Studies on the influence of Beauveria bassiana on survival and gut flora of groundnut caterpillar, Spodoptera litura Fab.

Laboratory studies using the spore of the fungus Beaueria bassiana were carried out at different concentrations to assess its influence on the survival of the larvae of groundnut caterpillar, Spodoptera litura (Fab.) (Lepidoptera: Noctuidae) as well its impact on the larval gut microflora. In the contaminated food bioassay, a spore density of 10 9 spores/ml caused 100% larval mortality while LC 50 value was found to be 0.5x10 6 spores / ml. The heterotrophic bacterial population and the generic composition in the digestive tract of the larvae treated with the entomopathogenic fungi were analyzed. Nine species of bacterial genera Bacillus sp., Proteus sp., Enterobacter sp., Salmonella sp., Pseudomonas sp., Escherichia sp., Klebsiella sp., were identified in the digestive tract. The ingestion of fungal spores eliminated three genera of bacteria in the digestive tract