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Honey can transmit AFB between colonies
We frequently warn beekeepers not to feed honey from untrusted sources to their colonies because it can carry the spores of American foulbrood (AFB). Furthermore, we know the spores of AFB can withstand standard pasteurization methods because they are highly resistant to heat. Pressure cooking at 250° F (121° C) for three minutes at 15 pounds pressure will kill the spores, as will other combinations of temperature, pressure, and time, but shortcuts don’t work.
However, as “saving the bees” has become a popular activity for many people, non-beekeepers frequently write to me and explain how they do their part to save the bees by feeding them honey. For many reasons, these individuals cannot become—or do not want to become—beekeepers, yet they want to help the honey bees.
Feeding honey to feral bees can be risky
When they write, I always take the time to explain the hazards of feeding honey, but of course, I don’t know if they heed the warning or not. But more problematic are all the folks who don’t write, don’t ask, don’t know, and assume they are doing the best thing for the bees. For every person who writes into a blog and asks, thousands don’t. And since I get a lot of e-mails about this, I assume the number of people feeding bees is staggering.
I have a picture in my mind of a scrupulous beekeeper, carefully tending his bees, taking precautions against the worst diseases, and doing everything by the book, while a neighbor down the road blithely buys imported honey from the grocery stores and fills a dozen feeders. It’s an uncomfortable thought.
How frequently is foulbrood transferred in honey?
So I began to wonder how often contaminated honey actually transmits AFB. We hear the warnings all the time, but I’ve never actually heard of a case where contaminated honey was thought to be the cause. So how common is American foulbrood in honey? Come to think of it, how common is American foulbrood in honey bee colonies?
The only time I ever saw American Foulbrood was in the hive of a friend, and that was many years ago. I seldom get mail asking about it. I’ve heard of a few recent cases of European foulbrood, but not AFB. Nearly all the mail I get is about varroa mites, deformed wing virus, nosema, CCD, chalkbrood, tracheal mites, and hive beetles, but nary a word about AFB.
The risk is real but the data is scarce
So how common is AFB? How big of a problem are AFB spores in honey? Should we worry about scores of people feeding grocery store honey to any honey bee that wanders by? Or is foulbrood in honey not a worry?
I’m curious to hear your thoughts and experience.
Honey Bee Suite