Management of Bemisia tabaci on vegetable crops using entomopathogens

Abstract

The sweetpotato whitefly, Bemisia tabaci Gennadius, is a devastating insect pest on vegetable crops around the world. This pest causes significant damage by directly feeding on vegetables, excreting honeydew, inducing plant physiological disorders, and transmitting plant viruses. The combined direct and indirect damage to vegetable crops has led to substantial economic losses. The heavy reliance on chemical insecticides for whitefly control has led to considerable resistance to many insecticides in whitefly populations. Therefore, integrated pest management (IPM) that includes entomopathogens is considered as a sustainable and effective approach against B. tabaci. This review focuses on biological control of B. tabaci using entomopathogens, including entomopathogenic fungi (EPF), entomopathogenic nematodes (EPN), and entomopathogenic bacteria (EPB). Among them, EPF is the mostly explored group of entomopathogens for B. tabaci control. In particular, Beauveria bassiana (Balsamo-Crivelli) Vuillemin, Akanthomyces lecanii (Zimm.) Spatafora, Kepler and B. Shrestha, Cordyceps javanica (Frieder. & Bally) Kepler, B. Shrestha & Spatafora, and C. fumosorosea (Wize) Kepler, B. Shrestha & Spatafora are the most commonly used EPF species for whitefly control. The control efficacy of EPN against B. tabaci varies with strains/species and concentrations of the EPN, whitefly nymphal instars, host plants, and environmental conditions. Most research on evaluating the virulence of various EPB isolates against whiteflies has been conducted in the laboratory. Entomopathogens offer a promising strategy for whitefly management in vegetables. This review discusses research updates on the three entomopathogen groups for whitefly control, barriers in broad adoption by vegetable growers, and future directions.