Friday, 14 June 2019

Meet the New Bees - Same as the Old Bees

Who's this...?


Well, it's queen Dorothy!  Regular readers will remember that she was last seen in June last year, heading off to her new home in Southcot burial ground.  The big news is - she's back!  And I have bees again!  Here's how it happened:

Towards the end of April, Jessica (Dorothy's new beekeeper) got in touch to say that she'd been doing a bailey comb change (in which the beekeeper temporarily puts a second brood box on the hive to encourage the bees to draw new comb).  But the bees had started to make queen cells, and Jessica wanted a second opinion before starting any swarm control.

I went down to meet Jessica at her hive - with an empty nuc in hand, just in case we needed it.  When we opened up, the hive was very busy, and there were lots of queen cells.  We decided there were enough bees and queen cells to do a three-way split, so we:

  • Found the frame with Dorothy on, and moved it into the nuc, along with two other frames, and added one empty frame to give the bees something to do.
  • Moved five frames (including bees and queen cells) into a new hive, with some fresh frames to fill the remaining space.
  • Left the rest of the frames (with bees and queen cells) in the original hive, and padded out the space with fresh frames.

Then we waited 2½ weeks to see if new queens had emerged in the hives, and had started laying.  They had!  We checked the nuc - all was well, and I added another empty frame.  And Jessica very generously offered to let me have Dorothy back, so that I could re-start beekeeping.

So, a couple of weekends ago (on 25th May) I arranged to meet Jessica to check on the nuc again.  Both her new queens were still laying, so we marked them each with a dot of paint.  Then we did a final check on the nuc - all well, and Dorothy was still laying happily.  I returned at dusk to collect the nuc and move it back to my apiary.  I put it next to hive #1, to make things nice and easy for moving the bees into the hive.

Three days later, I was ready to move the bees into their new home in hive #1.  Here's a photo of the nuc - with roof removed - and the hive, with an empty space to move the frames into:


Normally, it's a simple matter of moving the frames across and closing up the hive.  However, Jessica had been keeping her bees in a deep brood box, which is three inches deeper than my standard national.  The new frames I'd put in were national (14" x 9") sized, so that was fine.  Two of the three old frames were also national sized, and the bees had simply extended three inches of comb down from the bottom of the frames.  This was easily dealt with - I cut the excess comb off the bottom of the frames and put it aside (to burn later).

But one of the frames was a 14" x 12" frame that Jessica had put in.  There was plenty of brood and I didn't want to lose the frame.  So I decided I'd just have to cut off the bottom three inches.  A sharp pair of secateurs did the job nicely:


And that was it - the last frame put in place, a few new frames to to give the bees something to work on, and my new, old bees are back!

Tuesday, 23 April 2019

An End, and a Beginning

An End

On Thursday, I went to see what the bees in hive #1 (Laura's hive) were up to.  It was a warm spring day, so they should have been busy.  They weren't.  In fact, there were no bees going into or out of the hive.

A quick look inside confirmed my worst fears:


Another cluster of dead bees, and another dead queen.  They'd died in a very similar way to hive #2.  I'm not sure why - but I'd like to know - so I've kept 30 workers, plus the queen, to be sent away for analysis.  It may be disease - you can see some partially-capped pupae (that should be fully capped) toward the bottom-right of the picture.  Or, it may be that they starved because they couldn't hydrate the hard ivy honey that had crystallised in the cells (you can see a patch of it in the bottom-left of the picture).  But whatever the reason, I currently have no bees.

So, for the second time this year, I had to burn everything:


It's sad to have lost all my bees.  However, their bloodlines live on in Ian's and Jessica's bees and also in the ZEST hive.  So there are still Beechen Bees in Widcombe and Bathwick.  In other words, all is not lost, and I need to view this as more a setback than a disaster.

I'm going to concentrate on the ZEST hive for the next couple of weeks, and then think about what to do next.

A Beginning

Who's this furry friend?


It's Pippie!  Mrs Beekeeper and I drove over to an animal sanctuary in Cheltenham on Good Friday to collect her and bring her to live with us in her new Forever Home!  This is my very first picture of Pippie in our house - she is just leaving the bathroom where she had clearly been checking the facilities (an important task, since that is where we have put one of her litter trays).

No cat could ever replace our dear Patsy.  But it's nice to have the patter of little paws around the house once again.  Anyway, Pippie is already showing herself to have quite a different personality from Pats.  She is somewhat shy, but inquisitive, and when she is awake she is a little bundle of energy.  She has got to know the inside of the house, and has already been on a couple of excursions outside to enjoy the bank holiday weather and sniff all the spring smells in the garden.

Welcome to Widcombe, little Pippie - I think you will be very happy here.

Tuesday, 16 April 2019

When The Bee Stings - Part 2 - Chemistry

Science warning: this post contains actual science. You have been warned...

In part 1, we looked at the evolution and structure of the bee sting.  We know that the first venomous sting evolved in the common ancestor of all Aculeata around the late Triassic or early Jurassic.  Given 200 million years (give or take) of evolution, it's not surprising that the contents of the venom varies between bees, ants, wasps and hornets.  For example, bee stings are acidic (pH 5.0 - 5.5), whereas wasp stings are almost neutral (pH 6.8 - 6.9).

Anyway, we're not here to talk about wasps - this is a beekeeping blog.  And today's entry is about the chemistry of bee venom.  Those 200 million years of evolution have cooked up quite a cocktail of different substances, which work both in isolation and together to provide a precise pain experience when you get stung.  Let's take a dive straight into the detail - looking at the content of honey bee (Apis mellifera) venom, here are the approximate percentages by dry weight:

Melittin (peptide, 40-50%)

Melittin is a peptide, which means that it is a molecule formed of a short chain of amino acids.  This distinguishes it from a protein, which is a long amino acid chain.  Peptides turn up a lot in biochemistry, as they perform all sorts of useful functions including breaking down proteins; some peptides are hormones that are involved in physiological regulation.

Melittin is composed of 26 amino acids.  It has three principle actions:  firstly, it activates pain receptor cells.  Secondly, it causes holes to appear in cell membranes (which basically damages the cells).  The third action is to destroy red blood cells.  All of these are bad, obviously, which is why melittin is such an effective venom component.

Phospholipase A (enzyme, 10-12%)

Specifically, phospholipase A2.  This is an enzyme which breaks down phospholipids.  In turn, phospholipids are a major component of cell membranes, so phospholipase A2 has the effect of damaging the out walls of cells.  When the phospholipids break down, one of the components that is released is arachidonic acid.  This is then oxygenated by other enzymes, to form eicosanoids.  And eicosanoids signal the body's inflammation response.

Hyaluronidase (enzyme, 1-2%)

Another enzyme.  This one breaks down hyaluronic acid, which is a component of the tissue around the cells.  When this tissue breaks down, it increases the permeability of cells, and allows molecules to disperse more quickly around the cells.  In other words, hyaluronidase helps the other components of the venom to get around and into the cells faster.

Apamin (peptide, 2-3%)

This one is another peptide.  Fun fact - apamin was first isolated from the honey bee (Apis mellifera) - hence the name "apamin".  Another fun fact is that apamin is the smallest known peptide nurotixin - and the only one small enough to pass from the blood into the brain.  It acts on the SK channels, which are calcium-activated sodium channels inside neurons.  The job of these channels is to regulate (i.e. slow down) repetitive firing of the neurons - in other words, their job is to make the pain reduce after the initial sting.  But apamin blocks the SK channels, preventing them from slowing down the feeling of pain.  So apamin has the job of keeping going the pain that is caused by melittin.

Histamine (biogenic amine, 0.5-2%)

Histamine makes you itch.  anybody who has an allergy will be familiar with the action of histamine - if you have hay fever you get an itchy nose, while a cat allergy will cause very itchy skin if a cat scratches you.  It is also involved in the body's inflammatory response - inflammation has a number of effects, including making capillaries more permeable to white blood cells, which would normally be a way of fighting infection at a wound.  The inclusion of histamine is rather clever, as it uses the body's defensive system against itself by increasing inflammation at the site of the sting.

MCD Peptide (peptide, 2-3%)

Mast Cell Degranulating Peptide, to give it its full title.  Mast cells are found in connective tissue (including just under the skin) and contain granules which themselves contain histamine and heparin.  MCD peptide causes these granules to break down, releasing the heparin and histamine.  Heparin is an anticoagulant.  More histamine means even more itching and inflammation (see above).

Noradrenaline (biogenic amine, 0.1-0.5%)

Also known as norepinephrine.  Like adrenaline (which is chemically similar) noradrenaline increases heart rate and blood pressure, increases blood flow to the muscles, releases glucose for energy and can cause feelings of anxiety.  In other words, its use in bee venom is to deliberately stimulate the body's fight-or-flight response - presumably to encourage the victim to run away!

Serotonin (biogenic amine, trace amount)

At first sight it's odd to see serotonin here - it is, after all, one of the brain's "happy" chemicals, associated with good mood and feelings of well-being.  However, a side-effect of serotonin injection is localised pain, and that's what the bee is shooting for here.

Dopamine (biogenic amine, 0.2-1%)

Another chemical that is associated with happiness or pleasure.  This is because of dopamine's effect on the brain's reward-motivation system.  In fact, it's more correct to say that dopamine signals the perceived desirability or aversiveness of an event.  In this case, being stung is something to be averted, and dopamine is there to remind your brain of that.

Alarm Pheremones (trace amounts)

The function of the alarm pheremones is to increase the aggressiveness/defensiveness of other bees that are nearby.  So, if a colony is attacked, the first (and bravest) bee to sting the attacker will cause alarm pheremones to be released when the venom is injected.  This will encourage other bees to threaten, and then sting the attacker.  The longer they hang around, the more they get stung.  The wisest course of action is, of course, to run away!

References

I referred to a couple of useful articles when researching this blog post.

This is a piece of research that breaks down the components of honey bee venom by dry weight:
https://www.researchgate.net/publication/304012422_Bee_Venom_Production_Composition_Quality

And this is a nice infographic showing the different compositions of venom in the main groups of the Aculeata:
https://www.compoundchem.com/wp-content/uploads/2014/08/The-Chemical-Composition-of-Insect-Venoms-v2.pdf

Thursday, 4 April 2019

A Beginning, and an End

A Beginning

It was warm on Saturday - just warm enough to open up hive #1 (the only occupied hive) for a quick inspection.  Overall, the bees are doing fine - here's a brief list of observations:

  • There were bees on five frames.  For this time of year, that seems good.
     
  • The queen (Laura) has made it through the winter.  Also, she is laying - I saw eggs and both un-capped and capped brood.  The capped brood is worker (not drone) so that is also a good sign.
     
  • Some of the pupating brood - which should have been capped - weren't, or were only partly capped.  This is a slightly worrying sign, and I shall need to read up on possible causes.
     
  • There were a few dead bees in the hive.  Also, it looked like a couple of the larvae were not developing properly.  It didn't look like Sacbrood, but as there were only a couple I couldn't be sure.  I will need to keep an eye on this.
     
  • It may just be that the brood is cold (the hive is in almost permanent shade) and when the weather is warmer these problems disappear.
     
  • But it could be a sign of something worse.  For now there is no way of knowing.

Still, having done the first inspection, and re-configured the hive to its summer configuration (with the brood box at the bottom and queen excluder directly above it) my beekeeping year has officially begun.  Fingers crossed for good weather, healthy bees and plentiful honey.

An End

Many of my subscribed readers will know about our cat, Patsy.  On Friday, Pats was suddenly taken very ill, and we had to rush her to the vet.  Sadly, this is not a story with a happy ending.  The vet's opinion was that her condition was not going to improve, and in order to save her further distress we made the heartbreaking decision to let Patsy settle down to sleep for the last time.  Pats had been with us since she was approximately 8 years old, and had reached the grand old age of 19½.  A good age for a cat, although I wish she could have lived for ever.  Sadly it was not to be.

This is my very first picture of Patsy, taken just after she'd moved in.  October 2007.

Mrs Beekeeper and I rescued Pats from the mean streets of Willesden Green, when we lived in a ground floor flat.  Later, we moved to a house in Acton, which is when I got my first bees.

My very first bees, just after they'd arrived in a nucleus.  Pats is keeping an eye on them!

Patsy took some interest in the bees, and would sometimes watch from a safe distance when I opened up the hives.  She would also sometimes sit underneath the hives, and I used to wonder whether the sound of buzzing seemed like purring to her.

Patsy watching the bees.

After we moved to Bath, and the hives were located in Gill and Nev's garden, Pats would sometimes follow me along the path from my garden to the apiary.  Provided it didn't interfere with her other plans, of course.  While I got on with my beekeeping, Pats would sniff around the garden, and sometimes climb the willow tree to get a better view.

Climbing the willow tree in the apiary.

Pats was a practically perfect puss.  Our house is too quiet without her, and I shall miss being her butler and her doorman.  I don't know whether we go anywhere after the end.  But if we do, I hope Patsy is somewhere warm and sunny, with a few shady shrubs, some branches to climb up and down, birds to watch, and catnip to sniff.  That was Patsy's perfect day; she had many of them, and she deserved every single one.

Patsy having a perfect day in the garden.

Monday, 25 March 2019

The One That Didn't Make It

Last weekend I saw there were no bees flying in or out of hive #2.  So I took a quick peek under the roof, and my fears were confirmed - unfortunately, the colony hasn't made it through the winter.

There are a number of reasons why a colony is lost over winter.  Starvation is one, but I know that's not the case - there was still plenty of honey inside the combs in the hive.  Another possibility is infection - which can be caused and/or exacerbated by Varroa infestation.  I did see a couple of bees with mites on them, so this could be a possibility.

However, one of the more likely possibilities is that the colony was too small to keep warm through the couple of cold snaps that we had this winter.  I knew the colony was small - they'd been moved from the nucleus at the end of July, and their queen was a July hatchling.  This meant they were very late starters, and there was just not enough of the season left for them to build up numbers.

So, on Saturday, I went over to take a few photos and then brush all the dead bees off the hive floor, and burn the frames.  Here's a photo of what was left - you can just about make out the queen (with a pinky-red mark on her thorax) towards the top-right of the picture:


It's not a disaster - hive #1 will start making queen cells within the next six weeks and I'll be able to re-populate when I split the colony to prevent swarming.  But it's one of those setbacks that happens from time to time, and a reminder that beekeeping doesn't always go to plan.

I never got round to announcing the name of the queen of hive #2.  Regular readers will know that I always name my queens after scientists and engineers.  So, I've decided to posthumously name the queen of hive #2 "Maryam", after Maryam Mirzakhani.

Maryam Mirzakhani was a mathematician, and professor of mathematics at Stanford University.  She was the first - and to date, only - woman to receive the prestigious Fields Medal, which is the highest award in mathematics.  It really is a big deal - the Fields Medal is like the Nobel prize for mathematics (except there is no Nobel for mathematics - the nearest equivalent is the Nobel prize for physics).

Maryam was also the first Iranian to be awarded the Fields Medal, which she received for her work in the dynamics and geometry of Riemann surfaces and their moduli spaces.  She was a member of the United States National Academy of Sciences, and an associate to the French Academy of Sciences.  Asteroid 321357 Mirzakhani is named after her.

You can find out more about Maryam here:  https://en.wikipedia.org/wiki/Maryam_Mirzakhani

Monday, 18 March 2019

When The Bee Stings - Part 1 - Biology

Science warning: this post contains actual science. You have been warned...

Since it's still cold outside, and there's no beekeeping to do, I thought I'd take a look at some of the particularities of the honey bee's life.  One of these is the sting.  As I mentioned in a previous post, the sting of a honey bee is a modified ovipositor - which is why only female bees can sting.

It's worth looking at a bit of taxonomy, because it helps to understand how bees and wasps are related, and why they both have stings.  Bees and wasps are both members of the order Hymenoptera (bees, wasps, hornets, ants, sawflies), and all Hymenoptera females have an ovipositor, and so therefore do all female bees and wasps.

Within the Hymenoptera is the infraorder Aculeata, which contains bees, ants, hornets and some wasps (but no sawflies).

Outside of Aculeata, all other members of Hymenoptera (such as the sawflies, chalcid wasps and ichneumons) are unable to sting.  But Aculeata is really interesting in the evolutionary history of Hymenoptera because the Aculeata are the only members of the order that can sting.

Actually, there are plenty of members of Aculeata that can't sting - either because their ovipositor is modified differently, or because they've lost the sting - both of which have happened over the course of evolutionary history.  But we do know that the Aculeata all descended from one common ancestor species that lived sometime between 224 and 190 million years ago around either the end of the Triassic period or the beginning of the Jurassic.  And that species had a sting.

We also know that the bee lineage (the clade Anthophila) separated from the ancestor of common wasps and hornets (the subfamily Vespinae) around 130 million years ago.  An interesting thing happens after the lineages separate - the chemistry of the venom changes with evolution.  In the bee lineage, stings are acidic, whereas wasp stings are alkaline almost neutral (it is commonly thought they are alkaline, but it's not actually true).  More on that to come in part 2...

Back to taxonomy;  following the family tree down further, we get to the family Apidae and sub-family Apinae.  And finally we arrive at the genus Apis, which is the collection of 7 species that are referred to as honey bees.  My bees are the species Apis mellifera, but this is not the only species that are kept by beekeepers - in Asia, beekeepers keep colonies of Apis cerana.  On the other hand, Apis florea and Apis dorsata are not kept species - though people do harvest the wax and honey from wild colonies.

If we look back to evolution we find that the common ancestor of the Apis genus lived around 55 million years ago.  And that common ancestor probably had a barbed sting, which is a feature common to honey bees.  Other Hymenoptera didn't get this mutation, which is why honey bees are the only Hymenoptera that have a barbed sting - so they're the only ones that die when they sting you.

The actual structure of the sting is interesting.  The bit that penetrates the skin is, in simple terms, composed of three structures.  There is a pointed structure called the stylet, and two barbed structures called the lancets.  These are arranged roughly in a triangle, with a central canal running down the middle of the triangle.  The venom is delivered through the canal.

Diagram of a honey bee sting

At the internal end of the stylet is a bulb, which is the venom gland.  And at the internal end of the two lancets are two pairs of muscles.  When the bee stings, these muscles cause the lancets to slide up and down along the shaft of the stylet.  This is the clever bit - when one lancet moves up, the other moves down, and vice-versa.  And because of the barbs, which grip on the up-stroke but not the down-stroke, it has the effect of pulling the sting further down and deeper into the skin of the victim.  Even more clever - after the bee flies off, tearing the sting away from her body and leaving it embedded in the victim, the muscles keep working, the sting continues to dig into the victim's skin and the venom keeps pumping out of the bulb and into the victim.

So next time you're stung by a bee, just remember that you have had personal contact with a really amazing piece of evolution.

Further Reading

If you like reading science (and who doesn't?!) then this link is a fascinating analysis of the evolutionary history of Hymenoptera.  And if you'd rather just look at pictures, then the cladogram (family tree) on page 1015 is a joy:
https://www.cell.com/current-biology/pdf/S0960-9822(17)30059-3.pdf

This is a much more comprehensive description (with diagrams!) of the structure of the bee sting:
http://www.dave-cushman.net/bee/stingstructure.html

Wednesday, 16 January 2019

Feed The Bees

It feels like winter has been fairly mild, so far.  This isn't actually good news for my bees - they're supposed to be clustered in a tight ball inside the hive, and not moving round very much.  Instead, they are taking advantage of the warm weather, and spending time outside the hive flying and foraging.  The problem with this is it uses energy, which they would normally replace by feeding on nectar.  But of course it's winter, so apart from the odd daphne bush or winter jasmine, there isn't much nectar to be found.  So the bees are getting home tired and hungry, and eating through their stored honey (which is supposed to last them until the end of April).

Hive #1 is particularly affected as they have a much larger number of bees - which means more hungry mouths to feed, and faster depletion of their stores.  So, on Saturday I decided to top up their food to get them through until spring.

I've posted before about feeding bees - but that was using liquid feed (syrup).  In winter, the bees are unable to evaporate off the water from sugar syrup, because it's too cold and damp.  So feeding them syrup won't help them.  Instead, I need to feed them fondant, which they will ingest directly in the same way as honey (i.e. they don't need to process it first).  I had a 2.5 kg bag of fondant ready:


First, I needed to cut the bag open and fold the flaps back (as you can sort-of see in the photo above).  Then, it should be a simple matter of putting the bag, hole-downwards, over one of the holes in the crown-board.  Except...


... it was a fairly warm day, and there were lots of inquisitive bees who wanted to see what was going on!  Time to improvise - I borrowed two of the sliding entrance blocks to cover the crownboard holes, and make things a bit easier:

That's one...

... and the other!

It was then a fairly simple matter of putting the bag onto the crownboard, sliding it over the hole (while simultaneously sliding the entrance block out of the way) and trying to line up the bag hole with the crownboard hole (which requires a bit of guesswork):


And we're done!  Hopefully the bees will enjoy their sugary treat, and it will keep them going until spring.