Honey bee dysentery and water

Dysentery in honey bees is one of those unfortunate terms that results in nothing but confusion and misconception. It’s right up there with the word “organic” to describe food grown without manmade fertilizers and pesticides. If you apply the traditional meaning of organic—which, with a few exceptions, refers to chemical compounds containing carbon—then the large majority of chemicals used in conventional agriculture are definitely organic, including all those pesticides. No wonder people get confused.

In humans, dysentery refers to a condition caused by a pathogenic organism, but honey bee dysentery refers to a form of diarrhea caused by too many solids in their feed. To add to the confusion, honey bees also get diarrhea from pathogenic organisms such as Nosema, and it appears just like the other kind. If you feel confused, you are not alone.

Excess water is often blamed for honey bee dysentery, but the condition is actually caused by too much bulk in the honey bee intestine. You can compare it to a human eating too much fiber. During the winter, when honey bees cannot take cleansing flights due to the cold weather, the amount of solids stored in their intestines continues to increase. These solids come mostly from the honey they eat. Some honey has more solids than others and, typically, dark-colored honey has more solids than light-colored honey.

Since bees can only retain about 30 to 40 percent of their body weight in fecal matter, when the time between cleansing flights is too long, they will void inside the hive or just outside of it. This is what we call dysentery. Although solid material—not water—is the cause of dysentery, it confuses people no end.

For example, here is a statement from the Mid-Atlantic Apiculture Research and Extension Consortium (MAAREC) website: “Dysentery can also be caused by feeding bees anything with a high water content in the early spring.” This is a true statement. But to see why it is true, you have to look at how they qualify their words. They are not saying that water causes dysentery; they are saying too much water fed in the early spring may cause dysentery.

Why is this true? It is true because by early spring the honey bee’s gut is loaded with solids. It is probably approaching its limit of 30 to 40 percent of the bee’s body weight. So if the bee drinks a lot of water, the solids may absorb some of the water and push the bee over its 30 to 40 percent-by-weight capacity—sort of like the straw that broke the camel’s back.

Nevertheless, water all by itself does not cause dysentery. This may seem like a subtle point, but if the bee’s gut were empty in early spring (or any other time), the bee could drink quarts of water and not get dysentery.

One final note, although honey bee dysentery is not a disease, it can cause a hive to fail. Colony death may result from stress, diseases promoted by unsanitary conditions, or a breakdown in the internal communication system due to the overpowering odor inside the hive.

Rusty
HoneyBeeSuite

Comments

Emily
Reply

Very informative, thanks Rusty. Another common misconception seems to be that dysentery indicates nosema. From what I’ve read dysentery can lead to nosema spreading faster but bees can have dysentery but not nosema.

Rusty
Reply

Emily,

That’s exactly right; the presence of dysentery could mean nosema is present or not. You need laboratory analysis—or a good microscope—to tell the difference.

Karl Schroeder
Reply

Is it reasonable to feed Fumagillin-B as a prophylactic early in the spring and also before bedding down for winter?

Rusty
Reply

It is reasonable if you think you have or may develop a problem with Nosema. As with any drug, overuse may cause resistant strains to develop.

Laurel
Reply

I see the difference between the two. However, I didn’t see a remedy or real recommendation for a remedy.
Did I miss it? Or is this just to let beekeepers know that there is a difference between Nosema and Bee Dysentery?

Rusty
Reply

The point of the post was to explain that excess solids in the diet, not excess water, causes honey bee dysentery. To prevent honey bee dysentery a beekeeper must not feed bees things with too many solids. The only remedy would be to stop them from eating the things that cause dysentery.

Teri
Reply

So if my bees were loaded with buckwheat honey for winter, that may have contributed to their having dysentery?

Rusty
Reply

Teri,

It certainly could be a factor. Buckwheat honey is known for having a high ash content.

Teri
Reply

I’m following up on the dysentery/nosema thread here. Since I lost a couple of hives to dysentery and buckwheat honey may have been a factor, but the possibility of nosema has not been ruled out. I’ll assume that I shouldn’t give the honey from these two colonies to any other bees I have now, or to new colonies created in the spring. I need to find out whether this honey is a nosema spore source. How do you suggest I do this?
And by the way, this is/you are a fantastic resource.

Rusty
Reply

Teri,

I had to do some reading and check with a couple sources to verify what I thought about this. But the consensus is that honey, although it may possibly contain some Nosema spp spores, is not considered a problem. The spores are everywhere. You can compare it to the common cold in humans. The virus is everywhere. Contracting the virus is more or less the result of a weakened immune system than the presence or absence of pathogen, since the pathogen is always present. Bees will be exposed to many more spores from infected bees which accidentally make their way into the hive, come in contact with other bees in the field, or leave spores on flowers where they are nectaring. Any spores in the honey will not germinate and reproduce–it is not the right environment for them. If it were me, I would go ahead and move the honey into the next colony without a worry. I don’t know how to test honey for Nosema, but you can send some of your dead bees to a lab for analysis. Check with your state extension service for details.

Teri
Reply

This is good news! When I originally started my search into what had happened w/my bees and had come up with the possibility of nosema, the reading I did led me to believe that I had to destroy the infected equipment. I had a stack of boxes filled with honey and beautiful brood comb waiting by the burn pile for a “burn day”. I am so glad to have waited this out.
Thanks very much.

Jeff
Reply

Hey Rusty,

After careful consideration I think I see two common events that lead to the death of 8 of my colonies. Dysentry due to pollen substitute mixed in the candy boards and shrews.

Rusty
Reply

Jeff,

Don’t you know you’re supposed to tame your shrews?

Seriously, don’t leave me hanging. Tell me about shrews. This is all new to me. What did they do?

About candy boards, I never add pollen substitute until after winter solstice when brood rearing begins. Did you add it earlier, or is the solstice too early for your area?? Really interested.

keeweekid
Reply

We think we lost a hive this winter to dysentery. Is it ok to harvest the lost hive’s honey? What signs do I look for if it is bad? I poked my finger in one of the comb and it seemed really watery. But it could have just been built up condensation. We seem to have a separate issue with that too.

Rusty
Reply

keeweekid,

Honey bee dysentery is not caused by a pathogen, it is caused by a diet high in solids. In any case, the honey is perfectly safe to eat. The bees don’t cap the honey until it is at the proper moisture level. If the combs were really hot when you poked your finger in, the honey may have seemed runny. Or perhaps you poked your finger in uncapped cells? That would be different. Bring the honey to room temperature and then try again. Also, maybe you can borrow a refractometer and measure the moisture level.

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