Effects of stilbenes from bark of Picea glehnii (Sieb. et Zucc) and their related compounds against feeding behaviour of Reticulitermes speratus (Kolbe)

Abstract

The effects of stilbene glucosides and related compounds on termite feeding behavior were investigated using paper disc methods against the subterranean termite Reticulitermes speratus. The stilbene-rich fraction and isorhapontin (3′-methoxy-3,4′, 5-trihydroxystilbene-3-β-d-glucoside) from bark extracts of Picea glehnii showed avoidance by termites in choice tests. In the no-choice tests using compounds purified from the stilbene-rich fraction, the largest feeding deterrent effect was observed for piceid (3,4′,5-trihydroxystilbene-3-β-d-glucoside), followed by isorhapontin, and astringin (3,3′,4′,5-tetrahydroxystilbene-3-β-d-glucoside), at the concentrations from 0.63 to 2.5 µmol/disc. No change in activity was observed at retentions of more than 5.0 µmol/disc. When the activities of isorhapontin and its aglycone derivative (isorhapontigenin: 3′-methoxy-3,4′,5-trihydroxystilbene) were compared with that of taxifolin (3,3′,4′,5,7-pentahydroxyflavanone) in the no-choice test, the stilbenes exhibited a larger antifeedant potential. Methylation of isorhapontigenin increased its termiticidal activity.