Varroa Treatment: Api-Bioxal RTU

Varroa Treatment: Api-Bioxal RTU

Jeff Ott

Welcome to Beekeeping Today Podcast Shorts, your quick dive into the latest buzz in beekeeping.

Becky Masterman

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Jeff Ott

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Becky Masterman

Brought to you by Betterbee, your partners in better beekeeping.

Jeff Ott

Hey everybody, welcome to the Beekeeping Today. Short on Varroa Treatments. This is a multi-part series covering the different treatment options available to combat this honey bee pest Each short in the series will cover one specific treatment option.

For this series, we've invited Dr. David Peck from Betterbee to join us. In this short, we will be discussing Api-Bioxal RTU. Hey Becky, hey David Hey, how's it going?

Becky Masterman

It's so good to be reuniting around this parasite, Jeff.

Jeff Ott

Yeah. We know how to have fun, don't we? Right.

Every party is a Varroa party with us. Well, part of the series is we have quite a few out there on all the different Varroa treatments. After that initial rush of what, ten or eleven Episodes, we now have new treatment options available to us, and so we're going to continue adding to the series.

So today we're talking about RTU. David, what is RTU?

Dr. David Peck

It's the full product's name is Api-Bioxal RTU. And then, you know, it that's just three letters. It doesn't mean anything to people, so they don't know what it is.

But RTU stands for ready to use. This is a term that comes out of veterinary medicines. So sometimes you might buy a uh you know a medicine for a cow or for your cat and that might be an RTU medicine.

It means it's ready to use right out of the container. And that's the same idea here. This is Api-Bioxal, which is the brand name for oxalic acid powder, but it this is pre-mixed up into a solution so that you can do an oxalic acid dribble but you don't have to measure anything, you don't have to weigh anything out, you don't have to mix anything up or heat things or You know, switch them from container to container.

So it's just a bottle, it's full of a solution, of a liquid, and you dribble that liquid onto your bees and it kills Varroa mites. Simple as that. Yep.

Becky Masterman

Do you still go from bottle to syringe?

Dr. David Peck

Yeah, so ideally you're going to be going into some kind of a dispensing device. And so the way the label is written, and this was a little bit of cleverness when we when we got this registered It just says that you can dis- you know you can dispense it with a syringe or an applicator, but it doesn't define what an applicator is. So the company that makes it also makes a bottle called the Dosa-Laif bottle, which is actually a really, really good applicator. It's my favorite.

Jeff Ott

Yeah, Dosa-Laif. It does not look like that's how it sound, but that makes sense, Dosa-Laif. Well, that's the fun of an Italian company developing the product.

Dr. David Peck

But it's the Dosa-Laif dosing bottle basically is gonna let you dispense the correct amount. There are other dribbling solutions. You can use a syringe like you would with another any other kind of dribble treatment. Or you can, you know, use a backpack sprayer, as long as you can calibrate that to make sure that you're putting the correct amount of oxalic acid trickled down onto the heads of your bees. then you can use any applicator as long as it's gonna work to let you apply this in a controlled way.

Becky Masterman

So when you say the correct amount

Dr. David Peck

five milliliters per seam of bees or or space between the frames that is occupied by bees. So for as many bee spaces, occupied bee spaces between frames that you've got in your brood nest, whether you've got a nuc or an eight frame or a ten-frame or, you know, whatever it is that you're using. you're dispensing five milliliters per occupied seam of bees.

And you're just trickling it right directly onto their heads and it'll fall down over the frames. And you do that for every box. So if you've got a double story brood nest Then you're going to start dispensing on the bottom box, then you're going to you know set down the top box, and you're going to start dispensing onto that as well.

And the goal of this is just to distribute this oxalic acid with the water and the sort of wetting compounds that are in there to help keep it moist inside of the hive. And you want it to remain active and capable of killing Varroa mites, ideally for more than just So we already talked about oxalic acid dribble treatments in the series earlier, in the in the short on that subject And that was all about the homemade oxalic dribble that was taking these oxalic acid powders or or you know tablets, you mix those up. with your sugar syrup, and then you're gonna put that onto the heads of the bees.

But the advantage of this stuff is that it isn't sugar syrup. The thing, the humectant, the th the wetting agent that keeps this from drying out really quickly in the hive, isn't sugar. Instead, it's based around glycerin.

And so you wind up being able to put this stuff into the hive, but because it isn't sugar syrup, the bees aren't immediately gobbling it all up and then cleaning it up and removing the medicine that you just put in there to kill Varroa mites. And so it has sort of a what we would call a longer residual inside of the hive.

Becky Masterman

So you just said that RTU works better than what I make in my kitchen.

Dr. David Peck

So the advantages it has are that first of all you don't have to make it in your kitchen and then clean everything after. Second of all, it is it is likely to be biologically active, fighting mites, longer in the hive than the sugar syrup-based dribbles that you make. And importantly, it's also a higher concentration than the homemade dribbles It's a 6.2% oxalic acid dribble, whereas the stuff you're allowed to make with the registered powders doesn't get up to that concentration level. So it's it's a it's a longer Time active in the hive with more oxalic acid active for each treatment. How often do you so you five milliliter?

Per seam? Yeah, five milliliters per seam, and then the whole hive gets treated, the whole brood nest. Safety use with honey supers in place But like any oxalic acid product, the downside of it is that the oxalic is great at killing the mites that are out on the bees, and it's not very good at Killing the mites that are hidden and protected under the brood caps.

So in a broodless colony, maybe in a cold winter environment where you've got no capped brood, or if you've just caught a swarm, or if you've got a colony that you've caged the queen in or that you've done a split in, you know, and you've timed things properly, you can wind up with a broodless colony and a single application is going to do a great job of killing, you know, the lion's share of your Varroa mites. If you need to reapply it, if you have a colony that has brood and so you're not going to get complete control with just one application. This product, unlike a lot of others, really explicitly tells you how often and how many times you are allowed to do those reapplications.

So in the case of RTU, you're allowed to do a treatment every seven to ten days up to four times. And so that's that winds up looking like about a month of treatments, you know, day zero, day seven, fourteen, twenty-one And so that's going to allow you to have this in the colony killing mites, catching mites that had previously been under the brood caps, but then knocking those levels down. And we just did a test in collaboration with the University of Florida Bee Lab, Cameron Jack, and his student Marie Janšek.

Down there, we worked up here at Betterbeee in our own hives and we tested exactly that, these applications where we put the RTU into the hives repeatedly to see if we could take, you know, moderate mite levels and knock them down. And so what they found at at Florida really clearly was they were treating colonies with this, they were treating it with repeated oxalic acid vaporizations, they were treating with Apivar strips, sort of as an alternative to show what a synthetic chemical comprehensive control would would do. And at the end of the day, they basically all performed about the same.

Repeated applications of this you know, lots of OA vaporizations or the synthetic chemicals were all keeping the mites under control, knocking them down and then holding them down. So that was pretty cool that it performed as well as anything else. And I guess one real strong advantage that I see to this is I'm I'm two things, right?

I'm a beekeeper who wants to live a long time, and I'm also a cheap beekeeper. And I think a lot of beekeepers want to live long time, and I think a lot of beekeepers are cheap. And so what I like about this is cost conscious we could say.

But what I like about RTU is that it's a way for me to do oxalic acid treatments, either repeat or just, you know, in the middle of the winter. And I don't need to buy an oxalic acid vaporizer, which is pretty expensive. And I don't need to worry that there's going to be some gap in my oxalic acid.

protective face mask and I'm gonna wind up breathing in a snoutful of oxalic acid vapor, which I know that I don't want to do, right? Lung scarring. eye damage, all sorts of unpleasantness can happen if you get that oxalic acid vapor into or onto your own body.

And so what I like about this is that as long as I can avoid the temptation to drink any of it, I'm pretty well safe from the uh from the product. And I don't need to worry as much as I might with one of those, you know, heat vaporizers.

Becky Masterman

I want to clarify because you're using the word knockdown and in this series we've talked about controlling the populations versus a knockdown treatment. Are you considering this a knockdown treatment?

Dr. David Peck

So I would absolutely consider it a knockdown treatment if I was treating a colony that had little to no capped brood. In the winter, it's a knockdown. In a in a new swarm that I've caught or a split where I have no brood, it's a knockdown.

If I am using this to take my mites and bring them back towards the control threshold that I want them at, or below that, I can begin a hold down treatment, which is going to keep the mite levels from climbing. And what we saw, at least in the work that they did at Florida, was that it did gradually bring the mite levels down. And that's true for a lot of the hold-down treatments that we've talked about in this series.

is that yes, technically, if you use them for a long time, you would maybe start to see the mite levels come down, but they're not going to plummet over the course of a few days like you would with a good knockdown. So no, I don't consider this a knockdown treatment if the colony has a lot of capped brood, but it is still a usable tool in that scenario. You just have to know that it's not going to take you from six mites per 300 bees to one mite per 300 bees, but it might keep you at six, maybe even, you know, hedging down towards four or five over the course of the that month of treatment.

Do we know how the oxalic acid works yet? Has there been any more? Still don't know.

We'll have to wait for the next oxalic acid product to come out and then the next short, maybe we'll have figured it out. But no, at this point it remains a little bit opaque exactly what this molecule is doing inside of the hive, but we know the bees can tolerate it very well. We know that the mites don't and so Especially, you know, a nice winter cluster with no capped brood inside, dribbling this right onto the heads of those bees, you can really kill an awful lot of Varroa mites.

And at this point I'm I'm more interested in killing them than I am in knowing how I'm killing them.

Jeff Ott

And relatedly, has there been any research or knowledge gained about resistance to oxalic acid treatments by Varroa?

Dr. David Peck

At this point, again, there is no evidence to suggest that mites have developed any kind of physiological resistance to oxalic. I have heard some some interesting stories about things like the extended release oxalic acid products, and that might potentially affect something like this too, where if the mites have the opportunity to avoid interacting with the molecule Sure, they might be th they might be clever enough not to do that. It's also possible that in some of these cases the bees might be avoiding interacting with some of these acidified strips and that might be reducing the exposure of the mites to them.

That's going to be more of a strip a problem with a strip like, you know, maybe VarroxSan. than it would be with this because it's a dribble. You're literally putting it right onto the heads of the bees.

And so they have very little choice about getting a little little droplet or two of this onto their bodies. And it doesn't harm the Queen. Correct.

There's no evidence that we've seen that this causes any harm. And this is the you know, it's a new mitocide in the United States. But it's actually not not really a new product in beekeeping in general.

In Europe, this product has been available for much longer than it has been here. And it has worked very well. And you know, it's just a bunch of beekeepers who realized they didn't want to deal with the headache of measuring out, you know, thirty-seven grams of Powder and then exactly how much sugar do I need to mix in.

I need to make what a liter of syrup? Nothing nothing in my kitchen measures liters. How many cups are in a liter?

And at this point now you've dirtied up half the stuff in the kitchen and my wife is yelling at me that I have to go buy her a new set of tablespoons because I was using it to measure organic acids and so avoiding all of that is a real convenience and uh certainly has made my whole life a lot easier.

Jeff Ott

I was gonna say that sounds like personal experience David. Yeah absolutely it is

Dr. David Peck

What are the downsides of RTU? Well, the main downside is that like any oxalic, oxalic works great as long as you don't have brood, and as soon as you start bringing brood into the mix, it performs worse. Uh it's not going to be able to catch all of the mites.

The mites seem to be able to get into and out of the brood faster than we sometimes like like to imagine and so even if you do your math and you think, oh well I'll treat them and then I'll treat them five days later and surely I'll catch all of the mites now You know, the reality is that you just don't get the same level of control with repeated treatments during brood rearing that you do when the colony simply has no brood for the mites to hide in. So it's useful all of the time it's really, really useful when the colony is broodless or has very little capped brood. And so I would recommend that a beekeeper focus on those times to use this product and then probably look at other products for for other times of year where there might be a better choice to knock the mites down harder and get the mites under control without having to do four visits to each hive to do these these trickle applications.

Becky Masterman

David, this is sold in a nice bottle and you do you have to put that in any kind of refrigeration or are there temperature constraints to this actual this formula.

Dr. David Peck

What a marvelous question. See this is the advantage that you know how to do the sugar syrup dribble, so you know some of the things to be cautious about, right? So, when you mix oxalic acid powder and sugar syrup together, what you've done is you've created an acidified sugar syrup.

And high acid sugar syrups develop as we all hopefully know, that terrible molecule HMF, which is toxic to honey bees, it can form if you heat up sugar syrup that you're Feeding to your bees, it can form if you've got old honey that you feed to your bees. HMF can develop anytime you have a fructose molecule floating around next to some acidity, it might decide to turn into HMF one day. And so the beauty of this is that because it contains no sugar, no HMF can form.

So unlike the homemade sugar syrups that you always had to keep in the fridge, keep cool, and then throw away as soon as they started discoloring. This stuff is shelf stable for about two years, unopened. Once you open it, it's shelf stable at room temperature for a year.

And that's just what the company has tested and can sort of guarantee. I have no reason to believe that it's gonna be meaningfully degrading or turning into anything nasty. You know, still be mindful of those of those expiration dates, but I would be much less concerned about this than I would about other products where I know that the active ingredient is is certainly breaking down or causing some toxic byproduct to form as time passes.

Becky Masterman

And then I just want to confirm, we talked about the five milliliters per seam of bees, but is it up to fifty mils per colony still for this dosage?

Dr. David Peck

What a great question. No, so unlike the homemade sugar syrup dribble Where it's five milliliters per seam of bees up to a total of fifty milliliters in the entire hive. There's no such maximum restriction on this.

So you can put five milliliters per seam for as many seams of bees as you've got in your brood nest. There's no 50 milliliter cap. And so if you've got, you know, ten occupied seams of bees in the bottom box and ten up above, then you're putting you know, a hundred milliliters instead of just fifty milliliters into the whole hive.

So it's a higher concentration, but you also can ultimately wind up putting a higher dose in as long as you know you've got enough bees for that to be the appropriate dosage.

Becky Masterman

Interesting. So this is more than just convenient. It's actually potentially a tool that is going to address the Varroa on those those bees a little bit better For a couple of reasons.

Dr. David Peck

It's a tangible improvement on the sugar syrup oxalic acid dribble in a couple of important ways, and you don't have to make it yourself, which is great.

Becky Masterman

Are you concerned about how I make it? Because you've brought that up a few times.

Dr. David Peck

No, no, I'm concerned about how I make it.

Becky Masterman

Remember my wife yelling at me in the kitchen?

Dr. David Peck

That's the thing I'm trying to save everybody from.

Becky Masterman

I'm teasing. I think everybody is you know, w if we don't have a fume hood in our house, it seems very wrong to be mixing chemicals And most of us don't have that fume hood.

Dr. David Peck

Well, and there's there is always that very disconcerting moment where you're sitting in your kitchen, you've dumped this bag a baggie of white powder out onto the counter and then you grab a ruler and start trying to create, you know, a division in it, because you don't want to make all of the syrup and uh, you know, it could look pretty suspicious to somebody walking in and observing from outside. So let's just avoid all of that if we can

Jeff Ott

Oh, this is really good. So it sounds like a really good treatment option if you like to use oxalic acid. It's a naturally derived treatment. Yep.

Dr. David Peck

It's just one tool in the toolkit, but it's a tool I'm pretty excited about incorporating into my own mite management.

Becky Masterman

And very quickly, can you tell us the temperature range that this can be applied in?

Dr. David Peck

That's a great question. There is in fact no temperature restriction on it. As long as your bees are are accessible, as long as it's safe to open the hive, whether they're in a cluster or if they're moving around and foraging, there's no temperature restriction on the product label.

Jeff Ott

If that bottle of RTU is sitting in your truck all summer long and the truck cab gets hot Is that an issue?

Dr. David Peck

Probably not. If it starts boiling, we might get in trouble. But generally, no. The bigger concern is actually if it freezes.

If it freezes solid and then thaws out, you know, the stuff that's used to hold the oxalic and the glycerin in suspension can sometimes get a little behave a little peculiarly. The the solution doesn't stay quite as nicely mixed if it's been frozen. So if you can avoid that, that's good.

But I have frozen bottles and then thaw them out and have them work perfectly fine, stay perfectly clear. But long periods of freezing could potentially cause weird behavior of the of the solution.

Becky Masterman

This was very enlightening, David, because it does take away some of the obstacles to oxalic acid dribble because we have a shelf stable product that we don't have to use very, very quickly. We can we can use it as we need it. And it also has a higher percentage of oxalic in the mix and most of all your recent data show that it's pretty effective. especially in a broodless colony, but over a period of four weeks, which is the limit, is uh a great way to go ahead and attack that mite population and keep it low or lower it over time.

Jeff Ott

Yeah, absolutely. And I used it early in the spring and I Found it very convenient and it was a great way to start the season quickly with the bees. So thank you for joining us for this Varroa Treatments Shorts and uh check out our others in this series.

Thanks. Bye-bye everybody. Bye bye.