Nosema is a fungus that affects adult bees. With the correct treatment colonies will respond favorably. Nosema is most prevalent in colonies that are stressed, shipped in a package or confined.
The symptoms of Nosema are rather subtle.
Crawling disoriented bees
Bees abandoning the brood to cluster elsewhere
Colonies not consuming supplemental feed
Midgut is swollen and creamy white in color
Heave consentration of Bee feces at hive entrances, top bars, inner walls, and on other items in theye apiary.
Note: Dysentery can also be caused by poor quality food stores, confinement, and feed with heavy concentration of impurities in it.
How it Spreads