The Comparative Study Of The Preventive And The Rapeutic Effect To The Corn Aphids By Three Kinds Of Plants' Extracts

Walnut peel,Purslane Portulaca oleracea,Red-knees herb Polygonum hydropiper were common botanical insecticides resources,this study using the ethanol extract of Walnut peel,Purslane and Red-knees herb to do the control comparison test for Corn aphids Rhopalosiphum maidwas,and get the following results:1 The test of tag activity to the Corn aphids by three kinds of plants' ethanol extract.(1)The ethanolic extract of walnut peel has a positive correlation with the concentration of ethanol extract and the time of treatment.(2)The ethanolic extract of Purslane was directly proportional to the concentration and time of ethanol extract.(3)The tag activity of ethanol extract of Red-knees herb was not obvious,but its contact activity with Corn aphids was different with ethanol extract concentration,processing time and environment temperature.2 The comparative study on the tag activity of ethanol extracts from three plant extractsThe ethanol extract of Corn aphids was the strongest in the comparison test,followed by walnut peel ethanol extract,ethanol extract of Polygonum multiflorum ethanol extract on Corn aphid Serious effect.3 The test of antifeedant activity of three kinds of plants' ethanol extracts on Corn aphids(1)The antifeedant activity of Walnut peel was positively correlated with ethanol concentration and treatment time.(2)The antifeedant activity of Purslane was positively correlated with the concentration and time of ethanol extract.(3)The antifeedant activity of ethanol extract of Red-knees herb was positively correlated with the concentration and time of ethanol extract.4 The comparative study on the Antifeedant activity of three kinds of plants ethanol extracts to Corn aphidsThis Antifeedant activity test showe that the ethanol extract of walnut peel,purslane and Polygonum multiflorum has high antifeedant activity to Corn aphids,and the antifeedant activity of Walnut peel was the strongest,followed by Purslane.The ethanol extract of Redknees herb was the lowest in antifeedant activity for Corn aphids.