Field and laboratory evaluation of insecticide sprays against the rice leaf-roller Cnaphalocroos Medinalis guenee

Abstract

Twenty four insecticides were evaluated against the caterpillars of Cnaphalocrocis medinalis Guenee in the laboratory using a new laboratory technique of spraying them within leaf folds under a Potter's Tower and in field experiment in which the per cent reduction of larval population caused by spraying was assessed. The results of the two experiments showed strict correspondence. Ethyl parathion, carbaryl, carbophenothion, dimethoate, fenthion fenitrothion and leptophos were found very effective against C. medinalis larvae while phosphamidon, phorate, formothion, methyl demeton, quinalphos, monocrotophos, thiometon and acephate, were moderately effective.