A notifiable disease of honeybees which is caused by a spore-forming bacterium called Paenibacillus larvae. This bacterium forms spores when subjected to stress (such as lack of nutrients); it is these spores that actually cause and are the source of the disease. Spores enter the larva through feeding of contaminated food. The bacteria kill the bee larva by completely consuming the body tissues. The spores are highly resistant to extremes of temperature, chemical attack and other adverse conditions that kill most bacteria and remain viable for many years. Indeed, their purpose is to allow the bacterium to survive harsh conditions, and once the hardship has passed, for example when nutrients become available again, the bacterium will germinate and reproduce. The cycle will repeat if hardship occurs again. This means that it is difficult to eliminate the spores from colonies.
European Foulbrood is a notifiable disease of honeybees which is caused by the bacterium Melissococcus plutonius and multiplies in the mid-gut of an infected larva and causes the bee larva to starve to death by competing for its food. It is a stress related disease, occurring for example when there is a shortage of nectar, pollen or supplementary feed for bees, and concurrent infection with Varroa mites (which can be controlled). They remain in the gut and do not invade the larval tissue. This normally occurs shortly before their cells are due to be sealed.