The Classroom
The Classroom – September 2020
Q European Foulbrood
I have read your excellent guide on the treatment and diagnosis of European Foulbrood at https://edis.ifas.ufl.edu/in1272. In the past I have tried:
- Mite treatments
- Shook swarm
- Culling older frames (but not all frames)
- Feeding sugar syrup/pollen patties
- Requeening
Last year, requeening a hive was very effective; this year’s results are disappointing. I also find it strange that in the middle of summer, with a moderate-to-strong honey flow, this disease would still be prevalent. My questions have to deal with perennial issues with this disease.
- I have been advised that burning frames and hive bodies is extreme and not necessary, I hope this is true. Am I perpetuating the infection each year by using frames and hive bodies that have contained foulbrood at one time?
- I have read that requeening with a hygienic race is recommended as these bees are expected to be more aggressive at removing diseased larvae. Would this make an appreciable difference?
- If I were to add healthy brood frames from strong colonies, are those frames then contaminated? At what point can they be considered “clean,” after soaking in a bleach water solution?
Chris Wynkoop
Illinois, July
A
I am glad that you enjoyed the EFB guide my team and I produced. A student in one of our beekeeping classes put that together and we published it as a University of Florida electronic fact sheet.
Your comments about EFB are interesting to me because they fit the description of what a lot of commercial beekeepers have been telling me about a similar phenomenon that they have seen in recent years. Basically, it seems to be common for colonies to get EFB, or something like it, after the spring nectar flow when colonies otherwise should be strong and healthy.
To your specific questions:
1) I do think that destroying the combs/hives of these infected colonies is a bit extreme and unnecessary. If EFB really is the culprit, then doing what you note in your questions (the five steps) should help the colonies pull out of it. If those do not work, then a perfectly reasonable option is to treat the colonies with one of the available antibiotics labeled for use in honey bee colonies. This should clear it up.
2) It is generally held that using bees that display good hygienic behavior will help manage the disease. The research I have seen on this topic usually concerns American foulbrood and not EFB. However, the consensus is that it will help. Furthermore, you get the added benefit that hygienic bees help manage AFB, Varroa, and chalkbrood (likely among other problems). I do believe it will make an appreciable difference.
3) When you add frames from healthy colonies to EFB-infected ones, the frames do become contaminated. To my knowledge, there has been no work on how long it would take the frames to be free from infection post-exposure. However, my guess is that it would take weeks or months after you see your last signs of the disease. This is why I like the antibiotic option as a last resort. This controls the bacteria that causes EFB and helps rid the hive of it.
As an added note, the Bee Informed Partnership has some good information (and great pictures) about EFB on their website. You can also check out the information on EFB from the following groups: BeeAware (Plant Health Australia), eXtension (Bee Health), and the Food and Agriculture Organization of the United Nations (FAO). To find that information, just Google the names of those organizations with “European foulbrood.” The information is easy to find.
Q Plastic honeycomb
What is your opinion and experience with plastic hive frames with fully drawn plastic honeycomb on supers and brood? Being retired and ending up being a full time beekeeper, I am always experimenting with some of my hives. Was looking to get 10 frames and see what happens.
Terry Smalec
Colorado, July
A
Terry, to be honest out-of-the-gate, I have never used the frames that are entirely plastic with fully “drawn” plastic comb. I was sent a box years ago and wanted to put it on hives, but never did.
That said, I have discussed it with some beekeepers who have tried it and I will share what they told me. First, some of the beekeepers I know who have tried it really liked it. I mean, they really really liked it. They noted the standard benefits that the bees do not have to make comb, that they are sturdy, and there is no assembly required.
The drawbacks they noted were the standard ones you hear as well. Bees can be reluctant to use it unless it is all that is provided to them (i.e., they have no other option but to use it). So, they recommend not mixing the plastic combs in a super with wax foundation or wax combs. They say when you elect to use it, go “all in.” I have had one beekeeper suggest coating them with a little bit of wax or spraying them with sugar water to get the bees to accept it easier. However, I would take the radical approach and give it to them just the way it comes in the box.
Of course, the bees are the ultimate decision makers so I would put the test directly to them. You note that you like to experiment. I say go for it. Purchase one super, put it on your hive, and let me know what your bees do. I think that the bees will take and use it during a major honey flow. Good luck!
Q Bees not building comb?!?!
I am a new beekeeper and started my beehive on May 22. I live on 25 acres in Georgia and there are always lots of flowers; so, I only fed my girls the first two weeks. However, it has been five weeks now and the girls have only drawn 3½ frames of wax and only ½ frame in the past two weeks. I was wondering if/how I should encourage my bees to build more comb.
Jonny Dorminy
Georgia, July
A
Johnny, in my experience, bees build more comb when they have the resources needed to build it. What are the resources they need to build wax comb? They need carbohydrates (sugar). This is converted into the wax that they secrete and use to make the comb. A new colony on new foundation “wants” to draw comb. Thus, if they are not drawing comb, it is because they do not have enough resources to do it. The bees can be carbohydrate-starved even if there are flowers in the area. Not all plant species produce enough nectar needed by bees to build comb. Based on the fact that you live in Georgia (my home state) and said you started your hive on 22 May (near the end of the standard spring Georgia nectar flow), I suspect your bees simply ran out of resources and that you need to feed your bees.
Of course, there is an off chance that the bees have some sort of issue that keeps them from being productive. This could include Varroa, viruses, etc. However, this would be the exception rather than the rule for a new colony that is otherwise programmed to grow fast. I think feeding your bees will solve the issue you are seeing.
Q A hive under my hive?
I was wondering if you have ever seen this before. I have an open-air hive below my main hive which has two hive bodies and two supers. I was thinking an after swarm may have built a hive underneath this hive. What do you think? Thanks for your input and time.
Bob Eckenrod
Pennsylvania, June
A
Bob — your hunch is likely correct! I also think this is a swarm that ended up establishing under your hive. My guess is that if you go down to that comb, you will find brood, a queen, pollen, honey, etc.
Here is what I think happened. As you likely know, the primary (first/main) swarm of a colony usually contains the old queen. For many colonies, this is the only swarm they will issue during swarm season. Usually, the old queen will slim down prior to swarming so that she can get down to her flying weight. My guess is that this one did not lose enough weight or that she could not fly for another reason (tattered wings, etc.). I happen to clip my queens’ wings to keep swarms from happening. In my case (and I think in yours), my bees will try to swarm and the workers will all take to the air. The queen will come out of the hive as well, but be unable to generate lift. So, she sort-of just glides to the ground in front of the hive.
I have seen swarming workers land on the queen on the ground, forming their swarm cluster just a few feet away from their hive. I have also seen (more times than I can count), the queen walk back to my hive and crawl underneath, but not go into it. At this point, the swarming workers will coalesce underneath the hive with the queen. Occasionally, the queen and workers will go back into the hive. However, if they do this, they usually end up trying to swarm again the next day, with the same outcome happening. Given my queens are clipped, they can never fly. So, I end up finding swarms underneath my hives all the time. My response is that I am grateful that a swarm landed somewhere I can actually get to it. ☺ I, then, just collect the bees from underneath the hive, put them in a hive of their own, and set up a place for them in the same apiary. You could hive them and move them away for a week or two before bringing them back, just to avoid any drift to the old hive location that might happen.
You note specifically that this could be an “after swarm.” For the benefit of the reader, this is any swarm that occurs after the primary swarm. Afterswarms are headed by virgin queens that emerge after the colony has already swarmed. This can occur if two or more virgin queens emerge at the same time or if the colony is still large after its primary swarm. In either case, the bees will swarm again within days of issuing its primary swarm. These swarms are often smaller than primary swarms. Colonies can swarm 2-4 times this way. My only thought about this being an afterswarm is that virgin queens usually can fly (are less likely to have tattered wings for example), so it is less common for them to end up establishing under the hive. Furthermore, if they could not fly to swarm, they likely could not fly to mate, meaning that she would only be laying drones in the combs under the hive. If not an afterswarm, why would it be so small? This can happen because a lot of bees in the swarm underneath the hive end up just going back into the hive, leaving few bees and a queen underneath the hive to fend for themselves. Double check the combs, make sure the queen is mated (if she is there), and hive those bees.
Despite all of this talk about swarms, there could be another reason for the combs underneath the hive. I have, occasionally, seen strong hives continue to build comb underneath their hive. This usually only happens if they have direct access to the space under the hive, usually through a large hole in the bottom board. I think this is the less-likely scenario of the two. My gut tells me that it was a failed swarm and that you have a second colony underneath the main colony.
Q Honey bee genetics
The queen bee has 32 chromosomes, 16 of which she received from her mother and 16 from her father. When the queen lays a drone egg, she separates her chromosomes and only places …
