Entomotoxic effect of green nanoparticle an alternate strategy for stored grain pest management

Abstract

Corcyra cephalonica (S.) commonly called rice meal moth or rice moth is an important stored-product pest all over the world. The larvae feed on broken grains of cereal, pulses, oilseeds, dried fruits, nuts, and spices by constructing the silken webs. The excessive use of pesticides and chemical compounds used for the management of this pest led to the development of resistance and also harms the environment. To overcome these problems in the recent years, green nanotechnology has emerged as a promising tool for pest control. The present study of the experiment was conducted at the Centre for Nanotechnology Laboratory, UAS, Raichur. The green nanoparticles of zinc, copper, and silica were biosynthesized from Spinach leaves; tulasi leaves and paddy husk respectively, and these nanoparticles were characterized by Zetasizer, UV–Vis spectroscopy, X-ray diffraction (XRD), and Scanning electron microscope (SEM). The biophysical characterization revealed that the zinc, copper, and silica nanoparticle has Spindle, spherical, and agglomerated spindle-shaped with a mean particle size of 87.94, 84.15 and 23.65 d. nm respectively. The pesticidal effects of these green nanoparticles were used as stored product insect protectants compared to malathion as a standard reference. Data obtained from different concentrations (250, 500, 750, 1000, 1250, and 1500 ppm) of zinc, copper, and silica green nanoparticles indicated that the increase in concentration and exposure period resulted in increase in larval mortality, pupal mortality and adult deformity. Among the different concentrations, 1500 ppm of zinc, copper, and silica nanoparticles proved to be superior. Similarly, of the different nanoparticles, silica nanoparticles excelled followed by zinc and copper nanoparticles.