Antifeedant Activity of the Extracts of Four Wild Rice Species Aganist Insect Pests

Four species of wild rice E6-1,E7-4,E13-13 and E16-3 were extracted by methnol,the extract rates of the four wild rice species were 19.62%,18.9%,24.16% and 13.32% respectively.Non-selective antifeedant activity of the four species of wild rice were tested against the second instar larvae of Plutella xylostella and the 5th instar larvae of Pieris rapae.The results showed that the extract of the wild rice E13-13 against larvae of P.xylostella was better than the others,the non-selective antifeedant rates were 49.30% in 24 h and 46.19% in 48 h after treatment.The extract of the wild rice E16-3 against larvae of P.rapae was better than the others,the non-selective antifeedant rates were 49.97% in 24 h and 44.77%in 48 h after treatment.