Hello,

Thanks for reaching out with this question.

Nosema has been reclassified as Vairimorpha by some researchers, but I'll continue to use its old name (Nosema) to respond. 

Nosema apis is associated with dysentery, however, studies in recent years have found that Nosema apis is no longer commonly found in the U.S. Nosema ceranae is commonly found here, but it hasn't been shown to be associated with dysentery. 

Honey bees take cleansing flights outside of their hives, so it's normal to find bee feces on the outside of the hive and the landing board. 

Nectar sources or sugar syrups with high ash content can cause dysentery. Excessive feces, especially inside of the hive, can indicate that the colony is weak or otherwise stressed. We use white table sugar (beet or cane), since it has low ash content. Organic white sugar, raw sugar, brown sugar, etc. have more ash that can cause dysentery in bees.

Nosema infections tend to be seasonal in nature with high levels in the spring. It's common for the infections to clear up later in the spring during a strong nectar flow. 

If you want to check your bees for Nosema, you can see if the USDA ARS Bee Research Laboratory is willing to accept and check a sample of adult bees.

The University of Minnesota's Honey Bee Diseases and Pests manual and the USDA ARS Honey Bee Laboratory webpage on Nosema disease have more information on Nosema. 

Happy beekeeping!



Sounds good! Please feel free to reach out if you have any issues with the colony.