By Meghan Milbrath, PhD
Research Associate, Department of Entomology, Michigan State University
There is nothing worse than opening an overwintered hive to find the bees dead and the equipment streaked and spotted with bee feces—dark brown splatter on top of frames, on the front of the hive, and even on frames of capped honey. While it doesn’t seem safe to feed this honey to your healthy hives, it seems like such a waste to toss out full frames. So what can be done with all this leftover honey?
First, the spotting is a sign of dysentery—this means that the bees were not able to make it outside for their cleansing flight, and defecated within the hive. Generally this is caused by long periods of cold weather in combination with a problem with digestion. The parasite Nosema apis is one of these problems, but it isn’t the only cause. Fermented honey and food with indigestible matter can also cause the bee’s gut to fill up more quickly and create the need to defecate more than the weather allows.
If it is Nosema, the spores can survive on the contaminated equipment, and bees cleaning up the spotty feces can transmit the disease to each other. While a diagnosis will let you know if you have Nosema apis in your hive, it shouldn’t change the way you handle the equipment. Bees that are weak and have poor nutrition are at high risk for many other diseases, including ones that don’t leave visible signs in a dead hive. So even if you test negative for Nosema apis, there may be other diseases in the honey.
Can I extract and use the honey for myself?
Nosema diseases are very specific, and aren’t dangerous to humans, so the honey is safe to extract and consume from a pathogen standpoint. However, many beekeepers treat their hives after they have removed most of the capped honey, so make sure that this honey wasn’t on frames while you were using a treatment that isn’t safe for humans.
Can I feed the honey to my bees?
Nosema spores can remain infectious for months in honey, so there is a risk of infection with Nosema or other diseases if you feed frames from a dead out to other hives. While you can’t bring this risk to zero, there are things that you can do to reduce the risk of transmission.
- Scrape away as much of the feces that you can, so other bees don’t have to clean it. If you use your hive tool for this, make sure to clean it afterwards. Remove the stained cappings from the supers—there shouldn’t be as many pathogens inside the stored honey, because the bees should have been collecting it and covering it before the issues with the dysentery.
- Freeze the honey—Nosema and many other pathogens are susceptible to freezing. If the colony died early in the winter and you live in cold climate, nature has probably already put your equipment through many cycles of freezing. If you use a chest freezer, leave it in for long enough (a few days if possible) so that all the honey can get to a low temperature.
- Put these supers on your strongest colonies. A strong and healthy colony is always much more able to handle small amounts of pathogens than a weak or malnourished colony.