Assessing the Single and Combined Toxicity of Chlorantraniliprole with Bacillus thuringiensis against Maize Fall Armyworm Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) under Laboratory Conditions

Abstract

Use of synthetic insecticides for the management of fall armyworm (FAW) Spodoptera frugiperda (J. E. Smith) for a longer period will led to development of insecticide resistance. Identification of an eco-friendly synergistic agent to enhance the toxicity potential and reduced pesticide use as well become mandatory in due process. Hence the present study was formulated to find the single and combined toxicity of chlorantraniliprole and Bacillus thuringiensis (Bt) against the 2nd and 3rd larval instars of S. frugiperda. Single toxicity of chlorantraniliprole against 2nd and 3rd larval instars were 0.87 and 1.52 ppm (LC25); 4.08 and 6.50 ppm (LC50), respectively. With respect to Bt, single toxicity against 2nd and 3rd larval instars were 474.39 and 693.48 ppm (LC25); 1008.62 and 1228.62 ppm (LC50), respectively. Combination effect of chlorantraniliprole with Bt revealed that 2nd instar of FAW showed supplemental synergism at LC50 of chlorantraniliprole + LC25 of Bt. In the case of LC50 of chlorantraniliprole + LC50 of Bt, LC25 of chlorantraniliprole + LC50 of Bt and LC25 of chlorantraniliprole + LC50 of Bt combinations, they showed sub additive synergism. In 3rd instar larvae, the combined toxicity results were similar for all the combinations of chlorantraniliprole + Bt except LC25 of chlorantraniliprole + LC50 of Bt where it showed an antagonistic synergism. Activity of Carboxyl Esterase (CarE), Mixed Function Oxidase (MFO) and Glutathione-S-Transferase (GST) were found to be lesser in chlorantraniliprole LC50 + Bt LC25 combinations than single toxicity treatments. Therefore, combined use of chlorantraniliprole with Bt at LC50 of chlorantraniliprole + LC25 of Bt had supplemental synergism on fall armyworm under laboratory condition.

Serratia marcescens induces apoptosis in Diaphorina citri gut cells via reactive oxygen species‐mediated oxidative stress

“…Increasing microorganisms have been found for the biological control of agricultural insect pests. Bacillus thuringiensis has been widely used as an efficient biological agent to control various insect pests like Callosobruchus maculatus , Tirathaba rufivena and Hyphantria cunea , 9–11 and combinations of Bacillus thuringiensis and chlorantraniliprole markedly enhanced the toxicity of the insecticide to Spodoptera frugiperda larval 12 . Beauveria bassiana exhibited highly virulent to adult female Diaphorina citri 13 and accelerated mosquito mortality by affecting the gut microbiota 14 .…”

“…Bacillus thuringiensis has been widely used as an efficient biological agent to control various insect pests like Callosobruchus maculatus, Tirathaba rufivena and Hyphantria cunea, [9][10][11] and combinations of Bacillus thuringiensis and chlorantraniliprole markedly enhanced the toxicity of the insecticide to Spodoptera frugiperda larval. 12 Beauveria bassiana exhibited highly virulent to adult female Diaphorina citri 13 and accelerated mosquito mortality by affecting the gut microbiota. 14 Escherichia coli infection significantly affected development and survival of Callosobruchus chinensis larvae by activating immune-related genes encoding juvenile hormone and insulin pathway and altering iron homeostasis and chitin metabolism within the host.…”