This section has been created with the beekeeper in mind and is currently under construction. It focuses on bee diseases and parasites. The goal is to make it easy for you, the beekeeper, to find the necessary diagnostic information to make an informed decision on what may be affecting the health of your hive. This is a basic guide only. There is a boatload of information out on the web. You will need to assess the data and make the best management decision you can with that data. Research, decide, act and evaluate.
American Foulbrood (AFB)
American Foulbrood is probably the most feared of all bee diseases. American Foulbrood is highly contagious and is spread through the use of contaminated equipment and through robbing of the diseased hive by other bees. It is caused by the Bacillus larvae bacteria. The bacteria feeds on the larva and kills them in their pre-pupal and pupal stages. American Foulbrood has a distinct odor. Most beekeepers will notice the odor before they will notice the rest of the symptoms.
Here is a link to the USDA/ARS Bee site: http://www.ars.usda.gov/Services/docs.htm?docid=2882. Here is a short youtube video on determining if you have American Foulbrood in your hive: http://www.youtube.com/watch?v=v2Aa56jut7Y. Not into videos? Here is a nice .pdf. And another.
If you have confirmed that you have American Foulbrood, the classic recommendation has been to burn the hive, bees and all, to prevent further transmission to other healthy colonies. There are other options, however. Here are some videos and links to American Foulbrood treatments.
Both European and American Foulbrood Treatment Options by Jamie Ellis, University of Florida
Chemical Treatment Options by Dr. Eric Mussen, UC Davis
Moving an Infected Colony to Eliminate AFB by Tim Schuler, NJ Department of Agriculture
European Foulbrood (EFB)
European Foulbrood is less virulent than American Foulbrood as EFB does not create spores and spores can last for decades! It, too, is caused by a bacteria, Melissococcus pluton, but it only affects young, uncapped larva and, as a result, is quite a bit easier to diagnose. Instead of the brood being pearly white and glistening, the brood is discolored and dry-looking. As you may expect, there is an odor associated with EFB also. Here is a diagnostic video from Dr. Jamie Ellis of the University of Florida. Here is a link to some diagnostic images for reference.
Chemical treatment of EFB is the same as AFB. Chemical Treatment Options by Dr. Eric Mussen, UC Davis
Requeening is generally helpful also.
Chalkbrood is a brood disease caused by a fungus, Ascophaera apis. Chalkbrood produces bee larva “mummies” which you can see on the bottom board of a colony. These mummies are whitish in color resembling pieces of chalk which is how it acquired its name. Here is a picture of a heavy infestation of chalkbrood. Typically, in CO, chalkbrood is seen in the spring. It is rarely fatal. A colony entering into spring will generally “fix” the problem by merely growing and heading into larger populations for summer. The most common “treatment” is to requeen.
There are more brood diseases out there than these three–but these represent the most common diseases found here.
Varroa Mite (Varroa destructor)
It is hard to imagine beekeeping before Varroa but a mere 30 years ago, this was the case! Varroa destructor is aptly named and is the cause of a tremendous percentage of colony losses annually. Here is a link to a PDG (pretty darn good) description of Varroa from, not surprisingly, the University of Florida. Oh, if only we had this type of support from our universities here in Colorado! Too busy working on wheat, I guess.
There are a lot of different ways to manage Varroa. You can manage it with in-hive miticides or you can manage it with non-chemical alternatives or any combination in between. No matter what treatment method you use, you need to know whether you need to treat at all first. There are 2 methods of determining the Varroa load in your bee hive: alcohol wash and powdered sugar roll.