Insecticidal Effect of Green Bimetallic Nanoparticles from Crotalaria longirostrata on Cotton Mealybug, Phenacoccus solenopsis

The present study was conducted to evaluate the impact of bimetallic nanoparticles (NPs) of copper (Cu) and zinc (Zn) from Crotalaria longirostrata on the insect mortality and cell viability of Phenacoccus solenopsis. The biosynthesis of bimetallic nanoparticles (Cu/Zn-NPs) from C. longirostrata was confirmed by the presence of a single peak around 378 nm. The hydrodynamic diameter of the Cu/Zn nanoparticles varied from 59 to 119 nm and their zeta potential was found to be ???30.90 mV. The EDX analysis showed a strong signal for Cu and Zn (8 and 8.6 keV, respectively). The Cu/Zn-NPs showed an effective insecticide activity against P. solenopsis with 63% of insect mortality after 96 h treatment. However, further studies about nanotoxicity of Cu/Zn-NPs from C. longirostra are needed to reveal the exact mechanism of nanoparticles toxicity in insects.