Fabrication and characterization of microemulsion of some insecticides and evaluating their efficacy against cotton leaf worm on cotton crop under laboratory and field conditions

Abstract

Traditional pesticide formulations have some shortcomings, including limited efficacy and the usage of huge amounts of insecticide, which has a negative impact on the environment. Using nano‐pesticide formulations reduces the amount of pesticide applied, minimizing pest control expenses and environmental contamination. As a result, this study was conducted to develop a microemulsion formulation containing emamectin benzoate or beta‐cyfluthrin with improved morphology, droplet size, emulsion stability, and persistence of foam. Moreover to assess the efficacy of the developed microemulsion in comparison to the convention alone against the Egyptian cotton leaf worm, Spodoptera littoralis (Boisd.) under both laboratory and field conditions. The results showed that the optimum conditions for emamectin benzoate microemulsion was 2% active ingredient, 5% (w/w) ethyl acetate, and DMF (3:2), 3.5% (w/w) Geronol ff4 and Etocas 35 (6:1), 5% (w/w) ethanol, and 86.5% (w/w) water, while for beta‐cyfluthrin, a 5.0% active ingredient, 15% (w/w) Solvesso 100 and ethyl acetate (2:1), 7.0% (w/w) Geronol ff4 and Etocas 35 (6:1), 10% (w/w) ethanol, and 68% (w/w) water. Under laboratory conditions, emamectin benzoate was more toxic than beta‐cyfluthrin to Spodoptera littoralis second and fourth instar larvae. Emamectin benzoate was more effective that beta‐cyfluthrin against Spodoptera littoralis in the field, whether as a microemulsion or a commercial product. Thus, microemulsions of tested insecticides with better formulation qualities may be more effective than traditional ones in controlling cotton leaf worm.