Adulticidal efficacy of silica nanoparticles synthesized from Phyllanthus emblica and Punica granatum against Callosobruchus chinensis (Linnaeus, 1758) (Coleoptera:Chrysomelidae)

Abstract

The global production of legumes and other economically important food crops and cash crops is severely jeopardized because unfavorable biotic and abiotic stressors play a crucial role in undermining global agricultural production. The current study attempted to address the situation of a global decline in legume production and storage due to infestation by Callosobruchus chinensis (Linnaeus, 1758)(Coleoptera:Chrysomelidae) an obnoxious pest that threatens post-harvest storage, leading to a decline in both their quantity and quality. The experiment showcased the comparison of green silica nanoparticles (GSiO₂NPs) synthesized from aqueous leaf extracts of Phyllanthus emblica L. (Phyllanthaceae) and Punica granatum L. (Lythraceae) commonly known as amla & anar. These GSiO₂NPs were compared with chemically synthesized NPs, leaf extract, and untreated group. The characterization results of GSiO₂NPs determined to be nanosized within 30–80 nm (FESEM), exhibiting sharp peaks centered at 2Ɵ (XRD), strong signal peaks corresponding to silicon (EDX), and zeta values below −25 mV (Zeta Potential). Five pairs of adult C. chinensis were released into Vigna angularis (Fabaceae) seeds treated with varying amounts of GSiO₂NPs (5 ppm, 20 ppm, 35 ppm, 50 ppm, and 70 ppm). Highest adult mortality on the seventh day (86.65%), and least seed damage (15.36%) and seed weight loss (8.26%) on the 14th day were observed when treated with 70 ppm SiO₂NPs synthesized with P. emblica extract. Both two biosynthesized SiO₂NPs demonstrated the protection of seed grains from the test insect, offering an alternative pest control strategy for grain quality preservation.