Toxicity of newer insecticide molecules against lesser grain borer, Rhyzopertha dominica (Fabricius) (Bostrichidae: Coleoptera)

Abstract

To find out the insecticidal activity of commercial formulations of newer insecticides with novel mode of action viz., emamectin benzoate, lufenuron, chlorfenapyr, chlorantraniliprole are compared with check malathion and deltamethrin were evaluated for their toxicity against Rhyzopretha dominica by jute cloth disc impregnation method under laboratory conditions during the year 2015-16 at the Department of Entomology. Among the new insecticides tested for the management of R. dominica, chlorfenapyr was found to be the best at LC99.9 level with the highest relative toxicity of 7.45 times than malathion and 7.34 times than deltamethrin. Emamectin benzoate was found to be the best at LC99.9 level with the relative toxicity of 1.82 times than malathion and 1.79 times than deltamethrin. The relative toxicity at LC50 level of chlorantraniliprole 2.67 times than malathion and 4.25 times than deltamethrin. Lufenuron expressed relative toxicity at LC50 level 0.63 times than malathion and 0.68 times than deltamethrin and at LC99 level 1.00 times than malathion and 0.67 times than deltamethrin.