Pathogenicity of Sudan Isolates of Bacillus spp to the Greater Wax Moth Galleria mellonella L.

Abstract

Aims: To evaluate the pathogenicity of Bacillus spp isolated from Sudan against the greater wax wax moth Galleria mellonella L. measured as mortality percentages and reduction in the amount of food consumption. Study Design: This study is a laboratory experiment in a completely randomized design. Place and Duration of Study: Department of Biopesticides and Biofertilizers, Environment, Natural Resources Research Institute, during 2010. Methodology: In this study 500 ppm of liquid suspension of the dried spores-crystal mixture of 39 Sudanese Bacillus spp were prepared. This suspension was mixed with the food provided to the greater wax moth larvae. Larvae in the control were fed on food mixed with sterile distilled water only. Dead larvae were daily counted for ten days and the amount of food consumed was calculated by the end of the experiment. Results: Up to 81% mortality was recorded by isolate Wh-5 (Bt- JX674041) compared to 12.5% in the larvae fed on untreated food. However, the lowest mortality was recorded by isolate Om-5 (Bt-JX660701), which is 21.8%. Larvae exposed to this isolate consumed greater amount of food than that consumed by larvae fed on untreated food but are not significantly different. Significant differences were observed between different isolates in the mortality percentages and in the amount of food consumed by the different isolates. The least amount of food consumed was that of larvae served food treated with isolate Po-2 (Bacillus sp-KF 305081) which was one-third of that consumed by larvae fed on untreated food. While consumption of larvae exposed to some isolates was greater than that consumed by larvae in the control. Conclusion: This study showed the potentiality of the Sudanese Bacillus strains in controlling the greater wax moth. Detailed studies for determination of the lethal doses and specification for optimum production condition is important step for formulation, registration and commercialization.