Antifeedant Activity of the Extracts of Six Species of Wild Rice Aganist Spodoptera litura

Six species of wild rice E6 1, E6 3/6 4 (different ecotypes of Oryza grandiglumis), E7 4(O. granulata), E9 10, E9 20(different ecotypes of O. latifolia),E13 13(O. minuta), E15 13 (O. officinalis) and E16 3(O. punctata) were extracted with methnol by Sohxlet method. The extract rates of the six species of wild rice were 19 62%,15 60%,18 90%,8 50%,16 27%, 24 86%,10 04% and 13 32%, respectively. Selective antifeedant activity and non selective antifeedant activity of extract from the six species of wild rice against the 3rd instar larvae of Spodoptera litura showed that the extract of the wild rice E6 1 was better than the others.When the concentration was 1%, selective antifeedant activity of the E6 1 extracts was 100% in 24 h and 48 h and non selective antifeedant activity was 40 95% and 47 27% in 24 h and 48 h after treatment, respectively.The concentration of 50% antifeedant of the wild rice E6 1 extract against 2nd instar larvae of Spodoptera litura was 120 mg/mL in 24 h and 50 mg/mL in 48 h after treatment.