Which diseases commonly affect honeybee colonies?

The correct answer identifies common diseases that significantly impact honeybee colonies. American foulbrood and European foulbrood are bacterial infections that can devastate bee populations if left unchecked. American foulbrood, caused by the bacterium Paenibacillus larvae, affects larval development and is characterized by a delayed pupation process, leading to the death of affected larvae. European foulbrood, caused by Melissococcus plutonius, leads to a less severe, but still concerning, impact on bee health, usually affecting weaker colonies.

Nosema, a fungal infection caused by Nosema apis or Nosema ceranae, affects the digestive system of bees, leading to decreased life expectancy and poor foraging behavior. Chalkbrood, caused by the fungus Ascosphaera apis, primarily affects bee larvae, causing them to mummify within the cells.

These diseases are part of the most common health issues faced by beekeepers and highlight the importance of disease management in maintaining healthy honeybee colonies. In contrast, the other options contain diseases that are either not related to bees or affect different species altogether, making them irrelevant to the context of beekeeping.