γ-terpinen, ( )-4-carene and cedrene, but these four volatiles compounds were not released from the branches of healthy P. orientalis. Volatile components from the physically damaged branches of P. orientalis had changed.β-terpinene, myerene, isocaryophillene and caryophyllene were identified in both healthy and weak branches of P. orientalis. Only cedrene was identified in the baited wood. Electroantennogram (EAG) tests were conducted with nine volatile compounds from the branches of P. orientalis. Antannnae of male and female Semanotus bifasciatus (Motschulsky) were highly sensitive to these nine volatile compounds. Cedrene elicited the strongest response, whereas β-terpinene the lowest. Males and females showed no significant difference in their EAG responses to the nine volatile compounds.