Abstract

With increasing the awareness of the effects of the conventional formulations of pesticides, there is a notable trend in the developed countries toward switching over from such formulations to more safe, less dosing eco-friendly water based formulations. In such non-conventional formulations, toxic and environmentally hazard organic solvents are replaced with water. Chlorpyrifos is well known and widely distributed organophosphorus insecticide in the form of EC formulation in Egypt and all over the world. In this study, two types of chlorpyrifos-ethyl as water based (24% EW and 24% ME) formulations were prepared and characterized. Physicochemical of the prepared formulations with their spray solutions were studied and compared with the standard formulation (Dursban H 48% EC). All studied parameters of the three formulations meet the specifications of FAO and WHO organizations. The insecticidal activity of the new formulations was evaluated against newly emerged larvae of Pink bollworm (P. gossypiella) (Saunders) and 5th instar nymphs of the migratory locust (L. migratoria) and compared with the same standard insecticide. The insecticidal activity of the new formulations against Pink bollworm (P. gossypiella) (Saunders), showed promising activity where their LC50 values were 173.77, 179.062 and 311.12 ppm for EW, ME, and EC formulations respectively. While, field evaluation against migratory locust (Locusta migratoria) new formulations showed activity closed to the efficacy to that of the standard formulation. LC50 of the standard insecticide was 4.9 ppm and LT50 was 0.35 hrs. The LC50 values of the new formulations are 15.5 and 19.9 ppm for ME and EW formulations, and their average LT50 values are 4.71 and 7.28 hrs respectively.