A Primary Study on the Insecticidal Activity of the Roots of Aconitum flavum against Plutella xylostella

[Objective]The aim of the research was to study the pesticidal activity of the Roots of Aconitum flavum and its insecticidal substance.[Method] the insecticidal substances of the Roots of Aconitum flavum are extracted with alcohol in Ultrasound.And the contacting activities of extract to Plutella xylostella was tested by insect-soaking method;Petroleum ether、chloroform、ethyl acetate and n-butyl alcohol were taken as solvent to successively extract ethanol extract by liquid liquid extraction.And the contacting activities of extracts to Plutella xylostella was tested trackingly.[Result] Extract from the Roots of Aconitum flavum at the concentration of 0.05 g/ml had the pesticidal activity to Plutella xylostella.The corrected mortality rates after applying pesticide for 72h was 95.0%;the petrol extract at the 1concentration of 0.005 g/ml had the strongest pesticidal activity to Plutella xylostella,followed by the chloroform extract,and ethyl acetate extract 、n-butyl alcohol extract and water extract had no the pesticidal activity.[Conclusion] the insecticidal substances of the Roots of Aconitum flavum to plutella xylostella presented strong insecticidal activity and they are a kind of weak or non polar compounds.