Insecticidal activity of different solvent extracts and partitioned extracts from Humulus scandens

Insecticidal activity of different solvent extracts and different partitioned extracts of acetone extract from dry power of whole plant of Humulus scandens(Lour.) Merr.was studied.The results show that in petroleum ether,benzene,chloroform,ethyl acetate,acetone and ethanol extracts(333 g·L-1),contact toxicity of acetone and ethanol extracts against to Plutella xylostella L.is stronger,in which that of acetone extract is the strongest with 48 h adjusted mortality of 86.67%.Antifeedant activity of these extracts with 100 g·L-1 against to P.xylostella is weak only with 24 and 48 h antifeedant rate of 9.65%-20.45%.Contact toxicity of these six solvent extracts against to Aphis gossypii Glover is stronger.In which,that of acetone extract is the strongest,the adjusted mortality of A.gossypii treated by 50 g·L-1 acetone extract for 24 and 48 h is 76.78% and 85.64%,respectively,and that treated by 100 g·L-1 acetone extract for 24 and 48 h is 82.63% and 92.53%,respectively.All partitioned extracts of petroleum ether,chloroform and ethyl acetate of acetone extract from H.scandens have a certain contact toxicity and contact toxicity increases with rising of partitioned extracts concentration and prolonging of treatment time.In which,contact toxicity of petroleum ether partitioned extract against to P.xylostella is the strongest,and adjusted mortality of P.xylostella treated by 25.0 g·L-1 petroleum ether partitioned extract for 24 and 48 h reaches to 80.00% and 96.67%,respectively.It is suggested that insecticidal activity of acetone extract from H.scandens against to P.xylostella and A.gossypii all are the strongest,and its main active insecticidal constituents exist in petroleum ether partitioned extract of acetone extract.