Relative Toxicity of Certain Insecticides To Adelencyrtus mayurai (Subba Rao), A Parasitoid of Sugarcane Scale Insect, Melanaspis glomerata (Green)

Toxicity of seven insecticides viz.,carbosulfan, dimethoate, malathion, monocrotophos, cypermethrin, decamethrin and fenvalerate each at three concentrations were tested for their relative toxicity to Adelencyrtus mayurai (Subba Rao), the principal parasitoid of sugarcane scale insect, Melanaspis glomerata (Green), by exposing the adults to the treated surface. At recommended concenrratfori, both fenvalerate (31.3% mortality) and deltamethrin (49.9%) proved to be less toxic to the adult parasitoids. Malathion caused 93.0 % mortality, while the other insecticides inflicted cent per cent mortality. The mortality increased with increase in the concentation of the insecticides and decreased with increase in time lag between treatment with insecticide and exposure of the parasitoid to the treated surface.