Feeding Deterrents from Zanthoxylum schinifolium against Two Stored-Product Insects

Screening for insecticidal principles from several Chinese medicinal herbs showed that the fruit pericarp of Zanthoxylum schinifolium possessed significant feeding deterrence against two stored-product insects (Tribolium castaneum and Sitophilus zeamais). From the methanol extract, two feeding deterrents were isolated by bioassay-guided fractionation. The compounds were identified as schinifoline and skimmianine from their spectroscopic data. Schinifoline has feeding deterrent activity against T castaneum and S. zeamais adults with EC50 values of 47.8 and 85.6 ppm respectively. Skimmianine possess feeding deterrent activity against T castaneum and S. zeamais adults with EC50 values of 75.7 and 129.7 ppm respectively.