In a live interview at Apimondia 2025, Wolfgang, the inventor of the Varroa Controller, demonstrates a chemical‑free method for eliminating Varroa mites by heating capped brood frames. The method relies on the fact that most mites reside in capped brood in spring, allowing targeted heat treatment without harming bees. Wolfgang explains the step‑by‑step protocol: shaking bees off frames, placing up to ten frames in a heated chamber for a precisely controlled two‑hour cycle with specific temperature and humidity, then returning frames to the hive. He details a 12‑day and 24‑day brood‑frame cycling system that concentrates mites in two frames, which are then heat‑treated, providing immediate feedback on mite mortality. The conversation covers timing (spring when brood is limited to two frames, summer limitations, and autumn treatment of phoretic mites combined with oxalic acid), scalability (one machine can treat 5‑10 hives, with a modest 20 % increase in honey extraction), and the broader management cycle (queen caging, nucleus creation, pheromone traps). Wolfgang mentions a free handbook, “Handbook of Heat Treatment Against the Varroa,” that details every step. The overall message is that heat treatment, when applied with precise timing and environmental control, offers an effective, chemical‑free, scalable solution for beekeepers of any operation size.
Chapters
You can kill varroa mites with no chemicals, just using heat. This is the video for you. Wolfgang, thank you so much for agreeing to come on. Wolfgang is the owner and the inventor of the Varroa Controller, and he's going to show us how this really cool machine works. Thank you so much for coming on. Tell me about your invention.
Thank you for coming. It's a pleasure for me to show you this on Apimondia 2025 here in Copenhagen. It's day 5. We're already tired. We're sitting on the chair.
You can tell. You can tell from your eyes, right?
What is the Varroa controller? Indeed, it's a device where we kill the mite with no chemicals, as you said it. But what is it? We are using heat. Look, here is a brood frame.
Before Wolfgang tells you this yet, I want to put my first challenge in because he immediately counteracted it. And I said, I've seen people do this before. I've seen people try and kill Varroa with heat and it leads to drone fertility issues, it leads to queen fertility issues. And Wolfgang just said, no, stop. This is not what we do. I'll leave it up to you now.
There we go. Yeah, this is not what we do. Why? Because hypothermia, as we spoke, Works without bees. That's the main principle. So overheating the capped brood. Why the capped brood? Because in the capped brood we have in spring 80% of varroa, and all year round majority of varroa is in the capped brood. So now you want to know in one sentence what that is. That is a tool you can kill targetedly, super efficiently, mites in the brood anytime you want.
Yeah, and it's really nice. It's such a simple way, and I didn't really think of it like this before, but trying to heat the brood box with the bees and the queens and the drones was always going to be a Really bad result because you're putting heat in there for things that can't really control the heat. But the brood frames, they can handle it on their own. So your idea, your invention is you shake all of the bees off and just put the capped brood frames in there.
Exactly. And and that's super very well described. But when do we do that? Huh?
When do we do it?
Go. We start in spring. I'm coming from Vienna, Austria. My springtime is mid of March. Why? Because then the brood frame. More precisely, the capped brood is on two frames only. So I go there, shake off the bees, and take the frame to the machine. I'm not sitting; I'm standing. Then have two frames per hive, and the large machine. This is only the small one, too easy for transport.
This is the small one.
This is a ten-framer. We have a twenty-framer. So as you can imagine, bring in the brood of 10 hives at once. I run the cycle.
Nice.
Each cycle takes 2 hours.
Okay.
After 2 hours, the frames are heated up to exactly the temperature the mite cannot survive, but the bee pooper does. And you may think, wait a moment, in spring I also have open brood, I have larvae.
I was going to say open brood.
What happens to them? They are fine. Have a look, here is a humidification unit. You fill in water, Humidity is super important. So humidity, you have temperature, you have a special time running over the 2 hours, and then you take out these 2 frames, put it back, bees will take over. And latest 12 days later, you will see on your screening board, aha, these were the 2 frames. Ah, here I have the dead mite. So you have a feedback. Yeah, immediate feedback.
I love that. I've got so many questions building up. So the first one that Wolfgang said there was just an observation.
It's spring.
Spring in the UK is not a time that we normally treat for varroa. I completely understand the reasons. It's a really good point. So instead of trying to treat for varroa, Varroa and you've got a huge brood nest and you've not really got any other option than to try and treat with the bees on the frames. What Wolfgang does is does it in the spring when the brood nest is ever so small. That means that all of the varroa is going to be confined within that small brood nest. So you're going to get much greater efficacy using it in the spring versus trying to do it on more frames in the kind of autumn. And also it means that you can get like 5 or 6 colonies in one machine.
10.
10. So you can get 10 in one machine.
So you get efficiency.
Economies of scale, yeah.
So now you will maybe challenge me, how's about summer?
Go on then, how's about summer? Yeah, that is true, because it will knock them back, but it won't keep them there.
I cannot tell you that you can find a timing like in spring where you have only 2 frames.
Yeah.
But I do.
Okay.
Because we are catching the queen that she can breed only in 2 frames.
Nice.
That has a negative side effect, I have to say. You have 20% more honey you have to extract. Yeah, that's true. We can live with that negative Yeah, I can.
I'm a big fan of enforcing brood breaks.
Yes.
So we do it differently. We take the queen out and cage her so she cannot lay.
Yeah.
And then we use oxalic acid. But this is nicer. I like this.
Tell me why.
Yeah.
Why is that nicer?
Okay. Yeah, neat.
I answer your question that you didn't ask me. It's nicer because of several reasons. Here, the queen lays on 2 frames. When do I do it? When the main nectar flow is starting.
Okay, starting so just after the June gap.
Out of my house, there's this super large linden tree. I like him every day, but there's one day in the year I like him the most. Okay, when he starts blooming.
Yeah, and you hear that zzzz, and then this is the trigger for me. Nice.
Go and catch the queen. Yeah, because I want that linden nectar in my honey supper and not in excessive amount of brood.
No, no.
Uh-huh. So I cage the queen.
Yeah.
Put her in there, maybe on the frame where she's already laying eggs. I just take the frame, put it in, and next to it I take a built frame, and then I leave it in for 12 days.
Okay.
So there is brood, here is brood, everywhere is brood.
It's all emerging.
Starts emerging. After 12 days, I'm coming, I open, I take out these 2 frames with bees, everything, catch the queen.
Yeah.
Put the queen away, take these 2 frames, put it into my box for nucleus, and replace With another empty frame. Don't forget the queen.
Yeah.
Put the queen in, and then I have empty frames.
Okay, so it's cyclical. It's like you do one, then you do another one.
And now it's in for another 12 days. So 12 is more than 21. Now you're right.
This brood has— All emerged.
Everything emerged.
Yeah.
Everything is gone. So now you have a rower. You're in desperate need to reproduce. Where do you go?
Yeah, you go to where the open brood is. You need to get in there.
It's a pheromone trap. I created a pheromone trap for this beast.
Okay.
And they all go in.
Yeah.
And now it's day 24. Day 24, I'm coming, I take it out. Yeah.
And all of the varroa is there.
Correct.
Yeah.
And by— you got it.
Yeah.
And by taking out these 2 last frames on day 24, this, this movement is removing them. It's the varroa treatment for the commercial hive that just now, over the last 24 days, collected all the honey. A lot of Lindon honey.
With no chemicals.
With No chemicals and no effort. I just take it out. Okay, the effort was I had to be here on day 12, not day 13. I had to be here on day 24. This is in my calendar, don't do anything else there. So the next question that you are asking me now is, what are you doing with these 2 frames full of mites?
Well, I think you might have a nice solution for them that's rather yellow.
The question that you are asking me here is, how is it possible That these 2 frames— this is the main question here— that these 2 frames full of mites are not yet damaging the brood. Not many know that the varroa, the mother mite, goes into the cell just before capping. That was when— today is day 12, for the second time day 12.
Yeah.
They did it yesterday.
Yeah, yeah.
So they sneaked in and it takes her 60 hours to drill a hole into the pupa And inject viruses, etc. So I have 60 hours from yesterday on to kill her with heat.
Yeah, before the viruses are transmitted. Yeah, nice.
Before she can do damage.
Yeah, before the bees start producing the winter bees. So then you've got a low viral load in winter.
You cannot say, ah, this one I put in a box and they should hatch or emerge whenever they want.
Oh no.
Then they are full of viruses. Yeah. Okay. So what I do, again, I put, make a nucleus. Yeah. Bring it to the other stand, and there the next day, not the second next day, not in a week, just next day, I do heat treatment.
Okay.
I kill the mites before they damage the brood.
Right. So you want to make sure that you're waiting until you've got all of the mites in these frames.
Yes, they're all lined up.
And timing it to stop them impacting the pupa.
Perfect. Yeah. Okay.
Nice. And I love this. I really like that kind of like strategic timing of things, that you've thought about it. What works well for the bees, the brood, and the varroa life cycle. And you've got this really good system.
And now we summarize. What did we do? We made the commercial, the productive hive varroa-free. If you don't believe me, put heavy chemicals on that brood-free hive on day 24.
See what comes out.
And if you find more than 3 mites, call me immediately.
Yeah. Wow, really?
So they are not there anymore. Yeah, yeah, nice. Because it's such an emergency situation for the mite that they all go in here. So productive hive has no varroa. I created for every productive hive a nucleus of 4 brood frames. I take 1 and 2 on day 12 and 1 and 2 on day 24. And the disadvantage, I have 20% more honey.
Yeah, oh, it's a hard world, isn't it?
You get 20% more honey as well. And I have the empty frames, the dark ones I can exchange.
I really like that.
I'm a big—
I'm a strong believer of kind of constantly cycling out your brood frames. So you integrate this into your process for that as well. Nice.
I can immediately with the last 2 frames, I can assess the queen. How well is she laying? Because she's at the top of the cell. And if I don't like her, I don't like that. Or if she's old, then it's today to exchange her because I have a brood-free.
Perfect.
A brood-free.
A really like scalable and repeatable system regardless of whether you've got like 1 or 2 beehives in your back garden or 1,000 beehives. I'm going to give the last word to Wolfgang.
We missed autumn.
We missed autumn.
Go. We did spring, summer, and autumn.
Yeah.
Autumn is easy.
Okay.
It's like spring. I just did it before I came here with my bees. Okay. I do the final autumn treatment. Yeah. Now we need to know one thing. In autumn, we cannot say 80% of the mites are in there. It's still more than half. It's 60%.
Okay.
60%. And now you have to do a treatment for the mites that are sitting on the bees.
The phoretic mites.
The phoretic mites. And here you have to choose either what I do, the chemical route. Yeah. Or you can combine it with an oxalic treatment at the same time. You don't need to wait.
It was the first thing I said, wasn't it? I think that this system here combined with oxalic acid sublimation is a potent combination.
If that was too fast for you or you want to see more, I've written a book about it. It's the Handbook of Heat Treatment Against the Varroa.
Awesome.
You can download it for free on our website. You don't need to download because I give you this.
Oh, it's very kind.
You see, it has—
Wolfgang to sign it as well.
Yeah, yeah, I can do that. So you see, it has all these 3 things explained in every step. Yeah. And at least read chapter 6. Yeah. Spring.
I will do.
Summer, autumn. Yeah.
Awesome. Well, thank you so much. Let me just quickly show this to the camera. That is the book that I'm going to go home and read. I'll read that on the plane. Thank you so much, Wolfgang. I wish you the very best of success with your product. And thank you for taking the time to talk.
Thank you very much. By the way, The thing is not new. We do it since 15 years. 15 years!
How have I missed this one? All right, there we go. We're good. Thank you so much.
