30 July 2020

Honey bee health management – that sounds like something very abstract and technical. Like something that interests beekeepers who want productive colonies. Something economic, but nothing that connects to bee diversity. Or bee health as I defined it some weeks ago. There seems to be a barrier between those managing bees – mostly Western honey bees – and those who want to conserve bee diversity. You often find the sentence “saving bees by beekeeping is like saving birds by keeping chicken”. I do agree on some aspects of this. Honey bees are exceptions in the “bee world” in many aspects. They aren’t chicken, though.

My wise father taught me to think beyond barriers. And this one between beekeeping and conservation isn’t as final and unmovable concerning bee health. At least not as much as that sentence could make you believe. Bear with me, I’ll explain.

A practical example

First, let’s start with managed honey bees. Without any judgement on their “worth”, or blaming beekeepers for anything. I already wrote about honey bee diseases that can spill over to other bee species. Namely DWV in consequence of varroa infestations and Nosema ceranae. These are major problems in beekeeping, well-known and studied. Other diseases, like the fungal chalkbrood, don’t “score” as high when we talk about honey bee health. It’s generally considered a factorial disease, something the colonies can deal with for themselves. Most importantly perhaps, a disease without major economic consequences.

A recent case, however, made me think again. At a well-kept apiary, one colony showed symptoms of chalkbrood. It didn’t stop after spring, at every visit, there were about 20 mummies in front of the colony. Not that much, you might think – what’re 20 lost bees in a colony of 30,000*? Yet, this colony didn’t develop like the others. It began filling up the honey super later than its neighbours. And the yield was lower than the average on this apiary. Nothing too obvious, but still there. So, what happened?

Good practices as an element in honey bee health management

The main difference to the other colonies, in this case, was the position of the affected colony. It was the first in a row. It was the most exposed to cold winds. Cold is one of the major risk factors for the development of chalkbrood. It was a well-kept apiary but lacked some bushes or trees as protection to the North.

This is a good example of honey bee health management in a wider context. The quality of the apiary is one of the most important factors to keep colonies healthy. They should be protected against the cold, but well ventilated to avoid humidity. Which is another risk factor for chalkbrood, by the way. Then, I will never get tired of repeating this, the colonies must have access to diverse pollen sources. This makes honey bee colonies less susceptible for all kind of diseases, chalkbrood included.

From the beekeeper’s side, avoiding robbing behaviour and exchanging combs regularly keeps the risk of transmitting diseases low. Do you see it? Honey bee health management goes beyond varroa treatments. What’s still missing, you might say, is the connection why this helps bee diversity.

Spill-over and bee diversity

You might already imagine what I want to say: managing honey bees in a way that keeps them healthy, prevents their diseases from spill-over to other species. This is also the case in underrated diseases like chalkbrood. Which I learned only today was detected also in bumblebees. In their excellent review on fungal diseases in managed and wild bees, Sophie Evison and Annette Jensen conclude:

The historical research focus on honey bees should shift to include wild and solitary species, because they tend to be less resilient to environmental stressors (including pathogens).

Evison & Jensen, 2018

Something may seem of less importance to us, like chalkbrood. But how do we know, if we never studied it? Honey bees are an exception within managed animals: their contact with the environment is much more difficult to control than in other species. You can’t keep them in a stable, like chicken. Honey bee health management is closely linked to environmental health – the health of wild bee species.

Thinking beyond barriers

In the end, this also affects human health. Because all bee species are pollinators. Disease spill-over, together with other factors, causes bee (diversity) decline. A very recent paper says that crop production in the USA is frequently limited by lack of pollinators. Which then affects food security and by this human health. Here we close the One Health circle…

Of course, honey bee health management alone won’t prevent pollinator decline. In many aspects, keeping honey bees does help bee conservation like keeping chicken saves wild birds. Honey bees are social, they are managed, not native in many places of the world – you name it. But I hope that you now see that when it comes to bee health, the barriers between managed and non-managed species are quite… porous. So let’s think beyond them and not simplify.

*It doesn’t matter directly in this context, but it’s a myth that honey bee colonies are up to 80,000 bees strong. Counting the brood cells as well, perhaps. But in more than 20 years estimating honey bee colonies I’ve never seen more than 35,000-40,000. And those were fantastically strong ones!

4 Comments

  • Hi,
    I’d love to discuss chalkbrood with the author of this article.
    We run 1000+ hives in South Australia. Chalkbrood has gone from being a major problem to an extremely minimal one in our apiaries. I would like to think it is because of our attempts to take a holistic approach to the health of our bees and in particular our focus on bee nutrition. One experiment we conducted indicated nutrition had a huge effect.
    I will be very grateful if you choose to contact me.
    Kind regards,
    Simeon Valkenburg.

    • Hi Simeon,
      yes, of course we can discuss about this. I’ll write you an email (deleted your contact details from the comment to protect your privacy).
      Have a nice day,
      Claudia

    • Hi Simeon and Claudia,
      I gave up beekeeping 20 years ago when varroa first came to the UK, but have returned to it (SE London) as I now believe we have neglected bee health to make up for the stressors imposed on honey bees these days.
      I’ve spent lockdown trawling through online resources and found so much which agrees with this hypothesis, for instance,
      Bees ‘self-medicate’ when infected with some pathogens
      Researchers found that, when faced with a fungal threat, bees bring in significantly more propolis — 45 percent more, on average. The bees also physically removed infected larvae that had been parasitized by the fungus and were being used to create fungal spores.
      https://www.sciencedaily.com/releases/2012/03/120330111027.htm

      Diesels fumes alter half the flower smells bees need
      In polluted environments, diesel fumes may be reducing the availability of almost half the most common flower odors that bees use to find their food, research has found. The new findings suggest that toxic nitrous oxide (NOx) in diesel exhausts could be having an even greater effect on bees’ ability to smell out flowers than was previously thought.
      https://www.sciencedaily.com/releases/2015/10/151019085821.htm
      How quickly do flower strips in cities help the local bees?
      One year
      https://www.sciencedaily.com/releases/2020/03/200302113422.htm

      Aluminum: New factor in the decline of bee populations?
      Very high amounts of aluminum contamination has been found in bees, raising the question of whether aluminum-induced cognitive dysfunction is playing a role in the decline of bumblebee populations
      https://www.sciencedaily.com/releases/2015/06/150608082933.htm
      Overuse of antibiotics brings risks for bees, and for us
      …found that after treatment with the common antibiotic tetracycline, the bees had dramatically fewer naturally occurring gut microbes — meaning healthy bacteria that can help to block pathogens, break down toxins, promote absorption of nutrients from food and more. They also found elevated levels of Serratia, a pathogenic bacterium that afflicts humans and other animals, in the bees treated with antibiotics, suggesting that the increased mortality might have been a result of losing the gut microbes that provide a natural defense against the dangerous bacteria.
      https://www.sciencedaily.com/releases/2017/03/170314150933.htm

      Bees diversify diet to take the sting out of nutritional deficiencies
      honey bee colonies not only attempt to diversify their diet, but that they bias their foraging effort towards a diet that specifically balances nutritional deficits of the colony. How bees perceive and evaluate nutrient composition needs further elucidation. This new-found ability of honey bees to counter deficient nutrition contributes to mechanisms that social insects use to sustain homeostasis at the colony level.
      https://www.sciencedaily.com/releases/2016/04/160413084523.htm

      A spike in calcium consumption in the fall, and high intake of potassium, help prepare the bees for colder months
      honey bees alter their diet of nutrients according to the season. A spike in calcium consumption in the fall, and high intake of potassium, help prepare the bees for colder months when they likely need those minerals to generate warmth. A careful inventory of the bees’ nutrient intake revealed shifting sources and how limitations in nutrient availability from these sources can have implications for the health of both managed and wild colonies.
      https://www.sciencedaily.com/releases/2018/05/180530113226.htm

      Plants actively exudate water with low temperatures and high air humidity to maintain the water flow through them. Bees use these guttation droplets as a water source. Only little is known about the minerals in these droplets, but an old publication (Goatley et al. 1966) lists phosphorus, potassium, sodium, calcium and magnesium as the most prominent.
      https://www.bee-safe.eu/articles/bee-news-revisited/not-only-sweet-honey-bees-seasonal-salt-foraging/

      The changes in air chemistry impacted the number of bees able to detect food sources in a given time frame. In an ozone-free environment, it took 10 minutes for 20 percent of foragers to find the scent molecule beta-caryophyllene. When ozone rose to only 20 parts per billion, it took 180 minutes for the same amount of bees to find the scent.
      “We found that when we confused the bees’ environment by modifying the gases present in the atmosphere, they spent more time foraging and would bring back less food, which would affect their colonies,” said Fuentes. “It’s similar to being asked to get a cup of coffee at the nearest cafeteria while you are blindfolded. It will be hard to locate the coffee shop without using visual cues. The same could happen to insect pollinators while foraging for food in polluted air masses.”
      Declines in the pollination of wild plants may lead to increases in the population of plants that do not rely on pollinators, and pollinator declines would lead to decreases in crop yields, Fuentes noted.
      These findings highlight that air pollution is one of many factors influencing the decline of the bee population where bee populations in the U.S. have declined between 25 and 45 percent per year since 2010, including a 44 percent decline from 2015 to 2016.
      https://www.sciencedaily.com/releases/2016/07/160706131924.htm

      Trust these are of interest to you both, and thanks for sharing yourthoughts.
      Best regards…

      • Hi Frazer,
        thank you for your comment and all the resources you linked. And thank you also for linking one of my own articles I didn’t think of anymore… (the one on water exudated by plants, i.e. guttation).
        However, as I always try to explain in this blog, there are no simple solutions to complex problems. There are some basic principles that need to be respected. You mention a big one: nutrition. It’s an overarching principle for bee health, as I try to explain here: https://bit.ly/2Cdskfj. But it’s not about picking out single factors and those will be the solution. For instance, you mention calcium. Yes, it’s important. But setting up more calcium sources won’t help if other nutrients aren’t available sufficiently as well.
        You have to consider that scientific publications are always a little element of the whole picture. It’s impossible to do otherwise. Imagine it like a mosaic. A coloured stone alone doesn’t make the picture. In the discussion of these papers, the authors always give the context and the weak points of their own research. This often gets lost in the communication of their research in the media. And I try to give it back in my articles.
        So, yes, everything you listed is important. But every little thing is only a coloured stone building up the mosaic that isn’t complete yet. The purpose of this blog is giving a more complete picture and apparently, I didn’t manage that very well in this post.
        Thank you for making me aware of this and have a nice day,
        Claudia

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