Registered varroa treatments – are they really necessary?

Sometimes beekeepers ask me why they should use registered varroa treatments. The issue here is that for many years this wasn’t necessary: The currently known treatments were developed quickly after varroa arrived in Europe. And transmitted to the beekeepers in their “raw” form, they needed quick solutions after all!

This, in my opinion, created a few problems: Beekeepers know the active substance and often refer to their treatment method like that. “I always treat with formic and oxalic acid.”, for example. That’s something you surely won’t hear in other areas of (veterinary) medicine. There, people are used to product names and don’t really know about the active substance. And sometimes it’s just “the white pill”, so not even a product name.

Though being an informed consumer is a good thing, in the beekeeping case it went a little bit too far. In the beginning, most beekeepers followed the recommendations of the bee institutes. They just wanted to avoid losing all their colonies. But, as always, very soon some beekeepers thought they could change a few things. Mainly to make their life easier. But without considering that varroa treatments are veterinary medicine. And this needs a little bit more than just being a good beekeeper.

This relates to the second issue: These quick and unregulated solutions didn’t create the awareness that varroa is a veterinary issue. Beekeepers got used to do things themselves. If you have a headache, you might try fresh air and drinking a lot of water first. But if you decide to take something against it, you wouldn’t make your own pills, would you? So, why should you do this for your bees? Especially, as varroa really puts them at risk?

A background story

Finally, varroa treatments were developed in a time when the regulations weren’t so strict. And honey bees were a bit out of the range of the regulative attention. If the problem (varroa) was handled (treatments of some sort), that was ok. This began to change already in the 1990s, when I was doing my PhD in Hohenheim (one of the larger bee institutes in Germany). A vet from the local authority said to the director of the institute: “You could treat with water if this would help. But if it’s not registered, I’ll persecute it.”. And this was still in times with more “flexibility”, at least when it came to honey bees.

Here in Germany, for instance, there was a “standard registration” for formic acid. This meant, that every application form of formic acid was ok. At least, if it was of 60%, not higher concentrations. Originally, the institutes recommended 85% formic acid for treatment. But when the authorities began to look over the data, there was no evidence – at least no documented one – that 85% were better than 60%. In this situation, the principle of the lowest efficient dose applies.

There’s no desired effect (killing varroa mites) without potential risks (harm to the bees, residues, etc.). So, to keep the benefit higher than the risks, treatments are made with the lowest efficient dose. That’s why, in a first step of regulation, formic acid was registered only with 60%. It was deemed sufficient for the regular treatments and the concentration beekeepers can buy freely. If, in an emergency, they need the higher concentration, they would need the prescription of a vet and buy it at the pharmacy, not at a beekeeping supply store.

Why varroa treatments now are regulated (and should be)

During my master’s, there was a huge outbreak of swine fever (not the African one…). A lot of animals were killed to prevent the spread of the disease. It was then that I heard another sentence that stuck in my head: “It doesn’t matter that the disease itself isn’t transmitted to humans. But it puts food security at risk.”. This is because swine fever is highly contagious and deadly. So, without countermeasures, an important part of food supply would break down.

If you think this broader, it applies also to varroa treatments. Or veterinary medicine in general. It’s regulated, because it could affect a large portion of the (human) population. This applies to food security (so, enough food for all) and also food safety. I.e., food that isn’t contaminated with anything that may cause consumers disease, poisoning, or similar issues. So, everything you do with food producing animals, could potentially hit a great portion of the human population. To prevent issues, veterinary medicine is regulated.

Applying the concept to honey bees

Even if honey isn’t a food staple and an average person doesn’t eat that much of it, this is important also for honey bees. Food security is affected by varroa as a potentially deadly parasite. It’s not only about the honey, but also about the pollination services managed honey bee colonies provide. Though this is widely overestimated (other pollinators have their large part in this, too), it’s still a risk to avoid to lose too many colonies to a disease. Also because of the ecological impact it has, as we’re understanding in the past years. So, also on the wild pollinators.

Therefore, not treating varroa has an impact both on food security and food safety. To avoid this, the regulation now also applies to honey bees as managed animals. They need to be treated in the same way as any other food producing animal. And varroa treatments as veterinary medicine, with the full regulation behind it.

The EU may be overly bureaucratic sometimes. And sometimes, I’d like a bit more common sense in many procedures. However, when it comes to food, I’m very happy to live in good old Europe. In general, the risk of food borne diseases or poisoning is much lower than in other parts of the world.

What goes into registered varroa treatments

The objection many beekeepers have against registered varroa treatments are many. One of them being that they’re expensive. After a talk, a beekeeper once stopped me on the street to ask why he couldn’t do just a solution with the amitraz-based tick treatment of his dog to treat against varroa. That would be much less expensive! Sometimes it’s difficult to keep my calm… but here’s an answer to this question.

The right dose

Treating against a parasite like ticks or varroa mites, doesn’t only need a certain substance like amitraz. You also need to know how much of it is

  1. Efficient and
  2. Safe for the treated animal.

These two points always go together. So, if you just mix your dog’s tick treatment into water and give it to the colonies it could be

  1. Not enough for efficiently killing the mites or
  2. Too much for not harming your colonies.

Between the efficiency against the parasite (varroa) and the harm for the treated animal (honey bees), there should be a “therapeutic window”, so a safety space in which you kill the mites and not the colonies. With the dose (like “two strips per colony”) given on the label of registered varroa treatments, you’re on the safe side.

The right way of application

Beekeepers love strips. Mainly because they’re easy to use. But not every substance is suitable for strips. With amitraz or fluvalinate, this isn’t a problem. But the dose for formic acid, for instance, needs to be adapted to the strength of the colony, the external temperature, and other factors. With a strip, you bring in a fixed amount of formic acid, that easily could be too much or not enough – see above.

So, not every way of application is right for every substance. It depends on many details, which one is correct. This is one of the things tested for registered varroa treatments.

The right timing

In addition to these points, it’s also important when you treat. To avoid residues in the honey, for instance. This is why you never treat during nectar flow. On the other hand, the different substances also don’t work well at any time. Formic acid and thymol, for example, depend on the external temperature. They’re both suitable only for the late summer treatment. Amitraz, on the other hand, doesn’t work as well when there’s a large amount of brood. So, these strips are better with smaller brood nests.

All these things and many more are tested and proven during the registration process. Registered varroa treatments go through a detailed process of lab and field research for the clinical side (what I talked about here). But also the impact on the environment, the stability of the product, the risk for the consumer and much more is studied in detail. All of this together, makes the price of a product.

Are registered varroa treatments expensive?

Coming back to the frequent comment that registered varroa treatments are expensive: I don’t think so. The risk of not treating (or not correctly) is much more expensive. Compliance to the recommended strategies definitely pays off, we’re having more and more data on that.  

DIY “solutions” like putting a homemade amitraz solution on cardboard strips may be cheaper in that moment. But you’ll pay the price of dead or less productive colonies – which is a larger cost. Well-treated colonies produce about three times as much in honey and have about 20 times lower colony losses. Put that into relation of a price of 5-6 € per treatment and colony. It’s just a fraction of the money you make by treating well.

You may already know the answer of the question in the title by now: Yes, registered varroa treatments are necessary. They keep your colonies alive and healthy.

4 thoughts on “Registered varroa treatments – are they really necessary?”

  1. Can someone a scientist tell me ,how’s it even possible that bees will developed resistance should you continue to use the same registered treatment from one season onto the next ,when a bee ONLY lives 6 weeks – over the pass 18 months local (UK) bee suppliers have been selling oxalic acid and promoting the new on the market vaporisers at £450 but now that self same company will no longer as she says be selling oxalic acid powder 3 question in one – why use registered treatment when UK govt don’t put bee health part of veterinary medicine training , why resistance occur when a bee only lives 6 weeks and why is the suppliers choosing not to work along side the industry.

    1. Claudia Garrido

      Resistance doesn’t depend on the single worker and it’s lifetime. When it comes to treatments, resistance means the mites: they get resistant and genetically fixed, so it doesn’t depend on their lifetime either. So, a single mite has a small change in the protein that is attacked by the treatment because of a different genetics. Mites with this mutation don’t die during the treatment and, therefore, have a greater chance to reproduce. Over time, all non-resistant mites die, while the resistant one survive and reproduce. This happened already with coumaphos, fluvalinate, and flumethrine. Here I wrote how to avoid that: https://bee-safe.eu/articles/bee-series/resistant-varroa-treatments/
      Resistance is less likely for oxalic acid, formic acid, or thymol. They don’t address single proteins in the mites, but several physiological mechanisms. Also that doesn’t depend on the lifetime of single workers.
      The other “resistance” is that the colonies get resistant against varroa mites. I think this is nonsense, but also this wouldn’t depend on the lifetime of the workers, but the genetics of the queen and drones, which determine the genetics of the colony.
      I can’t say anything about UK politics and how they priotize vet training. Or about companies not working with the industry. However, that’s not a reason for not using registered treatments. Those you have on the market, were registered still being in the EU.

  2. Thanks for your informative posts and emails.

    What do you think of using vaporised oxalic acid monthly as a treatment for varroa more?

    Thanks, in advance for u your thoughts

    1. Claudia Garrido

      Hi, thank you for your feedback. Vaporizing oxalic acid is ok, but monthly is too much. There are two important things to consider: The colonies have to be without brood and the heating device should be one with electric resistance, heating up slowly. If it’s too quick or unregulated, then the oxalic acid decomposes and it doesn’t help. You can use that safely in winter, when there’s no brood or after caging the queen in summer for 25 days – so you don’t have brood.
      I’m not the biggest fan of vaporizing, because of user safety: you need some safety gear to make sure you don’t breath the vapours in.

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