Q: Mite-resistant bees
After reading the January 2026 issue of ABJ I am feeling somewhat frustrated regarding the lack of progress to develop mite-resistant bees. As I read the article by Bill Hesbach about vadescana, I thought that was a step forward but was reminded that resistance to this new pathway could not be ruled out.
Then I read Randy Oliver’s challenge to beekeepers to develop mite-resistant bees, but his method required literally thousands of hives to control drones and develop resistant queens and daughters. What is the backyard beekeeper to do? What can we do to be part of the solution? We have no control over the DCAs [drone congregation areas] to develop resistant bloodlines.
Keith Anderson
December
A
I certainly understand your frustration. Varroa was found in the U.S. in 1987, thirty-nine years ago. Yet this mite, along with the viruses it transmits, remains the greatest biological threat to honey bee health globally. Of course, scientists, bee breeders, and industry and government officials have worked hard on developing sustainable controls for Varroa. Even so, it still kills colonies year after year, largely because no single control has proven sufficient.
I am glad that you desire to use resistant stock as part of your effort to control Varroa. I realize that you feel hopeless regarding the creation and maintenance of resistant stock. What should you do? For one, I do not believe that you need to be worried about investing time, energy, and resources into the development of your own stock. Such stocks already exist.
Researchers and bee breeders have invested hundreds of thousands of dollars in creation of stocks such hygienic (including Varroa sensitive hygiene — VSH), Pol-line, Russian, Mite-biter, and New World Carniolan stocks. These are already at your disposal. You can purchase and use these even now, without worrying about how to breed toward these traits. These stocks have years of research and refinement behind them. Are they perfect? Certainly not. However, they do have documented resistance to Varroa, and when coupled with other treatment strategies, form the foundation of an integrated control strategy for effective Varroa control. With that in mind, I strongly recommend building your operation on the back of one of these stocks. Ask beekeepers in your area who have used one or more of these stocks and get their input on how effective the stock is in the area where you live.
The key to using resistant stock is that you must work to keep it in your colonies. You cannot purchase resistant queens one time, requeen all your hives, and expect the stock to persist in your colonies without maintenance. I recommend that you purchase and use clipped/marked queens. That way, you can follow the queens and know that they are from the stock you purchased. Every year, you will need to consider replacing all your queens with the same stock, but certainly replace the queens that were lost over the previous management year. Queens that are not clipped/marked were replaced by your bees.
As you state in your question, you cannot easily control the DCAs in your area, especially as a hobbyist beekeeper. Consequently, you need to rely on queen breeders to do that for you. Replacing at least the unmarked queens year after year (i.e., those queens that you know died the previous year) ensures that you are keeping the resistant stock in your hives.
Q: Importing Varroa-resistant Apis species
Given that other species of Apis are resistant to Varroa, cannot we just import those bees and start using them in the United States?
A
We cannot import other species of Apis into the U.S. First, it is illegal to do this. Second, this would not help us in the long term. Let me explain.
There are twelve species of Apis globally. Eleven of those occur naturally in Asia while the twelfth (Apis mellifera — the Western honey bee) has a natural distribution in Europe, Western Asia, and Africa. European stocks of Apis mellifera have been moved globally because of their ease of use, the relatively large colony sizes to which they can grow, gentle (usually) disposition, and productivity. Beekeepers moved this bee to Asia where it encountered pests and pathogens to which it was not adapted. One of these pests includes Varroa destructor, a natural pest of Apis cerana, the Eastern honey bee. Apis cerana has natural defense mechanisms that it can use against Varroa, making this mite only a minor pest of its natural host. The mite expanded its host preference when A. mellifera was introduced into eastern Asia. In contrast to A. cerana, A. mellifera suffers significantly when its colony is infested with the mite.
So why not just use A. cerana rather than A. mellifera?
Well, it is not that simple. Beekeepers do manage A. cerana in Asia. The management is similar, but not identical, to how they manage A. mellifera in the region. However, A. cerana makes smaller colonies and less honey per colony than does A. mellifera. Furthermore, the bee is likely not adapted to habitats outside its native range. Finally, since A. cerana gave Varroa to A. mellifera, it stands to reason that it can host other pests and pathogens that could shift hosts to A. mellifera.
The other species of Apis are not great husbandry candidates due to their preference for tropical environments, and lack of ease of management. Because A. mellifera and A. cerana are distinct species, they cannot be bred to produce more resistant bees. Our best option, then, remains to breed A. mellifera for resistance to Varroa and develop other control strategies for this pest.
Q: Wolbachia
Would you have anything to say about Wolbachia and honey bees (or even other Apis species)? I have read (to the limit of my skill) this article:
Russell, J.F.E.J. 2018. An attempted transinfection of Wolbachia in the Western honey bee (Apis mellifera). Open Access Te Herenga Waka-Victoria University of Wellington. Thesis. https://doi.org/10.26686/wgtn.17134223.
And this one:
Hoy, M.A., Jeyaprakash, A., Alvarez, J.M., Allsopp, M. 2003. Wolbachia is present in Apis mellifera capensis, A. m. scutellata, and their hybrid in Southern Africa. Apidologie, 34: 53-60. https://doi.org/10.1051/apido:2002048.
As I recall, you spent time in South Africa. I am wondering if a discussion of Wolbachia would be sufficiently germane to appear in The Classroom.
Dan Geer
January
A
Kudos to you for discovering the fascinating world of Wolbachia. I had never heard of this organism until I began working at the University of Florida in 2006. Upon joining the faculty at UF, I met Dr. Marjorie Hoy, an Eminent Scholar in our department. She is the first author on the second paper you read (Hoy et al., 2003). The final author on that paper, Mike Allsopp, is a colleague of mine and we continue to work on honey bee questions in South Africa. I was talking with Marjorie one day and she told me that she wondered if Wolbachia had something to do with the ability of Cape honey bee (Apis mellifera capensis) workers to produce other female bees from unfertilized eggs, a process called thelytokous parthenogenesis. But I am getting ahead of myself …
Wolbachia is the genus and common name for an incredibly diverse species of bacterium that infects, according to the internet, “hundreds of thousands of arthropods.” (Just FYI: There is an active debate on the diversity of Wolbachia, with some scientists saying only one species exists while others suggest multiple species exist.) Honey bees are arthropods and they have been shown to host Wolbachia. The neat thing is that Wolbachia can do so many different things in so many different arthropods. For example, it is responsible for sex determination in some insects. This is what led Marjorie to wonder if it plays a role in thelytoky in Cape honey bees.
Wolbachia is so widespread and diverse that it has remained a highly studied organism, just not so much in the honey bee world. I conducted a Google Scholar search for the terms “honey bee Wolbachia” and did not find many papers. Even still, I did find a helpful review article on Wolbachia in social insects. Here is the complete reference for that article:
de O Ramalho, M., Kim, Z., Wang, S., Moreau, C.S. 2021. Wolbachia Across Social Insects: Patterns and Implications. Annals of the Entomological Society of America, 114 (2): 206–218. https://doi.org/10.1093/aesa/saaa053.
The authors of this article do an excellent job summarizing what is known about Wolbachia infection in social insects. I think you will find the article to be fascinating. You really could read for days on this topic. Be ready to go down a rabbit hole …
