24 February 2023
When we speak about the challenges for bee health, first of all we need to define what “bee health” even means. Health is much more than the absence of diseases. Also for bees, managed honey bee colonies or wild solitary species alike. Very often, people talk about bee health as if it were only treating against varroa mites or protesting against pesticide use. There’s a growing tendency to oversimplify. As I’ve stated already several times, there’s a difference between making things accessible and simplifying.
Coming back to the challenges for bee health: There are some simple things everyone can do, but others need more work. Some are for single beekeepers, others need action at a community or political level. So, taking for granted that we all want to keep healthy honey bee colonies, let’s set a base line, shall we?
(Honey) Bee health has multiple layers
The first layer for bee health are intrinsic factors of an individual, like genetics, defence mechanisms, or physiological factors. For honey bees, consider that the individual is the colony, not the single bee. In contrast to solitary insects, for instance, the temperature and humidity within the nest are constant in honey bee colonies. The temperature in the brood nest is regulated around 35°C. In the nest of a solitary bee, on the other hand, the temperature will be more or less the same as outside. The health of the superorganism honey bee colony, therefore, also depends on the physiological ability of maintaining a constant temperature in the brood nest.
The second layer is the most intuitive: bee health also depends on the presence and frequency of parasites and pathogens. The Varroa mite is an example of this second layer. It’s still the main cause for winter losses. With the mites come virus infections that contribute substantially to the losses and the clinical picture of the disease “varroosis”. Treatments help to maintain colonies healthy, though they will never disappear completely. Meaning, the varroa mite is there, but a colony can still be healthy. You treat to keep the infestation of the mites and the infection with the viruses under the clinical threshold.
Finally, the third layer: environmental factors. First and foremost, the beekeeper and what he does with his colonies. Good practices are the keyword here… But we also have the overarching factor for bee health, nutrition. Yes, there is something like healthy nutrition for bees. Diversity and quality of flowering plants influence how susceptible they are for diseases and even intoxications. This layer also creates most challenges for bee health.
Environmental factors challenging bee health
Bees are in constant contact with the environment. This is true also for managed bees like honey bees. Unfortunately, the layer “environmental factors” is the least easy to control. For instance, bees need access to flowers to feed themselves. They need pollen and nectar to get the nutrients they need. This may seem monotonous, but actually it’s not. French researchers found that honey bee colonies are happy with a mass flowering crop as a nectar source. But when it comes to pollen, they use a variety of different flower species, one isn’t enough. Healthy nutrition for honey bees, therefore, means large flower diversity.
This gets an additional layer considering the results of an Austrian monitoring: they collected data from 6,655 beekeepers over six years. This added up to 129,428 honey bee colonies wintered over this period. They then linked the winter losses to the structure of the landscape around the apiaries. They distinguished urban , agricultural , and seminatural areas and pastures.
In regions dominated by seminatural areas, the risk for winter losses was lower than in regions with “artificial surfaces” (i.e. urban environment). Interestingly, agriculture isn’t the “bad guy” in this analysis. The authors explain that with the small-scale practices in Austria compared to other countries. What confirms my opinion formed by previous studies: The problem isn’t agriculture itself, but the intense, large-scale practices. Landscape structure also influences flower diversity and by this bee nutrition.
Looking at the larger scale
In addition to all of the above, we’re facing challenges at a larger scale. The climate crisis creates phenological mismatches between flowers and pollinators. This means that the flowering of certain plants and bee activity don’t “fit” anymore. Social bees like honey bees may support this better than solitary species that are specialized on certain plants as pollen sources. But as this mismatch happens mainly in spring, this could have an impact also on the more resilient honey bees. There’s some anecdotal evidence that early pollen sources like hazel or goat willow are blooming too early, at too cold temperatures for honey bees to fly out and use them.
But there are also other issues of the climate crisis for honey bees. For instance, warm winter temperatures mean that they continue breeding over these months. This means that varroa mites continue to reproduce and treatments get less effective. Warmer temperatures overall also could favour other parasites and diseases spreading over the globe.
In addition, biodiversity and climate crisis fuel each other. Biodiversity loss affects bee nutrition. Remember the positive impact of diverse pollen sources I mentioned above? A lower variety means that honey bee colonies are more susceptible to virus infections and other diseases. Even a short-term shortage can have carry-over effects for colony survival.
Approaching bee health issues
After reading about all these different layers and factors, you may understand that varroa treatments and banning pesticides aren’t enough to maintain bee health. I limited myself mostly to honey bees to keep it manageable. Obviously, some factors are valid also for other bee species, others not so much. So, to approach current and future challenges for bee health, we have to work at all these layers. Good practices for beekeepers are part of it. Good practices in agriculture, maintaining biodiversity in those areas are, too. And this means more than just not using pesticides. But that’s for another post. It also needs a political framework to address the climate crisis and biodiversity loss. And, most importantly: The end of constant oversimplification.
You may wonder why this matters at all. Well, simple: Simplifying opens the door for misinformation. And this has serious consequences, as we clearly see in the discussion of the pandemic, the climate crisis, or the biodiversity loss. Simplifying emphasizes certain details over proportion and gives easy solutions. Making accessible also can’t tell every single detail, but keeps it more balanced, explains the uncertainty in certain aspects. What I call “making science accessible” gives you the tools to evaluate information, to apply it to your situation. Simplifying, on the other hand, gives a one-fits-all solution. What rarely works for complex issues. Like bee health.
P.S.: This post is based on a talk I give on challenges for honey bee health and sustainable beekeeping. I’m talking about this both in real life as well as online. So, if your association or organization wants to book me for that, contact me for more information!