Dr. Erika Plettner: Using Chemoreceptor Confusion Against Varroa (S6, E43)

S6, E43 - Dr. Erika Plettner: Using Chemoreceptor Confusion Against Varroa

Phil McCole: Hi. This is Phil McCole from Dog Slobber Farm here in South Londonderry, Vermont. Welcome to the  Beekeeping Today Podcast.

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Jeff Ott: Welcome to  Beekeeping Today Podcast presented by Betterbee, your source for beekeeping news, information, and entertainment. I'm Jeff Ott.

Becky Masterman: I'm Becky Masterman.

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Jeff: Hey, quick shout out to all of our sponsors whose support allows us to bring you this podcast each week without resorting to a fee-based subscription. We don't want that and we know you don't either. Be sure to check out all of our content on the website. There, you can read up on all of our guests, read our blog on the various aspects and observations about beekeeping, search for, download, and listen to over 250 past episodes, read episode transcripts, leave comments and feedback on each episode, and check on podcast specials from our sponsors. You can find it all at www.beekeepingtodaypodcast.com. Hey, thanks a lot, Phil McCole for that great opening from all the way up there in Vermont. It's another state. We get the color in on our map of listener openers.

Becky: I think we're going to have to do more episodes this year so that we can get all 50 states in. No pressure but--

Jeff: That's true. Maybe we'll have to fill in some extra episodes. Our four-part series on how to get started in beekeeping threw a wrench in the works of getting our listener openers up there but we'll get caught up. I have faith.

Becky: Sounds good. Jeff, five lucky listeners found out that you were not fooling on April Fool's Day.

Jeff: For once. This is the truth. That's for sure. It was fun.

Becky: I loved seeing those emails come through and I wish we could have given everybody a mug.

Jeff: Wouldn't that have been nice that there were so many mug requests that came in that it was overwhelming? Thank you for everybody who listened to the very end of the podcast episode with Tom Seeley, and hope that they had won a mug.

Becky: Maybe we need to get a mug sponsor for the next podcast episode.

Jeff: Oh, wouldn't that be nice? We could have this mug presented by-- That's great.

Becky: There you go.

Jeff: We could call it your mug shot.

[laughter]

I want to say thanks to the following five winners of the mugs. Shelly Barnes, Tim Miller, Brandon Powell, Alan Judy, and Jacob Sublett. Congratulations.

Becky: I hope they enjoy their mugs.

Jeff: I'm looking forward to this episode today. I know to many of our listeners it may sound like we're overplaying the role of rural mites in a colony in our bee management practices, but I really don't think that we are.

Becky: I talked to a commercial beekeeper a couple of days ago. He runs a couple thousand colonies. He's just at his wit's end because we need more ways to control Varroa. We're at the brink of having bees become resistant to some of our synthetic miticides, and we need all hands on deck in order to figure out how we can keep our industry's bees safe.

Jeff: Even if you don't want to use chemicals, organic or otherwise, the time it takes to enact any kind of management practices is impractical for a commercial beekeeper. If you have 2 or 3, or 4, or 5, or maybe even up to 10 colonies in the backyard, you can do certain things. You can do rotations. You can do drone brood. You can do all those different little management techniques, but you can't do that times 1,000. You can't do that times 10,000. You can't do it really practically times 25. It just becomes a challenge. The impact of Varroa on beekeeping management today cannot be over-emphasized and that's why I'm excited about today's guest and the message that she is bringing.

Becky: I'm really looking forward to learning more about her innovative way to attack the Varroa problem.

Jeff: Our guest is Dr. Erika Plettner from Simon Fraser University. We'll meet her here in a moment, but her work is on the chemoreceptors of Varroa. Since you did so much work on Varroa, I'm going to put you on a spot, what are chemoreceptors? We can ask her too. Then I'll compare your answers.

Becky: I think she's going to give us a little bit of a better-- I don't remember doing a lot of work on Varroa, but I will tell you that both our honeybees and Varroa have ways to detect chemicals. It's how they smell. Erika is a chemist. She's going to be able to give us an excellent overview of these chemoreceptors. If you want to just get it to the bare bones, we're talking about how Varroa and how our bees smell different things and how they use those smells and how they use chemicals as cues.

A lot of our bees detect pheromones chemically and they're using that information to do different behaviors. There's that whole same world in Varroa, not as elegant as in honeybees, but Varroa, they can be messed up too, chemically. I think that's what we're hoping Erika is going to tell us that she's on the brink of helping us all do that to Varroa. I want to mess them up a little bit. Confuse them.

Jeff: Want to slip them a mickey. All right. Let's get in with our conversation with Dr. Erika Plettner, but first, a quick word from our friends at Strong Microbials.

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Jeff: Thanks a lot, Strong Microbials. Hey, everybody. Welcome back to the show. Sitting across this virtual  Beekeeping Today Podcast interview table is Dr. Erika Plettner, PhD from Simon Frazier University. She's my neighbor. She's just right up I5 in Vancouver. I'm down just south of Seattle. Hi. Erika, welcome to the show.

Dr. Erika Plettner: Thank you. Thanks for having me.

Jeff: You bet.

Becky: Thanks so much, Erika, for joining us. We can't wait to hear what you have to tell us about Varroa and everything you know about it. How's that?

Erika: Okay.

Becky: We know you know a lot.

Jeff: Everything you know in 30 minutes. Welcome to the show. We invited you here to talk to us about, well, we read the press releases on the work that you're doing on the chemoreceptor disruption for Varroa mites and honeybees. That's a very interesting topic. Anything that can help us manage our bees against the  Varroa destructor is very valuable and we want to get the latest and greatest news. Before we get down into the weeds, can you give us a little bit about your background? Who you are, your chemistry background, of course, and also any other bee background that you want to share?

Erika: I'm a chemist, a biochemist, I guess. I did my Bachelor of Science at Simon Fraser University, and during that time, I had organic chemistry with Dr. Keith Slessor. He recruited me to his lab as a summer student and I got to work. That's where I got to know bees for the first time. Also got to know Dr. Mark Winston, whom your audience, I'm sure, will recognize. I got hooked on bees. I decided to stay on after my BSc and do a PhD in biochemistry with the two of them.

With Keith Slessor and Mark Winston. My project was about the biosynthesis of the queen mandibular gland pheromone. At the same time, I studied similar biosynthesis in worker bees. The nice thing about that is the compounds are similar, the pathway is parallel. The difference is where the bees put what we call the functional groups. We all know about queen substance, which is a fatty acid, a 10-carbon fatty acid that the queen produces, and that's her dominant signal. It suppresses the reproduction of the worker bees.

We all know about royal jelly acid, which is also a 10-carbon fatty acid that's produced predominantly by the worker bees. It's added to royal jelly. It seems to have some properties, for example, preservative properties, I guess. No one really fully figured that out, but I did find an old paper where they said something like that. That's what my thesis was. It was figuring out these very subtle differences in the structure of the queen substance and related compounds the queen makes, and royal jelly acid and related substances that the workers make.

Jeff: I apologize for my unknowing, but when you'd say you study the mandibular secretions from the worker and the queen, how is that physically obtained to study enough to get the readings and understand?

Erika: What we did then was dissect bees basically and get the glands out. They're fairly large glands comparatively.

[laughter]

I learned how to dissect them and how to obtain them and then extract them, and run the extracts on an instrument called a gas chromatograph mass spectrometer. There's plenty of compounds to use that technique there to detect the differences.

Jeff: How many bees does it take to get a usable reading?

Erika: Oh, you can use a single bee, a pair of glands from a single bee.

Jeff: I didn't know that.

Becky: It's really pretty too. I mean the glands, when you open up head of the worker or a queen. It's bad for the bee, but the glands are just this really pretty wrapped around the brain.

Erika: Yes, they are.

Becky: Erika, you mentioned queen and worker pheromones, but I'm wondering, I just read someplace that said laying workers do develop some queen pheromones?

Erika: They can. Depends a bit on the bees subspecies, but yes, sometimes when a colon has been queenless for a while, laying workers emerge and they somehow manage to emit a dominant signal. It's only recently as a hobby beekeeper that I learned how bad it is to have a laying worker actually.

[laughter]

They'll kill her. They're quite naughty. Yes, we did study that a little bit. It is a continuum, so it's not black and white. The workers can synthesize a little bit in their mandibular glands of queen substance depending on conditions.

Becky: We're going to have to change the topic. Let's just stay down this road. Oh no, we won't do that. This is fascinating though. Thank you.

Jeff: Let's jump forward and start talking about the Varroa mite and its interaction with the honeybee, and its interplay.

Erika: Just briefly, the Varroa mite,  Varroa destructor jumped host. It's a parasite, it's an obligate parasite of the honeybee. It proselytizes two species of honeybee, the Afro-European species,  Apis mellifera, that's the one we all keep as beekeepers here in North America, for example, and in Europe, and the Asian honeybee,  Apis cerana. The original host that co-evolved with the mite is  Apis cerana, the Asian honeybee, which is used in many parts of Asia, China, India, and so on, Japan. In some parts of the, I guess Asian continent, beekeepers about 100 years ago had both species in some apiaries.

They were keeping both  Apis mellifera and  Apis cerana. This is where people suspect this Varroa mite jumped from  Apis cerana to  Apis mellifera. Because  Apis mellifera has not co-evolved over millions of years with the mite, the bees were naive. They, in evolutionary terms, did not know what to do with this. That's why they get attacked so badly by the mites.

Apis Cerana has evolved defense mechanisms which include smaller cells, hygienic behaviors, so they're able to smell when mites are producing inside a cell. They open the cell and remove the infected brood, and so on.

Apis mellifera doesn't have that advantage. This is why for about 100 years, we have been fighting this. Nobody knows where the original jump occurred. It must have been somewhere in Asia. We don't know where, but the mite eventually spread, and so it eventually spread to Europe, and because of movement of bee stock across the world, it ended up spreading here to North America. I remember when it was not yet in Canada and when the Canadians' government closed the border to imports from the United States, I was student then.

I also remember vividly when at our ferry terminal going to Vancouver Island, there were all these signs that you're not allowed to take bees over to the island because that was where the breeders were and they wanted that as a quarantine zone. Eventually though, the mite got there. Maybe it's not far away enough and drifter bees or somebody transferred it. Now, we have Varroa distribution pretty much worldwide. There's been an incursion recently in Australia, which it appears they're not going to be able to destroy, so they won't be able to stop that.

It might be establishing in Australia. The mite has been in New Zealand also where many of us get package bees, also has been established there for some time. The mite has moved around the world. Why is it such a problem? Because it parasitizes both adult bees and pupae, so brood. When it sits on the adult bees, it likes to hide on the abdomen. That's the tummy of the bee between the plates, because there, the skin of the bee, if you will, or the exoskeleton is not as thick. The mite can bite into there, create a wound which doesn't heal.

They do something to the bee, and they lap up the nutrients that come out of that wound. Recently in the literature, it has been shown that they like the abdomen also as their favorite spot because they feed on the fat body, which is a very important organ in the bee. It's a combination of the liver, the spleen, the fat layer. It does a lot of things. It's very important for the bee. That's why mite parasitism weakens the bees. If the mite infestation level is very high, this results in the bees not only being weak but getting sick with secondary diseases.

Jeff: That's where we often come into the end of summer, fall, with the colonies that don't make it through the winter. Ouch. Back on what you're saying, do you know if Newfoundland has Varroa on the island yet?

Erika: I don't think so. I think it's one of the few places in the world, but there's not that many total colonies in Newfoundland. It would be nice if we could keep it as a quarantine zone. There's a lot of talk across Canada to ramp up our own stock production, so to lower the amount of bee movement from other places.

Jeff: That would be nice if they are able to keep it Varroa-free.

Erika: Yes.

Becky: Erika, you mentioned that the Varroa feeding wound doesn't heal. Even if you knock the mite off the bee, the bee doesn't live long enough, it just doesn't heal, is that the case?

Erika: That's a good question. I don't know the full answer to that. I've never focused my attention on the actual wound. It's just I saw in various places that they make a pretty big incision between the plates, for example, between the tergites or the sternites, and they also hide there. You can't see the mite while it is between those plates. I think the mite has compounds that are in its saliva because it injects a little bit of its saliva into the bee, with digestive enzymes and possibly also substances that inhibit the immune response of the bee.

Becky: It's another piece of the picture where you think you put in a mite treatment, you see that drop, and turns out that maybe those mites are gone, but the bees that they fed on are probably not going to live a full productive life.

Erika: No. Also because of the viruses that the mites vector.

Jeff: This is at the adult stage of the mite as well when it's not in the cell. This is just carrying around the hive. They also affect the pupae and the larvae of the honeybee.

Erika: Yes. Late-stage larvae shortly before capping, that's when they might enter the cell and hides until the cell is capped. Meanwhile, the larva start spinning the cocoon and the mite starts its reproductive cycle.

Jeff: Nasty critters. Let's take a quick break and hear from our friends at Betterbee, and we'll be right back. We'll talk about chemoreceptor disruption.

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Becky: Welcome back. Erika, can you tell us when you started thinking to use your biochemistry background and look at Varroa instead of the honeybee?

Erika: When I returned after my postdoctoral studies, part of which were on the chemical senses, so smell in moths, I started an independent research program back at Simon Fraser University on that topic. When I started first, I was actually interested in feeding deterrent, so substances that discouraged feeding by the different moth larvae such as the cabbage looper, the diamondback moth, gypsy moth. These moths are quite picky eaters and they have ways of chemically sensing whether they're on the right host plant or not. Some are a bit more generalist, others more specialist. The point is insects do like to know what they're feeding on, I guess. I won't blame them.

[laughter]

The hypothesis behind my research was, can we find substances that we can apply at or near the plants that would discourage, that would confuse the insect and go, ew, and not feed on that plant, and thereby protect the plant without using an insecticide. That was the original idea. Eventually, I started and I was approached by another researcher. We started looking at feeding deterrents in Varroa mites. For a few years, we worked on the idea that Varroa would prefer nurse bees over foragers, which to some extent may be true, but I think if the Varroa mite is desperate, it it'll go for anything bee that it can find.

We did find some compounds that in an assay, in a glass assay dish in the lab did this and disturbed the way the mite detected the bee. Eventually we came across the compound we are studying now, which paralyzes the mites and eventually kills them. It makes the mites-- first, initially, if we do an assay and we pour a few mites in there and two free skilled bees just as food for the mites, the mites will immediately move from the middle of the dish to the bees and climb those bees and start feeding.

After about two hours or three hours in the presence of our compound at high temperature and humidity, the mites come back off. They climb off the bees. For some reason, they either don't realize that they're on a bee or they're experiencing something that makes them walk again. We don't know exactly what's happening, but they climb off the bees and so we find them away from the bees. Whereas, controls which don't receive the compound stay on the bee for the duration of the assay. That's one symptom that this compound causes. The other symptom it does is it paralyzes and kills the mites.

Jeff: They come off after a couple hours. How quickly are they paralyzed?

Erika: Also after a couple of hours, they paralyze and die. The both symptoms appear with a similar time frame.

Jeff: Wow. Boy, that sounds really exciting.

Becky: How many chemicals did you have to screen to get to that magic, magic chemical?

Erika: Once we were working with mites, we had a pretty good idea what we're looking for. There we screened in the maybe 20s, so not that many, but when we did the initial feeding insurance works with the moths, we did screen over 100.

Jeff: I was reading online the compound is dubbed 3c36. Are you up to like 38 or 39 now or are you still staying--?

Erika: No. The three and the six are code names for different chemical parts of the compound. That was due to a paper we wrote originally when we made little libraries of these compounds. The 3c just means that it has a certain shape with the two oxygens on opposite ends of the compound. The three and the six are just the constituent groups as we call them. It's a code name. It's not a numbering of the number of compounds.

Jeff: Version 36, version 37.

Erika: Yes.

Becky: That had to be a fun one though, to observe and then replicate, and then see it again. Was it an undergraduate that you sat in front of the samples for hours and hours of observation, or were you the lucky one?

Erika: It was a team of people. Eventually the bulk of the work we published in scientific reports was done by Soniya Dawdani, who was a master student who did this for her master's thesis.

Jeff: Was the compound given to the freeze dried bees as a gas, as a liquid, as a powder?

Erika: The compound is a low-melting, I would call it powder. It's like a solid crystals, but they are low-melting. It smells a bit, so it can also evaporate. When we give it into the hive, it is on a piece of wood. Basically we just coat a piece of wood. We dissolve the compound and paint it on basically in layers and then put that piece of wood vertically between the combs.

Becky: It doesn't stop all honey production in the hive or anything like that?

Erika: No, it doesn't. According to our measurements it does not stop brood production, does not affect honey production. Obviously one cannot be harvesting anything while treating for anything. The Varroa or antibiotic, or anything, one cannot have a super on at that time. Our experiments are always done after any honey harvest.

Jeff: Originally, you mentioned that it affected the chemoreceptors. At the point where you noticed that the bees were dying after feeding on the the feeder bees, at what point did you decided it was probably the chemoreceptor that was involved, as opposed to a pure topical poison pesticide, miticide?

Erika: The fact that the mites start walking again. Normally a mite, if it finds a bee, it just to hang on for dear life. Only if it has a reason or wants to reproduce, wants to find a cell to enter, then it'll start walking around. Other than that, they're fairly firmly latched onto the bees. They also, it's their instinct to hide a little bit. They go to exactly the spot where the bee cannot reach with its legs. The bees self-groom, and they even cross-groom, so each other.

When self-grooming, the mites, if you observe carefully and you count it, they're exactly where the bee can't get them. That's where they like to hang on. Once the mites find that sweet spot, then they have no reason to move, they won't move that much. The mites starting to walk again and getting off the feeder bee tells me that something-- It may be chemoreceptory in part, it may be something else too, some other form of reception. I don't know. At this point, we don't know for sure.

Becky: Have you tried it on  Tropilaelaps?

Erika: That's a big question. I was approached by a student, but we want to keep  Tropilaelaps out of North America. Out of the American continent, period, so no at this point. I am sure of the years to come, it will be tried because beekeepers who have the  Tropilaelaps problem are developing ways of managing it. It is my understanding that the places where it is now, colonies are managed up to a smaller size.

Us with our big multi-box, multi-super colonies might be in trouble if we get  Tropilaelaps. I understand that the  Tropilaelaps, being a mite as well, being a Acari, that they do respond to Acaricides like formic. I don't know if people have done a systematic study with things like Apivar, formic, thymol, et cetera. I don't know the answer regarding  Tropilaelaps, but in the years to come, we'll see how that develops. I hope we can keep it out of Europe, of Australia, of America.

Jeff: You are in the middle of field trials, or multiple different field trials. Does it have any effectiveness to the mites under the cappings of a cell, or is it just the external?

Erika: That's a good question, whether there is an effect about two mites under the cappings. So far, we have no evidence that once a cell is capped, the mite is affected. In other words, if the cell gets capped, a mite can reproduce even in the presence of this compound. What we do find, though, in our field trials, we always check the number of cells. We open 100 cells with advanced-stage pupa.

We check whether there's a mite in there or not, and whether the mites are produced or not. We do that before testing the compound and then after the experimental treatment. What we see is that in the treatments, there are much fewer cells occupied by reproducing mites, but that may just be this mite movement issue rather than the mites actually not reproducing. So far, we have no evidence that the compound works under the cap, basically.

Becky: Depending upon the time of year, even if you just make sure there's no sealed brood, then it would be able to reach all of the mite. Not all of them, but hopefully a high percentage of them?

Erika: Yes. Any mites that are phoretic or that are just walking around on the comb or on empty cells would be reached by the compound. It's just that we believe it doesn't cross the cap once the cap is there.

Jeff: The compound, is it transferred through the air? Basically, the mite breeds and it's not a physical contact where one bee touches another bee who's touched the compound, who spreads it, and the mite doesn't have to bite, for lack of a better term, or make the incision in the bee to be affected by the compound.

Erika: That's correct.

Becky: This reminds me of the studies where if you paint propolis in the walls of the boxes, you can see a quieting of the bee's immune system. It's the aromatic-- I've got a chemist here. It's the volatilization of the chemicals. Is that the same concept? Is it that? If you do the propolis, it's quite extensive where you need to apply propolis or encourage propolis. Is this a smaller part of the colony in order that you need to apply it in order to release it?

Erika: Yes. It's applied on these wooden sticks that we put between combs. In our last few trials, we used three wooden sticks. We put them, say, between combs three and four, and then between combs five and six, and then eight and nine, or something like that. Somewhere in the middle, but in-between combs.

Becky: Is this a single-deep or double-deep colony?

Erika: We did all field trials here in Canada in singles.

Jeff: I was also reading that you are working with Veto-pharma on some of your field trials. Is that progressing?

Erika: Yes. They're combing through our data right now, and that takes a little bit of time. That's where we're at, is basically exchanging information and talking about what the best step forward might be. I'm sure field trials will happen. I can't tell you exactly how or what we're going to do next.

Jeff: I guess the gist of it is that any commercial availability of compound kill the Varroa is a couple years off.

Erika: I'd say so. Because this is a new compound. Even though I've been researching similar compounds and this one for many years, it's all academic research. It's never been approved as a pest control agent, and so it has to go through basically the active compound registration, and if we come up with a formulation or an effective product, then it also has to go through the effective product registration.

Becky: I've written studies to see how if you put in thymol, it's all over the comb, and you can look at the comb well after you applied that thymol, and it is still there. Have you done any studies to see how this compound persists in the equipment?

Erika: We're doing that. I have a student who's doing a master's on that, and yes, we are finding it similar to thymol.

Becky: [laughs] That's the beauty of beeswax, right?

Erika: Yes.

Becky: Everything sticks.

Erika: Can be also its curse, but that's correct. You want to get rid of it.

Becky: That's why we keep our honey supers separate from the brood chamber.

Erika: Absolutely. Very important.

Jeff: The flames from the beeswax candle is a sparkly red.

[laughter]

This is really exciting. This really does hold promise as a future tool for beekeepers in battling Varroa. What are the next steps in the process that you're working on for this coming season?

Erika: Again, is agreeing on how we can move forward on the registration, so on the regulatory aspects of it. That's, I would say, top priority. The other thing, and in the meantime, it's very important to get the message out that monitoring is very important, and treating the bees as needed for Varroa to keep the numbers down, unless you're an experimentalist and you're trying to get high mite numbers.

Other than that, it shouldn't be allowed to happen, and try to rotate as much as is possible in your area. In the fall treatment, if you use, say, thymol one year, try to use something different the next year, the next fall. Then use the acids in-between, so the oxalic, and when there's no brood or very little brood, and the formic maybe in the springtime, just to keep those numbers down, and just to have a little bit of rotation.

Becky: When I asked about formic and if we're worried about any kind of resistance, I was told because of the mechanism, we had a low risk. I'm asking because I love formic. I love it as a control. It's so effective and easy to use. Is that true? We're not seeing any change in bees--

Erika: What is resistance? Resistance is just evolution in action. Whatever acaricide, for example, you're applying to the main population is selection pressure. Let's say that you have 10 mites and your agent kills 9 of them, and 1 of them survives, just barely, but it survives. Because mites are so clonal, as in theory a single female mite could infect a whole country because of its biology.

Having just a few mites left over after your treatment, if they survived because they could resist the treatment because they had a thicker skin or they had a way of avoiding the treatment, or something like that, they will pass that ability onto their progeny. In principle, you should be able to see resistance eventually against anything you throw in there. New, old, formic, oxalic, you name it. In theory.

Becky: Fair enough.

Erika: We don't really know how formic works. In part, it is very irritating. It is very corrosive. I'm beginning to like it too. I've started using it. It's good for one treatment per year, and it's nice because it evaporates away, doesn't leave residuals behind. It can get under the caps, so you can apply it when there is reproduction. We don't really know the molecular mode of action. What it's actually doing. I'm sure there will be some kind of mechanism. Otherwise, if it were just a general toxicant, then the bees would be killed as well. We can kill the bees with formic, but you really have to make a big mistake with it.

If you use a good formulation of it, then it's okay. I would be careful in saying that there cannot be any resistance. Although right now these organic acids, especially formic, is a very good option that-- It's good for spring treatments, for example, but even into the fall, it can help. The one thing people shouldn't do is mix acaricides or co-apply two acaricides or more at the same time, because they can react. For example, amitraz which is the active agent of Apivar, is very acid sensitive. If you co-apply Apivar together with oxalic or with formic, you are killing the Apivar, basically. That should not be done.

Jeff: How long is that treatment left on the colony?

Erika: We've done experiments with four-week treatments. That's our initial field trial, and then later we increased the dose and we did six weeks.

Jeff: I was thinking since it didn't get under the capping, it'd have to go through several life cycles to try to rid the colony. Very good. Dr. Erika Plettner of Simon Fraser University, we really appreciated having you on the show today. Is there anything that we haven't asked you about that you want to bring to our listeners' attention in the closing moments?

Erika: I think we've covered a lot of ground, and yes, it was great. Good opportunity. Thank you very much for having me.

Jeff: Do you take requests for the recipe for the compound? Just asking for a friend.

Becky: You're asking for a friend, aren't you? You're asking for me.

[laughter]

Let's let all the data be collected.

Jeff: That's right.

Becky: It's really important. Let's not go cowboy on this Varroa method of management. Let's do it right, Jeff.

Jeff: All right. Erika, thank you so much for joining us. I'd like to invite you back at any time if you have any news or updates that you would like to share with our listeners.

[music]

Erika: Thank you very much, Jeff and Becky.

Becky: Thank you so much for sharing this information with us.

Jeff: Becky, I'm sitting there wondering if I could get across the US-Canada border with a satchel of compound Varroa in my back pocket.

Becky: She knows what you look like, so I'm pretty sure when you show up to said lab in order to acquire the substance, you might get stopped when you just show up and say, "I'm looking for a tour," and you say, "Where do you keep the good stuff?" [laughs]

Jeff: I go across the border and some big burly border guard will say, "Hey, Roger, we got a mule here."

[laughter]

All kidding aside, this was a great conversation and it really does provide some hope for the future on providing management tools against Varroa.

Becky: Exactly. It's a tool that I did not know-- I know that there was a press release, but boy, it feels we're really close to this one, doesn't it?

Jeff: I'd really like to think so. The way that affects the Varroa so quickly, she said within two hours, but then again, what about the mites that aren't killed immediately by that, and is there an eventual buildup of a resistance to the compound?

Becky: If it's used as a tool, and if people are able to take out their integrated pest management playbook and make sure that they're using different kinds of treatments, they're using different management methods, this sounds like it could very well help a lot of beekeepers get through this Varroa crisis.

Jeff: So many of the tools that are available, especially the organic acids as we're talking, are temperature-dependent. It can't be too hot, it can't be too cold. It has to be the right time. I've been hesitant. I could be wrong here, so feel free to-- anybody, let me know how wrong I am. I'm used to it. The availability or the effectiveness of, say, formic acid over a period of time in the Pacific Northwest, I wonder sometimes because it's--

Either gets too cold or it gets too hot and I have to worry about problems with it too hot, and there's just not enough nice, even 70-degree days in a row to really make it effective. It'd be nice to have another tool hanging off that IPM belt that we all carry to control Varroa, and maybe, jeez, AAA lamps. Oh, let's not talk about that.

Becky: Way to bring it down. We were feeling so hopeful.

[laughter]

You're right. Beekeeping is all about timing. Then when you're trying to manage a bug on a bug, when you're also trying to produce food, it's a really complex-- It's a dance. You want to make sure that everything's healthy except for the pest you're trying to get rid of, but we want the bees to be healthy and we want all of the hive products to not be harmed, so hopefully this will really make a difference.

[music]

Jeff: Thanks to people, researchers like Dr. Erika Plettner up at Simon Fraser University working on these problems. Maybe there is hope for us. That's good. That about wraps it up for this episode. Before we go, I want to encourage our listeners to follow us and rate us five stars on Apple Podcasts, wherever you download and stream the show. Even better, write a review and let other beekeepers looking for a new podcast know what you like. You can get there directly from our website by clicking on the reviews along the top of any webpage.

We want to thank our regular episode sponsors, Betterbee, Global Patties, Strong Microbials, and Northern Bee Books for their generous support. Finally, and most importantly, we want to thank you, the  Beekeeping Today Podcast listener for joining us on this show. Feel free to leave us questions and comments at the "leave the comments" section under each episode on the website. We'd love to hear from you. Thanks a lot, everybody.

[music]