Field Application of Some Binary Mixture Insecticides Supplemented with Adjuvants for the Control of Spodoptera frugiperda on Maize in Egypt

Abstract

The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), is an insect pest that has increasingly spread throughout the world over the past few years, and it is commonly controlled by insecticides. Insecticides having different modes of action were evaluated for controlling the second instar larvae under field conditions. Thus, the aim of this research was to evaluate the impact of the following binary mixture insecticides: Chlorantraniliprole + Emamectin benzoate, Chlorantraniliprole + Indoxacarb and Chlorantraniliprole + Lambda-cyhalothrin. The results of field evaluation for Chlorantraniliprole 20% SC + Emamectin benzoate showed the highest acute toxicity with LC₅₀ of 0.39 and LC₉₀ of 0.43 mg/L against FAW when combined at a 1:9 ratio, followed by Chlorantraniliprole + Indoxacarb at 7:3 ratio with LC₅₀ of 4.88 and LC₉₀ of 7.43 mg/L, whereas toxicities of Chlorantraniliprole + Lambda-cyhalothrin were noted at ratio of 9:1, with LC₅₀ of 7.22 and LC₉₀ of 9.68 mg/L and by using the leaf spray method compared to the control. The improved binary mixtures insecticides(g/L) with different adjuvants showed high toxicities to fall armyworm in comparison with their binary mixtures insecticides alone. In the leaf-spray bioassay, the addition of the adjuvant reduced the LC₅₀ and LC₉₀ values of both binary mixtures in the field. The LC₅₀ of Chlorantraniliprole + Emamectin benzoate (1:9), Chlorantraniliprole + Indoxacarb (7:3) and Chlorantraniliprole + Lambda-cyhalothrin (9:1) mixtures were decreased when the adjuvants were added. This study measured the effective and promising binary insecticide–adjuvant mixture to control S. frugiperda in Egypt.

Keywords:

Binary mixture, insecticides, adjuvant, Spodoptera frugiperda, insecticidal activity.