Varroa Mite Control – Alternative Methods

So today I’d like to talk to you about alternative methods of mite control. And by alternative methods, I mean alternative to chemical controls, whether that be soft chemicals from natural sources or synthetic chemicals that are used in the strip form as you may have seen in some of our other videos. Now, these alternative methods are ways that we manage our bees to limit the reproduction of mites. So another term for that is cultural controls. Anything we can do that helps diminish the reproductive rate of the mites. And these are really all part of integrated pest management, where we combine a number of different methods to achieve our goal of having our bees survive and keep the mite levels down. The first one we’re going to start with is a screen bottom board. If we have a screen bodyboard underneath our hive, what happens is the mites fall through that screen bottom board. Just inadvertently, there’s some get the slides fall down through that onto the tray underneath the hive. 

Those mites that are fall down there, just wait for a bee to come along, but the bee comes along. And so they’re stuck and then they can’t go on to reproduce. So we can decrease our mite level by 15% just using a screen bottom board. And of course, of course, their primary purpose is for monitoring the mite levels in the hive, so they serve two functions that way. So really great setup. Watch our video on monitoring using screen bottom boards to learn more details about using these devices. Another method that can be used is what’s called drone brood removal. So here I have a drone frame, lots of big cells in there, drone size cells. These are made by a company called Pierco and they have the right size cell bees. So the bees build the right comb on there. If we install a frame like this into our colony, as the colony population builds, they will start filling this with their drone brood and then the mites preferentially move into drones. So those mites move in there because their reproductive rate is way better in drone pupa. 

The drones are capped for a much longer timeframe than the worker bees. So when you have one mite move into a drone brood, drone cell, 2.5 mites plus the original mite come out. With worker bees, 1.5 mites plus the original foundress mite emerge. So you can see that’s a much better reproductive rate in a drone brood. So what we do, though, is put these in, monitor them to see when the queen has laid eggs in there, and then approximately 20 days later, we’ll remove that frame and then freeze kill it. So just get all the bees off and stick it in the freezer that will kill it. And then we can put this back into the hive and the bees will clean it up. You can also scrape all this comb off kind of tough, kind of messy. But, you know, you can do it all in one trip. So that’s one way. Another way is using a shallow frame or medium depth frame in a deep brood chamber. So that’ll give all this extra space along the bottom and bees will build drone comb in there. And then it’s a matter of removing it and just cutting it off the bottom. 

Then you can do whatever you want, feed it to your chickens, whatever, so that it gets that accomplishes the same goal. And a third method that some beekeepers use is they’ll put a worker foundation here and then just leave this open. So the drones, they’re there, so they build drone comb in here, which can then be cut off and removed. A number of different ways of doing that. The key thing is that you do this on a very regular basis. If you’re not removing that drone brood and they emerge, then of course all the mites do too. And you’re actually helping the mites rather than hindering their development. Another method that we can use is just dividing our hives. If we divide our hives, half the mites go into one hive, half the mites go to the other hive. And those hives aren’t as strong. So they’re not rearing as much drone brood. So there’s less reproductive potential there, a little staying on the left, oh well. So that’s one method. Another method as far as this rate in hive management is using queen cells. 

So if we divide a hive, half the bees get the original queen. And the other half gets a queen cell, that call will go through a longer period with less brood in it. And so the mites don’t have the reproductive capacity. So just using queen cells can help. Another routine management method we use is requeening our colleagues. So we pinch the queen or remove the queen, and then we introduce a new queen. That gives us a slight break in the brood cycle. Not as much as with when we’re putting in a queen, so but a slight break. But the point I want to make here is that gives us an opportunity to introduce more resistant stock. So whenever you’re introducing Queens, I would be attempting to purchase queens from beekeepers that are actively selecting for low overall growth rate in their colonies.  

So in summary, let’s talk about some of the pros and cons of using cultural controls. Number one, as a pro, these methods can be used through the beekeeping season. They’re not timing or temperature dependent. And so we can use them through the entire season. And this will do two different things. It, because we’re using alternative forms of treatment, it should help delay resistance development with the miticides that we are using. So it should just give us a longer time period of being able to use those products.  

Another thing it does is it buys us time for getting our mite treatments in. So if the mites peak later in the year, because we’ve been doing these incremental kinds of controls, then we can apply a miticide after we’ve harvested our fall honey and keep our bees alive that way. So that timing can mean the difference between whether our hives survive the winter or not.  

As far as cons are concerned, there’s an extra bit of equipment that needs to be purchased. Nothing terribly expensive. But what may be more important is the amount of time required for doing this management. Beekeepers on a large scale, for example, would have a hard time implementing drone brood removal and being able to do that effectively, whereas somebody in their backyard keeping bees in their backyard could quite easily fit this in. And when they take that drone brood out, they uncap it, they can also be checking for mites and using this as a monitoring method as well.  

The, all these treatments don’t replace using a miticide. In our area, we have to use a miticide a minimum of one time a year, usually in the fall. So none of these methods will replace that currently, but they do complement the use of miticides very well. Keep your bees healthy. See you next time.