[Bonus] Short: Varroa Treatment Options - Formic Acid

[Bonus] Short - Varroa Treatment Options: Formic Acid (FormicPro)

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Jeff Ott: Welcome to Beekeeping Today Podcast Short, your quick dive into the latest buzz in beekeeping.

Becky Masterman: In 20 minutes or less, we'll bring you one important story, keeping you informed and up to date.

Jeff: No fluff, no fillers, just the news you need.

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

Jeff: Hey, everybody, welcome to this Beekeeping Today Podcast Short on varroa treatments. This is a multi-part series covering the different treatment options available to combat this honeybee pest. Each short in our series will cover one specific treatment option. For the series, we've invited Dr. David Peck from Betterbee to join us. In this short, we will be discussing formic acid. Hey, Becky. Hey, David.

Dr. David Peck: Hey, Jeff. How's it going?

Jeff: Oh, it's good. I apologize in advance to you and Becky, and to our listeners, that this afternoon, Frisco the parrot is very talkative, and you'll hear him in the background on occasion.

Becky: I think Frisco likes Formic Pro just like I do. [laughter] I'm glad Frisco's joining us. The more, the merrier.

David: Right.

Jeff: Formic Pro is a popular varroa treatment. Who wants to start off with this?

Becky: David?

Jeff: Becky, you're a pro. You're a fan. Becky, you're a fan.

David: You're a formic pro.

Jeff: Formic pro.

Becky: I'm a formic pro. I think that before we get to my feelings about this miticide, I would love for David to give us the dirt as far as--

David: The rundown.

Becky: Let's give us the rundown on exactly what we're dealing with here.

David: Formic Pro uses, as its active ingredient, formic acid. Formic acid is an organic acid, and a formic acid molecule is basically just a carboxylic acid group for those that still remember their organic chemistry. It's chemically very, very similar to an oxalic acid molecule, and it's not any surprise that both of those molecules are able to kill varroa mites without killing honeybees. There are two different products that are currently registered in the US for use on hives. One of them is Formic Pro. The other one is the Mite Away Quick Strip, and they're both made by the same company.

They're both very similar in design, and in fact, the Mite Away Quick Strips have now finally been fully discontinued. You can't get them anymore. The Formic Pro is a better, new, and improved formulation of the same basic idea. What they're doing is they're taking formic acid, they mix it with sugar, they then take that formic sugar mixture, and they mix it at just the right temperatures with some binding agents, some wood pulp or sawdust, and all of that together forms this really, really interesting gel.

That gel, it needs to be set, set it and forget it for a while until it's ready to be formulated into these patties, and then the patties are made, wrapped up in this very special proprietary eco-wicking paper, they call it, and then the whole thing goes into a little foil bag until you throw it onto your bees. It's a very, very sophisticated process. I had the privilege of getting to see their factory where they make this and meet all of their quality control scientists that are constantly checking little samples here and there to make sure things are going exactly right. It is a pretty high-tech product for beekeepers to be even able to handle.

Becky: You use the word patties and you use the word sugar. I don't want the beekeepers out there to get the wrong idea because we're not feeding this to the bees. We are providing it in the brood nest, and the mites are being killed by the off-gassing of the acid. Is that right?

David: That's right. It's the vapor of the acid. The sugar is really there structurally, not to be eaten by the bees. They don't get any nutrition out of these things, but it goes into the brood nest or amidst the brood and then produces this formic acid cloud. That vapor is unique in miticides in that it is able to penetrate the brood cap and actually kill the mites that are underneath the brood cappings, which no other miticide is capable of doing. When you apply formic acid to a hive, you're killing the mites that get exposed out on all of the bees, but you're also killing the mites that are underneath the caps.

Most of the other miticides, you either need to reapply so that you catch the mites that had been formerly protected, or you need to leave the whole thing in for so long that at some point, the mites are going to wind up getting exposed. A big advantage of Formic Pro is that that single treatment really does get to every mite or almost every mite, we should say.

Jeff: Formic acid is pretty dangerous stuff, right? It's not something you want to create your own pads.

David: It's not the kind of chemical you want to mess around with. Anybody who's ever gotten a big sniff of their formic acid patties is not going to want to sniff them again, but the formulation that they've got, it's a little hard to say the percent of formic acid because in many ways, it's not so much the amount of formic that's there, but it's the way that they've engineered the slow release of it into the hive that winds up having its effect. It controls how much comes out and how little comes out so that you don't have too much or too little compared to some of the other treatments that are used by some researchers on formic acid, where it involves soaking sticks in formics and then putting that into hives to see if that'll kill parasites, things like that. That's a much less controlled mechanism as opposed to this whole formulation.

Becky: David, could you explain the doses to us? Because there are two different ways to put the formic pads on the colony, correct?

David: This is actually, it's cool among miticides. Very few of them have any flexibility in how you can apply it. Sometimes, there'll be a certain number of days within which you're supposed to take it out or something, but for Formic Pro, there's actually two totally different ways to apply it to your hive. You can either reaching a hive the appropriate size, put in two strips, the full two-strip treatment, and that is a two-week treatment where the strips go in, in between your brood boxes, and then are left in place for two weeks. They off-gas their formic acid.

It has all of the effects it's supposed to have on the mites. Then you come back at the end of two weeks and take the strips out and throw them in the trash or into your compost. The other application is what's called the one plus one treatment. In that, you put one pad of Formic Pro into the hive. You then come back 10 days later, and you put a second pad of Formic Pro into the hive. Then you come back 10 days after that. It's a 20-day treatment overall. The idea behind that, at least, is that it's a gentler treatment on the bees.

That amount of formic acid from a single pad and a full-sized hive is generally not going to be enough to penetrate the brood caps and have all of those lovely effects, but by coming back 10 days later, a lot of the mites that were previously in the brood are now out, so you can hit them with the formic acid vapor. Realistically, though, I will say, even speaking to the manufacturers and people who work at NOD, Nature's Own Design, the manufacturing company, they generally tell me that they never use the one plus one treatment.

If they do, it's only under very rare circumstances where a colony is really not strong enough, they don't think to withstand the full brunt of the two-pad treatment. Otherwise, they're using that two-pad treatment at all times.

Becky: That's interesting. I know just personally, if I have a strong colony, meaning they are full-on in two deeps, I don't think twice about putting in the two pads. If I have a colony that is full-on in one deep and then a little bit into that second deep, then that's where I go for that one-pad treatment.

David: It's nice to have that opportunity as a beekeeper, to have the flexibility, right?

Becky: Exactly. I love that, and I think it works really well as far as protecting the bees from any of the negative impacts of formic acid.

Jeff: Is there a timing issue with the use of formic?

David: Formic can be used with honey supers in place. There's not a strict month of the year that beekeepers absolutely can't use it because they've got supers on. The issue is that formic is sensitive to temperature. Particularly, it's sensitive to hot temperatures. As soon as the bee colony is in an environment where they are basically actively trying to cool down their hive, they don't have the ability to manage and regulate the concentration of the formic acid in the hive as well. What that means, the effect of that is that the label makes clear you cannot use formic acid at temperatures above 85 degrees Fahrenheit, ambient temperatures.

What many people worry about is they say, "Well, I don't have two weeks or 20 days where the temperature is always going to be below 85 degrees." The vast, vast majority of the formic acid is coming out of those pads in the first three days. Really, that first three-day period is the time when you need to be very attentive to the 85 degree Fahrenheit. You can put it in when you'll have three days that are below 85 Fahrenheit, and even if the temperature gets warmer later, it's not going to have a negative effect, and you, as the person diligently following your pesticide label, is not going to have violated the rules because you put it in when it was below 85. It stayed below 85 for three days, four days.

If it did get up to that temperature or even a little higher, it's unlikely that you're going to have any real negative effects on your colony.

Jeff: This is what challenges me every time I think about using it is when you say 85, is it high temperature in the afternoon, reaches maybe 85, and then for an hour or 30 minutes? Is that over the line, or is it 85 from 10:00 AM to 6:00 PM?

David: Yes. Obviously, one would be worse than the other, but the answer is if it ever gets above 85 degrees in a day, then that would be a violation of the label that says you can't apply it when it's above that temperature. The thing to remember, even on the label or on the packaging, they'll tell you their research found issues when the temperature got above 90 degrees, and so they wrote the label to say, "You can't use it when it's above 85."

If I'm a beekeeper and I'm deciding when to put it on, I'd much rather that it be below 80 than below 85 if I can find it. Why get close to a danger threshold? Even their own labeling, they've eased back from where they started noticing negative effects. That's important to understand, is that each fractional degree closer to 85 or beyond 85 is going to make things worse, but strictly, what the label says is if it's above 85, don't do it. If it's below 85, you can do it.

Becky: David, what kind of personal protective gear do they require, and then maybe, what do you recommend?

David: The manufacturer on the label of the product says that you need to be wearing protective clothing. They want you wearing long-sleeve shirts, long pants, things like that. Acid-resistant gloves. Certainly, you don't want to get that stuff on your hands, and they recommend protective eyewear. You don't want any splashes or droplets getting into your eyes. There is no requirement to wear any kind of a respirator to protect your lungs from breathing the stuff in. If you have a respirator handy that you're using for other miticides, it might not be a bad idea to throw it on. If you've ever gotten, as I said, a sniff of this, you're not going to want to get any more sniffs of it.

I have been knocked directly on my butt by breathing in some formic acid gas. There's no downside to wearing extra protective gear, but the requirement doesn't call for a respirator.

Becky: I know. When I was working at the university, I think it was actually required at the time with the different formulation. Everybody who worked for me had to use a respirator to apply it.

David: It's not a bad idea.

Becky: Otherwise, you have to be really good at holding your breath. Sometimes, you're maneuvering that pad a little bit, and you're having-

David: Leaning right over it.

Becky: -to step away to take a-- Yes. Sometimes, it's just easier to not. One less thing to think about, especially if you're newer at applying pads, because it's quick to apply them. It's a quick process, but your lungs are pretty precious.

Jeff: How does formic acid work against the varroa mite?

David: Like a lot of the organic acids, we don't have a 100% satisfying answer. We know it kills them, and we aren't totally sure how. We think it, again, probably has something to do with those moist, relatively thin little foot pads that the mites use to crawl around and navigate their environment, that the absorption of these organic acids is getting them into their bodies and then wreaking havoc once it gets inside of the mite. We do not know exactly which molecule is involved in how the formic acid kills the varroa mite.

Jeff: Becky, this is your area of expertise. Let's talk about the advantages and disadvantages of using Formic Pro.

Becky: Sure. I want to share something that I'm sure David has heard a lot of. There are people who are extremely worried because they've used this product and they've seen bad conditions in their colonies when they check them again. I'm going to ask David a very important question. David, if your bees are overwhelmingly stressed by disease and parasites, how are they going to take this miticide?

David: Probably not as well as if they were healthy. A very, very sick colony is going to suffer any stressor less easily, and that certainly includes being hit right in the face with a big dose of formic acid. The thing to remember, I think, that not everyone fully understands, is that some of these miticides, an Apivar strip, you put it into the hive, it really shouldn't kill any bees to speak of. A formic acid treatment, this acid gas filling up the cavity, that's going to kill brood. It's going to kill some bees, and that's normal. It's to be expected. It's written right there on the label that you can expect it, and that's fine.

It is a tactical sacrifice of probably some of the oldest bees, some of the weakest brood, the brood that are unlucky enough to be close to where you put the pads in. By the time the two-week treatment is done, you should have very, very few living varroa mites, and you should have a colony that is perfectly capable of rebuilding their brood population, regrowing any of the lost bees, because now they're going to be even healthier than they were before. It does have an impact on bees. Colonies that are really stressed, it can have a bigger impact on.

Becky: I would say that you mentioned it in one of our earlier series that this is a great tool for a quick knockdown on mites if you have a high population. I do not hesitate to use it on a colony with a strong enough population. Using it before you have a mite problem is so much more effective than using it after your bees have taken on the stress of maybe parasitic mite syndrome.

David: Right. Overall, the thing to remember is that your job as a beekeeper is to manage your mite population year-round, not to just go in and try to hit it once. If you let it get to catastrophic levels and then you use even a really good, strong treatment like Formic Pro, you're going to have reached catastrophic levels, and there's consequences for that.

Jeff: Regarding the application, do you put the strips only in the brood box? If you have a two-deep system and your top deep has no brood, you only put the Formic Pro in the bottom box?

David: The way you do it is you put the strips in between your brood boxes. If you have two brood boxes, you're going to put it in between the two. If you have three, then you can choose whether you want to put it in between one and two, and two and three, or just between one or the other. It probably shouldn't matter very much. Formic acid gas is heavier than air. It falls down and then billows out of the front of the hive. Better to put it skewed a little bit towards the upper of those boxes. If you only have one box of brood, then it is important to know you can treat with Formic Pro, but you need to give them some extra ventilation space above the pads.

That means if I've got a box of bees living in a 10 frame deep, I'm going to put another deep, or even just a medium up above the formic acid when I put the strips in so that there's more space for the gas to get into and more space for the bees to move around in to help to ventilate it, move it around to the right spots before it comes out of the front of the hive.

Becky: I also take out the entrance reducers if they're in to make sure that that is open.

David: Yes, you must do that. If you have a screened bottom board, you put the tray into the bottom so that it's not just letting everything fall right out the bottom, but you have to open the entrance reducers so that you are allowing one hive entrance for the formic acid to escape at all times.

Jeff: Is there a possibility for a resistance to formic acid?

David: There's always a possibility, but there's no reason to expect it here. Just like the other organic acids, formic acid, we don't know the mechanism of action exactly, so we don't know exactly what could or couldn't change in a varroa mite to make them able to resist formic acid, but we really don't have any reason to believe that it would be easy for a varroa mite to develop resistance to this stuff. We've never seen any evidence of any kind anywhere that the mites are developing any resistance.

It's another really good, useful tool that you still want to practice rotation, you want to follow those best practices of using different miticides, but unlike a synthetic that binds to just one receptor, that if that receptor mutates a little, suddenly, it doesn't work at all, something like this is probably going to be more trustworthy in your hive for more treatments per year or more treatments year after year with not as much rotation into other active ingredients.

Becky: David, just so that it's a little easier to hold your breath during application, one of the things I like to do is put those pads into the freezer before I bring them out to the apiary. Is that an okay method?

David: Yes. The pesticide label talks about how to store it, and it doesn't say anything about not allowing you to put it into a freezer. There's no rule that says you can't keep it a little bit cooler when you're going into the hives and dosing it. As the pads get warmer, they do tend to get a little bit more gloopy, so it'll probably be a little bit easier for you to go ahead and chill it and put it in. Soon after the colonies' temperature is completely surrounding it, it'll get right up to whatever temperature it needs to be. There shouldn't be any real consequence of that for the bees. It's just going to, as you say, make it maybe a little less stinky when you're putting it into the hive yourself.

Jeff: Finally, because this causes consternation for many beekeepers the first time they use Formic Pro, often, they'll see a lot of bearding of bees that first day, maybe the first two days. Is that normal? Should they be concerned when that happens?

David: Yes. Obviously, I've made very clear, I don't like the smell of formic acid. Bees don't really like it either, and so they are going to remove themselves from the hive to some extent in order to hang out and beard. There's nothing to worry about there. That's a totally normal reaction. The thing that some people are very worried about, and I think people should only be very slightly worried about, is the possibility of losing their queens when they treat with formic acid.

The issues with queen loss that I have seen have often been when the queen gets stuck in between the formic acid pad, and she's trying to get to somewhere that has a lower concentration of formic acid, but now she's got a queen excluder right on her head, so she can't get through it. Now she's going to be exposed to that full dose. She can't go out on the front porch to relax and breathe the fresh air a little bit. That may be part of the trouble.

There is data that shows that using these formic acid products can contribute to a colony going queenless, but that's not quite the same as saying the formic acid kills the queen.

What it seems like it often does is treatment with formic acid, it kills a little bit of brood, it knocks the colony back a little bit. In that slightly more stressed environment, it seems like the bees look around a little bit with some skepticism at what might be causing their problem. They look at their queen and they say, "Why is this colony not doing well? Could it possibly be your fault?"

The queens that wind up getting replaced after a formic treatment, they tend to be older queens. They tend to be queens that are maybe having some other health issue in the first place, and then by adding the formic acid, it's the straw that breaks the camel's back. That seems to be what promotes the bees finally saying, "You know what, it's time to supersede you." A good, healthy queen, even though she'll stop laying for a little while, once the formic acid vapor has cleared, she'll get right back into laying, and the bees will be happy to have her.

The concern about queen loss is not imagined. There is the possibility that a queen will wind up replaced after formic acid treatment, but I think a lot of the time, the queens that we lose are the queens that we were happy to have replaced by our bees anyway.

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Jeff: All right. I think this does a good wrap on formic acid. I look forward to our next one.

David: Absolutely. It's been a pleasure talking to both of you.

Becky: Thank you so much.

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