Entomotoxic efficacy of aluminium oxide, titanium dioxide and zinc oxide nanoparticles against Sitophilus oryzae (L.): A comparative analysis

Abstract

The development of resistance in both stored grain and field insect pests to conventional insecticides, coupled with increased consumer awareness of the consequences of their residual toxicity in food crops and environmental contamination have led agro-chemical researchers to reappraise the use of inert dusts as alternative insecticide. Diatomaceous Earth or DE became popular as an alternative insecticide in last two decades for its low mammalian toxicity and physical mode of action. But due to several limitations of DE many researchers are trying to explore the possibility of using nanoparticles as potential insecticide. In this study, a comparison on entomotoxic efficacy of different oxide nanoparticles like aluminium oxide, titanium dioxide and zinc oxide was evaluated on Sitophilus oryzae. Though more than 90% S. oryzae died after 4 days of nano aluminium oxide treatment at 1 g kg−1 dosage, nano zinc oxide and titanium dioxide treatment could attain this efficacy at 2 g kg−1 after 14 days. Even then use of nano zinc oxide and titanium dioxide in agriculture sector is preferred to nano aluminium oxide as the latter nanoparticle has adverse effects on plant growth. Moreover due to the antimicrobial property of nano zinc oxide and titanium dioxide have antimicrobial property, they will not only protect the agricultural produce from insect pests, but also from microbial infection.