Studies on the relative toxicity of some insecticides to adults of Dacus cucurbitae (Coquillett) when used in bait sprays

Abstract

The relative toxicity of six new synthetic insecticides namely DDT, BMC, parathion , malathion, dipterex and sevin to adults of D.cucurbitae was ascertained by exposing the files : (a) to snake gourd leaves sprayed with the bait fluid and : (b) to droplets applied on glass surface. The order of relative toxicity of the different insecticides was Parathion= Dipterex > Malathion > Sevin = BMC > DDT. Coarso spray droplets of the baits were found to be more effective in killing the files than the fine sprays. An explanation for this phenomenon is given. It is concluded that field conditions for practical control, coarser will be better than fine sprays of the liquid bait.