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The University of Tennessee Institue of Agriculture

Bees and Beekeeping

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Bees and Beekeeping » Diseases/Pests

Bee Diseseases and Pests

Numerous diseases and parasites afflict the honey bee. This page provides a brief overview of the three most important diseases; American foulbrood, varroa mites, and nosema disease.

To learn more about these and other disease please see our:

American Foulbrood is the only regulated bee disease in TN. The severity of this disease warrants the state regulations regarding the transport of bees and comb, and the state intervention when this disease occurs in an area. Contact our state apiarist for assistance with this disease. Pictured right is a stringy mass that usually occurs with foulbrood in brood cells when probed with a match stick. However this stringy mass later dries out. It will contain millions of bacterial spores that will infect other larvae and hives.

USDA Image: D827-1, by Virginia Williams

Varroa mites are parasitic mites that reproduce in capped honey bee pupal cells while parasitizing the pupa and adult bees. A Varroa mite is seen in the left picture on the lower part of the bee abdomen.


Varroa mites transfer numerous viruses. Pictured left is a conditioned called 'string wings' that usually occurs with high levels of Varroa infestation.

Monitoring techniques, which are explained in "Beekeeping in TN", should be conducted to determine if Varroa infestation levels are over economic thresholds. Infestation at either low or high levels is normal. If numbers of Varroa are high, Apilife-Var and Apigaurd have proven to be an effective 'soft chemical' control. These products active ingrediant is thymol. Pictured right is an Apilife-Var wafer broken into four pieces and placed on the corners of the brood box on 3 occasions spaced about one week apart when honey supers are NOT on the hive.

Nosema disease is caused by single cell fungi that reproduce in the gut of the honey bee. Nosema apis and Nosema ceranae now commonly occur in honey bee populations in the USA. Traditionally, control of Nosema apis has been maintained by annual treatments of Fumagillian-B, mixed in sugar water, and feed to colonies when honey supers are NOT on the hive. With the rise of Nosema ceranae, and its associated problems, research into monitoring techniques and different methods of control are underway.

Queens raised from disease and parasite resistant stock are the foundation of an integrated pest management strategy to keep bees healthy and alive. Marking such queens with paint as pictured left, can help beekeepers determine if the queens they provided for their colonies are still present.


A solid brood pattern during a honey flow in queen-right colonies, such as pictured above, is a strong indication of a healthy hive. However, monitoring for diseases and parasites, in even the healthest colonies has become a critical piece of sustainable honey bee management.