Honey Bee Parasites, Pests, Predators and Diseases

Nosema (fecal staining on the outside of the hive)

Nosema disease may be present at any time during the year and commonly affects 20 to 30% of colonies. Damage to the digestive tract may produce symptoms of dysentery (diarrhea). Infected workers, unlike healthy workers, may defecate in the hive or on the outside of the hive rather than defecating out in the field. Diseased colonies usually have increased winter losses and decreased honey production. When queens become infected, egg production and life span are reduced, leading to supersedure. The loss of the queen in colonies newly started from package bees is the most serious effect of the disease.

Infection of worker bees inhibits digestion of food in the stomach and production of royal jelly. As a result, the productive life of the worker is shortened and its ability to produce brood-food decreases, thus retarding brood production and colony development.