Study on the Insecticidal Activity of Plantain Seed against Plutella xylostella L.

The insecticidal active substances were extracted from plantain seed with alcohol and ultrasonic method.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.And the contacting activities of extracts to Plutella xylostella was tested trackingly.The results showed that extract from plantain seed had the pesticidal activity to Plutella xylostella,and the LC50 was 10.300 mg / mL.The activities of each solvent extract were significantly lower than that of alcohol extract.So the insecticidal active substances had synergism in coordination to Plutella xylostella.