THE EFFECTIVENESS OF SUMITHION FOR CONTROL OF THE RICE STEM BORER CHILO SUPPRESSALIS WALKER

Abstract

Field tests were conducted to evaluate Sumithion [0, 0-dimethyl-0-(3-methyl-4-nitrophenyl) thiophosphate] against the rice stem borer Chilo suppressalis WALKER.
In 1960 at the young ear formation stage of rice plants, the mortality of released larvae in the field was examined after spraying, and the results were shown in table I. In 1961 at the tillering stage of rice plants, the number of damaged stems by natural infestation of the larvae was examined after spraying, and the results were shown in table 5.
It was concluded that Sumithion was more effective than parathion, but less effective than methyl parathion against the larvae in the stems of the rice plants. Residual effects of Sumithion against the newly hatched larvae seemed to be maintained longer than methyl parathion.