Evaluation of Beauveria bassiana (Balsamo) Vuillemin isolates against Bemisia tabaci Genn. (Homoptera: Aleyrodidae) based on laboratory and field efficacies

A total of 32 Beauveria bassiana isolates from soils in Jordan, in addition to the commercially available GHA isolate, were evaluated for their efficacy against the sweet potato whitefly, Bemisia tabaci. Screening of the isolates involved three-step bioassay procedure in the laboratory and the greenhouse to identify the most virulent isolates. The isolates were tested against the 4 th nymphal instar and the adult whitefly. Results showed that the four isolates: BAU007, BAU016, BAU018 and BAU019 were highly virulent to the whitefly and caused more than 80% mortality. The LC 50 values for the isolates BAU007, BAU016, BAU018, BAU019 and GHA were 3.16×10 6 , 1.17×10 6 , 9.33×10 5 , 5.62×10 5 and 7.76×10 5 , respectively. Further, greenhouse trials showed that the isolates BAU018 and BAU019 were as virulent as the commercial isolate GHA. These findings indicate the potential for B. bassiana isolates BAU018 and BAU019 to be developed as microbial insecticides for effective and safe B. tabaci management.