Isolation and efficacy evaluation of the fungus Beauveria bassiana (Bals.) Vuil. Against larvae and pupae of Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae)

Six different isolates of the fungus Beauveria bassiana were isolated from local soils, which collected from two different ecosystems (Natural and Cultivated), at the Syrian Coastal region, using the "Galleria Bait Method". The mortality caused by these fungal isolates against Galleria mellonella larvae was 100% after 3- 5 days post treatment. The pathogenicity of these isolates was studied against 3rd instar larvae of Spodoptera littoralis to detect the most virulent isolate. The mortality ranged from 75% to 100% for the all isolates at the 5th day post treatment. Spore suspension of the most virulent isolate was used at concentration 106spore/ml by spraying it on the pupae of S. littoralis. The percentage of adult emergence was 42% in the fungal treatment compared to the control treatment.