Tuesday, 18 July 2017

Why Do Bees Make Queen Cells?

I've mentioned queen cells several times over the last few weeks.  And with good reason - spring and early summer is the peak time for bees to make them.  However, they can make them at other times too, depending on their reason for doing so.  But why make them?  Well, the obvious answer is: "to make a new queen".  But there are actually three different reasons bees might want to make a new queen - let's look at each in turn:

Reason One - Reproduction

Like all living things, honey bees have to reproduce or they will become an extinct species.  I covered the mechanics of mating a few weeks ago, in this post.  And last year, I posted about how chemistry determines the difference between worker bees and queens.  Quick re-cap:  if a female bee larva is fed royal jelly - which contains royalactin - for the 8 days after the egg hatches, then she becomes a queen, she is fertile, and she gets to mate.  Otherwise, she becomes a worker, she's infertile, and sex is off the menu.

The thing about queen bees is that, apart from the mating flights (when they really don't want their more prudish sisters around) they don't travel alone.  This means that, if a colony of bees is going to reproduce, there needs to be enough workers to divide into two groups - half the colony will stick with the old queen, while the other half will hang out with the new one.  Also, there needs to be some drones around for the new queen to mate with, and hives don't start producing them until April.  The size of the colony starts to expand in March, because the queen resumes laying eggs after taking a break over winter.  The expansion continues through April, but here in the West Country it's only in early May that the colony will contain enough bees that it can split into two viable colonies.

So, once the colony is big enough to split into two, then the bees will need two queens - they already have one, of course, but they need to make another.  So, they start work on making one.  Firstly, they will make a "queen cup".  This is a concave wax structure that faces downwards.  As far as the queen is concerned, it's just another cell to lay an egg in, which she duly does (a fertilised egg, to be precise, i.e. female).  Here's a photo of a slightly opened-up queen cup (with egg) that I took last year:

An egg in a cup

Once laid, the egg will hatch into a tiny larva, and the bees will start to feed it with royal jelly.  As they do so, the larva grows, and the bees extend the cell downwards so that it is always a little larger than the larva.  They continue to feed with royal jelly for 8 days, at which point they stop extending the cell and cap it off with wax at the bottom.

A capped Queen Cell

Then, something happens.  Perhaps it's the last worker bee who finishes sealing the cell, or maybe a subtle chemical change in the hive.  But somehow, something alerts the whole hive to the fact that there is a sealed queen cell.  And then the bees start dancing.  Not like the "waggle-dance", which is the one they use to tell their sisters about nectar-bearing flowers nearby.  This is a mad, crazy dance, like a rave party - the hive is suddenly brimming with energy and the buzz raises in both pitch and volume.  The bees start to nudge and harass the adult queen, until she has had enough and starts to warm up her wing muscles ready to fly.  And then, no more than a minute later, one queen bee and 20,000 of her daughters take to the air - so many bees that the sky turns dark - in a magical co-ordinated aerial ballet that we call: A Swarm!

OK - if you're a non-beekeeper, you might not be thinking "magical".  You may more likely be thinking "terrifying", actually.  But swarms really aren't aggressive things - the bees are not at all in the mood for threatening anyone.  They're just moving house.  And after maybe an hour at most, they will settle on a nearby tree branch in a big cluster of bees.  Later, anything up to a day later, they'll make the final journey to a nice big cavity in a tree, usually around 500 yards from the original hive, and start building honey comb in their new home.

So, the adult queen and half the bees have departed.  The other half remain in the hive, with the new queen, which now starts to pupate.  8 days after she was sealed in her cell, the queen has finished metamorphosis and is now a fully-formed adult queen bee.  She is now oriented head-downwards in the cell, and she neatly nibbles a hole in the bottom end of the cell, to emerge as the new ruler of her hive.

Reason Two - Managing The Succession

Failure to ensure an orderly succession from one monarch to another can be messy.  Just ask the Plantagenets...

Not wishing to cause any such strife, bees have got quite good at making sure the transition from one queen to another is conducted in an orderly fashion.  Death comes to all of us, and queen bees are no exception.  The worker bees are able to sense when their queen is coming to the end of her productive life, mainly by detecting changes in the amount of pheromone that she produces.  They will then start to build one or more queen cells.  Usually this will be after the summer solstice.  The timing here is interesting - if bees make a queen cell before the solstice, then they will generally swarm.  If they make it after the solstice, they generally won't - instead there will be a managed succession known as supersedure.

There's good reason for this.  If the bees start making a new queen before the solstice, then there will be enough time before winter for the swarm to establish itself, build wax and gather enough honey to survive until spring.  After the solstice, time is very much against them, and a colony will normally be too small and under-resourced to survive the winter.

What I find really interesting is that bees have a very keen sense of time.  They know when the days are getting longer, through spring.  And they can detect when the calendar has passed the solstice, and the days have begun to get shorter.  My bees were quite difficult to manage before the solstice, and I had to get very involved to prevent them swarming.  Now that the days are already getting shorter, they have completely given up making queen cells.

So, back to supersedure.  Usually there will not be many queen cells, often only two or three.  And the worker bees will typically tear down all but one before the queens have finished pupating.  Then, the new queen emerges, goes on her mating flights and returns to start laying eggs.  So far, so normal.  But there is one thing that is unusual about this arrangement - the old queen remains in the hive, and continues to lay alongside her daughter.  Normally there is only one queen in the hive, but supersedure is the exception - the old queen and her daughter will co-rule the hive, often for several weeks.  This arrangement will continue until the old queen dies - or, sometimes, is "assisted" to her mortal end by the workers.  Bees can be both decisive and brutal, when they feel the need.

Reason Three - The Queen Is Dead

So, sometimes, things don't go according to plan.  The queen might die unexpectedly, be killed by an incompetent beekeeper, or be assassinated by her own worker bees.  So much for an orderly succession - it becomes paramount to raise a new queen, and soon.

Bees will normally detect that a queen is absent after around 12 hours.  This, as with much hive business, is determined by pheromones - the workers will detect that the normal queen mandibular pheromone emitted by the queen is no longer present.

The apparent problem, at this point, is that there will not normally be any eggs laid in queen cells for the workers to grow into a queen.  However, they can make use of a handy feature of brood feeding.  As it happens, all worker larvae are fed royal jelly for the first three days, after which they are switched to the lower-fat, royalactin-lacking "brood food".  So, as long as the colony has some larvae that are less than three days old, the bees can select two or three of them and decide to make them into queens.

How they choose the right ones is a mystery.  What they do is not.  Initially the larva will be in a normal, hexagon-shaped cell.  The workers will nibble away at the bottom surface of the cell, and then extend it downwards to create the typical shape of a queen cell.  Here are a couple of examples that I have photographed:

Emergency queen cells

This type of queen cell is referred to as an "emergency queen cell" (regular readers should be familiar with the pragmatic use of language among beekeepers!)  The cell will often be shorter than a "swarm" or "supersedure" cell.  However, inside the cell everything proceeds as with any other queen cell:  the larva continues to be fed royal jelly, the cell will be capped after 8 days, and the queen larva will spend the next 8 days metamorphosing into an adult queen.  Then, she will emerge, take her mating flights, and begin laying eggs, at which point order is restored.  The emergency is over, and the colony resumes its everyday work of building wax, raising larvae, collecting pollen and making honey.

Monday, 10 July 2017

Miriam's Neighbours

Readers of last week's post will recall that Miriam (along with the rest of her colony) has now gone off to live at the other end of St Mark's Road, in the Southcot Burial Ground near the bottom of Lyncombe Hill.  The good news is that the colony has now been moved to a full-size hive, and appear to be doing very well.

While Jack, Sarah and I were moving Miriam last week, we got chatting about their other colony, which is not doing so well.  In fact, it's been queenless for several weeks - which means the colony population is declining.  What they really need is some more adult bees, and also some more eggs with which they can raise a new queen.  Unfortunately, I'd already burned three frames of eggs and brood earlier in the day, which is a shame as that would have been just what the bees needed to get back going again.

Nevertheless, I had another three frames to change on Friday, so we agreed to meet at Friday lunchtime for Sarah and Jack to collect the frames.  Everything went pretty-much according to plan - we went through each colony, found the queen, isolated the frame she was on, and then selected one of the old frames of brood and eggs.  Then we put the queen and her frame back, along with a fresh frame, and shook the bees off the old frame, which we then kept aside.

One we'd done that three times, there were three frames of capped brood and eggs, all ready to go.  We took them to Jack and Sarah's hive over at the other end of the road, opened up and put them in the middle, where it will hopefully be warmest.  Next week, we'll see if the numbers have increased - and also see if the bees have made any queen cells.

Back in my own hives, the frames are getting heavy with honey - and my new jars have been delivered.  It may be time to take the honey off next week - stay tuned...!

Tuesday, 4 July 2017

Goodbye - and Good Luck - to Miriam!

Miriam's colony has been living in the blue nucleus for the last few weeks, and were doing well when I checked last weekend.  But with 2 full-sized hives, and 2 nucs to look after, I've really had my work cut out for me recently.  So, I decided I'd see if I could find another beekeeper who would be interested in adopting Miriam.

The nearest bees to mine are actually really close - just the other end of St Mark's Road, in the burial ground off Lyncombe Hill.  So I got in touch with Jessica, who keeps a hive there, to see if she was interested, or knew anyone who was.

It was good news - Sarah and Jack also look after a hive there and were interested in getting a new colony.  So, we arranged to meet at dusk on Sunday for them to collect the nuc, and move it to the other end of the street.

There was one important issue to consider though - the bees' excellent homing instinct.  Now, this is normally very much an advantage - whenever a worker bee goes out foraging, she really needs to return to the same hive.  And because bees have such a keen sense of direction and location, she always does.  Partly this is done through remembering geographical features over their foraging range - something which I find remarkable, since a bee's brain is only the size of a grain of rice.  But herein lies the problem:  Lyncombe Hill is well within the bees' foraging range, which means that they will recognise all the local features and, when it's time to head home, they'll come back to my apiary instead of their new home.

There are two ways round this.  The first way is to move the colony at least three miles away from the original location, which would put them outside of their foraging range.  Then, when they head out of the hive, they have to learn all the new geography, and they forget what they had previously remembered.  After a week, you move them to the new location.  Even though it's near the original apiary, they will by this time have forgotten their way around, and will have to re-learn it - but, with the new hive location as the point that they will return to after foraging.

That's all fine, but it's a bit of a palaver.  So, there's option two - bribery!  Basically, once the nuc is at the new location, you keep the bees confined inside for a day by turning the entrance block to the closed position.  And you feed them (I covered feeding in a previous article if you want to see how it's done).  Then, you open the entrance block up and keep feeding for a few more days - and hopefully the bees will stay around the nuc, taking advantage of the free food, rather than flying off back to where their old home used to be.

Obviously, we chose option two.

But, this meant putting a feeder bowl, and a spacer box (known as an eke) onto the nuc between the brood box and the roof.  I've done this before with the blue nuc - and it works fine in situ - but because the eke I have is actually a little small (it's sized for the brown nuc, which is slightly narrower) it's no good for transporting.  So, to get the bees ready for their move, I had to swap the whole colony with the bees in the brown nuc.  Luckily, local Hymenoptera fan Stew was on hand to help!

Once Miriam and her bees were all safely re-homed in the brown nuc, I put the eke on top, secured the feeder bowl in place (gaffer tape is one of a beekeeper's most useful tools!) put the roof on and secured the whole stack with a ratchet strap, ready for transportation.

I met Jack and Sarah at dusk as arranged, and it was such a short distance that they were happy to carry the hive down to the other end of St Mark's Road.  Sarah lifted the roof, topped up the feeder bowl with some syrup that she'd prepared, and then we left the bees to settle in to their new home.  It's a lovely little green space, with primroses in the springtime, and I think Miriam's bees will be very happy there.

Nothing much to report from the hives, except that the bees in number 2 were in a grotty mood again this week.  However, it's now July, and my thoughts are starting to turn towards honey.  There is already one box of ten frames (in hive number 2) that is fully capped with wax - which means that the honey is ready to extract.  Also, a box of frames in hive number 1 is getting close - around half the cells of comb are capped, and with fair weather this week I may have 20 frames of honey ready to extract by next weekend.  Time to order some more jars...

And finally - the bees' landlady, Gill, was in the garden this week with her camera and took some lovely shots of the hives, and the bees foraging on her lavender.  Enjoy!