Category Archives: Practice

Queen introduction

I’m probably less qualified to write about queen introduction than almost any other aspect of beekeeping. This is not because I’ve not introduced any queens. Quite the opposite, it’s something I do more or less routinely many times a season. 

The reason(s) I’m really not qualified to discuss the topic are:

  • I almost exclusively use the method I first used and I’ve not done any side-by-side comparisons with other methods to determine which work ‘best’. I have a method that works well enough i.e. somewhere between most of the time and almost always. That’s good enough for me.
  • I’m not aware of any recent scientific studies on the subject so cannot use those to make informed decisions – or interpretations – of why some methods work and others don’t 1.

Nevertheless, not being qualified has never stopped me before 2 and it’s a topic that some beekeepers struggle with and many beekeepers worry about.

Successful introduction ...

Successful introduction …

So here goes …

Art or science?

David Cushman/Roger Patterson make the point that: 

” … you can have two colonies in the same condition, in the same apiary, on the same day and if you introduce a queen in the same condition into each, one will succeed and the other will fail.”

This doesn’t mean that 50% of introductions fail (although it reads that way). What he/they mean is that there appears to be no rhyme or reason why one succeeds and the other does not.

On another day, both might succeed … or both might fail 🙁

Is it therefore an art or a science?

I don’t know. All you can do is get the basics correct and cross your fingers …

For understandable reasons, beekeepers feel rather precious about their queens. In particular, beekeepers who do not rear their own queens (and so have no spares waiting in the wings) can get a bit paranoid about queen introduction. 

What if it goes wrong?

The colony will potentially be left irretrievably queenless and – if you purchased the queen – you’ll be £40 out-of-pocket 3.

If you do rear your own queens you can perhaps be a bit more blasé about queen introductions. Potentially you can also do the sort of side-by-side comparisons I mentioned above … though there aren’t many studies where this has been done in a rigorous way. 

Most seem to find a method that works for them and then stick with it … which is what I’ve done and what I’m going to describe.

This is what I mean by ‘get the basics correct’.

I’ll also mention an alternate method I irregularly use for what I consider to be really difficult situations and/or really valuable queens.

But before we get into the methodology, it’s worth making some general comments about the state of the recipient colony and the queen being introduced.

Is the colony really queenless?

Trying to introduce a new queen into a colony that is not actually queenless will not end well.

One or both of the queens will probably not survive the experience. Either the workers will reject (and slaughter) the incoming queen, or the queens will fight and may both be damaged and lost.

It is therefore important that the recipient colony is queenless.

By queenless I mean that there is no queen present.

I do not mean no laying queen present. If you try and introduce a new queen into a colony with a failed (non laying) queen or a virgin (unmated) queen you will have problems.

Sod’s Law is explicit in these instances … the valuable new mated laying queen will be lost 🙁

Queen above the QE

A virgin queen (in this instance on the wrong side of the queen excluder)

The very best way to be sure the colony is queenless is to remove the current queen before introducing the new one. That necessitates finding the queen in the first place. 

What if you can’t find the queen but you’re sure that the colony is queenless?

Well, there are only two possibilities if you can’t find the queen, these are:

  1. The colony is queenless … you’re good to go.
  2. The colony is not queenless … but you’ve looked so hard for so long they’re now disturbed and running manically around the frames, getting more and more agitated and angry. Neither the bees or you are any sort of state to allow the queen to be discovered. Close the hive up. Have a cup of tea. Try again tomorrow.

I discussed methods of determining whether the colony is queenright (though not by extrapolation, the opposite i.e. queenless – see below) last season. Towards the end of that post I described the addition of a ‘frame of eggs’ to determine if the colony is queenright or not. I won’t repeat all the details here.

If the colony draw queen cells on the introduced frame then you can be sure that the colony is queenless. See (1) above … you’re good to go 🙂

Not queenless, but not queenright

That same post describes the concepts of queenright and queenless.

A colony that is queenright has a mated queen capable of laying fertilised eggs (though she may temporarily not be laying, for example due to a dearth of nectar).

A queenless colony contains no queen.

But there’s an intermediate stage … or potentially two intermediate stages if you allow me a little leeway.

A colony containing a failed queen that’s either not laying at all (and not going to restart), or only laying drone (unfertilised) eggs is neither queenright not queenless. This colony will not draw queen cells on the introduced frame. You cannot safely introduce a new queen into such a colony before first finding and removing the failed queen.

A colony containing laying workers will also not 4 produce queen cells from the introduced frame of eggs. 

Laying workers ...

Laying workers …

A colony with laying workers behaves as though it’s queenright but is actually queenless. It’s not really an intermediate stage, but the consequences are the same. Again, they are highly unlikely to accept an introduced queen.

Deal with the laying workers first and then requeen … and good luck, laying workers can be a nightmare 🙁

OK … let’s assume the colony really is queenless … what’s the easiest way to introduce a new queen?

Add a sealed queen cell

Almost without exception, a queenless colony can be requeened by adding a sealed queen cell. The virgin queen will emerge, go on one or two mating flights and return and head the colony. This method of queen introduction is almost foolproof in my experience. 

Where do you get the queen cell from? Another colony, your mentor, a friend in your beekeeping association, a local queen rearer … necessity is the mother of invention 5.

Assuming the cell is a natural queen cell … cut the queen cell out of the comb with a generous amount of surrounding comb. Don’t risk damaging the queen cell. Keep it vertical … there are stages during development when the pupa is susceptible to damage. Ideally choose and use a cell 24-48 hours from emergence as they’re a lot more robust late in the development cycle.

Use your thumb to make an indentation towards the top of a frame near the centre of the broodnest, above some capped and emerging brood. Using the generous ‘edge’ of comb surrounding your chosen queen cell push this into the indentation so the cell is secure. Close up the colony and a) check for emergence in 48 hours or so 6 and b) a fortnight later for successful mating.

Adding a grafted queen to a colony

If the cell is from a grafted larvae it is even easier … press the plastic cell cup holder into the comb and push the frames together. I describe this in a recent discussion of grafting.

How successful is this method of ‘queen’ introduction?

I’d estimate at least 85%.

A very small percentage of queen cells fail to emerge (or rather, the queen fails to emerge from the cell … but you knew what I meant 😉 ).

A slightly larger percentage of queens fail to mate (or fail to return from a mating flight). But, even in a bad season, it’s rarely more than 10-15%.

The new queen is accepted by the colony because she emerged there and they all live happily ever after 😉 .

What?

I know, I know … that’s not really queen introduction.

You’re right. But it works. Very well.

These are the two methods I use for queen introduction.

Candy-plugged queen cage

I have a large supply 7 of JzBz queen introduction and shipping cages. 

JzBz queen cages

JzBz queen cages

I really like them because they were free they are reusable, they have a tube-like entrance that can be plugged with candy/fondant and they have a central region to protect the queen from aggressive workers outside the cage. 

Some cages offer no areas of refuge for the queen and workers can damage the queen through the perforations. Avoid cages that are all perforations.

The JzBz cages can be purchased with a removable plastic cap (shown below the cage in the image). These fit over the end of the tube and can seal the cage until you judge the colony is likely to gracefully receive the new queen … as described below 8.

JzBz queen introduction and shipping cage

Using a JzBz cage for queen introduction:

  • Plug the tube of the JzBz cage with queen candy or fondant. Queen candy can be purchased commercially and kept frozen for long periods. I almost always use fondant these days as I have spare boxes of the stuff from autumn feeding.
  • Add a short piece of wire or a cocktail stick through the perforations at one end of the cage to hang the cage – entrance tube pointing downwards – between two frames. Do this before adding the queen to avoid risking skewering the queen at a later stage 9
  • Place the queen in the cage without any attendants (see below for comments on removing them). Close and seal the cage. Seal the candy tube with the plastic cap.
  • Hang the cage in the centre of the broodnest, above some emerging brood. Leave the colony for 24 hours.

The idea here is that the colony gets the chance to accept the new queen without getting the opportunity to slaughter her.

Look for signs of aggression

Colonies that have been queenless for a few hours (say 2-24) before adding the new queen are usually very willing to accept a replacement. Adding a queen immediately after removing the old queen is likely to result in some aggression to the caged queen.

Check the colony after 24 hours. I usually lift the cage out and place it gently on the top bars to observe the interaction of the workers and the queen.

Checking for aggression

If the colony show no aggression to the caged queen – look for bees trying to sting through the cage or biting at the cage – then remove the plastic cap and re-hang the cage between the frames.

If they show aggression leave them another 24 hours and check again 10

Once you remove the cap the queen will be released by the workers after they eat through the candy/fondant. This takes just a few hours. 

Check again a week later to ensure the colony has accepted the queen.

Nicot introduction cage

I use the method described above for almost every queen I introduce. 

The only exception is if I have to requeen a colony that has previously not accepted a queen using the method described above. Usually such a colony will also be broodless (just based on the timings of determining they are queenless and failing once to successfully introduce a queen). 

Under these circumstances I use a Nicot queen introduction cage.

Nicot queen introduction cages

I find a frame from another colony with a hand-sized patch of emerging brood. The comb needs to be level so that the cage can sit on top without gaps for the queen to escape.

Then do the following:

  1. Remove all the bees from the frame and place the Nicot cage over the brood using the short plastic ‘legs’ to hold it into the comb 11.
  2. Secure the cage in place using one or two elastic bands.
  3. Introduce the queen through the removable – and eminently losable 12 – door.

In practice it’s easier to do this in the order 3-1-2 … place the queen on the frame, cover with the cage and then secure it with the elastic band.

Add the frame and cage to the hive, locating it centrally. Push the frames together. 

The emerging workers will immediately accept the queen and feed her. Other workers will feed the queen through the edges of the cage.

One corner of the cage has an entrance tunnel that can be filled with candy/fondant. I don’t think I’ve ever used this. In my experience the colony releases the queen by burrowing under one edge of the cage after a few days. If they don’t, check and remove the cage a week later.

I don’t think I’ve ever failed to successfully introduce a queen using one of these cages, but it’s a relatively small sample size.

Thorne’s sell a metal mesh version of this cage that has integral ‘legs’. I’ve not used it, but the principle is the same. Keep it in a box or the sharp cut metal edges will butcher your fingers – it’s difficult picking up queens with heavily bandaged digits.

You could also ‘fold’ your own from mesh floor material. One with deeper ‘sides’ could be pushed down to the midrib of the comb, so reducing the chances of the bees burrowing under the edge of the cage.

Mated or virgin? 

I use the JzBz cage for introducing either mated or virgin queens. I’m not aware of any significant difference in the acceptance rate between them. 

However, it’s worth noting that acceptance is dependent upon essentially ‘matching’ the expectations of the colony with the state of the queen. 

A virgin queen will be less likely to be accepted by a colony from which a mated laying queen has recently been removed. Leave them 24-48 hours. 

Likewise, I remove nearly mature queen cells from a colony I’m requeening with a mated queen. I don’t want to risk an early-emerged virgin queen from ‘raining on the parade’ of the introduced queen.

I’ve only used the Nicot cage for mated queens. Since the latter is usually used for a broodless colony I want the minimum possible delay before there is new brood in the colony.

Alone or with attendants?

If you purchase a queen and receive her by post there will be a few workers caged with her.

I always remove these although some suggest that they do not adversely influence acceptance rates 13. I remove them because I’m a bit paranoid about viruses … these workers come from an ‘unknown’ hive (quite possibly not the same one that the queen came from) and will carry a potentially novel range of Deformed wing virus variants (and possibly others as well).

I don’t want these in my hive so I remove the workers

It’s also worth noting that Wyatt Mangum has an interesting report in American Bee Journal indicating that the presence of attendants significantly increases the acceptance time 14 for an introduced queen 15. In some cases the presence of attendants resulted in the colony showing aggression for longer than it took for the bees to eat through the candy plug … that’s not going to end well for the queen.

The safest way to remove attendants is to open the caged queen in a dim room with a single closed window. The bees will fly to the window (perhaps with a little encouragement).

A mated queen probably will not fly at all and can be re-caged. A virgin queen can fly well and will also end up at the window. Gently grab her by her wings and re-cage her.

You can do all this in the apiary … it requires confidence and dexterity. I know this because I recently tried it with a virgin queen in my apiary, using lashings of overconfidence and hamfistedness.

She flew away 🙁

Inevitably you can buy a gadget to help you with this – the queen muff

Conclusions

There is always a slight risk that queen introductions will not be successful. The queen pheromones have such a fundamental role in colony maintenance that disrupting them – or suddenly changing them – may lead to rejection. 

However, the methods described above are sufficiently successful that I’ve not found the need to look for better alternatives. They’re also sufficiently fast that I’m not tempted to try some of the ‘quick and dirty’ approaches 16 to save time.

Finally, it’s worth noting that it is usually easier to requeen a nucleus colony than a full hive. If I ever bought one of those €500 breeder queens I’d introduce her to a nuc first and then unite the nuc back with the original colony.

But that’s not going to happen 😉


 

DIY queen cell incubator

You can please some of the people all of the time, you can please all of the people some of the time, but you can’t please all of the people all of the time … so said John Lydgate (1370-1450).

And he wasn’t wrong.

This is something I’m particularly aware of writing a weekly post on beekeeping. Much like my talks to beekeeping associations, the ‘audience’ (in this case the readership) ranges from the outright beginner to those with way more experience than me.

An article, like the one last week, on transporting your first nuc home and transferring it to a new hive, is unlikely to be of much interest to an experienced beekeeper.

Conversely, a post on something esoteric – like Royal patrilines and hyperpolyandry – is probably going to be given a wide berth by someone who has recently started beekeeping 1.

There’s no way I can write something relevant, interesting and topical for the entire breadth of experience of the readers 2

Going by the popularity of certain posts it’s clear that many readers are relatively inexperienced beekeepers.

The post entitled Queen cells … don’t panic! contains little someone who has kept bees for five years doesn’t or shouldn’t already know 3. Nevertheless, it is one of the most popular pages over the last couple of years. It has already been read more times this year than all previous years 4.

I suspect the majority of these thousands of viewings are from new(ish) beekeepers.

If you’re in this group then I suggest you look away now 😉 5

I’m going to discuss a pretty focused and specialised topic of relevance to perhaps a fraction of 10% of all beekeepers

The 10%

When I started beekeeping I was certain I would never be interested in queen rearing.

In fact I was so certain that, when repeatedly re-reading Ted Hooper’s book Bees and Honey, I’d skip the chapter on queen rearing all together. 

By ‘queen rearing’ I mean larval selection, grafting, cell raisers, cell finishers, mini-nucs, drone flooding etc. 

Queen cells from grafted larvae … what a palaver!

What a palaver!

All I wanted was a few jars of honey.

Oh yes, and slightly better tempered bees.

And perhaps a nuc to overwinter ‘just in case’.

What about a queen or two ‘spare’ for those swarms I miss?

A year or two later I had the opportunity – through the generosity of the late Terry Clare – to learn the basics of queen rearing and grafting

A week later I had a go on my own.

Amazingly (though not if you consider the tuition) it worked 🙂 . I successfully reared queens from larvae I’d selected, transferred, produced as capped cells and eventually got mated.

It was probably the single most significant event in my experience as a beekeeper. I got my nuc to overwinter and I’ve gradually improved my bees through selecting from the best and requeening the worst. I know how to produce ‘spare’ queens, though need them less frequently as my swarm control has also improved 😉  6

I don’t know what proportion of beekeepers ‘actively’ rear their own queens. I suspect it’s 10% or less.

But even that select group aren’t the target audience for this post.

The target audience are queen rearers who need to incubate queens or queen cells for protracted periods (hours to days) without constant access to mains electricity.

Let me explain

The peripatetic beekeeper

I live on the remote west coast of Scotland 7 but keep the majority of my bees in Fife. 

My apiaries in Fife are 30-40 minutes apart, and I drive past one on my way to my main apiary (in St Andrews). If I need a ‘spare’ queen in an out apiary (and have one in St Andrews) it adds over an hour to what is already a four hour beekeeping commute.

That’s an hour of my life I’ll never get back and something I’d really like to avoid 8.

On the west coast beekeepers and bees are very thin on the ground. I’ve just started queen rearing here and (again) have a 45 minute commute between apiaries 9. I’m working with another beekeeper and larvae are sourced from one and the cells are raised in another.

You can move frames of larvae about if you keep them warm and humid – a damp tea towel works well – at least if the times/distances are not too great.

But there’s an added complication … this area is Varroa free and I don’t want to be moving potentially mite-infested frames into the area. Nor do I want to deplete any of the donor colonies of brood frames.

All I want to move are a few larvae … but they’re a lot more fragile and sensitive.

So … two slightly unusual situations.

It seemed to me that my life would be a lot easier if I had some sort of portable queen and queen cell incubator.

My trusty honey warming cabinet

More than most events in beekeeping, the timing of the various stages of queen rearing is very clearly defined. You graft day old larvae and use the cells 10 days later. This timing currently defines the dates of my trips … except that sometimes there are diary clashes.

If my apiary with the cell raising colony was a mile away I could just go later in the day. 

But it’s not … 🙁

Before I started this (temporary) life as a travelling beekeeper I’d sometimes needed to incubate queen cells that were near to emergence. Once the cell is capped you can put it in an incubator, either until you use it as a capped cell, or until the virgin queen emerges. You then requeen a colony using the recently emerged virgin queen.

This was clearly another option to make the diary clashes less of an issue – raise the cells and then incubate them (outside the hive) until emergence, and then use the queens.

I’d already used my trusty honey warming cabinet to incubate queen cells. When I built this I used an Ecostat chicken egg incubator element rather than a 100 W incandescent bulb. The Ecostat heaters are thermostatically controlled and do a pretty good job of maintaining a stable temperature, anywhere between the high 20’s (°C) and about 55°C.

A day in the life of my honey warming cabinet (click for explanation of fluctuations)

There were two minor issues … the incubator needed a 240 V mains supply and was about the size of my car 10.

Honey warming cabinet. The Apiarist

Honey warming cabinet …

However, it’s perfect if you need to incubate 800 queen cells at once 😉

What I needed was a smaller, more portable, ‘battery’ – or at least 12V – powered version … 11

Beekeepers have short arms and deep pockets

One obvious solutions was to use a commercially available hen egg incubator. Brinsea are one of the market leaders and I know several beekeepers who use them as queen cell incubators. 

Although they are usually mains powered, they actually have an integral transformer and run at 12V, so could be powered from a car cigarette lighter socket. Temperature and humidity are controlled. They start at about £80 and would need modifying to accommodate queen cells, or Nicot cages containing queens.

The beekeeping-specific commercial solution is the Carricell.

Carricell queen cell incubator

These are manufactured in New Zealand in three sizes – for 40, 70 or 144 queen cells. Swienty (and presumably others) sell the 70 cell variant 12 over here for €636 13.

Excluding VAT 🙁

Beekeepers are notoriously commendably parsimonious. Since I have an alter ego named Dr. Bodgit, it seemed logical to try and build my own.

For a little less that €636 …

And ideally less than £80 😉

But first I needed to know more about the influence of temperature on queen cell development.

Temperature and development

The usual temperature quoted for the broodnest is about 35°C. Numerous studies have shown that, although the temperature is never constant, it is always in the range 33-36°C 14

It is reasonably well known that temperature can influence the development time of honey bees. At lower temperatures, development takes a little bit longer.

More significantly, Jürgen Tautz and colleagues showed almost two decades ago that honey bee workers reared (as pupae) at low temperatures have behavioural deficiencies 15.

For example, workers reared at 32°C showed reduced waggle dance activity when compared to bees reared at 36°C. Not only were they less likely to dance to advertise a particular nectar source, but they would dance less enthusiastically, performing fewer dance circuits.

In tests of learning and memory – for example associating smells with syrup rewards – bees reared as pupae at 32°C were also impaired when compared to bees reared at 36°C.

Tautz also demonstrated that bees reared at the lower temperature were more likely to go ‘missing in action’. They disappeared at a faster rate from the hive than the bees reared at the higher temperature. This strongly suggests their compromised memory or learning also had a negative influence on their survival. For example, in predator evasion, flight duration or the ability to find the hive.

OK … so temperature is really rather important for worker development.

Perhaps very accurate thermostatic control will be needed?

But what about queens?

There are good reasons to think that queen development might not be quite as sensitive to lower temperatures.

Queen cells are relatively rarely found in the centre of the broodnest. Those that are are often considered to be ‘supersedure cells‘, though location alone is probably not definitive.

Where are queen cells more usually found?

At the periphery of the broodnest, decorating the lower edges of the frame and even protruding down into the space below the bottom of the comb.

Queen cells

Queen cells …

Logic suggests that these might well experience lower temperatures simply by being at or near the edge of the mass of bees in the cluster. 

Perhaps queen development is less temperature sensitive?

Fortunately, I don’t need to rely on (my usually deeply flawed) logic or informed guesses … the experiment has been done 16.

Chuda-Mickiewicz and Samborski incubated queen cells at 32°C and 34.5°C. Those incubated at the lower temperature took ~27 hours longer to emerge than those at 34.5°C (which emerged at 16 days and 1 hour after egg laying).

However, of the variables measured, this was the only significant difference observed between the two groups. Body weights at emergence were similar, as were the spermathecal volume and ovariole number.

In both temperature groups ~90% of (instrumentally) inseminated queens started laying eggs.

So perhaps development temperature is not so critical (for queens after all).

The cheque queen is in the post

Finally, I expected my bodged incubator would also be used to transport mated queens. There’s good evidence that these are very robust 17. After all, you can get them sent in the post 18

Again, the experiment has been done 🙂

Survival of adult drones, queens and workers at 25°C, 38°C and 42°C

Jeff Pettis and colleagues investigated the influence of temperature on queen fertility 19 and concluded that incubation within the range 15-38°C are safe with a tolerance threshold of 11.5% loss of sperm viability 20

In addition, Pettis looked at the influence of high or low temperatures on adult viability (see graph above). Queens and workers survived for at least 6 hours at 25°C or 42°C. In contrast drones, particularly at high temperatures, ‘dropped like flies’ 21.

Stand back … inventor at work

Version 1 of the incubator was built and has been used successfully.

Queen cell incubator – exterior view (nothing to see here)

It consists of a polystyrene box housing a USB-powered vivarium heating mat. This claims to offer three heating levels – 20-25°C, 25-30°C and 30-35°C – though these are not when confined in a well-insulated box where it can reach higher temperatures. I’m not sure I believe the amperage/wattage information provided and don’t have the equipment to check it.

I run it from a 2.1A car USB socket, or a similar one that plugs into the mains.

The battery pack in the picture above runs the Raspberry Pi computer that is monitoring the temperature 22. It’s important to have accurate temperature monitoring and to do some trial runs to understand how quickly the box warms/cools. In due course all this wiring can either be omitted or built in … but it wouldn’t be a proper invention unless it looked cobbled together 😉

Not a lot to see here either …

Inside the box is a lot of closed cell foam – some crudely butchered to accommodate Nicot queen cages – sitting on top of a large ‘freezer block’. This acts as a hot water bottle. There’s also a plastic tray holding some soggy kitchen towel to raise the humidity.

Define ‘success’

The box has been used for the following:

  • transfer grafted larvae from an out apiary to a cell raising colony an hour away. Success defined by getting the grafted larvae accepted by the cell raiser.
  • transport queen cells up to 7 hours by car 23. Success defined by requeening colonies with the cells.
  • transport and maintain virgin queens for 7-10 days. These emerged in the incubator and then accompanied me back and forth before being used. All are now in hives and out for mating.

While powered – either in the house or the car – the box is easy to maintain at an acceptable temperature for extended periods, though it takes some time to reach the operating temperature.

An afternoon collecting and distributing queen cells to an out apiary

Even when opening the lid as queen cells are added/removed the temperature fluctuates by no more than 2-3°C. The graph above was generated from temperature readings taking queen cells from one apiary to another.

I’ll describe maintaining queens for extended periods in an incubator (with no attendant bees) in a future post.

The future

This really is a bodged solution.

At the moment the temperature has to be changed manually to keep it within the 32-35°C range. This might only be every few hours, depending upon how frequently the box is opened.

The combination of the insulation and the ‘hot water bottle’ freezer block means it can be left unattended overnight.

However, it really needs to have automatic temperature control. This should be trivial to add but will require more time than I have at the moment and for the box to be empty. It’s accompanying me on an exotic holiday to Glenrothes for the next three days 24 and will be in use for much of July as I start to make up nucs for overwintering.

So … as promised, an inelegant but working solution for a fraction of the 10% of beekeepers who rear queens. 

At a fraction of the price of a commercial one 🙂


 

Your first bees

June is a good time to start keeping bees.

The long, cold, dark winter is a distant memory. The uncertainties of spring – the unseasonably warm days in March, the April (snow) showers, the “will they, won’t they” doubts over spring build up (in a cold year) or early swarming (in a warm one) – are over. 

If you did a ‘start beekeeping’ course in the winter then waiting until June to get bees might feel like a lifetime, but it actually makes a lot of sense.

You miss the roller coaster ride that spring sometimes provides. In a bad year, starvation or swarming can leave you without bees by the end of May 🙁

Instead, you benefit from better (more settled) weather, stronger colonies and at least three months to get to confidently work with your bees as you – hopefully – get some summer honey and prepare them for the winter ahead.

Buy local bees

There are compelling reasons to buy local bees. By this I mean queens reared locally.

More locally reared queens …

Not Greece or Italy 1, imported in large batches and dropped into a box of ‘local’ workers, all of whom will be replaced within a month. These are effectively bees from southern Europe and are quite possibly not suited to Cumbria or Essex 2.

Several scientific studies have shown that locally reared bees do better than imports, particularly when overwintering. 

But the benefits don’t end there. If you buy bees locally you’ll probably buy them from a local beekeeper 3. I’ve proposed before that this could be your mentor … and that, ideally, you could have helped split the nuc from a strong colony, watched it develop and then purchased it.

But that’s not always possible. Mentoring is time consuming and dependent on the organisation of the local beekeeping association, to say nothing of simple geographic factors 4 or Covid and social distancing.

When you buy local bees you should expect to get some of the ‘back story’ on the colony. When was the queen grafted, when did she start to lay? 

If you do agree to buy bees from a local beekeeper, don’t then go and then buy them from someone else. Preparing nucs is time-consuming and involves committing resources from honey production or making increase. At the very least, a beekeeper reserving a nuc for you probably means s/he is turning other potential purchasers away. Have some courtesy.

A 5 frame nuc when sold should contain a frame of stores, a laying queen (!) – clipped or marked if requested  – and 3-4 frames of brood in all stages.

There should be sealed brood in the colony laid by the queen heading the colony.

OK, enough preamble … what about the practicalities of getting the bees home, installing them in a hive and doing your first inspection?

Transporting bees

If you are collecting your nuc from a local apiary it will probably already be sealed up for transport. The entrance should be sealed securely and the frames should be wedged in place so they won’t flap around during transit. I use closed cell foam blocks for this, but it may not be necessary in some smaller nuc boxes.

Preparing a nuc for transport. Note the foam block to secure the frames.

You might not be provided with a strap, so bring your own. Ratchet straps are probably overkill for a nuc, but they certainly do the job. Gaffer tape works well, as do these ‘no moving parts but can I remember how they work?’ hive straps.

Standard hive straps

If you collect them at the beginning or end of the day there will be more bees in the box and fewer foragers out, er, foraging.

It’s always good to actually get the bees you’re paying for 😉

More importantly, it’s also cooler at the start or end of the day, which is one less thing to be concerned about when transporting bees. Since you’re buying locally you won’t be transporting the bees far. That being the case, it’s usually sufficient to make sure there’s good airflow under the open mesh floor, without using a travel screen.

If you move bees in the heat of the day expect to have to use some sort of mesh screen over the top of the frames. The last thing you want is overheating and stressed bees. 

Mesh and staples

Actually, that’s the penultimate thing.

The last thing you want is the combs melting and collapsing … avoid this at all costs.

Escapees

Secure the nuc in the car 5 so that it can’t tip over. The frames should be in line with the direction of travel.

It’s not the end of the world if they’re perpendicular to travel, but it reduces the ‘frame flap’ when accelerating and decelerating. 

I often put the bees on the car seat, strapped in place with a seat belt, with a sheet or two of newspaper underneath the OMF to stop getting nectar or pollen on the nappa leather upholstery my filthy car from soiling the nuc box.

I’ve moved dozens of nucs like this and never had a problem.

Drive carefully.

You might find one or two bees “escaping”. In my experience these are more likely to be ‘hitchhikers’ who were underneath the open mesh floor, rather than Houdini-like bees that have circumvented the sealed entrance of the nuc 6.

Stop and let them out at the earliest opportunity … it’s safer and they’re more likely to get back to the home apiary.

If you’re 10 miles away from the apiary their fate is probably sealed 🙁

Opening the hive entrance

Bees can be a bit disoriented and distressed after a car journey.

Therefore, don’t be in a rush to open them up too soon.

I always place them in the location they are going to be permanently sited and leave them for at least half an hour.

Then, and only then, I gently open the hive entrance.

If you do it as soon as you arrive the bees may come flooding out … if you leave them to settle they will be much calmer.

Correx, the beekeepers friend ...

Correx, the beekeepers friend …

Don’t bump or rock the hive.

Don’t wrestle with the sealed entrance.

Hopefully the 30+ minutes recuperation time has allowed you to work out a strategy to open the hive entrance with the minimum disturbance possible.

Those rotating entrance disks have got a lot to commend them 🙂

Ideally you want the bees to be barely aware that the entrance is now open when it wasn’t a moment before … for example, there’s usually no need for smoke 7.

Remember, the bees know nothing about their new environment. You want them to explore it at their own pace, rather than releasing a few thousand agitated bees all at once.

Open the entrance so the bees can come and go, but don’t leave a cavernous maw gaping that they might struggle to defend,

Take a few steps back and enjoy watching the first orientation flights of your new bees.

And that’s it for the day … leave them in peace.

Transferring the nuc to a full hive

At this time of the season the bees will rapidly outgrow a 5 frame nucleus hive. If you leave them in there too long the queen will run out of space to lay and they’ll start to think about swarming.

Remember that overcrowding is one of the (many) triggers for swarming and, once they’ve decided to go, it can be very difficult to stop them.

Here's one I prepared earlier

Here’s one I prepared earlier … an overcrowded overwintered nuc in April

Therefore you need to transfer them to a full-sized hive within – at most – a few days of acquiring them 8.

You will need a full hive – floor, brood box, crownboard and roof – together with five or six (or 7 for the new Abelo boxes I see) frames with foundation fitted 9.

Frame orientation – frames from nuc in red, new foundation in grey

Since this is probably also the first time you are going to open the nuc (and, if it’s not, why did you look earlier? See the final section of this post.) you’ll also need a beesuit, hive tool and smoker.

  • Move the nuc gently to one side and place the new floor and brood box where the nuc was, with the entrance facing the same direction.
  • Gently smoke the nuc. Just a couple of puffs near the entrance should be more than sufficient. You don’t need to ‘kipper them’.
  • Transfer the 3-4 frames of brood one at a time, placing them next to each other in the new hive. By all means have a brief look at each side of the frames, but place them in the new hive in the same orientation with regard to their neighbours. The goal here is that the brood nest is not unduly disturbed.
  • Flank these with a frame or two of foundation and then add the frame of stores.
  • If I’m arranging the frames the ‘warm way’ i.e. parallel to the hive entrance, I’ll place the occupied brood frames closer to the entrance. This helps the colony defend the entrance. If the frames are perpendicular to the entrance (the cold way) I place them in the middle of the hive 10.

Add the crownboard and roof. 

All done.

Feeding the colony

Probably the first dilemma faced by a new beekeeper is whether to feed the recently re-hived nucleus colony. 

This is what beekeeping is all about … making judgement calls based upon the strength and state of the colony, in the context of the local environment and with an understanding of what the weather is going to be like over the next week or two.

Get used to it … you’ll be making a lot of decisions like this 😉

Here are a couple of scenarios …

  1. Unseasonably cold weather with lots of rain and an understrength nucleus colony.
  2. Warm, settled weather with a very strong nucleus colony in an environment with abundant forage.

The first must be fed for it to survive, let alone thrive.

The second may well not need feeding at all.

It’s best to err on the side of caution and feed nucs if there’s any doubt they will not have enough nectar to draw fresh comb and expand the brood nest. 

This spring – at least since late May – the nectar flow has been exceptional and I’ve not fed any nucs. All have drawn comb ‘for fun’, often drawing successive frames one after another that I’ve rotated into the box.

If the colony does need feeding I prefer to use a contact feeder (a plastic bucket with a fine mesh grille in the lid inverted over the brood nest) containing 1:1 (by weight) syrup made of granulated sugar and water.

Welcome to your new home … nuc ‘promoted’ to hive with contact feeder in place

The aim it to imitate a good nectar flow rather than allow the bees to store large amount of syrup stores. You want them to draw new comb and rear lots of new brood.

I place the contact feeder directly over the top bars, separated by a couple of wooden spacers. I do this because most of my crownboards lack central holes. Use a spare super to enclose the contact feeder.

I think my contact feeders are ‘half gallon’ ones … they are just big enough to take a mix of 2 litres of water and 2 kg of sugar 11. If the weather remains poor, or the nectar remains elusive (you could always ask the local beekeeper you bought the nuc from … another advantage of buying local bees 😉 ), then it will do no harm to give them a second ‘half gallon’ of syrup to help them build up.

Do not spill syrup in the apiary. It encourages robbing and your new colony may not be able to defend itself. If in doubt, again err on the side of caution … reduce the entrance size of the hive.

Inspections and enjoyment

On a warm, calm, settled day you should conduct your first colony inspection. Nucs, even recently promoted ones in a full hive, are usually a pleasure to inspect. There are sufficiently small numbers of bees that you should be able to see what’s going on relatively easily.

Don’t worry about finding the queen. If there are eggs present and no sealed queen cells then she will be in the hive.

Marked queen surrounded by a retinue of workers.

They’re not always this obvious …

It’s always a bit risky making assurances like that as I can think of several scenarios when I would be wrong.

If there are eggs present then there was a queen in the hive within the last 3 days 12.

If there are sealed queen cells present then it’s possible that the hive has swarmed.

But what about eggs being present together with unsealed queen cells?

That'll do nicely

That’ll do nicely …

There are two obvious explanations, one of which is much more likely for a new beekeeper with their first colony:

  • The colony was dead set on swarming and has swarmed without waiting for the queen cell to be sealed. This happens, but it’s unlikely to occur with a nucleus colony just moved to a new hive 13.
  • The queen has very recently died – or, more accurately, been killed – and the bees are rearing new queen cells under the emergency impulse,

New beekeepers are understandably enthusiastic … but they can be clumsy.

It’s not unusual for a queen to be damaged or killed during a colony inspection by an inexperienced beekeeper 14. It’s easy to squidge the queen between the sidebars of the frame and the brood box, perhaps because she’s rushing about after the colony was smoked too much, or between frames when returning them to the hive.

If you can’t find the queen you can’t be sure where she is.

Accidents happen.

This was almost certainly the fate of my first ever queen which disappeared a week or two after I bought my nuc … and I thought I was being so careful 🙁

Which brings me to my last couple of points. 

Do not inspect the colony more than necessary.

Once every seven days is sufficient. Don’t meddle. Let them get on with things. When they get to 7-8 frames of brood add a queen excluder and a super. 

Observe and enjoy them … from a distance. 

Congratulations … you’re now a beekeeper 🙂


 

Little dramas

This post was originally titled Drama queens.

Apposite … it’s mostly about queens.

However, the term drama queen refers to someone who overreacts to a minor setback 1 … which is almost the complete opposite of what I’m intending to discuss.

Instead, this post is about the – sometimes unseen – little dramas in the apiary. Things that go wrong, or could go wrong but eventually go OK because you gently intervene … or often because you don’t intervene at all 😉

It’s also about observing rather than doing. It’s sometimes surprising what you see, and – with a little application – you can learn something about your bees 2.

Of course, in the end some things do not end well … but there’s no point in being a drama queen about it 😉

Swarmtastic

There’s a certain predictability to the beekeeping year. It’s dictated by the climate and latitude, by the forage available, by the need for bees to reproduce (swarm) and by our efforts as beekeepers to corral them and keep them producing honey 3.

All of which means that June has been pretty manic. 

After a record-breakingly cold spring things finally warmed up. Here in Scotland this was 2-3 weeks into May.

Since then it’s been a near-constant round of queen rearing, swarm control, making up nucs and adding supers. Most of the OSR supers are now off, meaning that I’ll be hunched over the extractor for hours when I’m not with the bees 🙁

All the OSR near my bees is well and truly over – this lot is sadly just out of range

The rapid warming in late spring triggered a lot of swarming activity. I found my first charged queen cell on the 18th of May and, in at least one or two colonies, at every subsequent inspection since then.

Visits to the apiaries have been hard work. Inspecting a double brood colony with four full supers involves a lot of lifting 4.

And the lifting is necessary because I need to check whether there are any queen cells in the brood chamber.

I know some beekeepers simply prise the two brood boxes apart and expect to see queen cells at the junction.

That certainly works … sometimes.

However, I’ve found several colonies with queen cells in the middle of frames, or otherwise in positions I would not see them if I just looked at the interface between the boxes. 

Queen cell … and what else?

And I would still have to remove the supers to prise the brood boxes apart.

Although I’ve invested in some better quality hive tools, I’d need a crowbar to separate the boxes if there was 80 kg of supers on top 5.

So, if I have to take the supers off, I might as well look through the box carefully.

More haste, less speed

But before I fire up the smoker and start rushing around prising off crownboards I always try and simply observe what’s happening in the apiary.

Are all the colonies equally busy? If it’s the time of day when the new foragers are going on orientation flights are any colonies much less active? Have they had a brood break?

Which direction are the bees flying off or returning from? Has the main forage changed?

Are there any drones on orientation flights yet?

What’s happening at the hive entrances?

Is there pollen going in?

Any sign of fighting?

Or robbing?

It’s surprising what a few minutes observation can tell you about the local forage, the state of the colonies and their relative strength.

If you’ve not already read it (and even if you have) it’s worth finding a copy of At the Hive Entrance by Prof. H. Storch 6. The book’s strap-line is “How to know what happens inside the hive by observation on the outside”. Recommended.

And, now and again, you notice something unusual …

Queen under the open mesh floor

Like – in my peripheral vision – a single bee flying out from underneath an open mesh floor.

My queens are generally clipped. If the colony swarms the queen often finds her way back to the hive stand after crashing – very unregally 7 – to the ground. She crawls up the leg of the stand and ends up underneath the open mesh floor (OMF).

The bees then join her. It’s not unusual to find a large cluster of bees under the hive floor, with lots of activity, and lots of bees flying to and fro from underneath the OMF 8.

But last Friday, by chance I noticed a single bee and this prompted me to investigate.

A quick peek confirmed that there wasn’t a swarm under the OMF.

But there was a queen.

I spy with my little eye … you can just see the marked and clipped queen under this Abelo floor.

Almost completely alone.

I presume the colony had swarmed, the queen had got as far as she could and the swarm had eventually abandoned her and returned to the hive. 

When I inspected the colony I found a single sealed queen cell and confirmed that the queen I found was the one that was missing.

This colony was one of my ‘middle third’ ones 9i.e. destined for requeening with better stock if I had any spares.

There’s a near-to-eclosion queen cell under there …

I did.

I had half a dozen ‘spare’ queen cells almost ready to emerge from grafting at the start of June. I removed the queen cell in the hive and carefully checked I’d not missed any others. I then added the grafted cell, seating it in a thumb-sized depression over some brood. She will have emerged the following day and might even be mated when I check early next week.

Had I not seen the bee emerge from under the floor I’d have never otherwise checked. There are always a few bees under an OMF, but it’s rare to find a queen all alone there.

Queen in the grass

In another apiary the previous week I’d found a satsuma-sized cluster of bees in long grass about 10 metres from the hives. The application of a little gentle smoke and some prodding around with my index finger resulted in a clipped and marked queen calmly walking up onto my hand.

Microswarm? … or more likely the remains of a much larger one …

Again, I wouldn’t have seen this had I not been taking my time checking the hive entrances and the activity in the apiary. I was being even more leisurely than normal as there was rain threatening and I was trying to decide whether to start the inspections or not

Because of the known state of other colonies in the apiary – most were nucs with virgin or recently-mated queens – it was obvious which colony the queen had come from. 

The ‘threatening rain’ looked like it would soon become a certainty. I ran the queen in through the front entrance of the hive and the remaining bees eventually returned to the hive, fanning madly at the entrance.

Bees fanning at the entrance

When I next checked the hive the queen had gone 🙁

There was no sign the colony had swarmed, but there was a recently opened queen cell in there. I assumed there’s a newly emerged virgin queen running about in there with ‘blood on her hands’ having done away with the original queen.

We’ll find out next week.

Again, a few minutes just watching things in the apiary meant I found the queen. Had I not done so I’d have only seen the end result – a queenless colony – not the events that led to it.

Preventative and reactive swarm control

I should emphasise that the majority of my colonies are a little more under control than the two described above, both of which clearly attempted to swarm.

In both cases the clipped queen saved the day, even though she may not have lived to fight another day.

My swarm control (and success thereof) this season has been in stark contrast to last year’s ‘lockdown beekeeping’.

Then the priority was minimising travel and guaranteeing I wasn’t haemorrhaging swarms that might cause problems for the the public or other beekeepers.

I therefore used the nucleus method of swarm control on all my colonies. I implemented it well in advance of the peak swarming period. By doing so, I undoubtedly weakened my colonies. I produced less honey and did no queen rearing.

But I didn’t lose a single swarm 🙂

This year the priority has been to maintain strong colonies. Some are being used for honey production 10 and others are being split to make up nucs.

Inevitably a few have got a little ‘overcooked’ … but the clipped queen has usually ensured the bees remain in the hive.

I don’t think I’ve lost a swarm, but I have lost a few queens.

Queen in the cage

One of my colonies went queenless in mid May. This was well before I’d got any spare queens – mated or otherwise. I’d hoped that they would rear another, but it was too cold for the new queen to mate and the colony started to look a little pathetic.

I considered uniting them but, for a variety of reasons, never got round to it.

When I finally had a spare mated queen (in early June) I popped her into a JzBz introduction cage. I’d already plugged the tube with candy and placed a plastic cap over the end. 

The bees could feed the queen through the cage, but could not release her.

This is my usual method for queen introduction. I check the cage a day or so after hanging it between the frames. If the bees are showing aggression to the queen I leave it and check again 24 hours later.

Once they’re no longer showing any aggression I remove the plastic cap. The bees chew through the candy and release the queen.

Job done 🙂

I then leave the colony at least a week before inspecting, by which time I expect to see eggs and larvae.

JzBz queen introduction & shipping cage with removable plastic cap

On returning a week after removing the plastic cap I was dismayed to find the queen still in the cage. Most of the candy had gone, but there was a plug at one end that was rock hard. Clearly the bees had been unable to release her.

The colony had now been broodless almost a month. Brood pheromone is really important in suppressing laying worker activity in the hive. Queen pheromone is no substitute for brood pheromone 11 and I was very concerned about the additional lost week due to my stupidity 12.

But there was no point in being a drama queen … I opened the cage and gently released the queen onto a seam of bees. Five days later there are eggs and larvae (and the queen) in the hive, though I also think there are a few laying workers as there’s a smattering of drone pupae in worker cells (a classic sign).

Fingers crossed 🙂

Queen failure

The final ‘little drama’ was played out in full view over almost two months. Its eventual unsatisfactory conclusion was largely due to my procrastination … though I suspect a swallow or house martin may have hastened events at the end.

In late April, during one of the rare warm days it was possible to actually open a colony, I noticed some strange egg laying behaviour in one hive. 

The colony was queenright. The queen was marked and clipped and laying. However, although she was laying single eggs in worker comb, she was laying multiple eggs in about 10% of cells, almost all of which were in drone comb.

A fortnight or so later she was still doing the same thing. Even if it wasn’t obvious to me, it was clearly obvious to the bees that the queen was failing as they started a couple of queen cells. Here’s an enlargement of an earlier photo in this post – blue arrows mark single eggs, red arrows indicate multiples.

SIgns of a failing queen

I removed the queen and added a near-mature queen cell from my first round of grafting. She had emerged when I next checked, but was not yet laying (and I didn’t bother looking for her).

But, unlike the queen stuck in the cage, this didn’t have a happy ending.

By early June there was no sign of the queen and I fear she failed to return from a mating flight. There’s a big pond bear the apiary and it’s a magnet for swallows and house martins 13.

I added a frame of open brood (including both young larvae and eggs) in the hive, but they ignored it 14.

Frames showing the characteristic dispersed bullet brood of laying workers

When I next checked it was clear there were laying workers and I cut my losses and shook the colony out. 

In retrospect what should I have done? 

I should have united the colony in mid-May.

It was obvious then – at least to the bees – that the queen was failing. I’d never seen a queen laying singles in worker comb 15 but multiples in drone cells. 

Uniting would have immediately provided both brood pheromone and a laying queen. This would have suppressed the development of laying workers.

My notes go something like:

  • 18/5 – Still laying singles in worker and multiples in drone. Weird. QC looks like supersedure. Give them a week.
  • 26/5 – Q out. Didn’t check further. Decision time next week.
  • 3/6 – Strange. Increasing drone brood. Behaving queenright. Decision time next week.
  • 12/6 – Laying workers. Shook them out. Will I ever learn? EEJIT 16

The second rule of beekeeping

Anytime I write Decision time next week (or variants thereof, like Give them another weekin two successive weeks then it’s almost always going to end in tears 🙁

If it happens three times in succession it’s a nailed on certainty.

The first rule is – of course – Knocking off queen cells is not swarm control 😉


 

More from the fun guy

Great fleas have little fleas upon their backs to bite ’em,
And little fleas have lesser fleas, and so ad infinitum.

Augustus de Morgan’s quote from A Budget of Paradoxes (1872) 1 really means that everything is preyed upon by something, which in turn has something preying on it.

The Flea, engraving from Robert Hooke’s Micrographia (1665)

As a virologist I’m well aware of this.

There are viruses that parasitise every living thing.

Whales have viruses and so do unicellular diatoms. All the ~30,000 named bacteria have viruses. It’s likely that the remaining 95% of bacteria that are unnamed also have viruses.

There are even viruses that parasitise viruses. The huge Mimivirus that infects amoebae 2 is itself parasitised by a small virophage (a fancy name for a virus that infects viruses) termed Sputnik.

Whether these interactions are detrimental depends upon your perspective.

The host may suffer deleterious effects while the parasite flourishes.

It’s good for the latter, but not the former.

Whether these interactions are detrimental for humans 3 also depends upon your perspective.

The deliberate introduction of rabbit haemorrhagic disease virus to Australia benefitted sheep farmers who were plagued with rabbits … but it was bad news for rabbit farmers 4.

Biocontrol

Beneficial parasitism, particularly when humans use a pathogen to control an unwanted pest, is often termed biocontrol, a convenient abbreviation for biological pest control.

There are numerous examples; one of the first and best known is control of greenhouse whitefly infestations with the parasitoid wasp Encarsia formosa.

Tomato leaf with whitefly nymphs (white) parasitized by E. formosa (black).

One of the benefits of biocontrol is its self-limiting nature. The wasp will stop replicating once it runs out of whitefly to parasitise.

A second benefit is the specificity of the interaction between the host and whatever is administered to control it; by careful selection of the biocontrol agent you can target what you want to eradicate without lots of collateral damage.

Finally, unlike toxic chemicals such as DDT, the parasitoid wasp – and, more generally, other biocontrol agents – do not accumulate in the environment and cause problems for the future.

And, with all those benefits, it’s unsurprising to discover that scientists have investigated biocontrol strategies to reduce Varroa mite infestation of honey bee colonies.

It’s too early for an aside, but I’ll make one anyway … I’ve discussed the potential antiviral activity of certain fungi a couple of years ago. That wasn’t really biocontrol. It was a fungal extract that appeared to show some activity against the virus. Although that story has gone a bit quiet, one of the authors – Paul Stamets – is also a co-author of the Varroa control paper discussed below.

Biocontrol of Varroa using entomopathogenic fungi

Entomopathogenic means insect killing 5. There are several studies on the use of insect killing fungi to control Varroa 6, with the most promising results obtained with a variety of species belonging to the genus Metarhizium

Metarhizium produces asexual spores termed mitospores. The miticidal activity is due to the adhesion of these mitospores to Varroa, germination of the spore and penetration by fungal hyphae 7 through the exoskeleton of the mite and proliferation within the internal tissues.

A gruesome end no doubt.

And thoroughly deserved 🙂

Although Metarhizium is entomopathogenic it has a much greater impact on Varroa than it does on honey bees. This is the specificity issue discussed earlier.

It is for this reason that scientists have continued to explore ways in which Metarhizium could be used for biocontrol of Varroa.

But there’s a problem …

Although dozens of strains of Metarhizium have been screened, the viability – and therefore activity – of the mitospores is significantly reduced by the relatively high temperatures within the colony.

The spores would be administered, they’d show some activity and some Varroa would be slaughtered. However, over time treatment efficacy would reduce as spores – either administered at the start of the study, or resulting from subsequent replication and sporulation of Metarhizium on Varroa – were inactivated.

As beekeepers you’ll be familiar with the limitation this would impose on effective control of mites.

Varroa spend well over half of their life cycle capped in a cell while it feeds on developing pupae. Anything added to kill mites must be present for extended periods to ensure emerging mites are also exposed and killed.

This is why Apiguard involves two sequential treatments of a fortnight each, or why Apivar strips must be left in a hive for more than 6 weeks.

In an attempt to overcome these limitations, scientists are using directed evolution and repetitive selection to derive strains of Metarhizium that are better able to survive within the hive, and so better able to control Varroa than the strains they were derived from.

Good news and bad news

Like many scientific papers on honey bees 8 those with even a whiff of ‘saving the bees’ get a lot of positive press coverage.

This often implies that the Varroa ‘problem’ is now almost solved, that whatever tiny, incremental advance is described in the paper represents a new paradigm in bee health.

This is both understandable and disappointing in equal measure.

It’s understandable because people (not just beekeepers) like bees. News publishers want ‘good news’ stories to intersperse with the usual never-ending menu of woe they serve up.

It’s disappointing because it’s a variant of “crying wolf”. We want the good news story to describe how the impact of Varroa can now be easily mitigated.

It gets our hopes up.

Unfortunately, reality suggests most of these ‘magic bullets’ are a decade away from any sort of commercial product.

They will probably get mired in licensing problems.

And they may not be any better than what we currently use.

You finally end up as cynical as I am. This might even force you to read the original manuscript, rather than the Gung ho press release or the same thing regurgitated on a news website.

And, if you do that, you’ll better understand some of the clever approaches that scientists are applying to the development of effective biocontrol for Varroa.

We’re not there yet, but progress is being made.

V e r y   s l o w l y.

The paper I’m going to discuss below is Han, J.O., et al. (2021) Directed evolution of Metarhizium fungus improves its biocontrol efficacy against Varroa mites in honey bee colonies. Sci Rep 11, 10582.

It’s freely available should you want to read the bits I get wrong 😉

Solving the temperature-sensitivity problem of mitospores

The strain of Metarhizium chosen for these studies was M. brunneum F52. This had previously been demonstrated to have some efficacy against Varroa. Almost as important, it can be genetically manipulated and there was some preliminary evidence that its pathogenicity for Varroa – and hence control potential – could be improved.

Genetic manipulation covers a multitude of sins. It could mean anything from selection of pre-existing variants from a population to engineered introduction of a toxin gene for destruction of the parasitised host.

In this study the authors used directed evolution of a population of Metarhizium to select for strains with more heat tolerant spores.

Directed evolution of Metarhizium to select mitospores with increased thermotolerance

This is not genetic engineering. They grew spores under stressful conditions and increasing temperatures. Hydrogen peroxide (H2O2) , a mild mutagen, was added in some cases. Nutritional stress also increases population variation. Spores selected using nutritional stress are better able to withstand UV and heat stress.

The optimal growth temperature for the strain of Metarhizium they started with was 27°C. By repeated selection cycles at increasing temperatures they derived spores that grew at 35°C, the temperature within a colony.

Ladders and snakes

A well known phenomena of repeated selection in vitro (i.e. in a test tube in the laboratory, though you actually grow Metarhizium on agar plates) is that a pathogen becomes less pathogenic.

It was therefore unsurprising that – when they eventually tested the thermotolerant spores – only about 3% of the Varroa that died did so due to Metarhizium infection.

Field selection after directed evolution of Metarhizium in the laboratory

They therefore modified the repetitive selection, but this time did it on Varroa-infested colonies in the apiary. Mites that died from Metarhizium mycoses 9 were used as a source to cultivate more Metarhizium.

They were therefore selecting for both thermotolerant (because the experiments were being conducted in hives at 35°C) and pathogenic fungi, because they only cultivated mitospores from Varroa that had died from mycoses.

And it worked …

Amplification of Varroa mycoses by Metarhizium. Black arrows indicate the treatment dates.

After four rounds of selection over 60% of the mites that died did so because they were infected with Metarhizium.

All very encouraging … but note I was very careful with my choice of words in that last sentence. I’ll return to this point shortly.

Before that, here’s the ‘proof’ that the strain selected by directed evolution (which they termed JH1078) possessed more thermostable spores.

Thermostable spores

They measured this by recording the percentage that germinated. At 35°C ~70% of JH11078 spores germinated compared to only ~45% of the M. brunneum F52 strain they started with.

But it’s not all good news

My carefully chosen “60% of the mites that died” neatly obscures the fact that you could get a significant increase in mites dying of Metarhizium, but still have almost all the mites in the hive surviving unscathed.

The authors continued repeated Metarhizium monthly treatments for a full season after the selection experiments described above. The apiary contained 48 colonies, 24 received Metarhizium JH1078 and the remainder received no treatment.

Did Metarhizium treatment stop the well documented increase in Varroa levels observed in colonies not treated with miticides?

Varroa levels in Metarhizium treated and untreated (control) colonies.

Er … no.

They describe this data (above) as showing a ‘delay’ in the exponential increase in Varroa … but acknowledge that it ‘did not totally prevent it’.

Hmmm … looking at the error bars in the last few timepoints I’d be hard pressed to make the case that there was any significant difference in Varroa increase caused by treatment.

And while we’re here look at the mite infestation rate … 10-25 mites per 100 bees.

These are catastrophically high numbers and, unsurprisingly, 42 (~88%) of the 48 colonies – whether treated or untreated – died by the end of 2018, succumbing to “Varroa, pathogen pressure and intense yellow jacket predation”

There was some evidence that colonies receiving Metarhizium treatment survived a bit longer than the untreated controls, but the end results were the same.

Almost every colony perished.

Metarhizium vs. oxalic acid

Typically a paper on a potential improved biocontrol method for Varroa would do a side-by-side comparison with a widely used, currently licensed treatment.

There’s only one comparative experiment between Metarhizium and dribbled oxalic acid treatment. It’s buried at the end of the Supplementary Data 10. In it they show ‘no significant difference’ between the two treatments.

Frankly this was a pretty meaningless experiment … it was conducted in June 2020 when colonies would have been bulging with brood. Consequently 90% of the mites would have been hidden under the cappings. They assayed mite levels only 18 days after a single application of Metarhizium or oxalic acid.

Although it showed ‘no significant difference’ – like the “60% of the mites that died” quote – it obscures the fact that most mites were almost certainly completely untouched by either treatment.

What does this study show?

This study involved a large amount of work.

The directed evolution in the laboratory is a very nice example of how the combination of phenotypic selection and natural variation can rapidly yield new strains with desirable characteristics.

Combination of this with in vivo selection for enhanced pathogenesis successfully produced a novel strain of Metarhizium with some of the features desirable for biocontrol of Varroa.

However, in the apiary-based studies the majority of the colonies, whether treated or not, died.

This shows that, although scientists might have made a promising start, they are still a very long way from having an effective biocontrol solution for Varroa.

Unmanaged Varroa replicates to unmanageable levels

One of the Supplementary Data figures illustrated the Varroa drop per month from colonies in the research apiary.

Cumulative mite drop per colony for the month of July 2018

This is relatively late in the study, July 2018. These hives were established from commercial packages of bees in April 2017. They were either treated with the experimental Metarhizium spores or were untreated controls for the 15 months between April 2017 and July 2018 11.

Look at those Varroa numbers!

This is the mite drop just after the peak of the season. Brood levels would be close to maximum in their short, warm summer 12. The majority of the mite population would have been safely tucked away feasting on developing brood.

This is not the mite drop after miticide treatment … it’s just the drop due to bee grooming, natural mite mortality and the general ‘friction’ in the hive.

The average is 2866 mites dropped per month per hive 😥

Maybe nothing could have saved hives as heavily infested as these? 13

Don’t wait for Metarhizium … be vigilant now

These numbers – of mites and dead colonies – are a stark warning of the replication potential of Varroa and the damage is causes our bees.

Left untreated, Varroa will replicate to very high levels.

Colony mortality – either directly due to the mite and viruses, or indirectly due to the weakened colonies succumbing to robbing – is a near-inevitable consequence.

I’ve discussed the importance of Varroa management repeatedly over the years. It’s a topic I’ll be returning to again – probably in August when it starts to become a necessity.

In the meantime, keep an eye on the mite levels in your own colonies as they get stronger during the season.

While you’re doing that think of the scientists who are looking for practical, effective and environmentally-friendly strategies to control Varroa. Understand that these studies are time-consuming, progress is glacial incremental … and they might not work anyway.

Of course, if we finally manage to develop a suitable Metarhizium-based mite control strategy then bees and beekeepers will not be the only beneficiaries.

Metarhizium has its own parasites. Some of the best characterised of these are small RNA viruses.

If beekeepers are sprinkling billions of Metarhizium spores over their colonies every year then these viruses will be having a great time 😉


 

Hard graft

Regular readers will have seen this image before …

Swarmy weather? I don’t think so …

… as I used it (with the same legend) towards the end of the post last week. 

I spoke too soon 🙁

The temperature on the 17th and 18th briefly reached 17.5°C … which was enough.

Grrrr …

But I’m getting ahead of myself.

Good morning America Glenrothes

I’m fortunate to live in a stunningly beautiful and remote part of the country. I open the blinds in the morning to panoramic views of the Morvern hills across a narrow sea loch. There are no houses in direct sight and – even when it’s damp 1 – it’s an idyllic scene.

Good morning Morvern …

But although I live here, most of my bees still live in Fife, so I have a commute to look after them and stay in convenient 2 hotels.

Opening the curtains on these trips provides a somewhat less salubrious view.

Uninterrupted views of the Macdonald’s drive-in

But at least I don’t have to cook my own breakfast, which is but a short walk away 🙂

As you can see from the photo above, it’s been raining overnight.

To make these trips economically rational 3 it’s necessary to book them several weeks in advance.

Despite the use of supercomputers, the BBC’s medium to long-range weather forecasts seem little more than guesswork. It’s worth remembering that a weather forecast competition over several weeks was won by a team that predicted ‘tomorrow will be like today’ for the duration of the event 4.

And for beekeeping, there’s a significant difference between 12°C, light drizzle with strong winds and 13°C, intermittent sunshine and gentle breezes.

The latter makes opening hives a relatively straightforward proposition … careful and quick, but the bees will cope just fine.

In contrast, the former makes everything rather hard work.

And this morning we’ll graft delicate larvae no larger than a comma on a page …

And these are exactly the conditions that greeted me when I did my first round of grafting on the 10th of May.

The weather is probably the major problem of long distance beekeeping. You have to be prepared for anything.

Queenright cell raising – the Ben Harden system

I’ve discussed grafting and using the Ben Harden queenright cell raising system extensively before. 

My Ben Harden setup was in the bee shed.

As it turned out, this was a (disappointingly rare) stroke of genius.

A strong, double brood colony had been modified be the replacement of 7 frames in the upper box by two ‘fat dummies‘. These have the effect of concentrating the bees in the gap between them. 

In this space were two frames containing pollen, one frame of young larvae 5 and the cell bar frame, into which I would be grafting larvae.

Ben Harden setup and pollen patties

This box sits on top of a queen excluder, below which was a single brood box (containing the queen) literally overflowing with bees 6. Positively bulging at the seams.

Since I didn’t have frames with sufficient pollen in them I’d also supplemented the colony with pollen substitute (a pollen pattie) which they were happily devouring. 

The hive also had a couple of half-full supers. These contained lots of bees but rather disappointing amounts of nectar.

The queen providing the larvae was in a nuc box in the same apiary. I’d been feeding this colony syrup and pollen to ensure the young larvae were well fed 7.

Grafting

The day for grafting dawned cool, grey and drizzly.

Great 🙁

I ended up doing the grafting in the passenger seat of the car, wearing a headtorch. I kept the larvae warm and humid using a damp piece of kitchen paper draped over those I’d already transferred from the comb to the plastic cups in the cell bar frame.

After gently inserting the cell bar frame into the space in the centre of the Ben Harden setup and filling the feeder in the fat dummy with syrup, I added a clearer board and then replaced the two supers.

The intention was to empty the supers into the cell rearing box, guaranteeing a huge number of bees would be there to help raise the queens.

Ben Harden cell raiser with clearer and supers

After another evening of junk food and a disappointingly similar breakfast I checked the grafts the next day for ‘acceptance’.

10/10 …

You do this by – ever so gently – lifting the cell bar frame from the centre of the Ben Harden setup and looking for a 5-6mm collar of fresh wax built around the lower lip of the Nicot cup into which the larvae have been grafted.

Amazingly, considering the dodgy conditions and the fact that this was my first attempt at grafting for a couple of years, all the larvae appeared to have been accepted 8. I didn’t brush any of the bees off and I certainly didn’t prod about in the densely packed bees on the frame … but things looked good.

So I closed the hive up and went off to inspect some other colonies in the rain before driving back to the west coast.

Coffee mishaps and colony inspections

I returned to the east coast about 8-9 days later to add the queen cells to nucleus colonies.

The ~150 mile journey didn’t go well. In mid-slurp the lid came off my mug, depositing a lap-full of lukewarm coffee over me. 

Never mind. The route I take goes through some ‘modesty-ensuring’ remote countryside. It was a five minute task to leave the trousers drying over the boxes of frames in the back of the car.

Since I had no spares I donned my beesuit and continued on the journey.

The weather improved as I drove east. I checked an apiary in mid-Fife where all was well and finally arrived at my main apiary in mid-afternoon.

It was a lovely day 🙂

So lovely one of the colonies had swarmed 🙁

There were actually two small swarms hanging about a metre apart in the willow trees I’d planted around the apiary 9

I didn’t really have time to think about the swarm … we needed a few hundred early stage drone pupae for work so went through the colonies to find these first.

These were quick ‘n’ dirty inspections … I checked every frame, but not every cell or every nook and crannie … 

  • brood in all stages?
  • eggs?
  • stores?
  • any charged queen cells?
  • temper, behaviour, stable on the comb?
  • anything weird or strange? 10
  • next please …

I didn’t check the hive I’d set up for queen rearing, or any of the nucs on site that contained virgin queens. However, all of the other colonies were queenright as determined by the presence of eggs and the absence of (obvious 11 ) queen cells.

Drone brood was either present in relative abundance – in the strong colonies – or notable by its absence. This should not be unexpected to those of you who read the post on drones last week.

To the tune of ‘Ten green bottles’ … all together now, ‘Ten capped queen cells hanging on a frame …’

And I still had 10 queen cells in the cell raising colony, all now capped and ready to use the following day 🙂

And the swarm?

The swarm (either of them if there were actually two) wasn’t really big enough to be a prime swarm. These contain a mated queen and ~75% of the workforce from the hive. None of the hives appeared short of bees and I’d found no (obvious 12 ) charged queen cells.

However, I’d not checked the queen rearing colony – packed full of bees and fed copious amounts of syrup – and one of the colonies on the site was very bad tempered 13.

Poor temper is often a sign of a queenless colony.

Anyway, back to the swarm.

I dropped each clump of bees into a separate nuc box containing a frame of drawn comb and a couple of additional frames. I left these in the shade until late afternoon when I’d finished with the other colonies.

Two into one do go

By late afternoon most of the swarm bees from one of the nuc boxes had abandoned it and joined the other nuc box. It was pretty clear that there was only one ‘swarm’ and that it had got separated when settling at the bivouac.

The bees were leaving the queenless box and joining the queenright one.

I checked the willow where the swarm was found. 

Small amounts of wax where a swarm settled

There were small amounts of wax deposited on the leaves and stem of the willow. I suspect that the swarm may therefore have been there overnight 14 but can’t be sure.

I ended the afternoon by putting the hived swarm on a hive stand in the apiary.

Before leaving I checked the bad tempered colony (which I was intending to split into nucs the following day).

During my fumblings I managed to get a few bees into my beesuit pocket 15.

The one with the hole in it from my razor-sharp hive tool.

That opened onto my leg.

Which was unprotected by trousers due to my fumblings with the coffee 9 hours earlier 🙁

Ouch 🙁

Getting nuked

The weather the following day started bright but rapidly degenerated.

That lot is about 10 minutes away … and approaching fast

By the time I’d got the nuc boxes prepared – feeders, frames, stores, dummy boards, entrance blocks, labels, straps – it was 11°C and there was rain quickly approaching from the west.

The first four nucs were prepared from the ‘bad tempered’ hive (#6). I decided it was wise to get this over and done with before the heaven’s opened.

Despite going through the box twice I failed to find a queen. Perhaps she went with the smallest prime swarm ever?

I divided the frames (by brood and bees, not number of frames) into four approximately equal nucs and added a queen cell to each. 

Here’s one I produced earlier … or helped produce

Each queen cell was removed from the cell bar frame, the adhering bees gently brushed off (with a handful of weeds) and pressed into a thumb-sized indentation in the comb, just underneath the top bar of the frame.

I then carefully pushed the frames together (avoiding crushing the cell) and closed the nuc box up.

As I opened the next hive to be split the rain started …

I should design a beesuit with an integrated sou’wester

… and the wind lessened, meaning the rain stayed.

And it rained for most of the afternoon.

Rain did not stop play

In the words of the late Magnus Magnusson “I’ve started, so I’ll finish”.

And it was miserable.

For the second time in two days I was soaked.

As those of you who have hunched over open hives in the rain will know, it’s your back, shoulders and hood that catch the worst of it.

This time my trousers stayed mostly dry … 

Nucs in the rain

The high point of the afternoon (and, let’s face it, the bar was pretty low) was the realisation that housing the cell raiser in the bee shed was an inspired choice.

When adding queen cells to nucs you either have to detach them in advance from the cell bar frame and keep them warm somewhere convenient, or collect them in turn.

Five gone, five to go … queen cells reared in a Ben Harden cell raiser

I had nowhere to keep them warm, so was returning to the Ben Harden setup to retrieve them one at a time. Since it was warm and dry in the shed I could leave the frame balanced (as shown above) still festooned with bees and fetch each cell as needed.

Had they been outside I would have had to stop.

It was difficult enough making up the nucs in the rain, one hand holding a frame, the other lifting the roofs on and off. 

It would have been impossible to juggle the cell raiser and cell bar frame as well.

But I eventually finished and moved half a dozen of the nucs to another apiary 16. I put the Varroa trays underneath 17, filled the feeders with syrup and opened the entrances a half inch or so to allow the bees to fly.

Half a dozen nucs, all in a row

And then I returned to the main apiary to tidy up.

And the swarm?

I still don’t know where the swarm came from 18.

I checked it between downpours. 

Despite opening the box very gently, with almost no smoke, the bees ‘balled’ the queen and killed her. I found her in the middle of a golf ball-sized clump of bees on the floor. 

Queen being ‘balled’ … it didn’t end well

After dislodging some of the bees with my fingers I found her, laying on her side, as dead as a dodo. You can just see her in the photo above., slightly below the middle of the image by the edge of the mesh.

Why did they do this?

I’ve inspected dozens of swarms the day after hiving them and don’t ever remember having this happen before.

Perhaps it was the poor weather? Maybe my ‘very gently’ wasn’t gentle enough?

The queen was unmarked and (obviously) unclipped.

To me, she looked like a virgin queen, rather than a slimmed down mated queen 19

There were two nucs in the apiary containing virgin queens. I didn’t inspect either, but a quick peek through the plastic crownboard showed both still appeared to contain bees. The size of the swarm, although small (as swarms go) looked much larger than the size of these nucs.

I’ll check again next week …

I added a queen cell to the swarm and set off for home.

Chasing the setting sun

It’s a beautiful commute, across Rannoch and through Glencoe, chasing the setting sun. 

And my trousers were finally dry 😉


Note

I’ve already grossly exceeded my self-imposed word count this week. This is not meant as a practical guide to queen rearing 20. For those interested in queen rearing – the most fun you can have with a beesuit on 21 – there are lots of articles here with the nitty gritty practicalities. Try these for starters … queen rearing, an introduction to the Ben Harden system, setup and cell raising.

It’s a drone’s life

What has a mother but no father, but has both a grandmother and grandfather?

If you’ve not seen this question before you’ve not attended a ‘mead and mince pies’ Christmas quiz at a beekeeping association. 

Drone

Drone … what big eyes you have …

The answer of course is a drone. The male honey bee. Drones are produced from unfertilised eggs laid by the queen, so formally they have no father. Drones are usually haploid (one set of chromosomes), whereas queens and workers are diploid 1

Anyway, enough quiz questions. With the relaxation in Covid restrictions we may all be able to attend in person this Christmas 2, so I don’t want to spoil it by giving all the answers away in advance.

The long cold spring has been pretty tough for new beekeepers, it’s been a struggle for smaller colonies and it’s been really hard for drones.

Spring struggles

New beekeepers have had to develop the patience of Job to either acquire bees in the first place or start their inspections. Inevitably new beekeepers are bursting with enthusiasm 3 and the cold northerlies, unseasonal snow (!) and low temperatures have prevented inspections and delayed colony development (and hence the availability and sale of nucs).

Small colonies 4 are struggling to rear brood and to collect sufficient nectar and pollen.

This is an interesting topic in its own right and deserves a post of its own 5. In a nutshell, below a certain threshold of bees, colonies are unable to keep the brood warm enough and have sufficient foragers to collect nectar and pollen.

As a consequence, smaller colonies are low on stores and at risk of starvation. 

It’s a Catch-22 situation … to rear sufficient brood to collect an excess of nectar (or pollen) the colony needs more adult workers. 

I don’t know what the cutoff is in terms of adult bees, but most of my colonies with <7 frames of brood have needed feeding this spring.

One feature of these smaller colonies is that, unless they have entire frames of drone comb 6, there is little if any drone brood in the hive.

There might be drones present in the colony, but I don’t know whether they were reared there or drifted there from another hive.

And, for those of us attempting to rear queens, drones are an essential indicator that queen mating will be timely and successful.

On a brighter note …

But it’s not all gloom and doom.

Strong colonies are doing very well.

Several of mine have a box packed full of brood and I’m relying on a combination of …

  • lots of space by giving them more supers than they need
  • low ambient temperatures
  • crossed fingers

… as my swarm prevention strategy 😉

Beginners take note … one of these is likely to help (space), one is frankly pretty risky (chilly) and the last is not a proven method despite being widely used by many beekeepers 😉

I’m pretty confident that colonies will not swarm at 13-14°C.

I am inspecting colonies every 7 days and have only seen two with charged queen cells. One was making early swarm preparations; I used the nucleus method of swarm control and then split the colony into nucs a fortnight ago 7.

The other colony contained my first attempt at grafting this year, which seems to have gone reasonably well 8.

Lots of brood, nectar and drones

A typical brood frame from one of these strong colonies contains a good slab of sealed or open brood, some pollen around the sides and an interrupted arc of fresh nectar above the brood. 

In the photo above you can see pollen on the right hand side of the frame and glistening fresh nectar in the top left and right hand corners.

Typically these strong colonies also have partially filled supers, though it’s pretty clear that the oil seed rape is likely to go over before the weather warms enough (or the colonies get strong enough) to fully exploit it.

Spring honey is going to be in short supply and my fantastic new honey creamer is going to sit idle 🙁

Drones

What you probably can’t really see in the picture above is that these strong colonies also contain good numbers of drones.

Strong colonies … ample drones

I can count about a dozen in the closeup above. 

I like seeing drones in a strong, healthy colony early(ish) in the season 9.

Firstly, the presence of drones indicates that the colony (and presumably others in the neighbourhood which are experiencing a similar environment and climate) will soon be making swarm preparations. This means I need to redouble my efforts to check for queen cells to avoid losing swarms 🙁  … think of it as a long-range early warning system.

But it also means I can start thinking about queen rearing 🙂

Secondly, although these drones are unlikely to mate with my queens, you can be sure they’re going to have a damned good go at mating with queens from other local apiaries.

In addition to being strong and healthy, this colony is well-tempered, steady on the comb and pleasant to work with. The production of a few hundred thousand frisky drones prepared to lay down their lives 10 to improve the local gene pool is my small act of generosity to local beekeepers 11.

How many drones?

Honey bee colonies that nest in trees or other natural cavities produce lots of drone comb. Studies of feral colonies on natural comb show that about 17% of the comb is dedicated to rearing drones (but also used for storing nectar at other times of the season).

Foundationless triptych ...

Foundationless triptych …

Similarly, beekeepers who predominantly use foundationless frames regularly see significantly greater amounts of drone comb (and drone brood and drones) in their colonies. With the three-panel bamboo-supported frames I use it’s not unusual for one third of some frames to be entirely drone comb.

In contrast, beekeepers who only use standard worker foundation will be used to seeing drone comb occupying much less of the brood nest. Under these circumstances it’s usually restricted to the edges or corners of frames.

However, given the opportunity e.g. a damaged patch of worker comb or if you add a super frame into the brood box, the workers will often rework the comb (or build new brace comb) containing just drone cells.

The bees only build drone comb when they need it.

A newly hived swarm will build sheet after sheet of new comb, but it will all be for rearing worker brood. If you give them foundationless frames they only build worker comb and if you provide worker foundation they don’t rework it to squeeze in a few drone cells.

The colony will also not build new drone comb late in the season. Drone comb is drawn early in the season because the drones are needed before queens are produced.

The timing of drone production

Studies in the late 1970’s 12 demonstrated that drone brood production peaks about one month before the the main period of swarming. Similar studies in other areas have produced similar results.

Why produce all those drones when there are no queens about?

The timing is due to the differences in the development time (from egg to eclosion) of drones and queens, together with the differences in the time it takes before they are sexually mature.

Drones take 50% longer to develop than queens – 24 days vs. 16 days. After emergence the queen take a few days (usually quoted as 5-6) to reach sexual maturity before she embarks on her mating flight(s).

In contrast, drones take from 6-16 days to reach sexual maturity.

Swarming tends to occur when charged queen cells in the hive are capped. These cells will produce new virgin queens about a week later and – weather permitting – these should go on mating flights after a further six days. 

Therefore a colony that swarms in very early June will need sexually mature drones available 12-14 days later (say, mid-June) to mate with the newly emerged queen that will subsequently return to head the swarmed colony. These drones will have to have hatched from eggs laid in the first fortnight of May to ensure that they are sexually mature at the right time.

Decisions, decisions

How does the colony know to produce drones at the right time? Is it the workers or the queen who makes this decision?

I’ve recently answered a question on this topic for the Q&A pages in the BBKA Newsletter. In doing some follow-up reading I’ve discovered that (inevitably) it’s slightly more complicated than I thought … which was already pretty complicated 🙁

The workers build the comb and therefore determine the amount of drone vs. worker comb the brood nest contains.

I don’t think it’s known how the workers measure the amount of brood comb in the nest, but they clearly can. We do know that bees can count 13 and that they have some basic mathematical skills like addition and subtraction.

Perhaps these maths skills 14 include some sort of averaging, allowing them to sample empty cells, measure them and so work out the proportion that are drone or worker.

Whatever form this ‘counting’ takes, it requires direct contact of the bees with the comb. You cannot put a few frames of drone comb in the hive behind a mesh screen and stop the bees from building more drone comb. It’s not a volatile signal that permeates the hive.

However they achieve this, they are also influenced by the amount of capped drone brood already present in the colony. If there’s lots already then the building of additional drone comb is inhibited 15.

Colonies therefore regulate drone production through a negative feedback process.

So … does the queen simply lay every cell she comes across, trusting the worker population has provided the correct proportions of drone and worker comb?

Not quite

Studies by Katie Wharton and colleagues 16 showed that the queen could also regulate drone production.

Wharton confined queens on 100% drone or worker comb in a frame-sized queen ‘cage’ for a few days.

Frame sized queen ‘cage’ …

She then replaced the comb in the cage with 50:50 mix of drone and worker comb and recorded the number of eggs laid in drone or worker cells over a 24 hour period (and then allowed the eggs to develop).

Queens that had only been able to lay worker brood for the first four days of confinement laid significantly more drone brood when given the opportunity.

The scientists showed reasonably convincingly that this was a ‘decision’ made by the queen, rather than influenced by the workers e.g. by preparing biased number of drone or worker cells for eggs to be laid in, by preferentially ‘blocking’ certain cell types with honey or by selectively cannibalising drone or worker eggs.

Interestingly, queens initially confined on worker comb laid significantly (~25%) more eggs on the 50:50 comb than those confined on drone comb. I’m not sure why this is 17.

Wharton and colleagues conclude “these results suggest that the regulation of drone brood production at the colony level may emerge at least in part by a negative feedback process of drone egg production by the queen”.  

So it seems likely that drone production in a colony reflects active decisions made by both workers and the queen.

Why has this spring been really hard for drones?

To be ready for swarming, colonies therefore need to start drone production quite early in the season – at least 4-5 weeks before any swarms are likely.

Late May ’21 forecast. Swarmy weather? I don’t think so …

But with consistently poor weather, these drones are unlikely to be needed. Colonies will not have built up enough to be strong enough to swarm.

Producing drones is a high energy process – they are big bees and require a lot of carbohydrate and protein during development.

Under natural conditions 18 a colony puts as many resources into drone production over the season as it does into swarms.

Thomas Seeley has a nice explanation of this in The Lives of Bees – if you take the dry weight of primary swarms and casts produced by a colony it’s about the same as the dry weight of drones produced throughout the season. 

Rather than waste energy in drone production the workers remove unwanted drone eggs and larvae. The queen lays them, but the workers prevent them being reared.

How do the workers decide the drones aren’t going to be needed?

Do workers have excellent long-range weather forecasting abilities?

Probably not 19

If the weather is poor the colony will be unable to build up properly because forage will be limited. As a consequence, the colony (and others in the area) would be unlikely to swarm and so drones would not be needed for queen mating.

Free and Williams (1975) demonstrated that forage availability was the factor that determined whether drones were reared and maintained in the colony. 

Under conditions where forage was limited, drone eggs and larvae were rejected (cannibalised) and adult drones were ejected from the hive.

Unwanted drone ejected from a colony in early May

Beekeepers are familiar with drones being ejected from colonies in the autumn (again, a time when forage becomes limiting), but it also happens in Spring.

And at other times when nectar is in short supply …

Those of you currently enjoying a good nectar flow from the OSR should also look at colonies during the ‘June gap’. With a precipitous drop in nectar available in the environment once the OSR stops yielding, colonies can be forced to eject drones.

It’s tough being a drone … which may explain why one of my PhD students has the name @doomeddrone on Twitter 😉


 

No risk, no reward

“April showers bring May flowers”, or something close to that, is a poem that has its origins in the General Prologue of Chaucer’s Canterbury Tales.

It means that the Atlantic low pressure systems that roll in from the west during April, often bringing rain, also account for the abundance of flowers that bloom in May.

Not much sign of any April showers last month …

April 2021 sunshine anomaly compared to 1981 – 2010

Most of the country was bathed in spring sunshine, with Scotland and the north of England getting 150-170% of the average seen over the last 30-40 years. 

Unsurprisingly, with that amount of sunshine, rain was in short supply. Much of the country experienced only 20-33% of the usual April rainfall.

Which should be great for beekeeping, right?

Well, not if it’s accompanied by some of the lowest temperatures seen for half a century.

April 2021 average temperature anomaly compared to 1981 – 2010

The entire country was significantly colder than normal, with the bit of Fife my bees are in being 3°C colder than the average over the last decade, with frosts on ~60% of the nights during the month 1.

And, for those of us interested in queen rearing, this sort of start to the season can cause frustrating delays … or encourage a bit of risk taking.

The heady mix of strong colonies, drones and good weather

Queen rearing needs three things to occur at more or less the right time – which doesn’t mean simultaneously.

  1. The colony needs to be strong enough to rear new queens. Good queens – whether reared from grafted larvae or naturally under the swarming or emergency impulse – require lots of nurse bees in the hive to lavish the developing larvae with attention. Three or four frames of brood isn’t enough. The hive really needs to be bursting with bees. A long winter, cold spring or bad weather can hold the colony back. 
  2. Drones need to be available to mate with the virgin queens. Drones take 24 days to develop from egg to emerged adult. However, before they can mate, drones need to reach sexual maturity and learn about the environment around the hive. Sexual maturity takes 6 – 16 days and, at the same time, the drones embark on a number of orientation flights which start a week or so after emergence. 
  3. Good weather for queen mating. After emerging the queen also needs to reach sexual maturity. This takes 5-6 days. She then goes on one or more mating flights, before returning to the hive for a lifetime of egg laying 2. Bad weather – either temperatures significantly below 20°C, rain or strong winds – all prevent these mating flights from taking place. 

With no drones, a weak colony, or lousy weather there’s little chance of producing high quality, well-mated queens.

Or perhaps of producing any queens at all 🙁

Second impressions

My Fife colonies were first inspected in mid-April. Most were doing OK, with at least 5-7 frames of brood and some fresh nectar in the brood box. 

Despite the low temperatures they were making the most of the sunshine and foraging whenever possible.

A week later, at their second inspection on the 25th, the majority of colonies had 1-2 supers 3 and were building up well. All had drone brood and some had adult drones.

By this time I’d identified – from my records, the overwinter performance (stores used, strength and build-up) and their behaviour when inspected under frankly rubbish conditions – which colonies I would be using for queen rearing.

I also knew which colonies would need to be requeened.

My ‘rule of thirds’

My colony selection for stock improvement is simple and straightforward.

Colonies that I consider form the worst third of my stocks are always requeened 4. Furthermore, I do my best to avoid these bees contributing to the gene pool. I don’t use larvae from them for grafting and I don’t split them and allow them to rear their own queens 5.

Ideally (in terms of the gene pool, not in terms of their fate 🙁 ) I’d also remove all drone brood from these colonies. These drones will most likely mate with queens from other hives 6, but if their genes aren’t good enough for me they probably aren’t good enough for the unsuspecting virgin queens in the neighbourhood either.

Colonies I consider in my top one third of stocks are used as a source of larvae for grafting, and can be split and allowed to rear their own new queens.

The ‘middle’ third are requeened if I have spare queens, which I usually do.

It’s surprising how quickly this type of selection results in stock improvement. By focusing on a series of simple traits I favour (e.g. frugal with winter stores, calm when inspected in persistent rain) or dislike (e.g. running on the comb, following, stroppiness) in my bees I’ve ended up with stocks that are pretty good 7.

Queen cells … don’t panic

On April 25th many colonies had play cups but only one had charged queen cells

Considering the 10 day weather forecast, my overall level of preparedness to start queen rearing (!) and the relatively early stage of development of the cells (24-48 hour larvae) I nearly squidged the cells and closed the hive up for another week.

It still felt too early and far too cold.

know that knocking back queen cells is not swarm control (and have suggested this is engraved on all hive tools sold to beginners).

However, swarming also requires good weather. If it’s 9-11°C the colony will not swarm … and I was pretty confident that the weather wasn’t going to warm up significantly in the week until the next inspection.

So, in my typical Do as I say, don’t do as I do” style, I reckoned it was a safe bet to destroy the queen cells and check again a week later.

I would have expected to find more queen cells then, but I’d have been astounded if the colony had swarmed in the intervening period.

Second thoughts

But this was a lovely colony. 

It has always been good, had overwintered on a single 12.5 kg block of fondant and was already on 10 frames of brood in all stages 8. And that was a full box as it’s a Swienty brood box that only takes 10 National frames. To give them more room I would have had to add another brood box.

Not only that, but the bees were calm when inspected under miserable conditions. They didn’t run about on the comb and they weren’t aggressive.

The colony was comfortably near the top of my top third …

If the colony had swarmed, despite the queen being clipped, there’s a good chance I’d have lost her. The apiary is ~140 miles from home and that’s not the sort of journey you can make to ‘quickly check the hives’

So, how could I ensure that I didn’t lose the queen and take advantage of the quality of the stock and its apparent readiness to reproduce?

Plan B

Looking after the queen was straightforward. 

I prepared a 3 frame nucleus colony containing the frame the queen was on and a couple of frames of emerging brood. I added a frame of sealed stores and a new frame of foundation.

A frame of sealed stores … perfect for feeding nucs

I stuffed the entrance of the nuc with grass, wedged the frames together with a foam block and pinned a travel screen over the top.

The travel screen really wasn’t necessary. I had to transport the bees to another apiary and, although there was now weak sunshine the temperature was only just double digits (°C) and my beesuit was still damp from an earlier shower. I didn’t fancy driving for 40 minutes with the windows open to keep the bees cool, so opted to ventilate them better and keep me a bit warmer 😉

This is the nucleus method of swarm control. It’s almost foolproof 9.

It is possible to get it wrong, but you have to try quite hard. 

In my experience it’s the most dependable method and has the added advantage of using the minimal amount of additional equipment.

The queen was safe in a new box. She had space to lay and lots of young bees to support her. The queenless colony had ample stores and 7 frames of brood in all stages. 

This nucleus colony will be used as a source of larvae for grafting in mid/late May. I can easily regulate the strength of this colony – to prevent them swarming – by stealing a frame or two of brood periodically. If replaced by a foundationless frame (or a frame with foundation) they will draw lovely new comb with the help of the nectar flow from the oil seed rape.

The original, and now queenless, colony was given three new frames and closed up.

One week later

In early May the cold, sunny weather was replaced by very cold, very wet weather 🙁

On the 3rd of May I drove through snow and heavy rain to get to the apiary. The following day I started inspecting the colonies in intermittent light drizzle and a temperature of 7°C. 

Not ideal 🙁

The weather gradually improved. By the time I finished in the apiary it had reached a balmy 11°C.

Notwithstanding the conditions, the bees were well behaved. 

With some bees, if you open the hive in poor weather they rush out mob-handed.

Before you get a chance to think “Can I smell bananas?” you’ve collected half a dozen stings and they’re recruiting reinforcements 10.

You know it’s going to be a long and painful day …

However, perhaps because the bees were sick and tired of the low temperatures this spring they just sat on the comb looking mournful … you could almost see their little faces as row upon row of upside down smilies 🙁 🙁 🙁 🙁 

This ‘calmness in the face of adversity’ (!) makes these bees easy and tractable to deal with in poor conditions. It’s a byproduct of selection from the ‘best’ third of my stocks year after year.

I don’t actively select bees for bad weather beekeeping, but it’s a nice bonus when it happens.

The queenless colony now contained 7 frames of sealed brood, many of which also contained queen cells. They had almost completely drawn the new frames I’d added the previous week when I made up the nuc.

More nucs

I prepared 3 two frame nucs from the hive, leaving the remaining frames – with some new ones – in the dummied down brood box.

Doing this sort of manipulation in poor weather takes preparation and planning. You do not want to be rushing back to the shed for an extra frame, or searching around for entrance blocks, or doing anything that leaves the bees exposed for longer than necessary.

Ready to go …

The poly nucs were all set up, with the entrances sealed, a frame of capped stores, two new frames and a dummy board. The foam travel blocks (to hold the frames tightly together), plastic crownboards, lids and hive straps were piled up within easy reach.

Making up two frame nucs

All of this was done before I’d even opened the queenless hive 11.

The queen cells were all sealed (as would be expected from the timing of the last inspection, 8-9 days earlier) and had been produced in a busy hive, with lots of nurse bees to attend to them.

The majority would have been reared under the emergency impulse.

I quickly and carefully transferred two frames from the queenless hive to each nuc. I ensured that each nuc received a frame containing a good queen cell.

In practice, the nucs and the colony remnants probably all ended up with several queen cells.

Not another “Do as I say, don’t do as I do?” situation?

I usually leave only one queen cell in a hive to ensure a strong colony doesn’t produce multiple casts.

However, this time I did not thin out any of the queen cells. 

This was a pragmatic decision largely based upon the weather. It was too cold to be searching across every frame to select the best cell. The bees would have been distressed and disturbed, and there was a risk of chilling the brood 12.

It was also a rational decision considering the strength of the colonies I was setting up. With a much-reduced population of bees it’s very unlikely the colony will allow all the queens to emerge. I expect most of the cells to be torn down by the workers.

The nucs were all transferred to an apiary over three miles away. This avoids any risk of them reducing in strength due to flying bees returning to the original site.

These nucs were relatively small colonies so will require some TLC. I’ll check them soon after the new queens emerge. If they look understrength I’ll add a frame of emerging brood (harvested from one of the bottom ‘third’ of colonies. They might not be good enough to split but they are still very useful bees 🙂 ).

I’ll then leave them for at least 2-3 weeks hoping that the weather improves significantly for queen mating.

This is the ‘taking a risk’ bit of the whole process. Mid/late May should offer some suitable days for queen mating, but if this weather continues it’s not guaranteed. 

Somewhere between ~26-33 days after emergence the virgin queen becomes too old to mate successfully.

For these queens, that will take us to the week beginning the 3rd of June.

If we’ve not had any good queen mating days by then things will be getting a bit desperate 🙂

Active queen rearing begins soon

Splitting a colony into nucs containing queen cells is one way of rearing new queens. The quality of the resulting colony is dependent – at least partially – on the quality of the colony you start with.

With a high quality starting stock it is effectively ‘passive’ queen rearing … very little effort with potentially good rewards. 

What’s not to like?

Preliminary setup for Ben Harden queen rearing

But with the weather slowly but inexorably improving (really!) it’s time to start thinking about ‘active’ queen rearing – cell starters, grafting, cell finishers, mini-nucs etc.

With the good quality queen busily laying away in her nuc box it was time to set up a colony for queen rearing using the Ben Harden approach.

In this instance the quality of the colony is largely immaterial. It needs to be strong and healthy, but its genetics will not contribute to the quality of the resulting queens. 

My final task before leaving the apiary was to add the fat dummies and additional frames in preparation for queen rearing using selected grafted larvae.

And that’s what I hope to be doing next week 🙂


 

Acting on Impulse

Men just can’t help acting on Impulse … 

This was the advertising strapline that accompanied the 1982 introduction of a new ‘body mist’ perfume by Fabergé. It was accompanied by a rather cheesy 1 set of TV commercials with surprised looking (presumably fragrant) women being accosted by strange men proffering bouquets of flowers 2.

Men just can’t help acting on Impulse …

And, it turns out that women – or, more specifically, female worker honey bees – also act on impulse

In this case, these are the ‘impulses’ that result in the production of queen cells in the colony.

Understanding these impulses, and how they can be exploited for queen rearing or colony expansion (or, conversely, colony control), is a very important component of beekeeping.

The definition of the word impulse is an ‘incitement or stimulus to action’.

The action, as far as our bees are concerned, is the development of queen cells in the colony.

If we understand what factors stimulate the production of queen cells we can either mitigate those factors – so reducing the impulse and delaying queen cell production (and if you’re thinking ‘swarm prevention‘ here you’re on the right lines) – or exploit them to induce the production of queen cells for requeening or making increase.

But first, what are the impulses?

There are three impulses that result in the production of queen cells – supersedure, swarm and emergency.

Under natural conditions i.e. without pesky meddling by beekeepers, colonies usually produce queen cells under the supersedure or swarm impulse.

The three impulses are:

  1. supersedure – in which the colony rears a new queen to eventually replace the current queen in situ
  2. swarm – during colony reproduction (swarming) a number of queen cells are produced. In due course the current queen leaves heading a prime swarm. Eventually a newly emerged virgin queen remains to get mated and head the original colony. In between these events a number of swarms may also leave headed by virgin queens (so-called afterswarms or casts).
  3. emergency – if the queen is lost or damaged and the colony rendered queenless, the colony rears new queens under the emergency impulse.

Many beekeepers, and several books, state that you can determine the type of impulse that induced queen cell production by the number, appearance and location of the queen cells.

And, if you can do this, you’ll know what to do with the colony simply by judging the queen cells.

If only it were that simple

Wouldn’t it be easy?

One or two queen cells in the middle of frame in the centre of the brood nest? Definitely supersedure. Leave the colony alone and the old queen will be gently replaced over the next few weeks. Brood production will continue uninterrupted and the colony will stay together and remain productive.

A dozen or more sealed queen cells along the bottom edge of a frame? The colony is definitely  in swarm mode and – since the cells are already capped – has actually already swarmed. Time to thin out the cells and leave just one to ensure no casts are also lost.

But it isn’t that simple 🙁

Bees haven’t read the textbooks so don’t necessarily behave as expected.

I’ve found single open queen cells in the middle of a central frame, assumed it was supersedure, left the colony alone and lost a swarm from the hive a few days later 🙁

D’oh!

Or I’ve found loads of capped queen cells on the edges of multiple frames in a hive, assumed that I’d missed a swarm … only to subsequently find the original marked queen calmly laying eggs as I split the brood box up to make several nucleus colonies  🙂

Not all queen cells are ‘born’ equal

It’s worth considering what queen cells are … and what they are not. And how queen cells are started.

There are essentially two ways in which queen cells are started.

They are either built from the outset as vertically oriented cells into which the queen lays an egg, or they start their life as horizontally oriented 3 worker cells which, should the need arise, are re-engineered to face vertically.

Play cup or queen cell?

Play cup or are they planning their escape …?

Queen cells started under the supersedure or swarming impulse are initially created as ‘play cups‘. A play cup looks like a small wax version of an acorn cup – the woody cup-like structure that holds the acorn nut. In the picture above the play cup is located on the lower edge of a brood frame, but they are also often found ‘centre stage‘ in the middle of the frame.

Play cups

A colony will often produce many play cups and their presence is nothing to be concerned about. In fact, I think it’s often a rather encouraging sign that the colony is sufficiently strong and healthy that it might be thinking of raising a new queen. 

Before we leave play cups and consider how emergency queen cells start life it’s worth emphasising the differences between play cups and queen cells.

Play cups are not the same as queen cells

Until a play cup is occupied by an egg it is not a queen cell.

At least it’s not as far as I’m concerned 😉

And, even if it contains an egg there’s no guarantee it will be supported by the workers to develop into a new queen 4.

However, once the cell contains a larva and it is being fed by the nurse bees – evidenced by the larva sitting in an increasingly thick bed of royal jelly – then it is indisputably a queen cell.

Charged queen cell ...

Charged queen cell …

And to emphasise the fundamental importance in terms of colony management I usually refer to this type of queen cell as a ‘charged queen cell’.

Once charged queen cells appear in the colony, all other things being equal, they will be maintained by the workers, capped and – on the 16th day after the egg was laid – will emerge as a new queen.

And it is once charged queen cells are found in the colony that swarm control should be considered 5.

But let’s complete our description of the queen cells by considering those that are produced in response to the emergency impulse.

Emergency queen cells

Queen cells produced under the emergency impulse differ from those made under the swarm or supersedure impulse. These are the cells that are produced when the colony is – for whatever reason – suddenly made queenless. 

Without hamfisted beekeeping it’s difficult to imagine or contrive a scenario under which this would occur naturally 6, but let’s not worry about that for the moment 7

The point is that, should a colony become queenless, the workers in the colony can select one or more young larvae already present in worker cells and rear them as new queens.

So, although the eggs are (obviously!) laid by the queen 8, they have been laid in a normal worker cell. To ensure that they get lavished with attention by the nurse bees, feeding them a diet enriched in Royal Jelly, the cell must be re-engineered to project vertically downwards.

Location, location

Queen cells can occur anywhere in the hive to which the queen has access.

Queen cell on excluder

Queen cell on underside of the excluder …

But they are most usually found on the periphery of the frame, either along the lower edge …

Queen cells ...

Queen cells …

… or a vertical side edge of the frame …

Sealed queen cells

… but they can also be found slap, bang in the middle of a brood frame.

Single queen cell in the centre of a frame

And remember that bees have a remarkable ability to hide queen cells in inaccessible nooks and crannies on the frame … and that finding any queen cells is much more difficult when the frame is covered with a wriggling mass of worker bees.

Location and impulses

Does the location tell us anything about the impulse under which the bees generated the queen cell?

Probably not, or at least not reliably enough that additional checks aren’t also needed 🙁

Many descriptions will state that a small number (typically 1-3) of queen cells occupying the centre of a frame are probably supersedure cells. 

Whilst this is undoubtedly sometimes or even often true, it is not invariably the case.

The workers choose which larvae to rear as queens under the emergency impulse. If the only larvae of a suitable age are situated mid-frame then those are the ones they will choose.

In addition, since generating emergency cells requires re-engineering worker cells, newer comb is likely more easily manipulated by the workers.

Some beekeepers ‘notch’ comb under suitably aged larvae to induce queen cell production at particular sites on the frame 9. The photograph shows a frame of eggs with a notch created with the hive tool. It’s better to place the notch underneath suitably aged larvae, not eggs. Clearly, the age of the larvae is more critical than the ease with which the comb can be reworked. Those who use this method [PDF] properly/extensively claim up to a 70% ‘success’ rate in inducing queen cell placement on the frame. This can be very useful if the plan is to cut the – well separated – queen cells out and use them in mating nucs or for requeening other colonies.

Eggs in new comb ...

Eggs in new comb …

Comb at the bottom or side edges of the frame often has space adjacent and underneath it. Therefore the bees might favour these over sites mid-frame (assuming ample suitable aged larvae) simply because the comb is easier to re-work in these locations.

And don’t forget … under the emergency impulse the colony preferentially chooses the rarest patrilines to rear as new queens 10.

Not all larvae are equal, at least when rearing queens under an emergency impulse.

Active queen rearing and the three impulses

By ‘active’ queen rearing I mean one of the hundreds of methods in which the beekeeper is actively involved in selecting the larvae from which a batch of new queens are reared.

This doesn’t necessarily mean grafting , towering cell builders and serried rows of Apidea mini nucs.

It could be as simple as taking a queen out of a good colony to create a small nuc and then letting the original colony generate a number of queen cells.

Almost all queen rearing methods use either the emergency or supersedure impulses to induce new queen cell production 11.

For example, let’s consider the situation described above.

Active queen rearing and the emergency impulse

A strong colony with desirable traits (calm, productive, prolific … choose any three 😉 ) is made queenless by removing the queen on a frame of emerging brood into a 5 frame nucleus hive. With a frame of stores and a little TLC 12 the queen will continue to lay and the nuc colony will expand.

Everynuc

Everynuc …

But the, now queenless, hive will – under the emergency impulse – generate a number of new queen cells. These will probably be distributed on several frames if the queen was laying well before she was removed.

The colony will select larvae less than ~36 hours old (i.e. less than 5 days since the egg was laid) for feeding up as new queens.

If the beekeeper returns to the hive 8-9 days later it can be split into several 5 frame nucs, each containing a suitable queen cell and sufficient emerging and adherent bees to maintain the newly created nucleus colony 13.

Active queen rearing and the supersedure impulse

In contrast, queenright queen rearing methods such as the Ben Harden system exploit the supersedure impulse.

Queen rearing using the Ben Harden system

In this method suitably aged larvae are offered to the colony above the queen excluder. With reduced levels of queen pheromones present – due to the physical distance and the fact that queen cannot leave a trail of her footprint pheromone across the combs above the QE – the larvae are consequently raised under the supersedure impulse.

Capped queen cells

Capped queen cells produced using the Ben Harden queenright queen rearing system

I’m always (pleasantly) surprised this works so well. Queen cells can be produced just a few inches away from a brood box containing a laying queen, with the workers able to move freely through the queen excluder. 

Combining impulses …

Finally, methods that use Cloake or Morris boards 14 use a combination of the emergency and supersedure impulses.

Cloake board ...

Cloake board …

In these methods the colony is rendered transiently queenless to start new queen cells. About 24 hours later the queenright status is restored so that cells are ‘finished’ under the supersedure response.

The odd one out, as it’s not really practical to use it for active queen rearing, is the swarming impulse. Presumably this is because the conditions used to induce swarming are inevitably rather difficult to control. Active queen rearing is all about control. You generally want to determine the source of the larvae used and the timing with which the queen cells become available.

Environmental conditions can also influence colonies on the brink of swarming … literally a case of rain stopping play.

Acting on impulse

If there are play cups in the colony then you don’t need to take any action 15, but if there are charged queen cells present then your bees are trying to tell you something.

Precisely what they’re trying to tell you depends upon the number and position of the queen cells, the state or appearance of those cells, and the state of the colony – whether queenright or not.

What you cannot do 16 is decide what action to take based solely on the number, appearance or position of the queen cells you find in the colony. 

Is the colony queenright?

Are there eggs present in the comb?

Does the colony appear depleted of bees?

If there are lots of sealed queen cells, no eggs, no sign of the queen and a depleted number of foragers then the colony has probably swarmed. 

Frankly, this is pretty obvious, though it’s surprising the number of beekeepers who cannot determine whether their colony has swarmed or not.

But other situations are less clear … 

If there are a small number of charged queen cells, eggs, a queen and a good number of bees in the hive then it might be supersedure.

Or the colony might swarm on the day the first cell is sealed 🙁

How do you distinguish between these two situations? 

Is it mid-May or mid-September? Swarming is more likely earlier in the season, whilst supersedure generally occurs later in the season.

But not always 😉

Is the queen ‘slimmed down’ and laying at a reduced rate?

Much trickier to determine … but if she is then they are likely to swarm.

Decisions, decisions 😉 … and going by the number of visits to my previous post entitled Queen cells … don’t panic! there are lots of beekeepers trying to make these decisions right now 🙂


 

Winter losses

I lost 10% of my colonies this winter.

It’s always disappointing losing colonies, but it’s sometimes unavoidable.

I suspect the two I lost were unavoidable … though, as you’ll see, they weren’t completely lost.

April showers frosts

Late April may seem like mid-season for many beekeepers based in southern England. While they were adding their second super, the bees here in Scotland were only just starting to take their first few tentative flights of the year.

This April has been significantly cooler in Fife 1 than any year ‘since records began’.

However, the records I’m referring to are from the excellent Auchtermuchty weather report 2 which only date back to about 2013 … I like it because it’s local, not because it’s historically comprehensive 😉

The average April temperate has only been 5.5°C with 15 nights with frost in the first three weeks of the month. In contrast, the same month in 2019 and 2020 averaged over 9°C with only 3-4 nights with frosts 3

In both 2019 and 2020 swarming started at the end of April. Several colonies had queen cells when I first inspected them and I hived my first swarm (not lost from one of my colonies 😉 ) on the last day of the month.

First inspections and winter losses

Unsurprisingly, with appreciably lower temperatures, things are less well advanced this season. None of the colonies I inspected on the 19th were making swarm preparations. Instead, most were 2-4 frames of brood down on the strength I’d expect them to have before they started thinking about swarming.

Nevertheless, most were busy on a lovely spring day … lots of pollen (mainly gorse and some late willow by the looks of things) being delivered by heavily-laden foragers, and fresh nectar in some of the brood frames.

Fresh nectar glistening in a brood frame

The first inspection of the season is an opportunity to not only check on the strength and behaviour of the colony, but also to do some ‘housekeeping’. This includes:

  • swapping out old, dark brood frames (now emptied of stores) and replacing them with new foundationless frames
  • removing excess stores to make space for brood rearing
  • removing the first sealed drone brood in the colony to help hold back Varroa replication

And, as the winter is now clearly over, it’s the time at which the overall number of winter losses can be finally assessed.

Winter losses

Winter losses generally occur for one of four reasons:

  • disease – in particular caused by deformed wing virus (DWV) vectored by high levels of Varroa in the hive. DWV reduces the longevity of the diutinus winter bees, meaning the colony shrinks in size and falls below a threshold for viability. There are too few bees to thermoregulate the colony and too few bees to help the queen rear new larvae. The colony either freezes to death, dwindles to the size of an orange, or starves to death because the cluster cannot reach the stores 4.
  • queen failure – for a variety of reasons queens can fail. They stop laying altogether or they only lay drone brood. Whatever the reason, a queen that doesn’t lay means the colony is doomed.
  • natural disasters – this is a bit of a catch-all category. It includes things like flooded apiaries, falling trees and stampeding livestock. Although these things might be avoidable – don’t site apiaries in flood risk areas, under trees or on grazing land – these lessons are often learnt the hard way 5.
  • unnatural disasters – these are avoidable and generally result from inexperienced, or bad 6 , beekeeping. I’d include providing insufficient stores for winter in this category, or leaving the queen excluder in place resulting in the isolation of the queen, or allowing the entrance to be blocked. These are the things that the beekeeper alone has control over. 

The BBKA run an annual survey of winter losses in the UK. This is usually published in midsummer, so the graph below is from 2020.

BBKA winter survival survey

Over the 13 years of the survey the average losses were 18.2% 7. Long or particularly hard winters result in higher levels of losses.

Lies, damn lies and statistics

I’ve no idea how accurate these winter loss surveys are.

About 10% of the BBKA membership reported their losses, and the BBKA membership is probably a bit over 50% of UK beekeepers. 

I would expect, with precious little evidence to back it up, that the BBKA generally represents the more ‘engaged’ beekeepers in the UK 8. It also probably represents a significant proportion of new beekeepers who were encouraged to join while training.

So, like Amazon reviews, I treat the results of the survey with quite a bit of caution. I suspect beekeepers who have low losses complete it enthusiastically to ‘brag’ about their success (despite its anonymity), while those with large losses either keep quiet or are happy to share their grief. 

Unlike Amazon reviews, I’d be surprised if there are many fake submissions to the BBKA and I’m not aware there’s a living to be made from selling fake colony survival reviews in bulk online.

For comparison, the Bee Informed Partnership in the USA runs a similar survey every year.

Bee Informed Partnership loss and management survey

This survey covers about 10% of the colonies in the USA. Again it is voluntary and likely subject to the same inherent biases that may affect the BBKA survey.

The USA winter colony losses average ~28% over the same 13 year survey period.

Are US beekeepers less good at keeping their colonies alive than beekeepers in the UK?

Perhaps the US climate is less suited to honey bees?

Or, possibly, US beekeepers are simply more honest than their UK counterparts?

I doubt it 9.

Running on empty

My two colony losses were due to queen failures.

Old winter bees and no brood

In the first colony there was no evidence the queen had laid any brood since the previous autumn. There were about 6 seams of bees in the hive, but the outer 2-3 frames were solid with untouched winter stores.

Unused winter stores

This is usually a dead giveaway … literally. The colony hasn’t used the stores because they’ve not had any hungry mouths to feed. With no new brood the colony is doomed.

This queen appears to have simply run out of sperm and stopped laying. She was present (a 2019 marked queen and the same one I’d seen in August last year) and ambling around the frame, but she wasn’t even going through the pretence of inspecting cells before laying.

I removed the queen and united what remained of the colony over a nearby strong colony.

Strong colony ready for uniting

Assuming the queen stopped laying at the end of year all the bees in the hive – and there were a good number – were old, winter bees. These won’t survive long, but will provide a temporary boost to the colony I united them with. 

Every little bit helps 🙂

Even more valuable than the bees were the frames they were on.

Most of the comb in the colony with the failed queen was relatively new. By uniting them I can quickly swap out the old comb (from the stronger hive #34) when I next inspect the hive. At the same time I’ll rescue the frames of sealed stores for use when making up nucs during queen rearing.

Drone laying queen

The second failure was a drone laying queen (DLQ).

These are usually unmistakeable … the brood is clustered, with drone pupae occupying worker brood cells. If the queen has been drone laying for some time there may be lots of undersized ‘runt’ drones present in the hive as well.

Drone laying queen ...

Drone laying queen …

Again, this colony was doomed. With no new queens available and a lot of pretty old bees in the hive they could not be restored to a functioning colony.

However, many of the bees could be saved …

The colony wasn’t overrun with drones. Going by the amount of stores consumed it had probably been rearing worker brood since the winter solstice.

The queen was unmarked and unclipped. I strongly suspect she was a late-season supersedure queen who was very poorly mated.

The 3-4 weeks of drone brood rearing 10 had wrecked quite a few of the frames, but the bees were worth saving.

Under these circumstances I decided to shake the colony out.

When I do this I like to move the original hive and the stand it’s on. If you don’t move the stand the displaced bees tend to cluster near the original hive entrance, festooned from the hive stand. 

In poor weather, or late in the afternoon, this can lead to lots of bees unnecessarily perishing.

However, the stand was shared with two other colonies, so couldn’t be removed. It was also late morning and the weather was excellent.

I moved the hive away and shook the bees out. 

Sure enough … they returned to their original location.

They then marched along the hive stand to the entrance of the adjacent hive.

This way sisters!

And, by the time I left the apiary in mid-afternoon there were only a few diehard bees clustered near where the original hive entrance was.

Why didn’t I just unite them as I’d done with the other failed queen?

Drone brood is a Varroa magnet

Varroa replicate when feeding on developing pupae. The longer development time of drone pupae (when compared with worker pupae) means that you get ~50% more Varroa from drone brood 11

Unsurprisingly perhaps (or not, because that’s the way evolution works) Varroa have therefore evolved to preferentially infest drone brood. When given the choice between a drone or worker pupa to infest, Varroa choose the drone about 10 times more frequently than the worker.

And that ~10:1 ‘preference ratio’ increases when drone brood is limiting … as it is early in the season.

What this means is that the first burst of drone brood production in a colony is very attractive to Varroa.

Unless there are compelling reasons to keep this very early drone brood – for example, a colony with stellar genetics I’d like to contribute as much as possible to the local gene pool – I often try and remove it.

Drone-worker-drone

Drone-worker-drone …

If you use foundationless frames this is often as easy as simply cutting out a single panel of drone brood.

But, in the case of this drone laying queen, it meant that the logical action was to discard all of the drone brood to ensure I discarded the majority of the Varroa also present in the colony 12.

Which is why I shook the colony out, rather than uniting them 🙂

Boxes of bees

Several colonies in one apiary went into the winter on double brood colonies. Inevitably, with the loss of bees during the winter months, the colony contracts and the queen almost invariably ends up laying in the upper box.

The first inspection of the season is often a good time to remove the lower box. It can be removed altogether, or replaced (above the other box) for a Bailey comb change if the weather is suitable.

At this stage of the year the lower box is often reasonably empty of bees and totally empty of brood. 

Emptying a box of bees

If the comb in the lower box is old and dark (see the picture above) I place the upper box on the original floor and add an empty super on top. I then go through the lower box, shaking the bees into the empty super. Good frames are retained, the rest are destined for the wax extractor and firelighters.

Using an empty super helps ‘funnel’ the bees into the brood box.

Sometimes the queen has already laid up a frame or so in the lower box. Under these circumstances – particularly if the comb is relatively new – I’ll simply reverse the boxes, placing the lower box on top of the upper one. This results in the queen quite quickly moving up and laying up the space in the upper brood chamber.

It’s then time to add a queen excluder and the first super.

The beekeeping season has definitely started 🙂


Notes

I commented a fortnight ago about the apparent lateness of the 2021 spring. I’m adding this final note on the afternoon of the 23rd and have still yet to see or hear either cuckoo or chiffchaff on the west coast. Last year they were here in the middle of the month. This, combined with the temperature data (see above) show that everything is a week or two behind events last year.

Which means I can expect to start doing some sort of swarm prevention and control in the next fortnight.