Relationship between release regularity of volatiles from Pinus tabulaeformis and the damage by Dendroctonus valens

The volatiles of Pinus tabulaeformis were collected by the headspace absorption method and analyzed by thermal desorption combined with GC- - MS from May to September in Qinyuan County‚Shanxi Province． 2 5 compounds‚mainly monoterpines‚which are the main components of the volatiles‚have been identified． Among them‚ （R）^-（-）^-α- Pinene‚（S）^-（-）^-β- Pinene‚（S）^-（+）^-3- Carene are the three main compounds which account for over 9 6％‚and a small amount of other monoterpines‚（＋）^- limonene‚ myrcene‚camphene‚phellandrene‚etc．The relative content differences of the terpine volatiles have been compared between healthy and damaged trees‚the trunk and needles‚in different periods of diurnal hours and at different breast perimeters．