Antifeedant activity of Catunaregam spinosa fruit extracts against Plutella xylostella

The fruit extracts of Catunaregam spinosa were used to tested for antifeedant activity against the larvae of Plutella xylostella in the study.The powdered fruit was extracted with petroleum ether,ethyl acetate and methanol,and the extract rates were 0.44%,1.80% and 17.10%,respectively.The methanol extract showed more antifeedant activity against the larvae of Plutella xylostella than the petroleum ether extract and ethyl acetate extract,and the antifeedant rate of the methanol extract in 24 h after treatment in the no-choice bioassay reached 82.49% at the concentration of 10 mg/mL.The active ingredients of the methanol extract were separated preliminarily.The results showed that the antifeedant components were mainly in the precipitate in the methanol /water partition(V/V=10/3),and in the n-butyl alcohol fraction after the methanol extract was partitioned in n-butyl alcohol and water.Antifeedant rates of the precipitate and the n-butyl alcohol fraction in 24 h after treatment were 96.77% and 91.24% at the concentration of 10 mg/mL,respectively.