[Bonus] Short - Varroa Treatments: Death By Varroa

[Bonus] Short - Varroa Treatment Options:  Death By Varroa

Jeff Ott: Welcome to Beekeeping Today Podcast shorts, 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, everyone. Welcome to this Beekeeping Today Podcast short on Varroa treatments and controls. This is a multi-part series covering the different treatment options available to combat this honeybee pest. Each short in the series will cover one specific treatment option, or topic in this case. For this series, we've invited Dr. David Peck from Betterbee to join us. In this short, we'll be discussing death by Varroa. Hey, Becky. Hey, David.

Dr. David Peck: Hey, thanks for having me back.

Becky: I think we'd start by calculating just how much death by Varroa has cost beekeepers over the past 30 years.

David: Oh, geez. I don't know if my calculator goes that high.

Jeff: That's right. Would you start talking about man-hours? You'd have to talk about control options and then-

David: Colony losses.

Jeff: Colony losses, yes.

David: Productivity losses, pollination contracts. If my colony is alive but less healthy, then the pollination contract might not pay as much.

Jeff: It's lots of money, Becky.

David: There's a lot of money that-

Becky: It's a lot of money.

David: -these mites have cost a lot of people.

Becky: Basically, we've been fighting this for such a long time. David, I know you do a lot of education. I tend to talk to a lot of beekeepers, but I'm always surprised when I find a beekeeper who doesn't know what death by Varroa looks like. If that's one thing we can share today, I think that would be a really valuable teaching tool.

David: Yes, absolutely.

Jeff: Can you define what you mean by death by Varroa?

Becky: I think that when I say death by Varroa and I'm looking at a colony, a lot of times I'm looking at a colony that is technically alive still. There's also the definition of what it looks like once the colony has died. I'm thinking about parasitic mite syndrome, where both the level of the parasite Varroa and the level of pathogens have just reached such a high level, where the colony has really broken down. When you're looking at that colony, you are able to identify signs of parasitic mite syndrome and really predict that this colony is not long for living. This is the time of year, we're recording this in September, and this is a really popular time for beekeepers to find this in their colonies.

David: A popular time to find an unpopular thing.

Becky: Exactly.

David: By the time the Varroa kills your colony, it's not just the Varroa, or even predominantly the Varroa that are causing problems. The Varroa mites slurp a little nutrition out of the bees here and there. When they're transmitting viruses between the colony, when they weaken the colony, when they shorten lifespans in the colony, now the colony is riddled with viruses. Now the colony is too sick to fight bacterial or fungal diseases. Now the colony can't defend themselves against yellow jackets and robber bees from the next colony over.

You might watch a colony get robbed to death and the ultimate cause of their mortality might be Varroa mites. That parasitic mite syndrome, which some people will call parasitic mite brood syndrome, but either PMS, PMBS, that classic set of symptoms is only one of the most common ways for Varroa to be killing your hive and for you to get to observe it. They truly are devastating when they aren't well controlled.

Becky: We're going to talk about the different symptoms, but what I find interesting is that everybody knows what American foulbrood looks like, and often a beekeeper might look at their frame and mistake the parasitic mite broody syndrome.

David: Parasitic mite syndrome. To be honest, I think there was a push to call it parasitic mite brood syndrome because they felt like a bunch of male beekeepers saying PMS were having too much fun with it.

Becky: You could tell how hard that was for me to say.

David: You're right. PMS is stuck. I think we'll just stick with that one.

Becky: Can I have permission to go forward with PMS? [laughs] The signs of PMS, if you're not used to looking at it, you might have been taught what the American foulbrood symptoms look like and really misdiagnose it early on.

David: Right, it can look like AFB, it can look like EFB, it can look like this, it can look like that. Confusingly, sometimes you will even have those bacterial diseases in the mix because the bees' health is so bad that they can't keep those diseases under control.

Becky: I hate to get too far up here, but isn't the technical term snotty brood?

David: Yes, snot brood is what most-

Becky: Or snot brood.

David: -people will call it. Yes. Snot brood because it honestly just looks like a bunch of snot down in the cells. The other term that you'll often hear used is shotgun brood, brood that looks like it's been hit with a shotgun, because just so many of the cells are uncapped, even in a hot colony that isn't very hygienic against Varroa. When the Varroa are transmitting viruses at such a high level that so many of the brood are starting to die, the bees will figure out that they need to start uncapping cells and pulling out brood. We just get these big gaps, half-removed brood or brood that have been uncapped but not been fully removed yet, or larvae that aren't being fed because the nurse bees are so distracted with all the dying brood. There's a lot of different parts at play that all manifest together as this parasitic mite syndrome.

Becky: If I'm looking at a colony and I see some perforated cells, some of the melted or snot brood, I see some chewed-down pupae, first thing I do is I tip it up and I look for that mite frass on the tops of the cells. That's just a quick confirmation. I think that beekeepers can see with their own eyes little white flecks on the top of the cells, and they can say, "Okay, that is a sign that there was a very, very high mite population in this colony."

David: That mite frass or mite poop or guanine, whatever you want to call it, those residues are going to be there every time any Varroa mite reproduces. Just seeing a little bit of mite poop in the top of one or two of your cells isn't that remarkable. We know that they're in there. The problem is when you tip up the frame and you look up at the tops of those cells and every other one has got signs of mite reproduction, that's a pretty darn good sign that you're suffering from a severe mite problem.

Jeff: It stands out, it really does.

David: One symptom that I want to bring up, which often causes a lot of consternation with beekeepers, and it's actually the source of a lot of the fights I get myself, because people will call and they'll say, "Hey, my colony died and I don't know what killed them." They'll describe the symptoms and I'll say, "Varroa killed them." They'll say, "No, no, no, they didn't because they were so strong, they were doing so well. They were doing really, really well." I'm looking at my inbox as we're talking and somebody's just sent me an email that's entitled Low Population, Queenless Colony. Don't think it's Varroa, and I'm sure it's going to be.

Becky: It's Varroa.

[laughter]

Jeff: I'm sorry, I didn't mean to send that to you today, David. I should have chosen another day.

David: The symptom that people will often report is they'll say, "The colony was just so strong. They were doing so well. They were so great. They had lots of brood. They were really, really, really powerful, I thought they were going to blast right through the winter and make me honey next spring." Then they'll come back a little while later and the colony's absolutely falling apart. They've collapsed.

Not to confuse with the clinical definition of colony collapse disorder, but they've gone through a population collapse, a demographic collapse, where the colony just isn't a functional bee colony anymore. What's left behind are a few bees doing their best and a whole bunch of this brood showing signs of parasitic mite syndrome.

I will put in a little plug for one of my favorite projects I've ever worked on, which is a video on the Betterbee YouTube channel called Collapse of a High Mite Hive. It's just an opportunity for people to really genuinely look at a hive that I had literally in my own backyard, where I put in a bunch of drone brood. I bred a lot of mites in there, and then I didn't do any treatments. I watched as this colony grew and grew and grew and boomed. They made honey, they were really happy, they were really healthy. Then all at once they were dead. The videos have us going out on a couple of repeat visits and seeing that unbelievable difference between a colony that's booming in August and more or less dead in September.

Becky: Oftentimes you'll find that colony with plenty of honey, plenty of stored pollen-- [crosstalk]

David: Unless they die before you notice, and then the robbers come in, because they might clean out all of the honey, and you'll think that there's some starvation problem when in reality it was the mites.

Becky: Depending upon the timing of that robbing event, some mites might have hitched a ride to a healthier colony. One thing that is a sign that you have an infection, but you might or might not find it, I'm finding it a lot this fall while I'm inspecting other people's hives, are deformed wing virus. Looking carefully for deformed wing virus bees, and sometimes they will just sit in the cells and rest, and if you poke their little abdomens, if you've got some bees just in the cells, and when they back their way out, you'll see that they're infected with deformed wing virus. That doesn't necessarily always happen, does it, David?

David: That's right. It's important to distinguish between bees that have wing deformities and deformed wing virus, and beekeepers get confused on both sides. Sometimes people will panic and call me and say, "Oh, look, I found this bee and she's got deformed wings, I must have a terrible virus problem." I'll say, "No, we probably got shields during development. She probably just was nutritionally stunted. There probably was some other problem that messed up that one bee." Because growing an insect wing is a complicated project, and sometimes it just doesn't go right inside those brood cells.

Sometimes you'll see bees with wing deformities, but they don't have deformed wing virus. Much more often, though, is beekeepers will call and they say, "I didn't see any signs of virus because there were no wing deformities." It's important to remember that it's only at very, very, very high levels of deformed wing virus that even the first bee in your hive is going to show up with those wing deformities. When I find a colony and I pull out a brood frame and there's five or six bees crawling around with deformed wings, I have to assume that almost every bee in that colony probably has extremely high levels of the virus. It's just those were the five or six that were the least lucky.

The other place to remember is that those bees with deformed wing virus do not contribute much to the hives, and so either because they're trying to not be a burden or because their sisters are just trying to get rid of them, they're going to wind up outside of the hive crawling around in the grass. Whether you see bees crawling around with deformed wings, bees just crawling around with a shaking, stuttering movement, all of those can indicate bees with high levels of virus that aren't in the hive, but they're in front of it.

It's one of the reasons that a hive inspection always begins at the entrance to the hive, because you want to be looking around to see if there's anything in front of it before you actually go in and start pulling up frames. Any and all of those can be signs of high levels of virus.

Unfortunately, a frequent call I get is, "I think I let my mites get out of control. I think my virus levels are too high. What can I do about the viruses?" My answer is, "Get a time machine, go back and keep your mites under control." Unfortunately, going in with every single mite aside, we've talked about in this series, absolutely killing every single mite in that hive is still going to be too little too late if the virus levels are too high. If all of the bees in that hive are sick, if they're raising the new generation of winter bees and trying to get them ready for winter, but all of those bees are going to be picking up high levels of this virus, no number of mites killed at that stage are going to keep that colony healthy going through into the next season.

Becky: If you do manage those mites at this late stage, it could keep other colonies in your apiary or your beekeeping neighbors' colonies healthy. Unfortunately, it's an investment that you might not benefit from, but the population in the area would greatly benefit from.

David: Right. The last thing you want is those mites that are loaded up with these viruses to be transmitted into some naïve colony and start causing trouble over there.

Becky: I really like Meghan Milbrath. She's got some great information about a collapsing, or about parasitic mite syndrome, I think help mite bees die. Something like that. We'll include it. I think one of the things she says is a sign is that you didn't have any record of successfully mitigating the mite population during the season.

I think that's where it gets a little tricky right now, because you might have gone in and done a great spring treatment and cleared up your population of mites, and you could still have a mite problem that would lead to colony death, depending upon where your bees visited, if they got into one of those collapsing colonies and took advantage of that free honey and gave the mites a ride home, or if you had a booming population and your mites were reproducing, because you can't control every single mite, you can't kill every single mite. You can still have enough reproduction in that hive to make enough of a difference to really end the life of that colony.

It just goes to show you why we've invested so much time in this series, because it's not a simple, "Do this and you'll be okay." It is, "Put a lot of thought into it. Make sure you have a way to know whether or not your efforts are successful, and make sure you're checking, but thresholds of when you should intervene are different depending upon where you are. There's a lot of information that goes into what you're going to do to control Varroa in your colony." I wish we could just tell people to do one thing and it would make a difference.

David: Yes. Believe it or not, even Varroa scientists like me don't like standing here talking on and on and on about Varroa. If there was just one magic treatment that absolutely worked, we'd tell everyone to do it, and then we'd move on to more fun topics in beekeeping. Unfortunately, we have to keep bringing this up. We have to keep going into all of the details and dealing with, "Oh, this doesn't work anymore, but that's starting to work better, and here's something new, and it's a little different than the old way of doing it because we've got to make sure that beekeepers are equipped.

If you ignore Varroa, you are going to at best have colonies that barely squeak by and have to keep getting lucky year after year and have really good genetics and really good swarming times and things like that to even be able to survive. If you manage your Varroa well, beekeeping isn't that hard. It gets back to what the old-timers used to talk about. You'd put some bees out in the yard, and you could go grab some honey a few months later, and then the bees would put themselves to bed for winter. You can get into a mode that's a lot more like that as long as you're going out and doing the regular work of Varroa mitigation.

Becky: I think, first and foremost, your colonies that are the biggest honey producers, the most successful, look at those colonies as the most susceptible to dying by Varroa. I think that instead of us looking at those colonies and saying, "Oh my gosh, they're so healthy," we need to look at those colonies and say, "You will be the first to go because you have been so successful."

David: Yes, they've just had more brood raised. Every new brood cycle that happens, every new larva that develops in a colony, right before she gets capped, there's a chance for a mite to run in and increase the mite population. That's it. The more growth a colony has gone through, the more at risk it is from Varroa, because Varroa basically come in and punish colonies for their growth, unless we do something to help knock those mites back.

Jeff: For our listeners who maybe go out to their bee yard this afternoon and find that they may have a colony that's collapsing because of the Varroa load or the Varroa viruses, what should they do?

David: First things to do is to reduce the chances of robbing, get a robber screen. There's various designs of them. I know Randy Oliver just published some work on tests that he had done, and there have been some redesigned robber screens that go along with that. A robber screen is going to keep those bees and mites, and all the honey they made, which you can still profit from, inside of your hive.

If you think that your bees might be able to make it through with a Varroa treatment, go ahead and do the treatment. You'll kill the mites so they can't spread and cause harm elsewhere. If things line up, all the planets align, there's a chance that your bees will still be alive next spring. If they don't survive, don't blame the Varroa treatment and say, "I used that stuff, but it didn't work," because recognize that you are already coming in and asking it to do something that it wasn't prepared to do.

Becky: I'll add, if you keep bees anywhere near me in the Twin Cities metro area, go ahead and treat them regardless because you're going to keep my bees safer. That might be abusing this position.

David: Exactly. One of the pieces of advice I always give beekeepers is, they say, "My neighbor doesn't treat their mites, and so they always lose their bees to mites every year, and then my mite levels spike up." I say, "What you can do is just buy some of these robbing screens, they're real cheap, and give it to the neighbor and say, 'Oh, I think my bees are in a robbing mood, so why don't you put these free robbing screens on, keep all your hard-earned honey inside?" That also keeps all the parasites inside their house.

Becky: Oh, I love that.

Jeff: It's a good idea. That's a good idea.

David: It's the most neighborly way to tell somebody you think they're not keeping their mites under control.

Becky: You just let the secret out.

[laughter]

David: No, because if their neighbor beekeeper was listening to this podcast series, then they'd be pretty likely to keep their mites under control.

Becky: There you go.

Jeff: I think that's a good way to end today's episode.

David: Thanks so much for having me on.

Jeff: Thank you, David.

Becky: Thank you, David. We appreciate it.

[00:18:31] [END OF AUDIO]