Influence of Some Novel Insecticides on Physiological and Biological Aspects of Spodoptera littoralis (Boisduval)

Document Type : Original Article

Author

Plant Protection Research Institute, Agricultural Research Center, Giza, Egypt

Abstract

Chloranitraniliprole, pyridalyl, indoxacarb, emamectin-benzoate and spinetoram are promising  insecticides in the Lepidopteran insects control. The effect of the sublethal concentrations (LC25) of these compounds on some physiological and biological aspects of the 4th larval instar of Spodoptera littoralis (Boisd.) laboratory strain using feeding technique was investigated. Based on the LC50 values, emamectin-benzoat was the most effective insecticide followed by indoxacarb while spinetoram was the least toxic one. Chloranitraniliprole and pyridalyl exhibited a  moderate toxic effect. The tested insecticides at LC25 significantly decreased the consumption index, relative growth rate and efficiency of converting ingested and digested food into body tissue, while did not significantly affect the approximate digestibility. All the tested  insecticides significantly prolonged the larval duration and decreased the pupal duration of S.littorallis without significant  differences among them. As  latent effects on survived larvae, these insecticides significantly decreased the percentages of normal pupae, adult emergence, fecundity and fertility of the pest  as compared with control. Spinetoram was the least effective on the biological aspects. Pyridalyl, chloranitraniliprole, emamectin-benzoate and indoxacarb could be used as important tools in integrated management programs of S. littoralis.

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