Relationship between the enantiomeric composition of α-pinene in host trees and the production of verbenols inIps species

Abstract

Upon exposure to the vapours of oleoresin from 8 conifers, bark beetlesIps typographus andI. amitinus produced verbenol, a terpene alcohol, in a predictable pattern. Apparently, this pattern changed in relation to the varied enantiomeric composition of the α-pinene contained in the resin of the various coniferous species. For calibration, defined mixtures of (+)-and (−)-α-pinene were used to establish the different levels of beetle response in the production of cis-and trans-verbenol. Methodical and ecological implications of the phenomenon are discussed.