American Foulbrood and the National Management Survey

Between editing videos for this website, I’ve been checking out my University colonies to see how they are doing. Not good. We (Dr. John Skinner, Philip Moore, and I) found American Foulbrood in all UTK apiaries and are currently attempting to eradicate it, or our bees, whichever comes first. This bacterial disease is rare in Tennessee with only a few cases reported each year.

Figure 1 and 2 are some pictures from the clean up effort. Click here for the large version of Figure 1.

Figure 1: American Foulbrood Symptoms: Ropey Dead Larvae and Black Scale. In this picture, you can see how a match stick is used to probe capped brood. Pick a cell with sunken, perforated cappings. When pulling the stick out from infected brood, a brown, ropey slime can be seen. Also pictured here are many cells with black, bacterial spore laden scales on the bottom of the cells, a condition unique to American Fouldbrood. Hold the frame in good light looking at an angle from the top bar towards the bottom bar of the frame. The inset picture shows a closeup of two cells with black scale in the bottom. PLEASE NOTE: in American foulbrood the scale remains stuck to the bottom of the cell. Melted larvae from European foulbrood can also produce a scale, but this scale will be rubbery and can be easily removed. Photo credit: Michael E Wilson


Figure 2: Burning an American Foulbrood Infected Hive. Cleaning bacterial spores from wax combs is not practically possible. Photo credit: John Skinner

One reason this is rare in Tennessee may be explained by a well organized state inspection program conducted by Michael Studer. He inspects every single colony owned by anyone producing bees in our state to ensure bees being sold or moved are free of this regulated disease. This is the first AFB occurrence in Tennessee this year. The control method is pictured in Figure 2.

Some beekeepers treat their colonies with prophylactic (preventative) antibiotics twice per year to prevent American Foulbrood symptoms from occurring. If the use of antibiotics improved these beekeeper’s overall success we might predict beekeepers using antibiotics might loose fewer bees than beekeepers whom did not use antibiotics. Results from the 2011 National Management Survey suggest otherwise. In the vlog below, Dennis vanEnglesdorp explains how beekeepers that used antibotics did not loose fewer colonies in winter than those who did not use antibiotics.

BUT, what about summer time losses? Its now spring and this disease is challenging our bees now, not in the fall. This year’s National Management Survey also includes questions about summer losses. So take this survey and we may be able to ask, “Do beekeepers that use antibiotics loose fewer colonies in the summer than beekeepers that do not use antibiotics?” Click the Participate Now button upper right to help.

Written By: Michael Wilson

Michael Wilson has written 15 post in this blog.

Michael's primary objective is to provide insight into the Bee Informed database by developing web-based tools for data reporting, data mining, analytics, and database management.