Right, Stacey, thank you very much indeed and good evening, everybody. And I'll just really just like to introduce you to what is possibly been the greatest disaster to hit, honey bees in, in really in recent years, and that is the Varroa mite. Which were determining rate to be the honey bee's enemy.
Just before we start, I thought I'd really just like to give you a little picture here of what we can consider to be honey bee and pollinator heaven. And this is, sort of open pasture, wildfi pasture. And this is really what an awful lot of the countryside used to look like, and really say since the war, we have lost 98% of wildlife and wildflower meadows in this country.
And unfortunately, it means that there's a huge loss of food and, for bees and other pollinators. It's a sobering thought. I'm going to just to take a few minutes to run through a little bit of basic, honeybee biology because there may be some in, in the audience who may be a little bit unfamiliar to, to how we look after bees in the modern world.
So any sort of experienced beekeeper there, please, please, bear, be patient with me and, and just bear with us. So here we have a modern beehive. Which at the bottom of the cur I'm showing is the, the base of the floor, and there's a tiny little gap just down here, and that's the entrance that the bees go in and out from.
And the box here at the bottom is slightly deeper than the rest. And this is known as the brood box. And this is where the queen lives.
And this is where all the eggs are laid and where all the bees are produced is in the brood box. There's a tiny little, the way you can see on your screen, a tiny little green line just here. And that is actually, it is a grill, it is known as a queen excluder, and it is a wire frame that only allows worker bees to come into the two top boxes here, which are known as supers.
The queen cannot get up through this, she's too big. And there's a very good reason for that is we only want her to lay her eggs in the brood box below, and the workers can then make honey for us above. And honey is actually deposited on these frames.
These are known as super frames. They're shallower than the frames that are actually in the brood box. And this is where honey is, is made, and this is where the beekeeper will take his crop from.
Show this again. This is actually just to show a little bit more in detail. Although this is a double reed box, you can see two red boxes here, and the frames that are in it.
The frames are actually wooden, and they have a thin, wax, what we call foundation, which is a start that we give to bees to help them to form the cells of which they will, both make bees and also make honey. If we didn't give them our foundation, they would still make this call, and, and it's a fascinating product really that they're able to do this with meticulous architectural accuracy. So we have this little frame here is the Queen.
So we can see it's like a wire mesh that only the queen or the queen cannot get through, but the workers can. So here we have some beekeepers trying to hive, and they're actually looking into the boot box here and you can see that the frame is bigger than the one we showed for the supers, and behind them here is the queen excluder and the super resting on a roof. And he's doing an inspection here, and the bees are certainly being very well behaved.
And also from the point of biosecurity, I think you will note that all the beekeepers here are on nice, fine, clean suits, which is what I like to see. So the occupants of the hive, there's 3. There's the workers, which make up the vast majority of the of the members of the hive.
Anything in and say by about early June time, there'll be anything from, say, 500 to 60,000 bees in a box and the hive, but there will still be only one queen. She is much bigger, much longer abdomen. Which I, which I'll explain the reason for that is because she lays a lot of eggs, and this is a male, this is a drone.
He has got much bigger eyes, and he has no sting, and he's much more muscles and a squatter, build. So if we go to the numbers within the hive, as I said, you can get up to 60,000 workers, and then still just one queen, and then the drones that say again about mid June, you'll have upwards of maybe about 2000 drones. And that is during the midseason in June time.
But in the winter, the numbers drop from workers it'll drop down to 10,000 or even lower. Still be one queen, but there's no drones. And by September time, the drones are thrown out of the nests by the workers to die.
That's their lot, I'm afraid. The only thing really that that they do is to relook for queens. So if we look at the queen, here we have a queen, the beekeeper is marked her, a lot of them are marked because they want to be able to find her easily.
And she has a much longer abdomen. She can lay, and the reason for that is that she will lay anything up to 2000 eggs a day again around late May into June, which is phenomenal. It's more than her body weight per day in eggs.
She can live for anything up to 3 to 5 years, and she produces this stuff called queen substance. You say, well, what is that? It is actually a pheromone that she produces in the glands, just behind her mandibles.
And she passes this out to the retinue of bees that are around her, and they use that substance, that pheromone to distribute that through all the bees in the hive. So in fact as they know that she is there and the, the pheromone then is the way that she keeps the actual hive and all the members of that hive cohesively together as one colony. It also has the effect of inhibiting the development of the ovaries and the of the ovaries in the worker bees.
So it suppresses that. So really all reproductive capacity is concentrated in her lung. When it comes to reproduction, say when if there's a swarm occurs and there are virgin queens emerge, they will fight to the death until there's only one queen left.
Workers. So they make up the vast majority of the of the bees in the hive. There is a difference between summer bees and winter bees.
Summer bees, which are the main, the ones who do all the work, they will in fact only live for 6 weeks, roughly 3 weeks in the hive, and then 3 weeks out foraging, and then they die. This the winter bees are the ones that look after the queen through the winter time. They have no brood to look after, so they do an awful lot less work.
So in fact they do live longer and will live anything up to 6 months. But physiologically, they are slightly different to the summer bees. Now, they do all the work inside and outside the hive.
And their duties are age-related. So whenever they initially emerge, they will spend some days cleaning out other cells ready for the queen to lay in. They then move on, they will start to feed the older larvae, and then as their glands develop and they start to be able to produce food for the larvae, they then start to feed the younger larvae.
And so on it goes, and as they get a little bit, maybe a week later on, they will then start to produce wax and become cone makers, and then very often coming up towards the 3 weeks, they will then do guard duty at the edge of the hive to ward off both bees from other hives, if they're not, if they're strangers to that hive, and also to keep out wasps and other insects and beekeepers. And their ovaries do not develop because of the influence of queen substance. Drones, drones are haploid.
They only have the the chromosomes of either queens or or workers, and this part is quite an involved reproductive system. But they developed by parthenogenesis, that is a completely unfertilized egg. There's no sperm involved, so in fact, drones do not have a father, they have a grandfather.
And that was, that's the way it works. It's quite a strange system. They're very strong fliers, they've got very good eyesight that you can possibly see from the size of their eyes.
They live up to 50 days because when they emerge about late April into May, they, they spend the summer in the hive and as I say, towards September, the workers throw them out because they are surplus requirements. They do not wish to feed them through the winter. Slightly longer antennae, and they die if they, the few that do actually manage to get to mate with a queen or a virgin queen, they unfortunately they, they die after the mating process because unfortunately, their sex organs are, are ripped off at the at the point of mating.
They learn to be food from the other workers, and they spend all their time just living off the rest of the workers. And they can move from colony to colony, which does have a bearing on disease. They, they, the guard bees do allow drones from other hives to come into their hive.
They, they don't seem to worry about them too much. The problem with that is, is that the drone is carrying the disease, it can then spread it from one colony to the next. Quickly run through what is a larval development here, which is to show the difference between the life cycle of the worker, the drone, and the queen.
So here we have at day one, we have a queen laying an egg, it stays an egg for about 3 days for all three of the casts and then becomes the larva. So if we take the worker here, coming up to say to day 8, and day 8, they then cap the cell. So larvae grows up very rapidly and will increase from here to here.
By a margin of about 2000 times. From and that is in in weight. And then from day, from here, from day 8, it's, it says cap, metamorphosis takes place and the adult emerged fully formed at day 21.
Now the same thing happens with drones, except they they cut the the sell a day later. And in fact, the drone's life cycle is 3 days longer. So in fact, it emerges at day 24.
Now you'll think there's not a huge difference here, but in fact, as I'll show you later, this is a huge effect on varroa mites, on their life cycle, because the varroa's mite life cycle is very intimately associated with the life cycle of, of the, honeybees. Queens have a slightly different one. They, they hang in a, in a vertical, cell, and I should actually point out that the cells, the drones, the workers actually although they're depicted here as being vertical, they actually are almost horizontal.
Anyway, the queen is a much shorter life cycle, and she will actually emerge by day 16. So much quicker development. So here we have a queen in the centre, surrounded by her court and these bees will be feeding her, grooming her, looking after she'll be laying, going around just laying eggs and cell to cell as I say up to 2000 a day, and they'll be constantly feeding her and looking after her.
Now, and, really what I would say if I could just go back to the previous slide, In this here, as you said, they have this retinue round and she and she's being looked after, . She's laying all these eggs a day, and at the same time they're, they're keeping her ground and she is passing out her queen substance to all of them. If I was to take her, if I was to go into the hive and take her out, she, the, the rest of the colony would know within 15 minutes that she was gone.
So that this transportation system of this pheromone, this green substance is very rapid to be spread around the colony. They put her back in again and everything will be fine again very quickly again because they will then know that she's returned. Right, here we have some eggs.
These are the eggs here and on the right side of the slide, sitting on the bottom of the cell. And then we can see here beautiful larvae. And we know these larvae are very, are very healthy because they are C-shaped.
They are like a glistening white colour, and they're segmented. If there's anything slightly different to that, then, you know, the beekeeper would see that there's a problem. And here's a very healthy comb, so a nice frame.
This is a brood frame, and you can see in the centre, this is all the covered brood, and it looks very healthy indeed. It's like a digestive biscuit colour. And then from round the edge of that, you can see that there is an area, another layer, and that is where the larvae and the eggs are before they're capped.
And another little area further out, you can see coloured cells, and that's the pollen. The bees are brought in the pollen and they're deposited in these cells here. And then this is honey, that's there for for stores.
So all the food, so the carbohydrate, and the, and the protein and certainly little bits of fat are all all close to hand. Honey is nectar that has been, said it had enzymes added to it, and the bees then reduce the water content from possibly anything up to 70% water down to 18%. And at that point they cap it over and that becomes honey.
So it's a super saturated solution of sugars, fructose and glucose, and it will keep forever. The pollen here, pollen is already protein and it would degenerate very quickly split into these cells, the bees actually add a little bit of, of, honey to it and they seal over the little areas and in fact the pollen. Like the same as grass and silages in a, in a silo, it's the same here.
The pollen, in fact, is preserved at a much lower pH. Like signage. Right, annual population through the year, it is, it is in fact as I say at the beginning of the year, the queen starts to lay eggs or she starts to lay here, but in fact, the, the population is still decreasing because the winter bees are still dying off.
But then as the queen starts to lay and broo starts to reproduce, so at this point then the population starts to increase because the new bees that season are starting to. To come through, into line as it were. Now, there's then during the springtime, there's this rapid increase both of the amount of brood and the amount of adults.
And so it comes up and it peaks and it comes up to this point. And then at this peak and then it starts to drop away. So by coming towards December, the population is dropping down to 10,000 or below.
The queen stops laying and so there's no more brood. So there's a period of time here in December and January that there is no brood, no covered brood, no nothing in the hive. And that in fact is an important part where the beekeeper will be able to attack the varroa mite, which I'll come to later.
So this is our Anyway, the Varroa mite. It's it is an arachnid. Same family as spiders and and really say other mites, hushto mites, all of those, and ticks.
Now it sucks hemolymph. Now hemolymph is the bee's blood. It's not red, it's more, looks like plasma, slightly straw coloured.
It does have cells in it but not red blood cells. Now, I've actually got a little sort of addition here to really say it sucks hemolymph. There is a a theory at the moment that perhaps forroa mites don't directly suck hemolymphs, that they actually suck fat bodies and this substance called fetalagemin.
Fat bodies are distributed all around the bee's body. They, they, in fact, the law that says it's fat, it's not adipose tissue. It is probably as close to it in human terms would be the liver.
It has a lot of functions, and certainly the fat bodies are different in summer bees than they are in winter. There's much more fat bodies in the winter bee. But it has an awful lot of this substance here called theogenin.
The telogenin is one of the storage sort of, substances, which is both, carbohydrate, fat and protein, all wrapped into one. Very, very important in, say in the development, say, of insects and also very important, for example, in eggs for birds. And, you know, it is quite a remarkable substance because it does have effects on the hormones of bees.
Anyway, the varroite also inject vast numbers of virus particles, and especially this one called deformed wing virus, DWV, deformed wing virus. And the varroa mite has actually jumped species from the eastern honeybee to the western honey bee. And that's where the problem has arisen.
So worldwide spread and there's a central factor really in all the sort of problems with bees at the present time. And in 2007, this particular the term was, was formed called colony collapse disorder, which was in fact to do with, varroa mites in United States with an awful lot of, they were causing an awful lot of trouble with, colonies and beekeepers were losing vast numbers of colonies and quite literally they go in, say a couple of weeks, the colony would look healthy, came back two weeks later, the colony had either absconded or most of the bees were dead. And all they were left with was a queen and some brood and a few workers.
And one thing that bees normally do not do, they do not leave the brood. The brood will be usually the last thing to be left, and this is what was happening in this particular event in America. It's happening to reported in other parts of the world, but I don't think it's a terribly good term, and, but it's one that that the media cottoned on to.
So the one we have here is called Varroa destructor. And really there are bees, that's the, western honey bees, which is called Apis mellifera. They have not, they have not formed, any resistance to this particular mite.
They've had a devastating effect and it's a combination of the viruses with the mites, the, so we mites itself has a much greater impact. And very often the effects are not that obvious until it's too late and the colony is collapsing. And really say one of the things they can look for very often is perforated cells and the what we call the, the bees have been trying to take out dead mites that might have been in the cells.
So the beekeeper has to really keep an eye on this and must monitor and control. So checking the bees and the other adult diseases. Acurine is another mite that affects the respiratory system of bees, which I'll not be getting into today.
But certainly I'll show you here some of the other viruses that can affect bees, between paralysis virus, which they just can't move, deform wing virus is the big one. Black queen cell virus that affect queen cells, can cause death at queens, cashmere bee virus is a bit like a a paralysis virus, and again, it's really acute paralysis virus. All different viruses unfortunately affect bees in different parts of the world.
But unfortunately, these viruses are spread all over. So, what has happened with Varroa? Well, the Varroa mite was originally a parasite of the eastern honey bee, and the eastern honeybee is known as Apis cerana.
And it is effectively the one that was always in the Far East, anywhere from Japan across to probably the borders of eastern India, and that was its domain, and it had this particular varroa mite that was known as Varroa Jacobsona. And it paras but over because of evolution, the The Apiserana was able, in fact, to resist the effects of varroa Jacobsoni. No.
It was there, but there were beekeepers in, in the Far East were were using Apis cerana for, for honey production for all various things. The problem was, is that the western honey bee, which is known as Apis mellifera. Is much more productive producing honey and was probably easier to, to keep than Apis cerana.
So what happened, of course, is that beekeepers took Colonies of western honey bees, Apis willlife across the far east to try and see if they could get more honey and so on and so forth. And what has happened, in fact, is that the Varroa mite, Varroa jacobsoni has jumped species to the western honey bee and has changed and has parasitized it and has been renamed then Varroa destructor. Anyway, to go back to the eastern honeybee, how did the eastern honeybee resist the effect of varroa jacobsoni?
Well, it had more hair, so it's harder for the mite to grip. It had a shorter life cycle, which is very important for the fecundity of the varroa mite. They were able to be able to groom them off because they were hairier, they could groom them off more easily.
And also the thing was is these particular mites only entered the drone pupa cells of Apis cerana. And the other thing, if the bees reckoned that there was a a varroa mite in a cell, they would in fact seal it and not allow it to be opened so that the mites would be entombed in the cell and would die off. Unfortunately, so did the pupa.
Western honeybee, Apis mellifera, it's got less hairs, longer worker and drone life cycle, and that could make a great difference. And the mites can enter both the worker and the drone cells, and the bees, unfortunately are unable very often to detect the mites in the cap cells. And also the mites mimic the exoskeleton chemical composition.
All to be. So to give you an idea of the worldwide spread, so about 1904, it was in Java and then as you can see as the years through the 20th century went on, it just gradually slowly. Went round the world.
OK. Until then, we came to 1992 and arrived in the United Kingdom. And as I say, eventually got to North Island in New Zealand and .
2000, but the only thing about it is so far in Australia, Varroa destructor has not arrived there. There is some concern is that colonies of Varroa or no of colonies of Apis cerana that were taken there, in fact, have taken Varroa jacobsona, but there does not seem to be Voda structure there yet. So this gives a worldwide distribution of where Varroa has got to in the last 100 years.
Right over all of North America and South America, most of Asia and into Europe, all of Europe, north part of Africa and southern Africa. Now, as you say, Australia has not been touched yet, but I do have a feeling that Varroa has maybe got into South Island, New Zealand since this map was done. You'd say, what about Central Africa?
Why is it not there? And the reason for that is, is that there is a subspecies of Apis mellifera. Which exists in this area very tropical.
It's called Apis mellifera scutilata. And it is a very aggressive bee that has a slightly shorter life cycle and also swarms very, very quickly. And you say, well, what difference should that make?
And the thing about it, shorter life cycle will make a difference, but also the fact that they swarm very very often because, swarming creates a break in the life cycle of the honey bee, and it will also cause a break in the development of the mite's life cycle and it interrupts it and will help to keep its numbers down. Apis, melliferousculata, by the way, was the subspecies that was taken to South America to see if they could improve it with the local, Apis manifera was there. Unfortunately, some idiot let them, let the queens out, and, they, have, caused havoc in there and they're known as the African killer bees because they swept their way up into America.
They're extremely aggressive and of course an awful lot of trouble. Right, so here we have mellifera Apis of Malifera pupa, and varroa mites on it. The thing about this is that the the sort of parasite to host ratio is probably one of the biggest in nature.
So if you consider, say, if a bee was the same size as a human, it's like having a crab the size of a dinner plate crawling over you and sucking your blood and injecting you with viruses. It's not pleasant. So again we're just showing.
Some mites here, and they, they can be there in large numbers. So if we go into the life cycle. The life cycle is intimately associated with that of the honey bee.
So we have a female varroa mites right here. She just before. The brood cell is capped, she nips into it.
And it seems to know that when it's going to be capped, we, we think it possibly, we think it possibly maybe is a, a pheromone that allows They allows them to know that their the cell is going to be capped the Varroite goes in, and she then goes down into what we call the brood food. And she stays there. It goes in up to 60 hours, it lays an egg.
The very first egg that we have goes through a protein and legitimate stage and becomes an adult male. The other thing that can then from then on, 30 hours after that, it lays another egg and it is a female, and she then continues to lay females every 30 hours, and they go through the proton lymph ju to nymph, an adult female, and then it comes to this point and then the adult male will mate with his sister. So as an infrared system.
It's an inbred system and so the bee would emerge and therefore, the original varroa mite female comes out along with daughter mites. OK, so we can get through this cycle again. Here we have a Varroa mite coming in.
It sits unfortunately in the brood food which is sitting underneath the larva. It actually turns itself upside down. And it immerses itself in the brood food, and it has a snorkel so as it can breathe.
The snorkel is called a peritrene, and it allows it to stay there and remain hidden from so the detection possibly of other bees. So then, Pierce the larval cuticle and start to suck the hemolyb or the fat bodies. And the interesting thing about it is Is that the wound that it makes with its mouth parts does not heal.
If I went into these cells here with a hypodermic needle and I inserted the hypodermic needle into these larvae or pupa. The wound would heal, but a varroa mites mouth, the, the piercing, wound that makes its mouth parts does not heal. So we have to say that the varroa then starts to lay eggs.
The first one is a male. The next ones are, are female, and then when they're mature, then the male mates with the sisters, and then at day 21, the worker emerges with the mites. OK?
Any mite that is not matured at that stage will just die off. So it's only mature mites that come out. And here they all are.
The family, the one here on the bottom left hand, oh sorry, bottom right hand corner is the male, and these other ones are the uniform female going up through protein nymph, juta nymph, and then immature adult and then the adult mite. Now, the, the thing about mites is that their population growth is can be exponential. So really what we do is we take a say we're down here at 10 mites, having a number of these cycles, the number of mites will only increase after up to from 10 mites up to here, which will come up about just less than 400 within 180 days.
Now, the threshold for what we're always trying to keep the the number of mites in the economy below is 1000. We want to keep it to 1000. If we can keep it at 1000, then the colony itself will not be in danger of collapsing.
But so you can see the difference here, if you've 100 mites. By the time it gets to 1000, we're actually up about just shy of 110, 115 days. And if it's longer, now that's say 200 miles, we hit the 1000 mark at about day 80.
It's much, much quicker, and that is important principle just to remember. So because really, say if we look back at our population curve of honeybees, once you get to this stage here, you've got an exponential rise in mites here. But you've got a decreasing number of bees here.
So in effect, the number of bees being infected increases dramatically during this part of the curve. Right, just to get an idea of how many mites can be involved here, and I think. You've got to get a little bit of imagination of this slide.
What we're actually looking here is a slide of open cells on one side of a frame. And there's any sort of eagle-eyed beekeepers in there, you will see that some of these cells have got eggs. So we're looking at one side and we're looking into eggs that's been recently laid, but we're seeing all these little red dots, and in fact, they are varroa mites that are at the bottom of cells on the other side of this frame.
And of course, because they're in cells, they will be capped. So I think you've just got to imagine we're not looking, they're looking at the varroa mites through the central partition. Between one side of a frame and the next, but you can see just how many mites are there.
Right, so here we have it, the worldwide distribution. Here we have a worker bee, and there's 123, and I think that there's 4 on here. And this is our lady with a varroa mite with scanning electron microscope.
So we take a closer look at her, OK, she's got a flattened crab shape that enables the mite to fit between the segments and the and the exoskeleton of the bee. Stiff ventral hairs prevents the removal from the bee. Also, as you say, they have this shape that you can burrow right down against the, against the bee.
So it's hard for the bee to groom them off because you would say, well, I mean, you know, how does the bee not know that there's this big thing there? Well, I'll be coming to that shortly, but you've got retractable, very suckers on their feet and these very fierce piercing mouth parts. But the big and amazing thing is there's chemical pattern of the bee of the mite's cuticle is similar to that of the honey bee.
So it's chemical camouflage. It's quite an amazing adaptation. So here we have Colony bees, and here we have a bee with a mite.
This is actually just known as a phoretic mite. In other words, it's one that's travelling on an adult bee. It's not confined to the cells.
It is moving on the bee. This is of course a bee that could move to another colony potentially and infected, or certainly if it was on a drone, it could go to another colony infected. But we have a pyretic.
Might on this bee. So why, why does the bee tolerate this? So, I'll try and explain this as simply as I can, but if you could have a look here.
This in fact is a like a chroma chromatography profile of the hydrocarbons that are in the cuticle of the bee. OK, so they're hydrocarbons are all really the oily waxy layer. There's all these long chain hydrocarbons, and this is a profile of what they are.
If you go and take a sample of the cuticle and the hydrochrobs and the cuticle of the varroa mite, this is what you get. And the profile looks very similar. So the problem really is, is that if the arroa mite.
Resembles this suchki, the bee, living in a dark world which it's relying on smells and mostly on smells, in fact, it does not detect the varromite. It doesn't know what's there. OK.
And to make it even more complicated in actual fact is that very often the, the cuticle profile, hydrocarbon profile on a forager B. It's different from that from a nursery within the colony. OK, so here's one of the horatic mites, just here, and then one in the nursery just here.
Now, to make it even again more complicated, the Profiles within bees in colony 1234 and 5 are all different as well. Now I think you can see, OK, they are certainly similar in some ways, but you can see somewhat to a greater level than others, and there are differences right through the whole number of profiles here. So there's differences in odour and that very often is how bees recognise is that a bee is from their colony because of the smells very often on the cuticle of their exoskeleton.
So, how does a mite do that? A mite comes in, say, a drone comes into the into the colony. It's got a particular smell, but the, the, the profile on the, on the forager is different from that in the hive.
So how does the mite get around this problem? So here we have it. Here we have a bee coming in.
It's got a Varroa mite on it, which has got a similar hydrocarbon profile. And here we have a pupa, and it is, if you look at the two, all the looks of it, there are quite considerable differences between the profile of the pupae here of the larvae here I should say, and the adult bee. And, and this is varroa mite that is on this particular pupa, a lot and or pupa, and indeed, it mimics.
The hydrocarbon profile of that pupa, and it's different from this one. So how does that occur? So, so when it's done, what speed does it do it at?
I'll try, try and show you this. So here we have profile of worker and a profile of a varromite. There we go.
Let me just, this is, and here we have the profile of a pupa. And The erroide within 20 minutes, you can start to see is the profile from this to this is starting to change. So it's becoming much more towards what the pupa is.
So there we have it. It's getting similar, an hour, and in fact this profile is getting more similar to this one again. I just have to keep going at this.
And after 3 hours, the profile here is pretty well the same as the pupa. Whereas it's now completely different from the profile that was in the worker bee. So this process starts in 20 minutes and is finished within 3 hours.
And that, how does it do that? And this was a vexed question of people didn't really quite understand how this happened. I mean, was it something to do with the cuticle, or in fact, was it something is that the varroa mite was getting something from the hemolymph or the fat bodies inside the, the bee that was allowing it to change the profile of its sexual.
After much experimentation, it proves that it's a lot simpler. It's done purely by touch in that the cuticle layer is very oily and there's a very oily layer on the arroite. Oils tend to attract one another, and it's merely a case of touch.
It's a passive process that enables the varroa mite to take on the The profile of the hydrocarbons on the cuticle of the bee, and therefore it becomes invisible to the bee. So they're really known as ghosts in the hive. So we can very quickly go through this again, the outer layer of the cuticus fatty waxy layer, .
The world, the bees live in this world of odours. The odour of the bee in each colony is different. Foragers and nurse bees and larvae all have different odours.
So the mite enter the colony on a forager moves to nurse bee, and then to larvae just from the cells capped. The mites are able to dic the hydrocarbons in the cuticle to match those of the bee or larvae, and so they therefore become undetectable to the bee. And this change, the critical chemical conditions can occur within 3 hours.
So if the bee does not recognise it, the mite is there, do not try to dislodge it. This is a common strategy among insects and arachnids, and there's a couple of examples of fire ant and the erasimo wasp and the bee wolf and the cuckoo wasp. Bee wolf is a solitary bee.
It lives in a little tunnel in the ground, and it is a solitary bee who will only We lay an egg and it gives the egg a provision. So whenever it develops into a larvae we'll eat that, but that's the only thing that the bee wolf will do. It'll stay around with the egg for a while protecting it, but the cuckoo wasp can come in, and the bee wolf will have lined the whole of the tunnel with her own cuticle hydrocarbons.
The cuckoo wasp comes in and nearly just rubs herself around the, around the, the lining of the of the tunnel and and effectively becomes invisible to the bee wolf. Very common strategy and but quite amazing. So here we have it, say we have a stranger bee coming in here with a varroa mite.
The Varroa might move over to the, well not a stranger, just maybe a forager comes in, the Varroa might moves then onto other a pupa or onto another nursey, and then becomes invisible and thereby becomes a ghost in the hive. Right, the next big thing really is to form wing virus. And as you can see, it's exactly what it says.
You can see the the wings on this bee are completely deformed. And this is due to to this virus, and really, this is a very sick bee. By the time you actually start to see that, it means that the virus level load in this bee is huge.
I think you might also see that it's actually got a stunted abdomen. These bees, when we see them, they will wander around the comb, they can't fly. They are also very weakened and very often they will die probably within a number of days if they're severely infected, or in fact they're really not much use to the colony at all because they can't really do very much work.
So, deformed wing virus, so prior to Varroa, Varroa, deformed wing virus was very rarely seen. And it really would have entered bees through the alimentary canal and very often in small numbers. So very often it was not a, a virus that was able to, manifest itself in clinical signs, very only very rarely.
The problem is that varroa mites inject these viruses into the bee in vast numbers, and therefore, it's a direct injection and therefore the virus has a field day. The larval on pupil development is affected. The viral load will affect performance and shorten the life expectancy and quite significantly at times.
So you say, well, that's it shortens a little bit. You're gonna be going to live 42 days, even if it's . Only loses a day or two, you think, oh well, does it make a difference, but whenever you multiply that those numbers in a hive, say 10 or 20,000 bees that have their life shortened by even a couple of days, that has a very significant effect on the colony.
OK, by the time you see the, the symptoms the form wing in a short abdomen, that shows a very heavy, colony load. It is something you know be careful with, but you start to see that you get, 00, we're gonna have to do something about varroa mites because it is, it means that the viral load within the whole colony is high, so I mean a lot of the bees may be sub-chemical. It can be transmitted both horizontally and vertically, and of course vectorally by the by the varoite.
And really DWV or deforming virus is now worldwide globally is very common, whereas before it was hardly seen at all. So here we have a few bees. Howard.
Here's a, a bee with a very heavy loads. There's 1234, possibly one under there, 5 and there could be ones underneath there, . She's holding her own.
Here is one here that's dead and shortened up. Here's one here, you think, oh well this, this bee has been broken in half, but in fact, it hasn't, it is dead. But You can see part of the abdomen here, it's abdomen has been so stunted, it's hardly there at all.
So these, these bees are not going to be a very good to colony, or much used to colony. So again, we're seeing the deformed wing. So how are we going to deal with this?
And we do say by by process work on integrated pest management. In other words, we try and do things which will keep on chipping away at the at the varroa mites population so as we keep it under control and to try and not allow it to get up over 1000 mites per colony. It's unfortunate because it's so intimately associated with the life cycle of the bee, unfortunately, it is, it is impossible then to eradicate varroa.
It just can't be done. So as I say, we want to get the number of mics down below 1000 and it requires good husbandry methods. We've got.
To then monitor the low levels and keep on doing, see what they are, and then if the levels start to get say above maybe a threshold of 1000, we have to do something about it. But in the meantime, what you're trying to do is keep on chipping away at the population to thwart this exponential growth in mice and try and keep it under control. Right, so there's a very different methods doing that.
Now, I'm going to try and just explain this is, is what the effect is, the difference between drone and worker brood. So if you have a robote going into a worker cell here, a female goes out and she starts to lay her eggs, the male first, then the females, and as you say, by the time that the That the adult emerges here at day 21. Although this depicts it shows two mites being surviving.
In fact, it's not, it's actually about 1.45. But one, so one female goes into the cell, she comes out again and with her comes out 1.45 more mites on average.
In the drone cell, the same thing, one female mic goes in, but in fact, when it gets down to here, lowest depicts 5 here, the answer is not, it's 4.15. On average, mites will come out with the mother mite.
OK. So those 3 days of extra, of, of the extra life cycle of the drone makes a huge difference to the survival rate of the number of Varroa mites that come out of the cell. So they have a umm have this predilection for drone cells.
They, they have a, they think it's a chemical or pheromonal thing that allows them to go to that, as I say, it probably is a pheromone, now we call it pheromone, but strictly speaking, it is what is called a caramone. A pheromone is a chemical that's produced by one organism that affects the behaviour or whatever of those members of the same species. A chiromone is one where a pheromone affects a different organism, and in this case, it's a varroa mite, so it's known as a chiromone.
Right, so the drone cycle is only 3 days longer than the worker yet. 1.4 mites comes out of the worker, 4.15 mites come out of the drone.
And when you multiply that, say, over 5 cycles, which could easily occur within one particular season of beekeeping season, you get an on average at the end of the season, 6.4 mites will come out of the worker cells, but 1230 mites out of the drum cells. So there's a huge advantage for the varroa mite to invade the drone cells.
Right, so these are just showing in various ways in which we try to reduce the varroa load. I'll not get into artificial swarm that maybe for another lecture sometime. I will touch on ship swarm.
That means that we change the bees from one box into another. We break the broo cycle of the honey bee, and we also then break the cycle of the varroa mite. Drone brood removal, I'll touch on that as well.
It's a way of trying to trap them in drone brood. Queen trapping won't touch. It's very complicated and hardly ever done.
An open mesh floor means that there's a floor below the actual colony. And if the bees are grooming and they do happen to knock a varroa mite off, instead of falling onto a solid floor, wooden floor at the bottom, and would have the ability to crawl back up onto the bees again, they fall out through a grid floor on through a mesh floor, further down, and they usually are then unable to get out of that again, and they will die. These are various, forms of, of, chemicals that we use.
Some are quite, quite harsh. Formic acid is very good, and we can use it at a time when the honey supers are on, so not contaminate the honey supers, but you will lose brood when you're using it, and it's quite difficult, difficult treatment. Thymol is extremely good.
But it can only be used when after we've taken the honey off, which is usually about late August, September. You can't use it when there's, honey supers there because it will taint the honey. It's quite smelly.
Oxalic acid. Is used. In fact, during that period that I mentioned earlier in December and in January, when there is no brood.
All the mites that will be in the winter cluster when bees cluster for the winter, all the mites that are there will be horetic mites, they will be on the adult bees. So in fact, it's a time that we can use axalic acid and it will kill the mites that are on the bees without killing the adults. They for all and Uistan were two forms of An insecticide called a fluvallamate.
Unfortunately, because they were used extensively when Varroa mites first arrived in the UK, unfortunately, the mites have built up resistance to these two particular insecticides, and at present time are not of the best of good value at all. So the part part of, of BQV is to keep them under control, keep your timings, keep an idea level of mites, getting below 1000. Me a few other things here.
There's one here called icing sugar. You thought, well, what is icing sugar got to do? And the idea is we sprinkle our bees very heavily with icing sugar, and they go into a very fierce grooming mode mode then to try and brush the icing sugar off their bodies and do sowing, they do dislodge some mites.
So it's not, you know, it's not the very best of methods, but at the same time, it reduces the number of mites are on the bee, and that's what we're trying to achieve. We're just trying to keep the levels down. A very new drug that's come in is in fact is Amitraz.
It's come in as a particular treatment and, there's a trade name for a substance called Amitraz 500. There is no one called Ativa and in fact, It has proved to be very good, and also insecticide, it seems to have, be seem to tolerate very high levels of it, but it is very good for killing Varroa mites. And so far, I think there's next to no sign of resistance developing to it.
Right, so, we have say bees are rising. They've arisen up to 1000 mite thresholds, so we apply a vario side and down the population drops. So how efficacious the treatment mod will depend on how quickly you're going to have to repeat it.
So if we have it here that we've that is extremely good, so it kills 99% of the mites, then the mite's ability to recover during that season. It's going to be very difficult. Right, so then we will not get to a very high level.
If there's a lot more, if it's not quite as efficacious, 100 might survive, then certainly then within. 50 to 100, so about another 110 days later, you will have to treat again. And then if it, if it's not as efficacious and and 200 survive, then where are we?
70 days, in a couple of months, you're gonna have to treat again. So it is very important that you've got to get a very efficacious product that's going to work, or do you just have to use it more frequently? This is a way of measuring how many mites you have.
It's called the sugar roll. So we take a quart jar, cut the lid out and a wire mesh in. We shake in some bees into a basin, and we pour the bees into the jar.
You can do this if you spray them lightly with water, they become subdued and you can put them then into the jar, and so you have about 300 bees. Then take a heat tablespoon of icing sugar into the jar and you roll it for about 30 seconds, let it rest and then you vigorously shake the jar over a white plate containing water. They The sugar will then go out along with the bees or the not the bees, with the mites that have been dislodged onto the water, the mites will float and you'll see them on the surface.
You can then return the bees alive to the colony, so they're not killed in this particular exercise. This again I was talking earlier about icing sugar, and this is what this beekeeper is doing. So he has a little grill or a sieve over his he's putting vast amounts of icing sugar over and dusting them down to dust the bees so as they go into a very vigorous grooming mode.
Drone removal is another way of of attacking it. And as I said, it goes to this thing, the Varroa prefers to lay in drone brood. It says there's a pheromone which attracts the romite to the drone, and so they will then tend to go into to that particular brood.
So what we do is we put in a shadow frame, the mites, go into that. And then when they're all sealed, we remove it. So here we have it, shallow frame.
He is they will naturally if you put this on the edge of the broo nest, they will naturally just do drone brood. And once those are all sealed, we then just cut that bit off and and discard it or feed it to chickens or whatever. We don't allow the the.
To hatch out because it'd be full of roms. We, well, we hope they'll be full of romites and certainly that way we're able to reduce the numbers in the house. So here we have it.
We're taking just a fork here previous slide, they've taken that drone brute, open it up, and you can see is that the level of drones or level of of romites on the drone pupa. And here we have it again, just showing drone brew with lots of raw mites around them and immature ones here. And this gives an idea of the numbers and if you have certain numbers at certain times of the year, then you have to take action.
So if you have more than 1 in 15, say, on the number of of drone pupa, then you would have to take measures to deal with it. So the chooks warm, I'm not gonna, this looks like quite a, a laver here, but effectively really it's the idea of finding the queen, but we take away the original blue box, the bees away and put a new brew box with all the new foundation in it, and, the idea of placing a queen suit at the bottom is not to allow the queen to abscond later on that she doesn't like the new box, but that's the whole idea because they're upset that it's not allow them get the chance to escape. But that is really how, how, how it is, done with through this particular process, and we'll show it here.
So here we have, they've moved the old box away and a new box with clean foundation has been placed here, and they're taking up a frame at the time from each of the box, shaking the bees into the new box. And then we're taking away this old frame and, and it'll be, well destroyed and or the watch be rendered and so on and so forth. Now you will use some brood on this, and this is done early in the season, so we tend not to use too much brood, but the idea is you have a break then in the life cycle of the bee, which also then will cause, a reduction in the number of mites because you get a break in their life cycle as well.
So here we have the bees, new foundation that bees can deal with, and they will build this up very quickly if this is done in early spring. So here we go. What are other possibilities?
What is the future of, of, treatment for varroa mites? How are we going to approach this whole worldwide problem. Now, there was some research done some years ago on fungi, enteropathogenic fungi, which would go into the hive, you'd encourage them to grow, and they will, in fact, not do the bees any harm, but these fungi will eat varroa mites, or they were parasite varo mites, destroy them.
There's a great deal of work on this in England, and unfortunately, it's like many things, the government pulled the plug on the research money and the research into it has dried up. They were certainly able to achieve very good results in the laboratory, and they were right on the, on the cusp of being able to develop something for the for the field for for beekeepers to use, and unfortunately, it all stopped. There are some other little creatures called pseudoscorpions, which will go into a hive.
You can put it into a hive, they won't do the bees any harm, but again, they eat Varroa mites. The problem with is that your varo mite level has to be quite high, for the pseudo scorpions to be able to survive. So unfortunately, it's one of these sort of things, it's a balancing act, and unfortunately they've never really taken off.
There is the idea of hygienic behaviour. There are bees that are able to recognise is that there is a problem in a cell, possibly the varroa m, possibly something that the that the pupa is giving off, that means that it's infected and therefore, the bees themselves will in fact open the hive and pull out and get rid of that particular pupa and thereby disrupting the life cycle of the varoomite and then dying. RNA interference, again, RNA interference is really where, A method is done where the RNA messenger is changed slightly.
So in fact, it produces a rogue protein, and the rogue protein that then could render, mean that the the fero mite would die. Now people that instantly turn around and say, oh, that's genetic engineering. Well, it's not, it is genetic engineering and such, but it's done in nature.
It's a purely natural process that happens, in all sorts of situations in other, in other systems. And so it, it is not genetic engineering, it's done by man, it's genetic engineering done by nature. And there is a merit in this.
The mice to be able to, they, they only used to be able to do it by injecting for all mites, which is not a very easy thing to do. But in fact they've now found a method of being able to feed them, the rogue messenger RNA and it will in fact causes change. So, you have those sort of things they're still in the pipeline.
The other thing though what's happening. In some way is that bees are starting to develop their own strategies of dealing with rom mites, such as some bees are seem to be biting the mite's legs off. And then also local bee resistance.
There is a beekeeper in the middle of England Swindon, I think he was, and he bred bees that were resistant. To aromites, and he certainly was able to prove that he had, bees that did not succumb to arromides. They were there, but they didn't seem to be causing his bees any harm whatsoever.
And I think the number, he seemed to be able to get the numbers down, thought, wow, he's got the resistance, the bees are resistant to romites. The problem was that whenever they took his bees, moved it to another part of the country, they unfortunately succumbed to romites. So the problem is, What, what is the reason for this?
And it would appear that there are certain places in the world where this phenomenon occurs. You should get local bee resistance. And apparently I've been told there's about half a dozen areas around the world where this happens, and the scientists are trying to figure out what it is that's causing it.
But it does seem to be. In a localised area. The other thing is whether feral bees are recovering because we're all mites totally devastated the feral bee population around the world.
A lot of the colonies just died out and that there are signs now certainly some of the feral coloies are starting to recover and being found in areas where they, they thought they'd completely lost. It is fair to say that there are still areas, area small areas, in the work of romites have not got to. Certainly, for example, the Isle of Man, the beekeepers there, got together and in fact do not allow imports of, of bees.
To the Isle of Man, and in fact, so far they've managed to keep their all nights out. There would also be some, islands off the coast of Scotland and also little valleys in County Donegal in Ireland with the same thing as occurred. So there are, there is hope for the future here.
That was a pseudo scorpion. And really a summary here is that the Varroaite jump species. Apis mellifera has little resistance.
Varroa is a factor for viruses expected to form wing virus, and Apis mellifera life cycle favours the varroa mite, and the worldwide spread was helped by beekeepers and white beekeepers a lot charge of this, and unfortunately it's it's impossible to eradicate. Right, so the British Bee Veterinary Association, as we said, we're doing our best to make everybody aware of bees and their problems. We would like to point out we'd like to make your practise bee friendly by joining the bee friendly, practise scheme.
Contact our secretary John Dixon, and the secretary of the British bee vets. And the website is there. I can thank Steve Martin and Meg Seymour for some of the slides, and any questions?
I'm sorry I've run over time. I do apologise, and I also apologise for the telephone in the middle middle of the, presentation. Oh, we'll let you off this time, John.
We've actually had a comment from someone who a few people may have heard of, Anthony Chadwick saying that he thought it was a very cool ringtone. Yeah. Thank you very much for your webinar, John.
I'm sure everyone watching the webinar found it very useful. And just before we go to questions, if I could ask attendees, if you can spare 30 seconds to complete the feedback survey that should have popped up in a new tab in your browser, we'd be really grateful, as I am pretty sure that everyone is aware that I'm a massive feedback nerd. I'm proud, so it's all very helpful.
As I know from reading some of your feedback, depending on which device you're using to watch the webinar, the survey doesn't always pop up. So if that's the case for you, please feel free to email me using the email address, Stacey at the webinar vet.com, and I spell Stacey S T A C E Y.
OK, John, so we've got some questions coming in. Anthony would like to know what does John think of the nicoinoid ban? Yes, now there's a big, that's always a subject for another web.
It is a very vexed problem and in fact, the British Bee Veterinary Association has not got a policy on this yet because they've been waiting for good scientific proof one way or the other. It is a little bit of a, of a, a difficult thing, in as much as there is concern, certainly is that, neonicotinoids will be having an effect, say, Not just perhaps on honeybees, particularly, but also on solitary bees and bumblebees. And that is of great concern because for example, in the UK we've got about 230 species of solitary bee, and you probably never see, you probably see them, you don't realise that they're there.
But between them and bumblebees and moths and hoverflies, they actually make up about 50%, nearly 50% of the pollinator force, honeybees make up the rest. Now, the, the problem with neonicotinoids is that they're there, the, the bees are certainly possibly do get a dose of them whenever they're sucking up nectar that unfortunately is contaminated with them by the neonicotinoids, and they're either potentially interfering with their nervous system, which means they can't navigate their way back to the hive. Because a colony has a huge number of bees, that's so was if some are lost, maybe they can withstand that.
But that's not really the point. They shouldn't have to, to deal with it at all. And also neither should the solitary bees, and we're not sure what effect, say, neonicotinoids are having on the micro microflora of the, not flora microhabitat of the soil and anywhere else and watercourses.
Trouble is, if we want to produce food, and we want to like oil seed rate to develop without the, without the flea beetle affecting it, then unfortunately you have to use them. And I think it is going to have to come down to an integrated approach, in as much as there will have to be areas, it'll be targeted areas where you would say use neonicotinoids, . But also then to have areas say round fields which will allow them to go back to like that photograph I showed at the very beginning of wildflower meadows, we'll have to look at all other areas, say the edges of motorways and so forth, can we make them into wildflower meadows, all of that.
We've got to provide food for bees and OK, if there's going to be areas that are used for crop production. Use them, but have other areas in which the bees themselves and the pollinators can thrive without neonicotinoids contaminated. Does that answer the question?
I think it's a very comprehensive answer. Thank you very much, John. A second question, from Sophie, should vets and nurses be encouraging good be husbandry, and how can we do this?
I think absolutely, yes. I mean, OK, you're not going to many, say, clients coming in with a, with a, with a sick bee. One thing that you can do and what really is what our bee friendly scheme is about would encourage everyone to sow wild flowers, and there's areas around every practise in this country where people could sow.
Seeds to make flowers to produce food for bees and other pollinators. And it's the same if it's a city, practise, you've got window boxes, or any little, if you're on any practise at all and there's any little bit of ground around them, please sow them out in seeds. It could be the the nicest flowers that you want.
You'd want ones that will be bee friendly. because unfortunately there's an awful lot of, garden centre flowers which are not conducive to bees, especially double flowers like begoniia and so forth. Unfortunately they, they're of no value to them, because they can't get into them, .
But certainly it is the one scheme that we're trying to promote, to try and make every practise in the, in the country be friendly. And certainly if you join a scheme, we can send you, some marketing material to window stickers and information and so forth to help make your practise be friendly. Brilliant.
Thank you, John. Just to round up, we've got a couple of comments, high praise indeed from Jeffrey saying, extremely interesting webinar, brilliant, brilliantly presented. Many thanks.
And Tim has also said, superb webinar, excellent. Explanations, one of the best. Thank you.
A round of applause. Thank you to everyone who attended the live webinar. It's always great to have your company and also for providing feedback on the webinar.
And finally, I'd like to thank Jess and Sophie for co-hosting with me on the webinar this evening. I hope to see you on another webinar soon, and I hope everyone enjoys the rest of the day. Thanks, everyone, and bye.