Joint Toxic Action of Chlorantraniliprole with Certain Insecticides against Cotton Leafworm Larvae

Document Type : Original Article

Authors

Department of Pesticide Chemistry and Technology, Faculty of Agriculture, Alexandria University, Egypt

Abstract

Toxicity of the anthranilic diamid insecticide chlorantraniliprole, the macrocylic lactone insecticide emamectin benzoate, the neonicotinoide insecticide imidaclopride and the bioinsecticide Agree® (Bacillus thuringiensis subsp. aizawi GC-91) against the 2nd, 3rd and 4th larval instars of Spodoptera littoralis (Boisd.) were studied. The joint toxic action of chlorantraniliprole with each of the other three insecticides was also investigated against the 4th instar larvae of S. littoralis. Emamectin benzoate against 2nd, 3rd and 4th larval instars (LC50 = 0.0004, 0.0020 and 0.0048 ppm, respectively) was more toxic than chlorantraniliprole (LC50 = 0.17, 0.51 and 1.5 ppm, respectively), followed by imidacloprid (LC50 = 1.19,43.65and 1085.69 ppm, respectively) and Bacillus thuringiensis (LC50 = 754.65, 1205.67and 2279.91 ppm, respectively) after 96 hrs of treatment by dipping leaf disc tequnique. Chlorantraniliprole/imidaclopride mixtures resulted in antagonistic effect more than the chlorantraniliprole/emamectin benzoate mixtures and chlorantraniliprole/Bacillus thuringiensis mixtures at different concentration levels. The chlorantraniliprole at LC50/other tested insecticides at LC50 mixtures revealed antagonistic effects higher than the mixtures of chlorantranliprole at LC25/other tested insecticides at LC25. The mixture of chlorantraniliprole at LC12.5/Bacillus thuringiensis at LC12.5 resulted in an additive effect. Therefore, mixtures of chlorantraniliprole with these tested insecticides can't be used for cotton leafworm control.

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