Brevibacillus laterosporus inside the insect body: Beneficial resident or pathogenic outsider?

Brevibacillus laterosporus is an entomopathogenic bacterium showing varying degrees of virulence against diverse insect pests. Conversely, it is regarded as a beneficial component of the intestinal flora in different animals and in some insect species including the honeybee. B. laterosporus was detected through a species-specific PCR assay in the body of different insects, including Apis mellifera and Bombus terrestris. A strain isolated from a honeybee worker was pathogenic to the house fly Musca domestica, thus supporting the development of either mutualistic or pathogenic interactions of this bacterium with diverse insect species, as the result of a coevolutionary process.