In 1885, Bacillus alvei was isolated from diseased larvae and identified as causative agent of the disease at that time still simply known as ‘Foulbrood’ (Cheshire and Cheyne, 1885). In 1906, the American microbiologist White failed to isolate B. alvei from ropy mass and instead cultivated an unknown bacterium in pure culture. Based on the rod-shaped morphology and the ability to form endospores he classified the bacterium, that was consistently found in diseased and dead larvae, as Bacillus larvae (White, 1906). He was the one who also realized that there were two different foulbrood diseases caused by different pathogens developing different symptom complexes. On the one hand European Foulbrood caused by Melissococcus plutonius with the saprophytes B. alvei and/or Enterococcus faecalis as frequent secondary invaders