Difference of taxis responses of Tomicus yunnanensis to volatile extracts from trunks and branches of Pinus yunnanensis

Significant difference between volatiles released from the trunks and branches of Pinus yunnanensis by a GC-MS analysis.α-pinene was the only main component in trunk volatiles of P.yunnanensis,percentage was 81.01%;In shoot volatile,the main components wereα-pinene and β-phellandrene,their percentages were 29.20% and 30.52% respectively.Compared with shoot volatiles,there were more α-pinene and 3-carene in trunk volatiles;there were more camphene,sabinene,limonene,β-phellandrene,terpinolene and caryophyllene in shoot volatiles than in trunk volatiles.Laboratory taxis response test showed that walking adults of shoot-feeding Tomicus yunnanensis displayed positive response to extract of shoots of P.yunnanensis,whereas repellent response to that of trunkts.