Testing the banana trick for chalkbrood

by Flow Hive 18 min read

Today we’re testing whether adding bananas to a hive can help with a chalkbrood infestation. Cedar inspects a hive with chalkbrood, explains a bit about the disease and the idea behind the banana trick. He also answers your questions on chalkbrood. We’ll come back to this hive in a month to see if it worked.



Video Transcription

Good morning and thank you for joining us today. We are going to do some myth-busting. Now, it is said that bananas can help with chalkbrood. Some beekeepers swear by it. Others say it's Hocus Pocus. So why don't we give it a go? I've never done it before. And we'll see what the effect of is on this poor hive that has a bad infestation of chalkbrood. Come and have a look at this. I'm just pulling out the pest management tray down here, and we have a bad case of chalkbrood. Look at all these poor bees that were in their larval stage. The fungus got hold of them. They're turned into a chalky lump, and that's why it gets called chalkbrood. Now those have been pulled out by the bees. They've been ejected down through the screen. Sometimes you'll see them on the landing board out the front, and that is chalkbrood.

So the theory is we cut bananas, we put them on top of the brood nest, and it's a bit of a bomb in the hive. Some say it's an alarm pheromone which causes the bees to go into this kind of frenzy and start cleaning the hive, pulling out all of that chalkbrood. Some say bananas release ethylene, which then reacts with the oxygen from the air making ethylene oxide, which then has a helping hand in getting rid of that fungus in your hive. Well, let's see whether this is Hocus Pocus or not. If you've used this before, chime in on the comments, let us know. If you've got a chalkbrood infestation in one of your hives, try it out, let us know what it does. Together we can do some myth-busting. What we're going to do is slice these, put them on top of the brood nest and wait a month and see if the chalkbrood problem goes away.

Now, this is quite a bad infestation. It's really slowing down this colony. If you look in between the frames here, you can see the bee numbers are getting a little bit thin. They're still there, which is good. The issue with the hive getting weak is other things like beetles will take over. A strong colony is the best defence against chalkbrood. So what we need to do is nurse this colony back into action. If you have a look in the side window, there's bees there, there's still a thriving colony, but they're thin on the ground. So this chalkbrood is really harmful in terms of the number of bees they're able to have. We're basically gonna go through a brood inspection, have a look at the frames. Then we're going to come back once this is been in there for a month and have a look. So if you have a look at the hive next to it, for comparison in the same location, we've got a lot more bees in the window, a lot more honey stored, and they're looking much more healthy. It has been quite a slow time, bit of a dearth in nectar. They are starting to bring in a little bit. Now we're getting an autumn flow, which is nice, but they are all a little bit weak.

Hive inspection

So first things first, let's open the hive. Now I'm gonna jump right up here. I've got my smoker out already and I'm gonna blow some good puffs right into the entrance of this hive. And that's gonna calm them down a little bit. We've got a nice, beautiful sunny day here, and that's the best time to do your brood inspections. You can't always get that, but a nice light wind sunny day is when your bees are usually the calmest. First of all, protect yourself. Make sure if you're new to beekeeping, you're wearing a good beesuit, you've got your gloves and you are minimising the issues of stings.

First of all, we're gonna take off this roof and put it aside. I'm actually going to leave the inner cover on for the moment because we're inspecting the brood. We don't necessarily need to also inspect the Flow Frames. We're gonna crack this box off and just rest it out the front here.

So with my hive tool, I'm going to just pry all around. Typically what happens is they get nice and stuck and what you need to do is lever it up all the way around by putting your hive tool in. In this case, I'm gonna go underneath the excluder. So you can see a little position there and I'm just lifting like that. Now I'm gonna lift up and have a little look to see whether any of the frames are stuck to the excluder, which they are. And that's a common thing that can happen. So what I'm gonna do is just pry them off like this and then they drop off. The bees get really annoyed if you lift a whole lot of their frames up with the excluder. Now I'm going to take the side windows out to give myself an extra handle. I don't really need it, I'm gonna lift front to back. I'm trying to keep this box up so we don't squash any bees unnecessarily. And I can see the box is quite light. I'm just going to place this down on the end, so we don't squash any bees, just out the front here.

So now we've got access to the brood nest. The excluder decided to stay down after all and we're just going to peel that off slowly. Having a quick look on the underside for the queen, occasionally she can be there, you don't want to orphan her from the hive. So I'll just lean this excluder up like that. So if I have missed her, she can walk back in. Next I'm going to pull out a brood frame and just have a look at it. You can see a healthy number of bees here, which is good. So this hive has a fighting chance against the chalkbrood. Blowing a bit of smoke on the frame I want to pull out because I don't want to squash any bees and it helps get them out of the way. Going sideways first, just to loosen up the frame. Otherwise sometimes when you lift, you will lift the nails right out of your brood frame. 


So let's have a look here for chalkbrood. I can see one, two. Yeah. It might be hard to see it's just back here at the end of the J-hook. See that chalky mummy down the bottom of the cell there. That is a larva that has ingested spores from chalkbrood, which can come in from the outside environment. And it's a mycelium calledAscosphaera apis.

What happens is that larva will die and turn into a chalky little mummy and then eventually it'll go black. And that's when it's spreading out more spores around the hive and the infestation continues. So first thing you do, if you get chalkbrood, is move your hive into the sun. They do better when it's nice and sunny. However this hive is already in the sun. So next we're gonna try this banana thing. But if that doesn't work, what we're going to do is cut out a bunch of the old comb and give them some fresh new frames. And we may also introduce a new queen, which is hopefully having more hygienic traits and the bees can then get in and clean out that chalkbrood. Having a look on this side, not seeing any chalkbrood on this side, some nice pollen there. Look at that bright yellow pollen. That's really beautiful. That bee's done an amazing job of collecting that pollen and scraping it off all its hairs and pushing it down to its pollen bags on its back legs. And it's flown back with almost its body weight in pollen and nectar to the hive. And now it's looking for a good cell to store it in.

Also looking for signs of AFB. If we see any sunken dark cappings. Here we go, one more chalkbrood. So we've got three or four on that side and one on this side. Not to be confused with pollen down here, which you can see these beautiful yellow pollen stores, which they're fermenting into bee bread. There's also whites as well. Let's put this frame aside and have a look at another one. We're gonna go through and have a look at a few frames and just ascertain the levels of chalkbrood. Obviously we're seeing a lot in the tray that hasn't been cleaned out for a month or so. And that means there must be a lot in the frames here, but that frame there wasn't too badly infested. Having a look at this next frame, lot of brood there, which is good. So that's going to help boost the numbers and get the hive back to being strong. So it looks like this hive actually might be getting on top of it. Now Isn't that beautiful to look in at their world and what they're doing.

Can you see any chalkbrood there? I'll have to have a little look. There's one in the centre. There is another one there. So we've got basically the levels of infestation are two or three chalkbrood mummies per frame side at the moment. There's another one on this side. Another one there. So it's 1, 2, 3, 4, counting four on this side five. And what we have here is a queen cell. Look at that.

I want to have a look down there. This is a pretty old frame, so it can handle being tipped over. There's nothing in it yet so it's a queen cup. If it had a really raggy edge, I would say it would have had a queen emerge out of it, but it looks reasonably neat there, showing that they haven't actually used it for a queen yet. But it could be a good idea for this hive to supersede its queen and hopefully get some genetics that are more hygienic for cleaning out chalkbrood. So as we're going, we're realising there's so many factors here and this is why it's hard to prove whether the banana thing works or not. Because they might requeen themselves. And that might mean that they get rid of the chalkbrood problem on their own or they might just get on top of it as we're seeing, they've kicked a whole lot out, but there's not a huge infestation in here anymore. So they might be on the way to solving it themselves with their current queen as they get stronger and more sources of nectar come in. So let's have a look at another one.

Banana trick

But as said today, we're doing some myth-busting. Does the banana thing work or does it not? Obviously a test of one isn't enough to know that. So if you have experience with the banana thing, then let us know, see if bananas in the hive actually helps in getting rid of chalkbrood and we can do some citizen science here for anybody that's got chalkbrood out there by following what we're about to do and seeing if it works for you. This one, What are we seeing? Seeing drone brood. See these big more bullet-shaped kind of brood here. That's the drone, the male bees. There's less of them in a hive, 600 or so. And the drones don't do any work around the hive. Look at this one here, this big black drone. They're bigger, more Teddy bear shaped, their eyes connect together in the middle. There's a few on this comb. They don't have stingers so they're good ones to pick up and show the show the children.

So there's chalkbrood there and there. So we're consistently getting two to five chalkbrood cells per frame side. So that's the level of infestation we've got. Let's put these frame back in and let's put the bananas on top and then what we're gonna do is close it up for a month and check in and see how we went. What I'm gonna do is put these frames back in at trying to keep the same order, because the bees will have connecting variations in their comb. And if you push the comb parts together, then that can be a spot where the bees can't actually service and hive beetles can get in there and lay their eggs and you end up causing a bigger problem for the bees. These frames are nice and straight, which is good. And we're gonna blow a little bit of smoke in here. Let them settle down a bit more. At first it agitates them, but then they calm. The reason being is I noticed a couple of them were just going for my hand.

Smoking my hands is a good idea because that helps mask my own pheromones because I guess I'm like a mammal or a bear coming into their hive. So I want to disguise myself a bit from the bees. Frames going back in nice and gentle. Try not to squash in bees as we go. And here we go back in again. So we've seen lots of brood. We're happy there's a laying queen. We didn't make an effort to find her. Doesn't matter. As long as you can see the presence of the young larvae and brood, then we're happy we have a laying queen. I'm just pushing the frames back together. And what I'm gonna do now is put what's called an eke on top. Now I've just made this from an old inner cover, I've just cut the centre out. And what that's gonna do is provide a spacer so we can fit our bananas in without having them squashed directly under the excluder. It's not something I use very often, but can also be useful as a bit of a shim. If you need to put a feeder on top of the hive and things like that.

Next, we need a knife, we need our bananas. Now just to be sure we're gonna use two types of bananas. We've got the Cavendish here and we've got some ladyfinger banana as well. What we're gonna do is slice right down the centre like this with that knife. And we're just going to lay them right on top of the frame. And let's just observe what happens. To see whether the bees are alarmed at all with the sudden introduction of banana into their hive. Right. They don't seem too alarmed at all. Maybe they're not ripe enough yet. Let's try this ladyfinger. This is a nice squishy old ladyfinger.

And we're gonna put that right in the centre like this. Okay. We're not seeing any alarmed activity, which is interesting. Here we go, they're coming for a little nibble. They're going "beautiful, thanks for breakfast." So it's said that bananas contain something that mimics one of their alarm pheromones, which means that it turns them into a frenzy and hopefully they get in there and do a better cleaning job. Now we're not seeing a frenzy. We're just seeing happy bees going "Hmm. This is nice and sweet. It's a bit like honey." But let's see what happens over the coming months. What I'm gonna do now is put back on the excluder, put back on the top box. I'm gonna shake these bees in. If you want to get bees off something, you really gotta shake it with a vigorous shake. And that way, those bees won't get squashed. On top of there is going our honey super. So these can be heavy. This one isn't because it doesn't have a whole lot of honey. This hive is weak. So I can quite easily just pick that up. But if it is a bit hard for you to lift your super, then just get help from a friend when you need to lift it.

All we need to do now is put our roof back on and wait one month to know whether this banana thing is a myth or not. Of course it's only a test of one. So help us out there if you've got a hive with chalkbrood. At the beginning, we showed you what that looked like. Have a look here at all of these poor chalkbrood mummies that have gone down through the screen. It's a fungal infection. They ingest it. It can come from the bees, bringing it in from wherever they're foraging from, and it affects the larvae and turns them into a little chalky mummy when it goes brown and black that's when they're producing more spores. So we do need to clean that out so the spores don't end up reinfesting the hive. Any questions?

Chalkbrood Questions

You mentioned cleaning chalkbrood mummies out of the pest management tray. If you clean it, can you just wash it or do you have to do something more to actually kill the fungus in there?

Beekeepers will often burn frames that are infested with a lot of chalkbrood for the reason of really getting rid of that fungus. So it'd be a good idea if you have a fireplace or something like that, to scrape all of that chalk out into the fire, that way, you know, it's going to be burnt and not be hanging around producing spores for your bees.

Could you just cut the sections out that contain the chalkbrood in the brood frames?

I guess some beekeepers do get in there and pull out every chalkbrood they see, so that could be a good thing to do. Because when it's in the white phase, it hasn't actually produced its spores yet. It's a good idea to get rid of it before it's producing more spores, infecting more young larvae. The best defence against chalkbrood is a strong colony. So if we can get this colony back to some really good numbers, the chances are they'll look after the problem and it'll go away.

Do the bananas have to be ripe or does it matter?

I've never done this before so I don't know. In this case we used reasonably ripe ones and very ripe ones. But as time goes on in a day or so, they're going to get riper anyway. So they'll turn black, they'll be releasing a lot of ethylene, which is said to mix with oxygen, which is said to help with the chalkbrood as well. But all of this has not been scientifically proven. And with citizen science, hopefully we can get more answers and know whether it's helpful or not.

We had a chalkbrood infestation in our Classic Flow Hive. We reduced the amount of ventilation and the problem cleared up.

Oh, interesting. Some beekeepers would say the other way around, give your bees more ventilation to help dry out any moisture in their hive and that it would be better for chalkbrood. So whatever works for you. Beekeeping's a classic thing where almost thing people say is correct in a given situation. So it's a case of experimenting and find out what helps, what works. And the idea is whatever you're doing, you are trying to nurse your colonies back into being really productive and in good health, plenty of numbers. And that's what keeps most of the problems away.

How long would that chalkbrood have been in that tray for?

So it's been in there a month. We're a bit remiss to leave it that long because as those chalk mummies turn grey and black, that's when they're releasing more spores. So we really do need to get them out, clean that out, put it back in, and then we can also see how many mummies are falling through and get a bit of a measure of the level of infestation going forward.

We've had a lot of rain lately and bee numbers are down due to this rain. would the rain have caused more chalkbrood also? (Southeast Queensland, Australia)

I think certainly. There's two things that happen with the rain. One is a lot of moisture, which does tend to increase infestations of things like chalkbrood. And also it often washes the nectar out of the flowers. So we've had the paperbark flowering down here in the valley below, which is a great thing and the rain actually sets it off. But more rain washes the nectar right out of the flowers. And then the bees don't get to bring that nectar in. So it's been nice to have a few sunny days here where the bees can get out and forage. Yesterday afternoon, you could see the nectar all around the cells in the rear window view here, as they were drying out that nectar and condensing it and going through their amazing process of making honey. However, we do have more rain coming apparently tomorrow. We've had way too much rain, intense flooding disasters here in this area, which I've already told you about. So hopefully the rain doesn't last too long this time.

If you don't have a pest management tray should you open up the brood box to check for chalkbrood?

So if you don't have a pest management tray like that, then look at your landing board early in the morning. You can tell a lot from early in the morning, because that's when the undertakers are doing the job of bringing out the dead. Now here, it's already late in the day, the bees have all gotten up and done the job of removing dead chalkbrood that's sitting on the landing board. That's typically what they're trying to do, but because we've got a screened bottom board with fairly generous size orifices in it, those mummies have fallen right through into the tray, But in the morning you should see them also on the landing board. And if you're seeing that, then that's a sign of chalkbrood.

Is chalkbrood something that is also not just in Australia? Is it for all beekeepers?

I believe it's everywhere in the world, but I'm not sure. I suspect that the drier areas would have it a lot less often. And the more humid moist rainy areas would have more presence of it. It's a fungus and fungi like that moist damp environment.

Note: Chalkbrood has a wide distribution and is found on every continent.

Will you just leave this hive for a month? Or will you come back and check on it regularly?

I'll leave this to complete the experiment, leave it for a month and see if they will clean it out. Now there's a few reasons for that. One is you want the bananas to do their thing and gas off. And if the theory is about the ethelyne and the oxygen, then you want that to stay within the hive. So if you do have a cover and top with the plug in it, the inner cover, then leave that in place just to keep that ethylene inside the hive. Ethylene is the ripening gas that bananas emit and sometimes bananas are used to help other fruit ripen. And sometimes they'll use a synthetic ethylene to help ripen fruit in the supermarket chains,


Good old bananas! And Bianca who's on the camera today was telling me that she's been drinking banana tea.


Another interesting fact about bananas is they are radioactive. They tend to draw up radioactive potassium out of the ground. And there's a measurement, which is actually a banana worth. So if you get a measurement of radiation, one banana is actually a measurement of how much radiation from that radioactive potassium. Quite interesting, I've tested, I put a geiger counter right in a bunch of bananas and it definitely picks up a bit. So there's something new.

I recently saw a bee dragging a white larva out of the hive. Could the queen had killed a developing queen or was the bee maybe cleaning out a mummified chalkbrood? I think it was probably a queen, because it was so much bigger than the bee that was dragging it out.

That could be a case of supersedure, only once in my life have I seen the hive drag out the queen. So that's a rare and special moment. It also could be a drone, which are a bigger bee as well. So for all sorts of reasons, bees will drag larva out. Now, if it was squishy and kind of fresh jelly looking, then it's not chalkbrood, chalkbrood is very chalky and it's quite easy to tell. Whereas there could be some damaged larva that needs to be ejected from the hive. That damage could be caused by hive beetles, the larvae worm their way through the combs, damaging the brood and the bees will then eject those. It could be the hive got stressed for some reason. Sometimes you'll transport a hive a long way, and the bees will get stressed. And when you put the hive down, they'll eject larvae from the hive. In other countries, you have things like the deformed wing disease, which we don't get here luckily, but that could be a reason why young bees before they're fully formed are being ejected from the hive. And there's probably other reasons. So it's pretty normal and don't be alarmed unless it's on a massive scale. If you are looking for chalkbrood, then look for the chalky little lumps and mummies like we were showing you earlier.

Can chalkbrood wipe out your hive?

It tends to weaken your hive because all of those bees that died are bees that aren't able to do their job and the numbers get lessened, and it is a case of then the spores producing more and it goes downhill. And it's typically not the end of your hive, typically something else will take over, like the hive beetles at that point or some opportunistic pest that eventually is the demise of your colony.

Do you always have to put the bananas on top of the brood rather than on top of the super? Could you put them up in the roof cavity?

It's very experimental. So try and see what works for you. Now we could have done both. We could have put bananas up on top of the Flow Frames as well, but in this case we did an experiment where we're putting it directly on top of the brood nest. My thinking there was, that'll be nice and close to where the problem is. And hopefully cause a bit of a frenzy of that activity, bit of an alarm and the bees will get in there and clean out all of those chalkbrood cells and get rid of their spore load. And the hive will pick up numbers and then be able to deal with the problem.

So let's come back in a month and see whether it's fixed our problem or not. And if you have experience with this, let us know what woked for you. And if you do have chalkbrood, then please try it. Let's see if we can get some citizen science going and find out whether this is myth or whether it is true. Thank you very much for tuning in and let us know what you'd like us to cover in future live streams like this.

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