Antifeedants against Acusta despesta from the Japanese cedar, Cryptomeria japonica

During our studies on the components in Japanese cedar, Cryptomeria japonic a, we found that the crude methanol extract of C. japonica showed intense a ntifeeding activity against one snail species, Acusta despesta, which is we ll-known as a pest of many vegetables and crops. The active components in the extract were separated into the hexane and eth yl acetate soluble fractions. From the active ethyl acetate soluble fractio n, two norlignans, sequirin-C and agatharesinol, were isolated and identifi ed as the active compounds. Both compounds inhibited feeding behavior of A. despesta at 30 mug/cm(2) and 40 mug/cm(2) concentrations, respectively, wh en applied by an eggplant leaf or filter paper containing 20 mul of 5% sucr ose solution.