EFB

The first time I encountered this notable disease was in 2005. My professor at the time had a frozen frame with European Foulbrood. He held up the frame and asked what we saw wrong with it. The first thing I noticed was the shotgun brood pattern. I looked closely and observed contorted/twisted larvae. The symptom is caused by the bacteria Melissococcus plutonius. The larva dies before the cell is sealed because the bacteria out-compete the larvae for the food. The images below demonstrate symptoms I first noted.

The next time I saw this unique disease was the summer of 2008. A beekeeper called with concern, that one of his hives was not doing well and the larvae looked “Funny.” So I headed out to inspect the hives on a bright sunny day. I remember this yard very distinctly, there was a row of hedges and a garden with two honey bee colonies painted white at the end of the row. Upon approaching these hives I noticed a strong odor of what to me smelled like “moldy cheese.” This interested me because it did not smell like AFB. I did recall reading that sometimes EFB has a fishy odor, so I monitored the entrances of the two hives for a minute and cracked the lid on the stronger hive. When inspecting this hive I found no signs of EFB or any other diseases.

When entering the next colony, I used my hive too to remove the inner cover; I instantly found the source of the strong smell. After removing and inspecting a few frames it was clear that the hive was infected with European Foulbrood. Some of the symptoms, besides the characteristic smell, are pictured below. Note that there are several other bacteria commonly found amongst M. plutonius. The associated bacteria can be linked with different odors and symptoms. The disease can be odorless so this symptom alone cannot diagnose the disease.

Fortunately the beekeeper can clean up this disease pretty easy. I recommended the beekeeper use Terramycin to clear up the disease. A few months later I saw the beekeeper at a beekeeping association meeting I was speaking at and he said that the Terramycin worked great and bees were healthier within two weeks. It is always nice to get the beekeepers feedback; it helps me learn more about the bees, treatment and beekeepers.

Written By: Rob Snyder

Rob Snyder has written 62 post in this blog.

I currently work out of the Butte County Cooperative Extension in Oroville, CA as a Crop Protection Agent. I received my B.S. in biology from Delaware Valley College, PA. There I attained a majority of my entomological knowledge from Dr. Chris Tipping and Dr. Robert Berthold. After graduation, I was an apiary inspector for 2 years at the Department of Agriculture in Pennsylvania. In my third year there, I still inspected some colonies but I mainly focused on The Pennsylvania Native Bee Survey (PANBS) where I pinned, labeled, entered data and identified native bees to genus species. Leo Donavall assisted me in learning the basics on positive Identifications of the native bees. Around the same time I began working on coordinating kit construction and distribution for the APHIS National Honey Bee Survey. I was also fortunate to conduct many of these surveys with fellow co-worker Mike Andree and Nathan Rice of USDA/ARS throughout California. All of these experiences have led me to where I am today, working to assist beekeepers in maintaining genetic diverse colonies resistant to parasites while reducing the use of chemical treatments in colonies. The BIP Diagnostic Lab at the University of MD is in an integral part of this process by generating reports in which we can track change and report to beekeepers vital information in a timely manner which may influence their treatment decisions.

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