D-Catechin: An Oviposition Stimulant of Azuki Bean Weevil Callosobruchus chinensis in the Host Azuki Bean

Abstract

An oviposition stimulant of the azuki bean weevil Callosobruchus chinensis was isolated from aqueous extracts of its host, the azuki bean Vigna angularis. The kairomone was identified as D-catechin, (2S, 3S)-3, 5, 7, 3′, 4′-pentahydroxyflavan. It was active at 0.2-2ng per glass bead and was located only in the seed coat. A bean (average weight 136mg) contained 17.6μg of the compound. The fact that the purified D-catechin fraction was somewhat more active than commercially available D-catechin suggested the presence of other components of the kairomone or its synergist.