Parathion is comparatively the most effective insecticide. A space 0. 05% spray applied at intervals of 10 days and 20 days increased the grain yield by 45% and 21%, respectively. D.D.T. 0.1% applied at 10 days interval increases the yield by 22% whereas the same concentration applied at 6 weeks and 20 days intervals is ineffective. BHC to be effective will have to be used at still higher dosages applied at more frequent intervals. It is however clear that if a contract insecticide is to be used those superior residual action, e.g. D.D.T. are indicated. In case of Endrin a 0.25% spray applied not more than three times during the crop season will effectively control the pest.