The Classroom

The Classroom – March 2023

- March 1, 2023 - Jamie Ellis - (excerpt)

The Classroom - ABJ - Jamie Ellis
Commercial Beekeeping With 8-frame Equipment

As a sideline beekeeper, I am thinking of taking my business to the next level. This includes providing locally adapted queens, nucs, and pollination services. I live close to the Missouri Bootheel and the watermelon producers of northeastern Arkansas. My question to you is this: Am I making a huge mistake by having a commercial business that utilizes only 8-frame medium woodenware for every situation, including brood boxes, supers etc.?



Congratulations on taking the next step to become a commercial beekeeper. Many people who keep bees enjoy it so much that they elect to move their hobby or sideline business to the next level. I am sure you know that this will take a lot of work but it sounds like you are up to the challenge. Your question is an important one and it is worth considering in some detail.

I will give you a quick disclaimer. I have never kept bees using 8-frame equipment. I have always used the conventional 10-frame equipment. That said, many beekeepers share with me that they prefer to use 8-frame equipment, often simply due to the fact that the hives are lighter than 10-frame equipment when full of bees, brood, honey. Other folks like to use it because they believe that the bees prefer it or do better in it than they prefer/perform in 10-frame equipment.

In essence, you are asking a question about hive configuration and I receive a fair number of these types of questions. In fact, a second question in today’s column concerns hive configuration. Usually, when I answer the question, I make the comment that hive configuration is almost completely up to the beekeeper. The bees likely really do not care much at all. Furthermore, I have not seen any research showing that bees perform better in one configuration versus another one. I have definitely heard many arguments for one configuration over another, but those arguments are not usually supported by data. They are all preference driven.

With that long preamble, how would I approach what you are doing? First, as you likely know, the commercial beekeeping industry in the U.S. is a 10-frame, Langstroth hive world. There are exceptions. I know a commercial beekeeper who makes honey and provides pollination services using top-bar hives. In fact, I am sure other commercial beekeepers do as well. The same is true for just about any hive configuration you can consider. However, those beekeepers are the exceptions rather than the rule. Just ride out to California during the almond bloom and you will see what I mean.

In your case, you are still using Langstroth-style hives. You have simply chosen to keep those in 8-frame equipment rather than 10. Thus, you will find that your frames still fit nicely in nucs, extractors, and 10-frame equipment. You manage 8-frame hives almost identically to how you would manage 10-frame hives. Yet, you may still run into a few roadblocks. For example, I know that you can purchase pallets (should you elect to keep your colonies on pallets) for 10-frame equipment, but I have not seen pallets for 8-frame equipment. Additionally, growers may be accustomed to scoring the quality of a pollinating colony in 10-frame hives, rather than 8-frame ones. Nevertheless, these types of issues are remediable, even if it requires you to make your own pallets, do a bit more explaining to growers, etc. I think the good news is that 8-frame equipment is popular enough that you would be able to purchase lids, queen excluders, etc. for them. This hive configuration does not seem to be going out of style any time soon.

All that said, I would not move forward with 8-frame equipment in a commercial operation until I spoke to at least three commercial beekeepers, or large sideline beekeepers, who have experience managing bees in 8-frame equipment. There may be other pros/cons that I have not considered. Frankly, their opinion on this topic would be more valuable than would mine. Honestly, I think this is generally good advice when considering the jump to commercial level anyway as there will be other things besides hive configuration to consider.

How do you find commercial beekeepers who do this? There are a number of commercial beekeeper listservs, Facebook pages, etc. These would be great places to post this question to see what the responses are. As I noted earlier, I generally make the point that hive configuration is up to the beekeeper’s personal preference. However, I usually recommend digging deeper when considering the jump to becoming a commercial beekeeper.


Varroa resistance to oxalic acid?

Within the past year, I read an article in the either the American Bee Journal or Bee Culture (that I have been unable to find again) in which the author discussed the problem of Varroa developing resistance to a miticide if it was used continuously. While this was not a new concept for me, she went on to write that resistance to oxalic acid could happen despite what some other authors are writing. I found this very shocking because I have assumed that developing an evolutionary resistance to oxalic acid would be about as likely as developing an evolutionary resistance to fire. Is there a definitive answer to this question?

Dave Skidgel
Kansas, January


The short answer is that Varroa can eventually become resistant to it, even if it is something that is unlikely to happen quickly. As far as I am aware, there is no reported resistance of Varroa to oxalic acid anywhere globally. There is a neat study by Maggi et al. [2017, The susceptibility of Varroa destructor against oxalic acid: a case study. Bulletin of Insectology, 70(1): 39-44] where the authors tried to test this assertion. They were unable to see any evidence of Varroa resistance to oxalic acid, even after 64 consecutive applications. They concluded that the development of mite resistance to oxalic acid is unlikely. I would say that even if this is true, “unlikely” does not equal “impossible.” Given the number of beekeepers who use this compound to treat colonies for Varroa globally, there can be selective pressure somewhere for some population of mites to develop resistance to it.

I am fortunate to share a laboratory with Dr. Cameron Jack, who is our resident expert on oxalic acid. I pitched this question to him and here is his reply:

Varroa, just like any other pest, can become resistant to a selective pressure placed on them. Thus, we need to be prudent in our use of oxalic acid and rotate our chemical treatments. However, I think one of the biggest advantages of oxalic acid is that it is a fast acting treatment that does not stay around in the hive for long. As most other natural chemicals, oxalic acid is water soluble and breaks down in the hive environment quickly which prevents much sub-lethal exposure to the chemical. To this point, there have been no documented reports of oxalic acid resistance, despite it being used widely throughout the world, which is great news for us. That said, an area of research that I believe still needs to be explored is the mode of action of oxalic acid, so we can better understand how to prevent future resistance issues, enabling us to keep oxalic acid as an arrow in our treatment quiver for many years.

I agree with Dr. Jack. It is always advisable to rotate treatments when trying to control Varroa in your colonies. In other words, even if the likelihood of Varroa developing resistance to oxalic acid is low, you would still want to avoid using it as your exclusive mite control treatment. Even Maggi et al. (2017) made this statement in their paper. I really like the resources developed by the Honey Bee Health Coalition on this topic. They talk a bit about resistance development. They even constructed a decision support tool to help you decide which treatments to use when. They developed this tool in a way to help you avoid overuse of any one compound. You can find their materials by Googling “Honey Bee Health Coalition Varroa.”


Bt use in honey bee colonies

 Eugene Makovec in his “From The Editor” section of the December 2022 American Bee Journal issue, mentioned he loved to use Bt (Bacillus thuringiensis, B402 Certan) to spray on stored comb as a safe protection against wax moths. I also noticed in Tina Sebestyen’s article (Integrated Pest Management for Honey Bees Against Varroa destructor) in the December 2021 issue, she mentioned Bacillus thuringiensis was one of five fungi and bacteria tested in lab experiments against Varroa which resulted in 95% mite mortality. Do you think spraying Bt onto stored comb, especially comb that has had brood, when introduced back into a hive will add additional protection against Varroa? Farmers spray Bt on corn to prevent corn worms. Will it also work against small hive beetle larvae and would it be an effective ground drench under a bee hive? Apparently, Bt does not harm bees or bee larvae.

Bill Hendley
North Carolina, January


Unfortunately, Bt does not work against Varroa or small hive beetles in the field. Bt is shorthand for Bacillus thuringiensis, a bacterium with a wide distribution globally. This bacterium produces a type of proteinaceous crystal that is toxic to some insects when they ingest it. There are many strains of Bt and each strain seems to be toxic to a different type of insect. Bt is used primarily to control beetle and moth larvae, though it has activity against other insects as well. An added benefit is that honey bees do not appear to be impacted by the crystal toxins produced by Bt. In fact, Bt toxicity to wax moths, but not to honey bees, is one of the reasons that there is a Bt wax moth control on the market. That is the good news.

The bad news is that the same is not true for small hive beetles or Varroa. This is unfortunate in the case of small hive beetles as beetles are one of the types of insects known to be controlled by Bt. In fact, this is what led scientists to look at Bt control of small hive beetles. Those scientists tested three different strains of Bt against the small hive beetle and found that none of them increased mortality in developing larvae over that of larvae consuming untreated food [Buchholz et al. 2006. Evaluation of Bacillus thuringiensis Berliner as an alternative control of small hive beetles, Aethina tumida Murray (Coleoptera: Nitidulidae). Journal of Pest Science, 79: 251-254]. You can also find that study here:

I suppose the good news is that these scientists only tested three strains of Bt. There are many other strains of Bt that could be tested and may, one day, prove to be efficacious against small hive beetles.

In contrast, there have been Bt strains that were shown to be toxic to Varroa [Alquisira-Ramirez et al. 2014. In vitro susceptibility of Varroa destructor and Apis mellifera to native strains of Bacillus thuringiensis. Apidologie 45: 707-718]. You can find the article here:

The authors in this study tested 22 isolates of Bt and found that nine of them caused >80% mortality, with one causing >96% mortality to Varroa. To my knowledge, these strains were never tested in field colonies as all of the work was performed exclusively in the laboratory. I think the key problem with this, and other types of biological control agents for Varroa, is how to deliver this type of product to the mites in an actual hive. In the study I cited above, the mites were submerged in a  …