When I was a child, obesity was much less common than it is now, and we ate things like lard. In fact, lardy cake was a delicious treat that I used to purchase on a Saturday from a baker shop in Brockenhurst (they still sell it occasionally). We ate bacon and eggs, steak and kidney pie, pork with crackling, and other fatty delights. Then came the craze for low-fat food, then high fibre, and I’m not quite sure where we are today. The consensus seems to be that sugar and simple carbs are dangerous unless eaten in moderation, and bacon is a carcinogen. So the science-based advice on nutrition has changed considerably, and many of us are carrying a few more extra pounds than we need.

Something similar has happened with beekeeping advice; it has evolved – treatments come and go, and various techniques have their moment in the sun before the next thing comes along. It seems to me that advice changes because bees live in a moving target of interacting stressors, while research is forced to simplify. The gap between those two things is where most ‘new guidance’ is born.

This article is about why that gap exists, how it creates churn in advice, and how to read the next wave of recommendations without either cynicism or gullibility.

Stacked Problems

Colonies experience multiple stressors simultaneously – sometimes referred to as the “death of a thousand cuts”. Death is not inevitable, of course, but the more that stressors stack up, the more likely it is that one will be the “straw that breaks the camel’s back.”

Varroa + Deformed Wing Virus (DWV)

I have written about this a lot, and for most beekeepers it is this combo that is the one most likely to kill your bees, whether directly or indirectly. There’s solid evidence that varroa and DWV interact in ways that strongly increase winter mortality risk. In one recent study¹, DWV-positive colonies with mite levels ≥1 per 100 bees had markedly higher odds of mortality than DWV-positive colonies below that threshold.

Nutrition Deficits

The quality and quantity of pollen available to bees can vary considerably. Forage gaps cause stress, as does a lack of variety of pollens coming into the hive if prolonged. Honey bees can utilise proteins from within their bodies to make up for nutrient shortfall, but that has knock-on implications for lifespan. We now know that one particular sterol (isofucosterol) is critical too.

Weather Volatility

A favourite topic of Brits, the weather really does dictate the success or failure of many seasons, and there’s not much we can do about it. Migratory beekeepers may be able to mitigate this somewhat, by moving bees to places where the weather and forage are good, but occasionally the weather is rubbish everywhere. There have been seasons when it’s rubbish for the whole season, which then has an impact on the following season (high winter losses, small colonies in spring).

Queen Events

Supersedure, mating success, availability and quality of drones; it’s not straightforward out there. Queen events often feature prominently in loss surveys. Virus load and chemical exposure can affect the fertility of drones and queens. Many old-timers claim that today’s queens do not last as well as queens did in the past.

Chemical Exposure

It’s a shame that high levels of viruses in bees wreck their fertility and/or kill them, but some chemicals used to control varroa (and thus the viruses) also have sublethal yet damaging effects. It’s the synthetic miticides that cause the big problem, as they stick around in the wax, increasing the likelihood of resistance by varroa. This is why more and more people are including organic varroa treatments such as oxalic acid in their regimes. Nasty stuff can also be picked up in the form of fungicides and insecticides that are sprayed onto various crops.

Beekeeper Mishaps

Try as we might to help our bees, it is frequently said that the activities of beekeepers can cause difficulties for them. How many times do queens get killed or lost as we carry out our manipulations? With experience these mishaps should diminish, but, in my case at least, they do not disappear.

So advice changes partly because the relative importance of each driver changes over time and place. A ‘right answer’ in one landscape and year can become the wrong emphasis in another.

Isolating Variables

A good experiment tries to change one thing at a time. But you can’t realistically run a colony while holding everything else constant:

• forage changes weekly

• weather changes daily, or hourly (!)

• queen quality varies

• drone supply varies

• mite re-invasion varies with neighbouring apiaries

Researchers often end up studying caged bees in a lab or nucleus colonies. There is a world of difference between a nuc and a strong full-sized colony. They focus on a single factor (diet, pathogen, pesticide) and it tends to be in one region, one season, with one management style. This doesn’t mean it is bad science, but it does mean that there is typically a question about how well the results can be applied generally to beekeeping as a whole.

That’s why modelling frameworks have become more prominent. These try to integrate multiple stressors and landscape dynamics. The European Food Safety Authority’s (EFSA) work² evaluating the BEEHAVE model is an example of regulators grappling with multi-stressor reality. I suppose it’s a bit like weather forecasting models, which have apparently improved enormously over recent years.

Changing Methods

Another reason for advice to be different or changing is that there are often several ways to do something, each with their advocates. What’s more, newer and perhaps more effective methods occasionally come along. Think about how many ways there are to make queens – it’s mind-boggling. The underlying general principles are the same, but each method is different. The monitoring of varroa mites is another one. Natural mite drop through a mesh floor is easy, but I’m not convinced it’s very reliable, as the mite drop depends on colony size, brood level, where mites are in the cycle, grooming, and so on. I like using a mite wash (alcohol or soapy water) because, done properly, I believe it is pretty accurate. Using different methods gives different results.

COLOSS’ BEEBOOK methods exist precisely because inconsistent measurement makes results hard to compare. Dietemann et al. (2013)³ is the standard reference for how to do varroa research methods properly — not because it’s glamorous, but because without standardisation, ‘evidence’ becomes a tower built on sand.

Evolving Pests

The varroa mite has evolved, so advice has had to change in order to keep up. The UK has a well-documented history of pyrethroid resistance in varroa. Resistance was detected in the UK⁴ in the early 2000s following widespread use of the limited authorised pyrethroid treatments available at the time. More recently, concern about amitraz resistance has grown internationally; the evidence base is now substantial enough that resistance reports are being mapped⁵, and discussions about the variability in protocols and regional results abound.

Evolving Science

As more research is carried out, new things are discovered, which leads to a change in the advice given. This is a good thing, but it does mean that beekeepers have to be ready and willing to adapt. Pesticide-risk guidance has evolved: EFSA’s bee risk assessment guidance was published in 2013 and later reviewed/updated⁶ to incorporate newer science, reflecting how regulatory science updates methodologically as evidence accumulates.

Bias and Distortion

Who chooses what research to fund, and why? I think it’s safe to say that the type of research most likely to be funded is the one that helps to sell a product or idea, but maybe I’m too cynical. Then there is the choice about whether to publish or not. Perhaps if some research does not support the goals of the funding organisation, it is never published – I am guessing, but it does not sound too far-fetched.

How likely is this statement to grab any headlines: “we replicated the last result, and it still holds.”? That’s not very sexy, is it? Journals and conferences love a novel discovery, and social media loves it. Beekeepers are therefore likely to encounter a distorted sample of the available evidence. The newest thing, delivered by the most confident speaker, tends to win the day. Meanwhile, the slow, dull, dependable work — multi-year field trials, standardised methods, negative results — gets less attention.

This is why advice often shifts towards whatever is currently shiny and new, not necessarily what is most robust.

Differing Experiences

When somebody with five colonies does something to their bees, and it works, this does not mean very much. The sample size is tiny. Is there a control? In other words, “works” compared to what? There are different ways of working with bees, and this becomes especially marked at a larger scale. But still, large-scale beekeepers have different ways of working, and every season presents different challenges. It is not surprising that one person’s ’truth’ is not universally accepted.

I have noticed a failing in myself, and often see it in others; we have enquiring minds, and we desperately want everything to make sense. We take a small amount of evidence and build a convincing theory (story) to explain what we see. Then we think it is the ‘truth’ until it stops working, whereupon the next theory is formulated.

Proper science carried out on large populations over several years, with standardised methods, and suitable controls, is not easy to do on honey bees. In fact, it’s pretty close to impossible.

Practical Steps

I think that when I hear of some new research or idea, the best approach (for me at least) is to try to understand at a biology level what is going on and why. I’m not great with super-complicated terms, and most science involving genetics makes my head explode, but I do try to see what the new advice is getting at, deep down. The source is critical; lab studies are interesting but may not translate to the field, and field studies are fantastic IF the conditions are close to mine. Something spouted by the latest YouTube sensation might cause a raised eyebrow or two.

My approach to introducing changes to my way of working, whether based on research or just my curiosity, is to endeavour to run a trial at one apiary for a season, to see what happens. It probably doesn’t mean much, but perhaps by doing that I reduce the odds of some catastrophe. Ideally, I would perform the new technique/treatment/idea on half of the hives at that place, and continue as normal with the other half.

Conclusion

The glorious uncertainty discussed in this article is one reason why beekeeping is endlessly fascinating and addictive. We try our best, we learn, we improve. In any season, something will go horribly wrong and something else will go right. What unites us is far more than the few differences in our methods or experiences. We get hot, we sweat, we get stung, our back aches … and yet, how wonderful it is to be a part of the lives of our bees.

References

1. Claing G, Dubreuil P, Bernier M, Ferland J, L’Homme Y, Rodriguez E, Arsenault J. Varroa destructor and deformed wing virus interaction increases incidence of winter mortality in honey bee colonies. Can J Vet Res. 2024 Jul;88(3):69-76. PMID: 38988334; PMCID: PMC11232088.
2. EFSA (European Food Safety Authority) PPR Panel (Panel on Plant Protection Products and their Residues), 2015. Statement on the suitability of the BEEHAVE model for its potential use in a regulatory context and for the risk assessment of multiple stressors in honeybees at the landscape level. EFSA Journal 2015; 13(6):4125, 92 pp. doi:10.2903/j.efsa.2015.4125
3. Dietemann, V., Nazzi, F., Martin, S. J., Anderson, D., Locke, B., Delaplane, K. S., Wauquiez, Q., Tannahill, C., Ziegelmann, B. & Ellis, J. D. (2013) ‘Standard methods for Varroa research’, Journal of Apicultural Research, 52(1), pp. 1–54. DOI: 10.3896/IBRA.1.52.1.09
4. Thompson, Helen & Brown, Michael & Ball, Richard & Bew, Medwin. (2002). First report of Varroa destructor resistance to pyrethroids in the UK. Apidologie. 33. 357-366. 10.1051/apido:2002027.
5. Bertola, M.; Mutinelli, F. Sensitivity and Resistance of Parasitic Mites (Varroa destructor, Tropilaelaps spp. and Acarapis woodi) Against Amitraz and Amitraz-Based Product Treatment: A Systematic Review. Insects 2025, 16, 234. https://doi.org/10.3390/insects16030234
6. EFSA (European Food Safety Authority), Adriaanse P, Arce A, Focks A, Ingels B, Jölli D, Lambin S, Rundlöf M, Süßenbach D, Del Aguila M, Ercolano V, Ferilli F, Ippolito A, Szentes Cs, Neri FM, Padovani L, Rortais A, Wassenberg J and Auteri D, 2023. Revised guidance on the risk assessment of plant protection products on bees (Apis mellifera, Bombus spp. and solitary bees). EFSA Journal 2023; 21(5):7989, 133 pp. https://doi.org/10.2903/j.efsa.2023.7989