First confirmed report of a bacterial brood disease in stingless bees.

Susceptibility to brood pathogens in eusocial stingless bees (Meliponini), alternative pollinators to honey bees, is unknown. Brood losses in managed colonies of the Australian stingless bee, Tetragonula carbonaria, were studied over 20months. We isolated a disease-causing bacterium, Lysinibacillus sphaericus (Firmicutes, Bacillaceae), from worker and queen larvae, brood cell provisions and honey stores. Pathogenicity experiments confirmed this bacterium as the causal organism. It took 22days from infection to first appearance of brood disease symptoms. This is the first confirmed record of a brood pathogen in stingless bees.