Nanostructured alumina: biocidal properties and mechanism of action of a novel insecticide powder

Abstract

Pest control using synthetic chemical pesticides is facing economic and environmental challenges worldwide. In this context, nanomaterials, emerge as potential tools that need to be investigated. The aim of this study was to examine the insecticidal effect and mode of action of nanostructured alumina (NSA) on Sitophilus oryzae (L.) (Coleoptera Dryophthoridae), an insect pest of stored products. Results demonstrated that the mechanism of insecticide action of NSA is based on physical phenomena rather than on biochemical mechanisms. Charged NSA particles attach to the insects cuticle due to triboelectric forces, sorbing its wax layer by surface area phenomena, resulting in insect dehydration. Moreover, intake of NSA particles was observed to be an addi-tional mortality factor in exposed insects. Results show that NSA could provide an alternative to conventional synthetic organic insecticides and warrant further research on the development of enhanced NSA derived products.