Insecticidal effects of zinc oxide nanoparticles and Beauveria bassiana TS11 on Trialeurodes vaporariorum (Westwood, 1856) (Hemiptera: Aleyrodidae)

Abstract

Greenhouse whitefly, Trialeurodes vaporariorum is a major pest of horticultural and ornamental plants and is usually controlled with insecticides or biological control agents. In the current study, we examined the effects of synthesized zinc oxide nanoparticles (ZnO NPs) and Beauveria bassiana TS11 on T. vaporariorum adults. ZnO NPs were synthesized by precipitation method. Field emission scanning electron microscope images indicated that ZnO NPs were non-compacted uniformly. X-ray diffraction results confirmed the hexagonal wurtzite structure of ZnO NPs. Fourier transform infrared analysis showed an intense absorption peak at a range of 434-555 cm-1 related to Zn-O bond. In bioassays, adults were exposed to different concentrations of ZnO NPs (3, 5, 10, 15, 20 mg l-1) and fungi (104, 105, 106, 107, 108 spores ml-1). LC50 values for ZnO NPs and fungi were 7.35 mg l-1and 3.28×105 spores ml-1, respectively. Mortality rates obtained with ZnO NPs and fungi at the highest concentration were 91.6 % and 88.8 %, respectively. The results indicate a positive effect of ZnO NPs and B. bassiana TS11on adults. The current study was conducted under laboratory conditions, therefore, more studies are needed in field.

Keywords

• entomopathogenic fungus
• nanoparticle
• metal oxide
• insecticide
• bioassay