Insecticidal efficacy of microbial-mediated synthesized copper nano-pesticide against insect pests and non-target organisms

Abstract

Currently, medical and stored grain pests are major concerns of public health and economies worldwide. The synthetic pesticides cause several side effects to human and non-target organisms. Copper nanoparticles (CuNPs) were synthesized from an aqueous extract of Metarhizium robertsii and screened for insecticidal activity against Anopheles stephensi, Aedes aegypti, Culex quinquefasciatus, Tenebrio molitor and other non-target organisms such as Artemia salina, Artemia nauplii, Eudrilus eugeniae and Eudrilus andrei. The synthesized copper nano-particles were characterized using, UV-vis spectrophotometer, Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Energy Dispersive X-Ray analysis (EDaX), High Resolution Scanning Electron Microscope (HR-SEM) and Atomic Force Microscope (AFM) analysis. Insects were exposed to 25 µg/mL concentration produced significant mortality against larvae of A. stephensi, A. aegypti, C. quinquefasciatus and T. molitor. The lower toxicity was observed on non-target organisms. Results showed that, M. robertsii mediated synthesized CuNPs is highly toxic to targeted pests while they had lower toxicity were observed on non-target organisms.