Q Is it okay to use “old” beebread?
Here is a common scenario we have all encountered: You lose a hive or two over the winter and, while going through the deadout the following spring, encounter numerous frames of unused pollen and/or frames containing both pollen and capped honey or nectar. Can/should these frames be used to supplement weaker hives or used for a walk-away split? In other words, has anyone studied how long pollen will stay “nutritionally viable” within the frame for later use? Are there significant drawbacks in using these frames or should they be scraped and cleaned?
Bob Ratterman
New York, April
A
It should be okay to use it. There are only two scenarios under which I would not use it. First, I would not use it if I suspected that the colony died from pesticide exposure. If pesticide exposure was responsible for the colony’s death, residues could remain in the comb, ready to kill the next round of bees feeding on the pollen. The other time I forgo using old beebread is if I suspected the colony died to American foulbrood (AFB). Spores of AFB can hang around in comb for decades, so combs from AFB-killed colonies should never be reused. Thus, I would happily reuse the combs containing beebread if pesticides and/or AFB were not implicated in the colony’s death.
Now, you are asking if the beebread remains nutritionally viable. The jury is mostly out on this issue. I conducted a literature search to see if I could find research on this topic and found nothing. All information that I found on bee bread nutritional shelf-life concerned shelf-life from a human perspective. In other words, “How long can I store pollen and it still be nutritionally okay for me?” I answered this very question in the September 2023 column.
Long story short, I do not think this pollen will hurt the next colony, unless, as stated earlier, pesticide exposure or AFB killed the original colony. I would not hesitate to reuse it. If the pollen is of no nutritional value, the bees will get rid of it. If they can derive something from it (which I suspect they can), they will use it. Either way, the outcome is okay. The same holds true for the honey still present in the comb. It should be okay for the bees to consume.
Q Questions about queens and smoker fuel
I was checking my bees and saw queen cells on the upper half of the frame. I did not do anything about it. I guess I should have destroyed them right away, but I did not. The next few days, I went on a trip. When I came back, I checked them again. This time I took the cells off. I did not see anything in them. While I was doing it, I also saw a queen.
1. Was the queen I saw the queen that was always there? Or was it a queen that hatched?
2. Why would the bees want to replace their queen? Is there a chance I injured her when I took off the burr comb? (This is a new hive, started from a package this year.)
3. What should I be doing?
On a different subject, would grilling pellets make a good smoker fuel? I did not try it as the bag said, “Can expose you to wood dust and carbon monoxide.”
Joni Miller
May
A
1. Did you see eggs in the hive? If so, it was the original queen, i.e., the one present the first time you inspected the colony. After all, new queens need ~2 weeks to mate and begin laying eggs. If you did not see eggs, then you likely saw a new queen. My gut feeling, though, is that you had the same queen both times. Bees build queen cells with some regularity, especially the time of year you sent your email (May). May is honey flow season for much of North America. Honey flow season tightly coincides with swarm season, which is when bees make new queens. Of course, it is entirely possible that your colony was not trying to swarm. Bees also build queen cells and tear them down with regularity. It is possible that this is what was happening as well. Either way, I suspect you still have the same queen in the hive. Another possible option is that you did not see queen cells, but rather queen cups. Queen cups are the base of a queen cell, but they do not contain any developing queen. You say that you did not see anything in the cells, which makes me think you were seeing queen cups. Queen cups are always in the hive and do not need to be removed unless you see something in them.
2. As noted above, they could be in swarm mode. Bees preparing to swarm begin building queen cells. After all, the old queen is the one that leaves with the first swarm. She is replaced by a queen the bees rear. Thus, seeing queen cells during the honey flow could be an indication that the colony is ready to swarm. It is also possible that the bees were superseding the queen. Maybe she is beginning to fail, and the bees want to replace her. I suspect this is not what is happening. A third option is that they were building queen cells and would have torn them out themselves, which also happens, for no clear reason. However, it remains possible that they were queen cups, given you saw nothing in them.
3. What would I do? I remove all queen cells I see every time I inspect a nest, if there is clear evidence that the colony has a good queen. How can I tell? I confirm she is present, usually by looking for eggs. I also look at the brood pattern. If she is present (or if eggs are present — indicating she is likely present) and the brood pattern is good, I remove the queen cells. I do not bother removing queen cups. There really is no need to remove them. They pose no risk to the colony.
4. Smoker fuel — I would not use grilling pellets. I am not sure what, if anything, is added to these pellets. The additives would not necessarily be harmful to you. After all, they would be added to wood that you are using to cook your food. However, it is possible that any additives could be harmful to bees. I would stick to using standard smoker fuel, including pine straw, cut/dried grass, and pellets you purchase from beekeeping supply companies.
Q Bees and radio waves/magnetic fields
Are you aware of anyone using a Farraday cage around their hives to block the detrimental effects of radio waves/magnetic fields? I wonder if this would mitigate Colony Collapse Disorder near power transmission lines, radio towers, etc.?
Szeth Magnus
Washington, May
A
I am not aware of any beekeeper who uses a Farraday cage around their hives. I do not believe there is any compelling evidence that radio waves/magnetic fields affect bees significantly in the field. Thus, I do not see a reason to take action to protect bees from exposure to these phenomena. Some scientists have investigated how exposure to these waves/fields affect bees in very controlled studies. However, I do not believe the exposure scenarios represent what bees are likely to encounter in the field. You can find quite a few articles on this topic if you go to Google Scholar (just do a Google search for “Google Scholar”) and then search for “Farraday cage honey bee.” This, and similar searches, will take you to a host of manuscripts outlining research that scientists have conducted on this topic. Again, most of it was super controlled, conducted in the laboratory, etc. I have not seen compelling evidence that this is a big risk to bees in the field.
Q Sampling Varroa and treating with OAV
We are told that about 80% of the mites in a hive are on pupating bees in the capped cells. Dewey Caron also tells us that the 20% of the mites that are phoretic are not evenly distributed throughout the hive, but rather are in clusters found randomly throughout the hive. Furthermore, we are told that we need to test for mites using some type of wash that kills both the mites and (unfortunately) about 300 bees each wash. Randy Oliver has made suggestions on where in the hive to collect these 300 bees to test, but it seems to me that if the phoretic mites are not randomly spaced throughout the hive, you risk either over or under sampling for mites no matter where you collect the bees to sample. Since only about 20% of the mites are out there on the bees you are sampling, your chance of getting a good representation of the number of mites in a hive is quite slim. A “random” sample of 20% of the mites in the hive is not necessarily a good sample. I personally do not want to kill 300 bees to get a questionable mite count.
I am repeatedly told that using oxalic acid vapor (OAV) to treat for mites is a waste of time, since 80% of the mites are under the cell caps and therefore protected from the OAV. But I counter, that if I am killing 20% of the mites in the colony (close to 100% of the phoretic mites) and only the few bees that attack my vaporizer and are cooked alive by the heat, that I am getting a better mite count (multiply 20% by 5 to get the full count) than anyone who kills 300 bees and may or may not get an accurate mite count.
I have also read that the immature mites that exit a cell with an adult bee need to wait three days to mature before they can go back into a cell with a larva to start laying eggs to produce their next generation of mites. I have also been told that the oxalic acid crystals that coat everything in the hive after an OAV treatment are only toxic to the mites for 72 hours (3 days). So, if I treat with OAV every three days and kill 20% of the mites in the hive each time, I will, over time, reach a near zero mite count, the same as if I had used a more toxic mite treatment (and in doing so, only cooked a few dozen bees). Obviously, a brood break by removing the queen, or a natural break around the winter solstice, will allow me to kill close to 100% of the mites in the hive, but there are always more mites in other hives that somehow find their way into my hives.
Steve Winchell
May
A
These are all good comments. I agree with your math and reasoning. The only catch is despite all of this, research has consistently shown that a mite load ≥3 mites/100 adult bees is a pretty reliable indicator of impending damage to the colony. This is generally recognized, almost globally, as the economic threshold for Varroa. Of course, you get more or less accurate counts based on what cohort of bees you sample, where you sample bees, the number of bees you sample, how good you are at performing mite washes, etc.
I do not usually recommend making colony-level decisions about Varroa treatments. Instead, I would perform mite washes on all colonies in an apiary and make the decision at the apiary level. That way, the over/under sampling of mites that happens in one colony will be averaged out with the mite loads you see across all colonies in the apiary.
I, too, am not a huge fan of having to kill bees to get these numbers. The good news is there are ways to perform mite washes without “washing” the bees. You can, for example, do a powdered sugar shake. You get reasonable accuracy, and you can return the living bees back to the hive after you perform the count.
I really like the mite count estimation you propose, where you treat the hive with oxalic acid and assume the mites that fall onto a sticky board can be counted to estimate whole colony mite populations. However, you must assume 100% efficacy of oxalic acid (which is not realistic) and that exactly 20% of the mites are on adult bees (a percentage that can vary significantly throughout the year). Thus, your method may also be based on large suppositions. Nevertheless, I do like the idea that you are sampling all the adult bees and getting a more accurate estimate. I was speaking to a bee researcher from Israel recently and he said that commercial beekeepers in Israel also apply a compound (not oxalic acid) in vapor form to colonies and use mite fall to determine if colonies need to be treated. This is similar to what you propose. I will discuss your idea with team members in my laboratory to see what they think. This seems like a neat idea. Thanks for sharing.
To your point about oxalic acid efficacy when used every three days: There has been an explosion in oxalic acid research globally. You can find many research manuscripts on this topic if you go to Google Scholar and search “oxalic acid honey bee.” I did not find a study that tests the exact method you propose (i.e., treating with oxalic acid vapor every three days). You do not mention how long you do this. For example, do you do this three times, five times, ten times? My guess is that it would take many times (maybe 10+) to get the desired efficacy which, as you note, could be improved if you do this when less/no brood is present in the nest. Jennifer Berry and colleagues (2022) tested using oxalic acid vapor every five days over seven applications and found that it was not effective. I realize this is not the 3-day interval you propose, but it is the closest I could find in the literature. Please let me know what you find as you try this. I am interested to hear your results. …
