Which statement defines European Foulbrood (EFB)?

European Foulbrood (EFB) is primarily recognized as a stress-related bacterial infection affecting honeybee larvae, caused by the bacterium Melissococcus plutonius. This disease does not produce spores, which distinguishes it from some other serious bee diseases. EFB typically emerges under conditions where the bees are stressed or unhealthy, such as in poor nutrition or environmental factors. The larvae infected with EFB become discolored and are unable to develop properly, leading to a significant decline in bee population.

The other choices either describe characteristics of different pathogens responsible for other diseases or incorrectly attribute properties to EFB. For example, some diseases do produce spores, while others may be viral or fungal in nature, but those definitions do not accurately elucidate what EFB is. Understanding the specific characteristics of EFB helps beekeepers identify and manage the disease effectively.