- Herman Van Reekum
- Apr 24
- 6 min read
What the latest research says about breeding varroa-resistant, cold-adapted queens — and why Canadian beekeepers should be paying attention
Our company produces queens reared in Alberta and we want to breed queens that can handle a Canadian winter. We also want queens whose colonies manage Varroa without falling apart. Queens that are calm on the frame because workable bees make every inspection more productive. Finally, queens whose daughters do all of this without losing the honey production that pays the bills.
That’s a long list. Over the past several months, I have been surfacing research through the Bee Spaced digest on Substack, and I’ve noticed that the science has moved. Practical breeding tools available for queen producers at our scale are better than they’ve ever been. Here’s what I’ve been reading and what it’s changing about how I think about our program.
The genetics of Varroa resistance are real — and getting clearer
For years, “breeding for Varroa resistance” felt like wishful thinking. You’d hear about VSH bees, or Russian stock, or survivor colonies, but the results were inconsistent and the traits seemed to wash out after a generation or two of open mating. That picture is changing.
A study published in Scientific Reports this year tracked 236 hybrid honey bee colonies in Southern California over four years. These bees which are a genetic mix of Western European, Eastern European, Middle Eastern, and African lineages consistently showed lower Varroa mite infestation rates than commercial stock. They exceeded standard treatment thresholds less frequently and required fewer miticide treatments. The researchers attributed this to the genetic diversity of the population and its history of surviving without human intervention.
Meanwhile, a separate study in PLoS ONE explored the connection between gut microbiota diversity and hygienic behavior in a breeding population of western honeybees. Hygienic behavior which is the ability of workers to detect and remove diseased or mite-infested brood is one of the most important Varroa resistance traits a breeder can select for. The study found that the microbiome plays a direct role in expressing this trait. Bees with more diverse gut communities showed stronger hygienic responses.
This matters for breeders because it suggests that genetics alone isn’t the whole picture. The environment a queen’s daughters develop in, what they eat, what microbes they’re exposed to, and how the colony is managed influences whether resistance traits are expressed. You can have the right genetics and still not see the behaviour if the conditions aren’t there.
For a queen production operation like ours, the question is always: what can we actually measure and select for in our own yard?
The three traits that the research consistently points to are Varroa Sensitive Hygiene (VSH), grooming behavior, and suppressed mite reproduction (SMR). VSH bees detect and remove mite-infested pupae from capped brood cells, interrupting the mite’s reproductive cycle. Grooming bees physically bite and dislodge mites from themselves and their hive mates. SMR colonies reduce the number of viable female mites that emerge from brood cells.
The USDA Honey Bee Breeding Lab in Baton Rouge developed the original VSH line, and commercial breeders like Ryan Lamb and Wes Card have been selecting for these traits for over a decade. Lamb’s BEST protocol which is a field-based selection method that any breeder can adopt uses brood evaluations to identify colonies where mite reproduction is consistently suppressed. It’s not high-tech. It’s a frame of brood, a magnifying lens, and careful record keeping.
Project Apis m. published results this year showing that both Lamb’s and Card’s operations have made substantial progress in their selection over many years. Most potential breeders in both operations had very low mite infestations in the brood.
On the genetic marker front, researchers in New Zealand tested a specific SNP on chromosome 9 that’s associated with VSH behavior in North American stocks. Queens homozygous for the VSH-associated allele were compared to queens without it. While the marker-assisted approach showed promise, the researchers noted that open mating where you can’t control the drone genetics dilutes the effect. This is the challenge every small breeder faces: you can select your queen mother's carefully, but you can’t control who they mate with unless you’re running an isolated mating yard or instrumental insemination. We have produced queens using instrumental insemination and we plan to increase the program in 2026.
Why cold-climate adaptation matters more than we think
This is the piece that’s most personal to our operation, and most relevant to Canadian breeders.
Canada imports approximately 300,000 queen bees every year from warmer climates like Hawaii, California, Chile, New Zealand. A study published in Scientific Reports compared the performance and winter survival of imported and domestic queen stocks in Alberta. The result: domestic queens were 25% more likely to survive winter than imported ones. New Zealand stock performed particularly poorly, with high chalkbrood loads and low bee populations.
The researchers found that energy-related mitochondrial pathways differed between stocks from colder and warmer climates, suggesting that some metabolic adaptations simply don’t transfer when you move bees from a warm breeding origin to a northern winter. European studies have shown similar results. Locally bred queens survive longer with lower overwintering mortality than non-local queens.
More recently, CBC covered the work of Brendan Daisley at the University of Guelph, whose Canadian Bee Gut Project is mapping honey bee microbiomes from coast to coast. His team is now focusing specifically on queen bees, comparing the gut health of queens that overwinter successfully with those that don’t. The insight is that an imported queen arrives not just with genetics attuned to a warmer climate, but with a microbiome equally mismatched to Canadian forage, pathogens, and seasonal stress.
For someone building a queen rearing operation in Alberta, this research points in a clear direction: breed locally, select from survivors, and pay attention to the whole biology not just the genetics. The queen’s microbiome, her colony’s nutritional environment, and the landscape she’s adapted to all matter for whether her daughters will make it through a prairie winter.
Temperament: Wouldn’t It Be Nice to Work Without Protective Gear?
I read Reverend Langstroth’s work when I first became a beekeeper and the advice he gave that has always stuck with me is that if you get stung, you need to ask yourself what you did wrong, With me it’s usually because was in too much of hurry when working with my bees.
Yet, we know that there are colonies that are more prone to aggressive behaviour and, although gentleness is the trait we care about most after disease resistance and winter survival, it gets the least attention in the research literature.
If you’re a hobbyist with three hives in a suburban backyard, or a small commercial operator working alone, defensive bees are a serious practical problem. They slow you down. They stress you out. They make your neighbours nervous. And they discourage new beekeepers from staying in the craft.
Carniolan lines are widely favored for cold climates precisely because they combine strong overwintering performance with calm temperament and fast spring buildup. Buckfast stock, originally developed by Brother Adam at Buckfast Abbey, was bred specifically for disease resistance and gentleness. Both are worth considering as foundation genetics for a Canadian breeding program.
But temperament is also highly heritable and responsive to selection pressure. If you’re grafting from your best colonies and the colony that’s calm, productive, and healthy is also your top performer on mite counts that’s the queen to graft from. You don’t need a genetics lab for that decision. You need good records and avoid grafting from colonies that don’t meet your standards.
Where we’re headed
This year we’re going to be selecting breeder queens exclusively from colonies that overwintered successfully in Alberta. Using mite wash data and brood evaluations to identify colonies with the strongest hygienic behavior. Keeping detailed temperament records using our proprietary Be the Bee app. And sourcing drone mother queens with the same selection criteria, because the drone side of the equation matters just as much.
The science is clear: locally adapted, Varroa-resistant, gentle bees are not a fantasy. They’re a breeding program. And for Canadian beekeepers, the case for building that program domestically has never been stronger.
If you’re breeding queens and working on any of this, I’d love to hear from you.
This is part of "From the Archive", a series where I dig into topics surfaced by the Bee Spaced weekly digest. Each week the digest brings in research papers and news articles. Sometimes one of them grabs me and won't let go. This series is what happens when I pull on the thread.
Sources: This article draws on research covered in the Bee Spaced: Global Beekeeping Digest archive. Key studies cited include Chong-Echavez & Baer (2026, Scientific Reports) on hybrid bee Varroa resistance; De Iorio, Tiezzi & Minozzi (2026, PLoS ONE) on microbiota and hygienic behavior; Daisley et al. (2026, The Conversation / CBC) on the Canadian Bee Gut Project; and the Scientific Reports study on queen quality and winter survival of imported vs. domestic stocks in Alberta. For links to the underlying research, visit globalmobility.substack.com. Learn more about the Bee Cube® at beecube.io.
