Isolation, characterization, and bio-insecticidal efficiency of Ethiopian isolates of Bacillus thuringiensis against Galleria mellonella L. (Lepidoptera: Pyralidae) and tomato whitefly, Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae)

Abstract Background Bacillus thuringiensis is a Gram-positive, rod-shaped, and spore-forming microbial entomopathogen. The silverleaf whitefly, Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae), worldwide important cryptic species causing serious economic damage to several vegetable crops including tomato. aim of this study was characterize evaluate the bio-insecticidal effects locally isolated ( Bt ) against Galleria mellonella . Results Thirty-one isolates were obtained from 70 soil samples based on cultural characterization coupled with insecticidal crystal protein detection. All 31 bacterial pre-screened for their property greater wax moth, L. larvae. Only 20 (64.5%) virulent G. percentage mortality that ranged 2.50 95%. groEL gene sequences all entomopathogenic indigenous displayed 99–100% similarity isolates. Bioassay evaluation 12 selected 3rd 4th nymphal instars B. spore-crystal suspensions 1 × 10 9 spores/ml caused 0 31.25%, 57%, 82.5% within 48, 96, 144 h accordingly. Among , isolate AAUDS-16 had highest virulence, followed by AAUES-69D LC 50 values 9.67 6 1.16 107 spores/ml, respectively. tested growth response different temperature range between 15 40 °C. showed maximum rate around 30 Conclusions high potential nymphs larvae, in wide temperature. High virulence temperature-tolerant should be candidates diverse toxin studies.