Abstract: 【Objective】Insecticidal activities and active compounds of Derris cavaleriei Gaghep were studied.【Methods】Insecticidal activities and action mode were determined by bioassay.On the basis of bioassay tracking,active ingredients were isolated from the root and identified by extraction,column chromatography, thin layer chromatography(TLC),recrystallization ,MS,NMR and so on.【Result】The result showed only the root of D.cavaleriei exhibited insecticidal activity. Methanol extracts from the root of D.cavaleriei had toxicity against the Myzus persicae, the 3rd instar larva of Pieris rapae (L.),the 4th instar larva of Aedes albopictus, the 3rd instar larva of Ostrinia furnacalis,the adult of Phyllotreta striolata (Fabricius), Aphis gossypii Golver and the 2nd instar larva of Herse convolvuli (L.),With LC50 value 24h after treatment being 30.9 mg.L-1,38.4 mg.L-1,135.4 mg.L-1, 161.7mg.L-1,180.3mg.L-1,212.9mg.L-1 and 244.5mg.L-1,respectively.Five active ingredients,Rotenone,6a,12a-Dehydrodegulin,Tephrosin,Isolochcarpin and Pongaflavone,were isolated for the first time from the root and identified. Rotenoids,Rotenone, 6a,12a-Dehydrodegulin and Tephrosin ,had significant insecticidal activity against the 4th instar larva of A. albopictus,P. striolata, A. gossypii Golver and the 3rd instar larva of P. rapae.,with the mortality being from 62.3% to 100% at the concentration of 100 mg.L-1. Isolochcarpin and Pongaflavone didn’t exhibited insecticidal activity,but the two chemicals had antifeedant effect on the 3rd larva of H.convolvuli, with AFC50 value 48h after treatment being 195.5mg.L-1 and 106.6 mg.L-1,respectively.【Conclusion】Only the root of D. cavaleriei Gaghep had insecticidal activities against kinds of agricultural insect pest.Rotenone, 6a,12a-Dehydrodegulin,Tephrosin,Isolochcarpin and Pongaflavone were the main active ingredient from the root.

Key words: Derris cavaleriei Gaghep, Insecticidal activities, Active compound