Antifeedant Bioactivity of Extract from Macleya cordata against the Larvae of Pieris rapae

[Objective] The aim of the research was to determin the bioactivity of antifeedant of extract of Macleya cordata against the 5th instar larvae of Pieris rapae.[Method] Using leaf-disc method,the antifeedant bioactivities of ethanol extract from the plant Macleya cordata against the 5th instar larvae of insect Pieris rapae was determined resp.[Result] The 5th instar larvae of the insect Pieris rapae was feed the leaf disc treated with 0.400% ethanol extracts from the plant Macleya cordata,The selective antifeedant rate of extract against the larvae was 87.50% and 89.56% after 24 and 48 h rspe.The 5th instar larvae of the insect Pieris rapae was feed the leaf disc treated with 1.000% ethanol extracts from the root,stem and leaf of plant Macleya cordata,The non-selective antifeedant rate of extracts against the larvae was 91.78%,91.01% and 90.63% after 24 h resp.,and 89.33%,88.91% and 86.76% after 48 h resp.[Conclusion] The bioactivity of antifeedant of extracts from Macleya cordata against the 5th instar larvae of Pieris rapa.was strong.