Flavanonol Glucoside and Proanthocyanidins

Oviposition Stimulants for the Cerambycid Beetle, Monochamus alternatus

Abstract

An oviposition stimulant for the cerambycid beetle, Monochamus alternatus, from an aqueous acetone extract of inner bark of Pinus densiflora, was identified as a flavanonol glucoside, (-)-2, 3-trans-dihydroquercetin-3′-O-β-D-glucopyranoside. Two dimeric proanthocyanidins, along with polymeric proanthocyanidins, were also isolated from the extract and identified as procyanidins B-1 [epicatechin-(4β→8′)-catechin] and B-3 [catechin-(4α→8′)-catechin]. In the presence of a fraction of the extract, a mixture of the polymers and either B-1 or B-3 stimulated oviposition of the female beetle. However, the glucoside, B-1, B-3 and the polymers were inactive alone.