Which condition is commonly referred to as 'bee diarrhea'?

The condition commonly referred to as 'bee diarrhea' is Nosema. This is a fungal infection caused by the Nosema species, specifically Nosema apis and Nosema ceranae, which affects honeybees. Bees infected with Nosema may exhibit symptoms such as disorientation, decreased foraging activity, and the presence of watery feces, which is why it’s colloquially called 'bee diarrhea.'

This condition is particularly concerning for beekeepers, as it can lead to weakened colonies and reduced honey production. The feces may appear on the exterior of the hive or on the bees themselves, indicating poor health and cleanliness within the colony.

In contrast, American Foulbrood, European Foulbrood, and Chalkbrood are all diseases that primarily affect the brood (the developing bees) and do not typically manifest as the observable symptoms associated with 'bee diarrhea.' American Foulbrood is caused by the bacterium Paenibacillus larvae, European Foulbrood is caused by Melissococcus plutonius, and Chalkbrood is a fungal disease caused by Ascosphaera apis. While these diseases are serious threats to bee colonies, they do not involve the distinct fecal symptoms seen