Runs-test of Controlling Effects of 40% Lesang Emulsion on Mulberry Geometrid

To opt for a more appropriate insecticide and substitute for Methamidophos to control the pest in the mulberry field, we determined LC 50 of 40% Lesang(Chlorpyrifos) emulsion on mulberry geometrid in the laboratory, and analyzed the data from tests which were performed in Jiangxi, Shandong, Jiangsu and Zhejiang provinces during 2003-2004 by the approach of runs-test ascribed to nonparameter statistics. Furthermore, a comprehensive appraisal method of the field control effect of various regions in distinct years was established. The result showed: LC 50 of 40% Lesang Ec was 175 40 mg/L higher than the value (315 69 mg/L) of the 50% Methamidophos, the controlling effects of 40% Lesang Ec on mulberry geometrid were 78 54%, 81 78%, 87 62%, 90 96% and 91 01% in the 1st and 7~th day after spraying of 267 mg/L, 1st, 3rd and 7~th day of 400 mg/L respectively, whereas the controlling effects of 50% Methamidophos were 79 85%, 85 52% and 80 63% in the 1st, 3rd and 7~th day respectivey after treatment of 500 00 mg/L. These results indicated that 40% Lesang may be substituted for Methamidophos to control the pest in the mulberry field.