Facile Synthesis of Silver Nanoparticles Using Vernonia anthelmintica (L.) Willd. and Their Toxicity Against Spodoptera litura (Fab.), Helicoverpa armigera (Hüb.), Aedes aegypti Linn. and Culex quinquefasciatus Say

The present study was aimed to evaluate the antifeedant, larvicidal, pupicidal, biochemical effects of Vernonia anthelmintica seeds mediated AgNPs against Spodoptera litura, Helicoverpa armigera, Culex quinquefasciatus and Aedes aegypti. The potential antifeedant activity of synthesized AgNPs were 86.90% and 89.83% and larvicidal activity of (LC) 56.42 μg/mL and 63.65 μg/mL against S. litura and H. armigera respectively. Furthermore, larval growth duration was increased as 13.66 and 15.85 days on S. litura and H. armigera as compared to control 7.83 and 8.05 days. The AgNPs caused larvicidal activity of (LC) 45.14 µg/mL and 53.23 µg/mL against Ae. aegypti and Cx. quinquefasciatus. The increased α esterase level of 85.00, 85.33 0.49 and 0.53 μg napthol produced/min/mg larval protein and β esterase level of 92.66, 101.67, 0.53 and 0.48 μg napthol produced/min/mg larval protein and glutathione S-transferase enzyme level of 146.33, 160.00, 0.75 and 0.65 μmol/min/mg larval proteins on S. litura, H. armigera, Ae. aegypti and Cx. quinquefasciatus. The damaged midget cells and peritrophic membrane was observed on treated larvae of S. litura, H. armigera, Ae. aegypti and Cx. quinquefasciatus. Conclusively, biosynthesised of AgNPs using V. anthelmintica seeds were used as potential biopesticide for controlling S. litura and H. armigera, Ae. aegypti and Cx. quinquefasciatus. Graphic Abstract: [Figure not available: see fulltext.]