Activities of carboxylesterase and glutathione S transferase in Anoplophora glabripennis larvae feeding on eight different kinds of poplar trees were tested. The results showed that the activities of the two enzymes were significantly different when the larvae feeding on different poplar trees. The contents of fourteen secondary metabolites in eight kinds of poplar trees were also tested with the method of high pressure liquid chromatography (HPLC). Stepwise regression analysis was carried out to test the relationship between the activities of the enzymes and secondary metabolites of poplar trees. The analysis results demonstrated that the contents of benzoic acid and catechin decreased together with the increase of carboxylesterase activity while the contents of catechol increased, but the content of p hydroxybenzoic acid decreased together with the increasing of glutathione S transferase activity while the content of phenol, coumaric acid, syringic, salicylic acid and salicin in poplar trees increased.
