The Effectiveness of Suspension of Beauveria bassiana Mixed with Silica Nanoparticles (NPs.) and Carbon Fiber in Controlling Spodoptera litura

摘要

Spodoptera litura is one of the major potato pests that feeds on leaves during the vegetative and generative phases. This pest may cause low quality as well as quantity of potato production. Entomopathogenic fungi can be used to control plant pests. Beauveria bassiana has been reported as pathogenic to many insect pests. However, its effectiveness in controlling S. litura is low. To increase the effectiveness, it can be mixed with plant micro nutrients such as silica, which also protects plants from biotic stress, and a carrier material. Silica Nps. (silica nanoparticles) and carbon fiber as a carrier were used in this study. The experiment was objected to evaluate the effect of application of the mixture of B. bassiana + silica Nps. in various concentrations + carbon fiber on the mortality of S. litura. There were 16 treatments, i.e. the application of single B. bassiana, single carbon fiber, mixture of B. bassiana + carbon fiber, mixture of silica Nps. at 1, 3, and 5% + B. bassiana, mixture of silica Nps. at 1, 3, and 5% + B. bassiana + carbon fiber, mixture of silica Nps. at 1, 3, and 5% + carbon fiber, single silica Nps. at 1,3, and 5%, and a control. The treatments were applied on the larvae of S. litura by infesting the larvae with the suspension of the S. litura spores. The concentration of the B. bassiana was 10~8 spores/ml. Mortality of S. litura larvae was assessed up to eighteenth days after application. The results showed that the application of the mixture of B. bassiana + silica Nps. 5% + carbon fiber caused the highest mortality of S. litura larvae (53.33%), compared with 6.67% mortality on the treatment of single B. bassiana. Although, 1% of silica Nps. was adequate.