Preparation of nanosilica from sugarcane bagasse ash for enhanced insecticidal activity of diatomaceous earth against two stored-products insect pests

Nanosilica was prepared from sugarcane bagasse ash (SCBA) and used as additive to the diatomaceous earth (DE). Nanosilica was characterized using laser light scattering (LS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). Nanosilica has uniform spherical shape and monodisperse distribution with particle diameters of similar to 100 nm. The insecticidal activity of silica nanoparticles (SNPs), Mamaghan DE, Mamaghan DE plus 15% SNPs and Mamaghan DE plus 20% SNPs was determined against adults of Tribolium confusum Jacquelin du Val. and Rhyzopertha dominica (F.) at the rate of 400 ppm. Nanosilica enhanced the insecticidal activity of Mamaghan DE, and after 14 d of exposure the adult mortality was more than 86% and 95% for T. confusum and R. dominica when SNPs were added to the DE, respectively.