Healthy Cordovan queen.
To determine if something is wrong with your hive, you must first know what a healthy, productive hive looks like. Knowing what a healthy colony looks like takes time, patience, and many hours in the hive to get a feel of what is going on in the colony throughout the year. Sometime the colony does not look so great and the size of the colony starts to dwindle. You can do two things here, panic or take a look at what is actually going on. Look at the brood, look at the bees(size, wings, uniformity, behavior), look at the sealed brood, look at the food stores, look at the entrance, feel the weight of the hive, notice any odors that may be emitting form the hive, and listen to the hive. These simple things can help identify problems in the hive.
The way I learned these diseases was from my professor Dr. Robert Berthold. He had frozen frames of the different diseases that he has showed us. There were also detailed lectures on the different diseases. This was enough to get me started, but didn’t really mean much to me until I started inspecting hives for the PA Department of Agriculture where I was able to utilize the information and knowledge learned to help beekeepers diagnose problems with their honey bee colonies. Over the years I have learned a great deal more and seen many problems that I couldn’t identify but that I could at least rule out some causes. During this learning curve, I have taken hundreds of photographs of diseased bees, healthy bees and bee behavior. Recently my co-worker Mike Andree and I have started to document some of these disease and behaviors on video. In the near future we will be posting some of these videos with our experiences to help beekeepers identify problems in their hives.
Below are images I have taken comparing healthy frames of brood to ones that are not so healthy. It will cover a majority of brood diseases and other problems found in the hive. This is not a comprehensive guide; it is a collection of images displaying different diseases and symptoms within the hive to help diagnose these problems. Hopefully this will help beekeepers identify issues in their colonies.
This is a frame of sealed brood from a healthy hive. Notice the solid brood pattern. Also note that there is no pollen stored on this frame. It’s important to look for pollen on other frames to assure they have adequate pollen stores.
This frame of brood has Chalkbrood, There are arrows pointing to the cells infected with the fungi Ascophera apis. Notice the shotgun brood pattern. There is not much chalkbrood on the frame so the bees are removing the chalkbrood mummies out through the entrance.
Drone pupae infected with the Ascophera apis fungus. Shortly the whole pupae will be a chalky sponge-like mummy.
Chalkbrood mummies just outside the hive entrance. If the brood pattern has a very spotty/shotgun appearance, look at the entrance to see if these mummies are present. I almost always look at the entrance before going into the hive.
Here is another sealed brood frame from a healthy colony. Notice how this colony has much more pollen stored around the brood nest.
This brood frame has European Foulbrood. Melissococcus plutonius is the causative bacteria that out competes the larvae for food killing it before it is sealed. For more images see my blog on EFB.
This brood Frame has AFB or American Foulbrood. You can tell by the perforations in the cappings. Also note the shotgun brood pattern. You can also see sunken or concave cappings on the frame where they are normally convex shaped.
Paenibacillus larvae is the American Foulbrood bacteria that infects larvae and kills them once they are sealed. Here you see sunken cappings, perforations in cappings and infectious larvae.
Here is another frame of sealed brood from a healthy colony. The lighter color cappings represents newer wax that has not been contaminated with debris yet.
The final stage of Sacbrood Virus(Morator aetatulas) is when it changes from grey/white to black. The bees will often remove them before they get to this stage. See my blog on SBV for more information and images.
PMS or parasitic mite syndrome. Notice there are no larvae or eggs in the open cells, the bees are unable to rear healthy brood.
This image shows PMS with mites feeding on brood, you can also see an arrow pointing to a chewed down pupa and varroa mites in the cells.
This images shows bees with Deformed wing virus (DWV), Parasitic mite syndrome (PMS) and also you see pupa being uncapped by bees that detected mites in the cell.
Here you see DWV and more pupa being chewed down. These are signs of heavy varroa mite infestation.
The bee on the far left has disjointed wings also called K-wing. A number of things can cause this incuding nosema, tracheal mites and possibly viruses.