Category Archives: Miscellaneous

Autumn cleaning

Over the last fortnight, despite some occasional warm and sunny days, the autumn has made its presence known. 

Flaming autumn aspen

The aspen down the road are a stunning colour at this time of the year. Although I’ve planted a couple of dozen, they’re still not more than thigh-high and it will be quite a few years until they can match the display shown above.

Almost overnight hundreds of redwing have arrived from Scandinavia and many of the rowan have already been stripped bare 1.

In Fife, the leaden skies are filled with skeins of geese forming raggedy V’s as they fly in from the North Sea. It’s an evocative sight … it reminds me of my first weeks as an undergraduate student at Dundee University half a lifetime ago

And it also emphasises that the beekeeping season is over.

Of course, there will be jobs to do in the winter, but the bees are pretty much on their own for at least the next five months.

Apivar

The final essential task of the season for me is to remove the Apivar strips that went into the hives in August. Initially the strips were placed on either side of the – still large – brood nest. A few weeks ago I removed the strips, scraped them free of propolis and wax and re-inserted them around the, now shrunken, brood nest.

Mid-autumn and time for the Apivar strips to be removed

You can just about see them in the photo above, flanking the four central frames.

It is important to remove the strips. Although Apivar has a relatively short half-life, some residual activity will remain. If you leave them in the hive any surviving Varroa – and there will be survivors 2 – will continue to reproduce in the presence of trace levels of amitraz, the active ingredient in Apivar. 

With reduced – and possibly borderline for killing – levels of amitraz present, these are ideal conditions in which resistance may develop. Although this has been reported it does not appear to be widespread. 

Therefore, to ensure that Apivar remains an effective miticide it is important to remove any remaining strips before the winter.

Your next adventure in Glenrothes awaits!

Tragic isn’t it?

That’s the subject line on the emails I receive from Travelodge where I stay when I’m doing my beekeeping in Fife. 

Have you ever been to Glenrothes?

‘Adventure’ isn’t the word most people associate with Glenrothes. 

Good morning Glenrothes

GetMeOuttaHere is. 

This is a town where every third car being driven late at night has a raucous exhaust, lowered shocks, tinted windows and a spoiler. The drive-in queue for McDonald’s sounds like the pit lane at the Indianapolis 500 and there are more donuts in the car park than in the fast food outlets 3.

But none of that usually bothers me as, by the time I get to the hotel, I’ll have been driving for 5 hours and will have spent about the same amount of time inspecting colonies or lifting cleared supers. I may also have squeezed in a couple of hours of meetings at work.

The environment might be noisy, but the beds are comfortable. 

But visits in late autumn are a bit different.

No colonies to inspect, no grafting to do, no nucs to check for mated queens and no supers to remove.

All I need to do is gently lift a few crownboards and pull out the Apivar strips now that treatment is complete.

So, what do I do for the rest of the day?

Long range weather forecasting

Is that an oxymoron?

I book my trips to Fife to fit in with what the bees need. To make the hotel affordable I book many weeks in advance.

I therefore put up with whatever the weather throws at me. Usually it works out OK.

Furthermore, as regular reader know, several hives are in a bee shed, so the weather is largely irrelevant.

But ~60% of them are outside.

And Monday was really wet. 

Having driven for four hours through increasingly heavy rain – stopping en route to make a honey delivery – I fortified myself with a cappuccino and excellent almond croissant from Taste, the best independent coffee shop in St Andrews 4.

Essential fortifications

I then sat in the shed enjoying my late breakfast listening to the rain hammering on the roof.

I needed something to occupy me until either:

  • the rain stopped
  • it got so late in the day that I’d just have to open the hives and remove the strips anyway

And the obvious thing to do was a bit of spring autumn cleaning. 

During the season the bee shed is used on a daily or weekly basis depending upon the experiments underway. In addition, we have a storage shed on the same site and a number of additional hives in the same apiary. I also do most of my queen rearing in this apiary (the bee shed provides a near-perfect environment for grafting), distributing the nucs to other apiaries for mating.

And all that beekeeping tends to leave a bit of a mess. At least, it does where I’m involved.

Super job

For the last couple of years I’ve not bothered returning the extracted supers to the hives for the bees to recover the last of the honey.

Instead I’ve just stacked them ‘wet’ in the shed, protected from wasps, mice and robbing bees, by covering the top of the stack with a well-fitting roof.

Or a snug-fitting crownboard and a badly fitting roof.

Stacked ‘wet’ supers

Experience has taught me that the floor of the shed isn’t level and/or has gaps between the planking. Rather than seal all these gaps I simply stand the stack of boxes on the sort of closed cell foam sheeting used for packing furniture, or – when I run out – on double thicknesses of cardboard 5. This stops the wasps, ants and bees from getting access. 

So I started by tidying the stacks of supers. Inevitably this necessitated moving them first, sweeping the floor clean, laying out the foam/cardboard and then restacking them. There’s not enough space in the shed to move ~60 supers so they went out in the rain.

So I got wet 🙁

Floors, roofs, boards, unidentifiable objects and wax moth

Once they were back I could turn my attention to the other side of the storage shed which houses spare roofs, nuc feeders, floors, boards (split, crown, surf, Morris, Snelgrove etc. 6 ), a breeding colony of queen excluders 7 and a motley collection of other items that:

  • might come in useful
  • don’t logically belong anywhere else
  • appear valuable and/or difficult to make … but I don’t know what they are
  • are essential and were needed several times in the season … but I’d lost them 🙁

Sorting this lot out took another hour or two, and involved a further soaking as I needed to clear the space before I could refill the space.

Early on in the process … 

Is beekeeping the largest volume hobby?

… and when at least partial order had been restored …

Floors from Abelo, Pete Little and some homemade abominations

I also found several brood boxes full of drawn comb or sealed stores.

Excellent 🙂

And I found a nuc box lurking in the far corner containing comb riddled with wax moth 🙁

Wax moth larvae and damage

Aargh!

DiPel DF

Wax moth are something I’ve largely avoided or ignored for most of the last decade. The cold winters in Scotland seem to keep their numbers down.

Not this time … 

All of the infested frames were bagged up for burning at the earliest opportunity. The remaining brood frames were treated with DiPel DF, a suspension of Bacillus thuringiensis kustaki spores and toxins. If ingested by the larvae of wax moths, the δ-endotoxin component dissolves in the alkaline environment of the gut, is activated following cleavage by gut proteases and then ‘punches’ a hole through the gut wall.

Ouch.

And the spores germinate, allowing the bacteria to grow inside the larva.

As I wrote in a post several years ago about this treatment:

This isn’t good for the moth larva. Not good at all. Actually, it’s probably a rather grisly end for the moth but, having seen the damage they can do to stored comb, my sympathy is rather limited.

DiPel DF is non-toxic for bees.

DiPel DF

I’ve not had problems with wax moth infesting supers stored ‘wet’ … they’re after the old cocoons and other rubbish that accumulates in brood frames.

Vita used to sell a product called B401 – also a suspension of Bacillus thuringiensis spores and proteins – which was withdrawn from sale in 2019. Despite assurances that a replacement – imaginatively labelled B402 – would be available ‘soon’ it appears to only currently be sold in the US.

Out with the old … and the not fit for purpose

I was on a roll … 

All this organisation meant I discovered things that I’d lost … like a small stack of contact feeders hiding in the corner that had not been used this season as I hadn’t done any shook swarms.

There they are! Contact feeders lurking shyly in the furthest corner (unlike those brazen frame feeders at the front)

I also found some mini-nucs I’d built for queen mating almost 10 years ago. They were made of ply and housed a tri-fold full-size brood frame (you can now buy these, but couldn’t when I built them). 

Tri-fold brood frame

However, the ply was starting to delaminate and it was pretty clear that they wouldn’t survive a Scottish summer season so they were unceremoniously binned.

And I finally bit the bullet and got rid of all my XP Plus queen excluders. These were bought from Thorne’s a few years ago and had been used only when I ran out of everything else.

In principle they are a good idea. A white plastic queen excluder with bee space on the underside provided by a raised rim and a series of small X-shaped spacers that stand on the top bars.

XP Plus queen excluder (the plus must mean ‘plus warp’)

However, in practice, they’re rubbish. They were the ‘ugly’ in my 2017 description of queen excluders that included the phrase ‘the good, the bad and the ugly’.  

They warp really badly. The photo above – if anything – obscures the warp because the QE is not being held flat. When you place them under a super the centre bows up and contacts the underside of the super frames.

Rubbish. 

Out they went.

The little things

There’s something rather poignant about the death throes of the beekeeping season. It can end with a bang as autumn storms roll in, or it can end in a protracted stutter as intermittent good days allow the bees to forage late into October. 

Of course, it’s au revoir 8 and not a final goodbye

It forms such a large part of my life for six months of the year that little things found during the clear-out bring back a flood of memories …

Nicot cup and (partly squidged) queen cell amongst the debris on the shed floor

A Nicot cup and vacated queen cell reminded me what a good queen rearing season we’d had on the east coast. Although the first round of grafting was a near-total failure, successive rounds were excellent, and queen mating was very successful. One of the best seasons in memory 9.

Coffee stirrer … or AFB test kit

Not all the memories were good ones though. I received one of the dreaded ‘AFB alert’ warnings for the apiary and spent a very long couple of days checking every cell on every brood frame in every colony, and testing any that looked suspicious.

I don’t take sugar, and the coffee stirrer shown above is provided in the AFB LFD kit to lift the dodgy-looking larva into a tube for analysis. Everything looked clear, but it gave me a few very stressful days.

And … after all that tidying, and repeated trips to the industrial-scale bins, it finally stopped raining.

Finally … some practical beekeeping

I fired up the smoker and quickly, but gently, removed all the Apivar strips. The crownboards on all the hives were very firmly stuck down with propolis and the bees, although calm, weren’t exactly overjoyed to see me.

Autumn still life – smoker, hive tool, Varroa trays and Apivar strips

I still had another apiary to visit. With rain threatening there wasn’t time to monitor the level of brood present so I slipped cleaned Varroa trays under the hives. This will allow me to inspect both residual mite drop and look for the presence of the characteristic biscuit-coloured cappings when brood is uncapped.

And then, after about half an hour of practical beekeeping, I set off back to the west coast as the rain started again.

The Moidart hills – An Stac, Rois-Bheinn and Sgùrr na Ba Glaise

Two days later the Moidart hills had their first dusting of snow.

It’s official, autumn is here and the beekeeping season is over.


 

Dancing in the City

Beekeeping is an increasingly popular pastime. Since ~84% of the UK population live in urban areas (up from ~70% in 1950’s) it is not unsurprising that the number of hives kept in cities is increasing.

Of course, not everyone who lives in a town or city keeps their bees in the back garden. When I lived in the Midlands I lived on a small estate that was indisputably ‘urban’, although there was farmland within sight 1. My bees were on the nearby farmland and I just kept a few mating nucs and a bait hive in the back garden 2

Hive in a field margin

I kept my bees in the farmland because 3 I reasoned that there were both larger amounts and a greater range of forage available for them there.

But I was probably wrong.

It wouldn’t be the first time, and it certainly won’t be the last.

Too many bees?

Before discussing urban bees and forage in more detail I’ll digress a minute to mention the suggestions that the inexorable rise and rise of urban beekeeping is threatening our native pollinators.

Actually … more than suggestions.

There are a number of scientific reports and reviews that indicate that urban beekeeping harms – by outcompeting – native pollinators like solitary bees. A recent report by the Royal Botanic Gardens at Kew states:

‘Campaigns encouraging people to save bees have resulted in an unsustainable proliferation in urban beekeeping. This approach only saves one species of bee, the honeybee, with no regard for how honeybees interact with other, native species.’

‘In some places, such as London, so many people have established urban hives that the honeybee populations are threatening other bee species.’

Our bees (Apis mellifera) are generalists. They are not particularly well adapted to any flower or nectar/pollen source.

They are equal opportunists.

Individually, there are many solitary bee species or non-hymenopteran pollinators, that are ‘better’ adapted. They pollinate more efficiently, or collect more nectar, faster.

But honey bees arrive in the environment mob handed.

Thousands of them.

Actually, tens or hundreds of thousands of them if there are several hives in an apiary. They are a formidable force and can easily outcompete other pollinators that are either solitary or only live in small colonies.

Save the bees, save humanity

When you see the phrase “Save the bees” what it usually means is save the honey bees.

Save the bees ...

Save the bees …

What it should be encouraging is “Save anything but the honey bees, because they don’t need saving … actually, there are possibly too many of them altogether”.

But that’s a lot less catchy … and it won’t let the supermarket, or food manufacturer or whatever, illustrate their campaign with cute photos of pollen-laden honey bees returning to quaint white-painted WBC hives in some sort of idyllic rural scene 4.

I suppose a photo of a honey bee would be better than drawing of a wasp though … which is what the NRDC used for a (mis)information campaign on CCD (colony collapse disorder) a few years ago.

D’oh!

Anyway … saving the bees is usually “greenwash” or bee-washing as it was termed by MacIvor and Packer in a 2015 paper on bee hotels 5

I’ll return to this topic, and urban beekeeping, later in the winter 6.

The Town mouse bees and the Country mouse bees

Where was I?

Oh yes, my – as will shortly be clear – incorrect assumption that country bees have access to more diverse and richer sources of forage than their poor relatives living in the town.

There are many sorts of countryside and many sorts of urban environments.

A hive in an intensively farmed arable landscape could be located in hundreds of acres of wheat fields, where all of the hedgerows were grubbed up years ago and replaced – if they weren’t just removed altogether – with barbed wire 7

How different is that environment to the ‘concrete jungle’ of a modern city? 

Tokyo

Surely that must be a terrible environment for bees?

In contrast, the suburban sprawl that surrounds most cities is possibly a good place for bees to live. Lots of neat little gardens, each 8 with a profusion of flowering plants, each chosen to provide vibrant colour for a much longer period than native plants.

And I’m sure we can all think of forage-rich rural environments. Here the bees gorge on early crocus, then gorse, willow, oil seed rape, clover, lime, blackberry, fireweed and himalayan balsam, before finishing the season will full crops and corbiculae from the ivy.

Now, in a recent publication 9 scientists have compared the forage available to town and country bees, and the results are quite surprising.

Let the bees tell you

If you live in a country with enlightened right to roam laws (like Scotland) you could wander around the countryside recording all the forage available to bees.

But the laws in England are much less enlightened. However, your right to roam in either country does not extend to the land around a private house or building. 

So, although you might be able to determine the forage available in the Scottish countryside, you can’t be certain you would have good enough access to do the same in England. And in a city you could only map what forage was available by peering over fences from public roads. 

So Elli Leadbetter and colleagues let the bees do the work.

They established 20 observation hives. Ten were in the the centre of London and 10 in agricultural land to the North East and South West of London. The hives were 5 km from each other to avoid overlapping areas of forage. They used observation hives so that they could watch and record the waggle dances of foragers in the hives.

I’ve discussed the waggle dance before. It is used to communicate three important pieces of information about a forage source:

  • direction
  • distance
  • quality

The first two bits of information are encoded in the angle of the waggle run to the perpendicular and the duration of the waggle run. The quality is conveyed by the number of circuits a dancing working performs. It’s a case of ‘the more, the better’ … energetically higher quality resources 10 result in more circuits.

Having recorded thousands of these waggle dances, they used the direction and distance information to ‘map’ where the bees were foraging.

GIS data, land use and foraging bees

For many locations there exists a wealth of land use data (GIS data; Geographic Information Systems). Much of this is at high resolution. For each of the 20 observation hives they produced a map of land use within 2.5 km of the hive at a resolution of 25 m. 

Land use was defined in broad categories such as 11 buildings, woodland, arable, pasture, fruit, OSR (all in agricultural areas) and dense or sparse residential, parks, amenity grassland or railways (all in urban landscapes). 

They then used some clever mathematics to decode the waggle dances 12 to work out where the bees had been, converting the distance and direction components to geographic locations.

Urban (top) and rural foraging heat maps, overlaid on GIS land use maps (5 km diameter)

These locations were overlaid on the land use maps to produce ‘heat maps’ showing where the bees were foraging. The image above shows these heat maps. In the spring the urban bees (top left) were foraging intensively to the east and west of the hive and the rural bees (bottom left) were mainly foraging in two large areas to the south east and south west of the hive.

Foraging distance and nectar quality

Even a cursory look at the image above shows that the urban bees tended to forage closer to the hive than the rural bees. But remember, that’s just three snapshots during the season.

Waggle run duration – rural bees fly further

However, more detailed analysis confirmed that this was the case. Throughout the season, the bees in the agricultural landscape foraged further from the hive. I’m showing the log-transformed median waggle run duration (above) as this allows slightly easier comparison across the season. The further the wiggly ‘best fit’ line is above the horizontal axis, the longer the duration of the waggle dance run, and so the further the bees are flying to find the forage.

Interestingly, the median foraging distances were relatively short when compared with the maximum foraging distances from the decoded waggle dances. This applied wherever the bees lived. For urban bees the median was 492 m (max 9375 m) and for agricultural bees it was 743 m (max 8158 m 13 ).

Perhaps the agricultural bees were flying further because there was better quality nectar available at more distant sites?

Nectar concentration (% w/w) sampled from returning workers

They controlled for this by recovering returning foragers and robbing them of their nectar load before analysing the sugar content. There was no significant difference 14 between the nectar from agricultural or urban landscapes. The sugar content of the nectar was recorded as reducing through the season.

Foraging preferences

So where did the town bees and the country bees prefer to forage?

City rooftop bees

City rooftop bees …

In urban areas the bees exhibited a strong preference for residential gardens (the ‘sparse residential land’) … these are presumably the flower-rich urban gardens that the homeowners also tend to prefer.

In contrast, bees in an agricultural landscape showed an entirely unsurprising reliance upon mass-flowering crops like oil seed rape (in spring only). They also showed weaker preferences for arable land and fruit crops throughout the season.

Mid-April in the apiary ...

Mid-April in a Warwickshire apiary …

I’ve skipped over a host of additional observations from the study, and almost all of the controls. Two things that are worth mentioning though.

Firstly, hive strength had no influence on waggle dance duration (and hence foraging distance). It therefore wasn’t the case that stronger hives had a larger workforce that could survey and exploit more distant forage. 

Secondly, cities are warmer due to the urban heat island effect. However, temperature also did not affect waggle dance duration when it was factored in. So, the city bees aren’t foraging at shorter distances because the dance is truncated at higher temperatures.

Conclusions

So, although cities are predominantly filled with buildings and roads, city bees travel less far to forage when compared to bees in agricultural landscapes.

This strongly suggests that the urban landscape consistently provided more available forage 15

Conversely, the bees in agricultural landscapes had to fly further, not because there were better quality nectar sources available at long-range, but because there wasn’t enough nectar nearby.

There were a number of additional interesting points in the paper, some of which were known already from other studies. For example, the high sugar content in spring nectar was already known (and confirmed here). Similarly, foraging distances in midsummer were longer than those in spring or autumn. This could be predicted due to the reduced rainfall in summer, and consequently the reduced overall level of nectar available.

I need to think more about how this study contributes – if at all – to the ‘too many bees in cities’ argument. If anything, forage-rich towns should be able to support a greater number of bees 16 without the honey bees impacting on other species. In contrast, honey bees in agricultural landscapes might dominate the available nectar sources because they can forage at long distances and then communicate to their nestmates the location.

Perhaps it just shows that that heavily farmed land is actually very poor in terms of nectar availability? It’s either boom or bust … once the OSR has finished, or the clover has been ploughed in, or the fruit trees stop flowering then there’s nothing left 🙁

It would be interesting to conduct a similar study in a forage-rich, non-agricultural, rural landscape.

Access all areas

Finally, I think a particularly neat thing about this study is the use of bees to ‘map’ the forage availability using what the authors term “a large-scale search effort that has no access limitations”. The scientists interpreted the waggle dance to get information that would otherwise have been difficult or impossible to determine.

However, using the bee’s own perception of the distances flown might actually lead to inaccuracies in the calculations. As discussed previously, bees measure distance by optic flow. Optic flow increases in complex landscapes … and cities are likely (at least to us, and certainly when compared with arable farmland, to bees) to be complex landscapes. Increased optic flow leads to a perception of increased distance, and hence to longer waggle runs.

This means that bees in complex landscapes might overestimate the distance they have actually flown to forage. Conversely, those in uniform landscapes might underestimate.

Which means that the results of this study may be a conservative estimate of the differences in foraging distance.

And therefore a conservative estimate of the differences in forage availability in urban and agricultural landscapes.


Notes

Dancing in the City was a pretty cheesy song that reached #3 in the charts for the rock-pop duo Marshall Hain in 1978. Having remembered the track when thinking up a title for this post, I made the mistake of listening to it on Spotify.

I now can’t get the damned thing out of my head. 

But it gets worse. I rummaged through Wikipedia and discovered that Kit Hain, the vocalist, subsequently had a very successful songwriting career with people like Roger Daltrey, Chaka Khan and Fleetwood Mac. Impressive. 

In contrast, Julian Marshall, the keyboard player became a member of the Flying Lizards who had a minor hit with a cover version of Barrett Strong’s 17 Money (That’s What I Want)

… and now I can’t get that out of my head 🙁

Counting by numbers

Can bees count?

If they can count, what’s the highest number they can count to?

Do they understand the concept of ‘more than’ or ‘less than’? And what about zero? These are very much more complex concepts than simple numbers.

If bees have simple counting skills, can they do mathematics? Addition, subtraction, multiplication and division?

What about more complicated maths like differential equations or Fourier transforms? 1

And finally, if we can determine the answer to all these questions, do we know how bees count? Do they simply see things and think “Ah Ha! Two flowers each with four petals”, or do they count in a non-numerical way?

Numbers, arithmetic, more than, less than, zero etc. are complicated concepts that involve aspects of neuroscience, psychology and even philosophy. I’m a molecular biologist/virologist and so singularly ill-equipped to understand the more esoteric or advanced aspects of these topics.

Don’t say I didn’t warn you 😉

Can bees count?

Yes.

Bees, like many other animals have basic counting skills.

In studies going back 25 years, Lars Chittka 2 demonstrated that bees exhibited what he called protocounting. He positioned a feeder between distinctive landmarks (tents in a field) and showed – by altering the number of tents between the hive and the feeder – that the ability of the bees to find the feeder was at least partly due to their ability to count the landmarks.

Counting by bees

If he added more tents between the feeder 3 and the hive, the bees flew a shorter distance to where they thought the food supply was. If he removed some of the landmarks, the bees flew further.

Chittka used the term protocounting because he reasoned that the things that the bees were counting – in this case tents in a row in a field – may not be transferrable to different objects. For example, bees trained to a feeder between tents 3 and 4 in a series might not return to the same position in a series of trees in a row. He didn’t test this, but others now have.

Bees also measure distance flown and this had a greater influence on where the bees searched in the series of landmarks. Nevertheless, these early studies provided compelling evidence that bees had some basic counting skills … or numerosity as it is called.

Is this ‘just’ protocounting and how high can they count?

To understand numerosity in more detail scientists moved the experiments into a laboratory setting where they could control the environment much more tightly.

Landmark counting in a laboratory flight tunnel

These use uniform flight tunnels containing painted or taped on landmarks. For some of the detail read the legend in the figure above 4. By using flight tunnels they could change the landmarks – see (a) above – from stripes to dots to baffles. In doing so they demonstrated that the bees were counting landmarks per se, rather than a particular type of landmark.

For example, bees trained to search for food between the third and fourth set of stripes would look between the third and fourth set of dots. This is much more advanced than the protocounting proposed in the initial study by Chittka and colleagues. … it shows a degree of abstract numerosity.

The use of baffles prevented the bees ‘looking ahead’ (or behind) to visualise the entire set of landmarks together … they had to keep a running total in their heads.

Finally, the highly controlled environment of a flight tunnel enabled the researchers to determine that bees could count up to … wait for it … four.

Not a huge number but, in terms of cognition, a significant advance on none, one or more.

But let’s not get ahead of ourselves.

We’re going to tackle the concept of zero and ‘more than’ in a minute.

It has been argued that the upper limit of four – a limit shared with a number of other animals – might be a consequence of the small size of the bee’s brain 5 and the small percentage of the neurones in the brain being dedicated to counting 6.

However, it may represent a more fundamental limit of cognition and perception that reflects the capacity limit of working memory. This isn’t restricted to bees … it’s something shared with beekeepers. For more detail on this I recommend Nelson Cowan’s The magical number 4 in short-term memory: A reconsideration of mental storage capacity. 7

Go on … knock yourself out 😉

More or less … and zero is not a number

Actually, it is.

What’s more, it’s an even number … 0, 2, 4, 6, 8 are the first five even numbers from zero.

It’s the ’empty set’, smaller than one.

It’s also, conceptually, a difficult number to grasp. Children take much longer to understand that zero is a number (e.g. that they can do maths with) than they do to understand that zero means “nothing”.

There are four steps defined in the acquisition of the understanding of zero in human history, psychology, animal cognition and neurophysiology” 8, which are:

  1. defining zero as ‘nothing’
  2. the categorical definition of zero as ‘nothing’ versus ‘something’
  3. an appreciation that zero is a quantity at the low end of the positive integer numerical continuum (see above)
  4. the symbolic representation of zero i.e. 0, the Arabic number for use in maths

Can bees distinguish ‘more than’ or ‘less than’? And what about zero being ‘less than’ one?

The experiments to determine this were simple but elegant (as all the best experiments are 9) and involved training and rewarding bees to select targets that displayed more items or fewer items.

Bees trained to select ‘more than’ targets would choose one displaying four items over one with two or three. Similarly, the ‘less than’ trainees 10 would select two items rather than three or four.

More than, less than and zero

These experiments confirmed that bees ‘understood’ the concepts of more than or less than. The experiments were controlled to exclude the possibility that the bees were responding to other stimuli that changed in the target e.g. signal density or colour intensity.

And if that wasn’t enough 11 they also showed that the ‘less than’ trainees would choose an empty target when offered the choice between ‘some’ and ‘none’.

But there’s more … or less

The ‘popularity’ of the empty set – zero items – was directly related to the difference in the number of items displayed on the non-empty targets. For example, bees more frequently chose the zero option when numbers were numerically more distant (0 vs. 5 or 0 vs. 6) than those closer together (0 vs. 1 or 0 vs. 2).

This relationship between accuracy and numerical distance is called Weber’s law.

This demonstrates a significant degree of understanding of the place of zero in a numerical continuum, an extraordinary feat in a honey bee.

This appreciation of the concept of zero as a number is similar in ability to that shown by African grey parrots, non-human primates … and pre-school children.

That’s impressive.

Counting by numbers

These numerical skills, amazing as they are 12 demonstrate an appreciation of numbers, but not the ability to manipulate numbers.

Can bees count?

For example, could bees solve this testing little equation?

Uh oh ... swarming ...

Maxwell’s equation – the foundation of classical magnetism, optics and electric circuits … but you knew that already

OK, not so fast … is that really a fair test?

These coupled partial differential equations are quite challenging. As bees have yet to be trained to hold a piece of chalk, they can’t write QED 13 at the bottom of the blackboard to indicate they’ve solved it.

So what about these instead?

1 + 1 = 2

3 – 1 = 2

To test this Adrian Dyer 14 and colleagues substituted colours for mathematical operands during the training e.g. blue for addition, yellow for subtraction, coupled with shapes for the numbers.

Y shaped maze to determine if bees can do maths

They trained the bees using a classical reward-punishment system. This sounds worse than it is. It means they received delicious syrup 15 when they got the right answer, but bitter-tasting quinine when they got the wrong answer.

The more training the bees received, the better they got at maths – both addition and subtraction. Once trained, the bees were tested.

Honey bees can do basic maths

In this subsequent testing phase the bees got the correct answer about 75% of the time. If they had been choosing the answer at random they would have achieved only ~50% of correct answers.

So, if more than, less than and an appreciation of zero aren’t enough, bees can also do mathematics.

Though probably not partial differential equations 😉

How do bees count?

It’s not yet clear how bees actually count objects – like the shapes scientists train them to recognise in the Y shaped maze shown further up this post.

Numerical cognition is considered a higher cognitive activity. In humans we’ve abstracted the process and – for at least the last 1100 years – used Arabic numbers to indicate quantities of ‘stuff’.

Of course, humans could count long before this, as could the apes from which we are descended. But they don’t use Arabic numerals and nor do bees.

3 + 1 = 4

Humans can look at a diagram like the one above and immediately recognise and count the similar shapes – this is a process called subitizing and is restricted to small numbers of shapes. You can train computers to do the same thing using neural networks, object detection and counting the instances of the objects detected.

However this is both computationally expensive and exploits symbolic mathematics, neither of which are achievable in the tiny brain of a honey bee. They cannot inspect a complete field of view and conclude “four apples”, or “three black circles”.

Bees cannot subitize … their brains don’t work fast enough and their visual acuity, and compound eyes, are probably incompatible with the process.

Instead, recent modelling studies have suggested that bees might count objects by serial sequential processing.

If you observe honey bees traversing a Y shaped maze they closely inspect each and every element in the patterns they are presented with.

Simple neural model for counting in honey bees

Using just four neurones, this method appears to allow the bee to achieve the known capabilities of their numerosity i.e. counting to four, concepts of more than or less than, understanding zero, and the fulfilment of Weber’s Law.

This area of the science is even more outside my comfort zone than Maxwell’s equation (see above) and I recommend you read the article cited in the legend to the figure above for further details.

Unanswered questions

There’s clearly a lot more to understand about the numerical and mathematical abilities of honey bees. This will take time, but good progress has been made over the last decade or so.

A full understanding of the neuronal processing involved in object discrimination and counting will probably require an ability to determine which neurones are firing, and the pathways of neuronal communication.

Scientists are years away from being able to do this with honey bees. It necessitates the ability to introduce specific reporter genes (for example that turn green when a neurone fires) into individual cell lineages. We don’t have the tools to do this (yet), but it can be done with fruit flies (Drosophila) and some of the same methods do – or might – work in bees.

In the meantime it’s worth thinking about what the ability to count contributes to the biology and behaviour of bees.

Do plants with more petals have more nectaries, and do bees follow these numerical clues rather than – or in addition to – other visual or scent stimuli?

And why on earth do bees have the ability to do basic maths?

I can’t think of an advantage that this would confer to bees.

Can you?


Notes

The title of this post was going to be 0 … 1 … 2 … 3 … 4 … more’ but that would have looked terrible as a URL and would have sunk without trace in Google searches.

Instead I’ve used a play on the title of the 1988 Peter Greenaway film Drowning by Numbers. This has a fairy tale-like plot that involves three generations of women – all called Cissie Colpitts – drowning their husbands. Bernard Hill plays Madgett, the coroner encouraged to cover up the crimes and involves a series of invented games, one of which is called ‘Bees in the Trees’ (which seemed appropriate).

Drowning by Numbers … going by the number in the background, a scene from about half way through the film

If you’ve not seen the film (and enjoy slightly surreal movies and black comedies) I can recommend it. See if you can count the numbers 1 to 100 that appear, almost all in sequence, either in the background or spoken by the characters. Michael Nyman wrote the music which is similarly highly structured, and based entirely upon a Mozart Sinfonia Concertante in E flat.

Of course Counting by numbers is also relevant as bees probably count in a different way altogether. Perhaps I should have ended the title of the post with a question mark?

Hydroxymethylfurfural

Excuse me?

Hydroxymethylfurfural which, for very obvious reasons is usually abbreviated to HMF, is an organic compound that forms in sugar-containing foods, often as a result of heating.

Hydroxymethylfurfural (HMF) Oxygen = red, Hydrogen = white, Carbon = black

HMF is relevant to bees because, at high levels, it is toxic for them. Since beekeepers often heat (or use ready-made feed that has been heated during production) sugar-containing syrups or fondants it’s worth being aware of it.

HMF is also relevant to beekeepers as high levels of it in honey are an indication of prolonged heating during storage and preparation or potential adulteration. For this reason there are legal limits on the levels of HMF in honey sold for human consumption.

I suspect beekeepers in the UK who know about HMF – and many may not – probably worry about it unduly. In tropical countries or regions where high fructose corn syrup is used as a bee food then HMF is likely to be of more immediate importance.

Natural occurrence of HMF

Hydroxymethylfurfural is essentially absent from fresh foods. However, in sugar-containing foods, particularly those that are acidic, HMF levels can build up. A chemical process called a Maillard reaction is responsible for HMF formation (there are other reactions that generate HMF as well, including caramelisation) and the reaction works about five times faster for every 10°C rise in temperature.

Therefore processes such as drying or cooking result in elevated HMF levels. The precise amount varies depending upon the foodstuff, the amount of heating and other factors; typical figures are bread 3 – 180 mg/kg, prunes 240 mg/kg, sugarcane syrup 100 – 300 mg/kg and roast coffee 900 mg/kg 1.

All of these foods can be consumed perfectly safely (at least in terms of their HMF content … prunes can have some adverse effects 😉  ).

It should therefore be obvious that the 40 mg/ml limit 2 of HMF in honey has nothing to do with its safety for human consumption.

Dietary HMF has been extensively studied as there were concerns it may be carcinogenic for humans. Several studies showed that non-physiological levels and/or prolonged exposure were cytotoxic or inhibited key enzymes in the cell such as DNA polymerase. However, no evidence for in vivo carcinogenic or genotoxic effects have been demonstrated 3.

HMF is currently considered safe and has been shown to have beneficial antioxidant activity, to protect against hypoxic (low oxygen) injury and to counteract the activities of some allergens.

HMF in honey

Readers familiar with the chemistry of honey will be aware that it is often rich in fructose (one of the sugars from which HMF is derived) and is acidic.

Add a little heat and you have near-perfect conditions for the production of HMF.

How much heat? 

It’s actually not just heat but a combination of heat and time.

The higher the temperature, the less time is required for the production of a certain amount of HMF. There are several studies of this, but one of the most frequently quoted is from White et al., in 1964 4 which has this slightly skewwhiff, but nevertheless useful, graph of the influence of storage temperature and time on HMF production in honey.

HMF production in honey – influence of storage temperature and time

That’s barely legible – check (and enlarge) the original if needed – but the approximate times/temperatures required to generate 30 mg/kg of HMF in honey 5 are as follows:

30°C ~250 days
50°C ~10 days
70°C ~10 hours

All of which is good news … heating a 15 kg bucket of rock-solid OSR honey overnight at 50°C to melt it before making soft-set honey is unlikely to significantly increase the HMF levels.

How to avoid the generation of HMF in honey

But, if you are worried about HMF levels, you could always produce creamed honey which just requires overnight warming at 33°C.

This is what I now do; not because of any concern over the HMF levels but because it’s:

  • faster
  • produces a honey with better batch-to-batch consistency of texture
  • generates a jarred honey much less susceptible to frosting

Long-term storage of honey results in the formation of HMF. The lower the temperature it is stored (and the shorter the time) the less HMF is produced. For an exhaustive list of HMF levels quantified in honey stored at different temperatures have a look at Table 1 in Shapla et al., (2018).

Store honey carefully in a cool place … or sell, eat or gift it quickly

It makes senses to store honey in a cool place with a relatively stable temperature.

Quantifying HMF

There are a variety of ways of detecting HMF. Unfortunately, all require laboratory equipment and none are really suitable for home use.

There are spectrophotometric methods – essentially detecting a colour change after adding an indicator that reacts to the presence of HMF – but these can lack both sensitivity and specificity. Some of the chemicals involved are carcinogenic.

More accurate and sensitive are methods use reversed-phase high-performance liquid chromatography. These have been in routine use for years.

Orbitrap ID-X Tribrid Mass Spectrometer

Probably the newest and most advanced methods involve the use of time-of-flight mass spectrometry (MS MALDI-TOF). These ionise the constituents of the sample and measure the time they take to reach a detector. Mass spectrometry is exquisitely sensitive and specific … and the equipment is eye-wateringly expensive. 

Since you’re unlikely to have one in your honey processing room 6 you’re better off doing your best to avoid conditions that lead to the build-up of HMF in the first place.

OK, enough about honey and humans, what about the bees?

HMF is toxic for both adult bees and developing larvae. The level of toxicity depends upon the concentration of the HMF, the duration of exposure and the developmental stage of the bee.

Krainer and colleagues 7 looked at toxicity of HMF to developing larvae and showed that concentrations up to 750 ppm (i.e. 750 mg/kg) did not reduce larval or pupal mortality.

Larval and pupal mortality when exposed to HMF at different concentrations.

They calculated that the LC50 (concentration that produced 50% mortality) at day 7 and day 22 was 4280 ppm and 2424 ppm respectively, with a calculated LD50 (dose per larva that resulted in 50% mortality) of 778 μg and 441 μg at day 7 and day 22 respectively.

Adult bees were less sensitive to HMF in the first week after emergence than during the first week of larval development.

Adult bee mortality when fed a diet containing HMF at the levels specified

What does all this mean?

It means that high levels of HMF are likely to have a significant impact on adult bees, but – at least until the levels are exceptionally high (grams, not milligrams, per kilogram) will probably not adversely impact brood levels.

Further validation of the adverse effects of HMF to adult bees

A similar study was recently conducted by Gregorc and colleagues 8 using lower concentrations of HMF.

Survival of adult bees fed with HMF-spike Apifonda

Again, there was a time/dose response, but note that only about 30% of the control bees survived 30 days and this was only double the number that had been fed the lowest level of HMF-spiked Apifonda. Note the clear evidence of a dose-response with increasing levels of HMF in the diet.

Dysentery

Several studies, dating back at least 50 years, report that high levels of HMF result in dysentery-like symptoms due to ulceration of the gastrointestinal tract of honey bees.

Gregorc and colleagues used immunohistochemistry to investigate the integrity of the gut tissues in the honey bees fed HMF. They stained cells red that were undergoing a process called ‘programmed cell death’ or apoptosis. This is a natural physiological response to damage. The more red staining, the worse the damage.

Midgut of formalin-fixed, paraffin-embedded tissue of worker bees exposed to HMF

At higher doses of HMF and/or longer exposure there was increased apoptosis in the gut tissues, presumably accounting for the dysentery-like symptoms often seen (though these were not recorded in this particular study).

Real world beekeeping

All of these bee corpses and fancy-dan immunohistothingamajiggery really just confirm that high levels of HMF are a bad thing™

In terms of honey processing and storage the allowed levels are nothing to do with human (or bee) health, but everything to do with evidencing overheated, poorly stored or doctored honey.

And since no readers of this blog do these things then there’s no need to be concerned 😉

Assuming your honey starts with low HMF levels (on extraction) then any reasonable levels of heating to liquify honey for filtering, blending or jarring should not result in HMF levels anywhere near to those that would prevent the honey being saleable 9.

Refer to the graph above from the 55 year old paper from White and Co. (shown above) for further validation.

If you’re making thick (2:1 by weight sugar to water) syrup to feed bees perhaps use warm rather than boiling water. However, considering the time involved and the absence of the acidity of honey, even with the latter HMF levels should not get close to high enough levels to endanger the bees.

If you’re making thin (1:1 by weight) syrup then use cold water. Just stir it a bit longer to dissolve it all.

However, take care – or avoid altogether – the use of high fructose corn syrups (HFCS) for feeding bees. I don’t know anyone who does this in the UK and have no experience of it myself. To learn more have a look at this article in Bee Culture. HFCS is high in fructose (the clue is in the name) and acidic, so HMF readily forms.

Studies of commercial HFCS show levels of HMF can start at 30 – 100 mg/kg before any long-term storage. 

Oxalic acid

The only time most beekeepers probably need to have concern about HMF levels is in the preparation and storage of oxalic acid solutions for trickle treating colonies in midwinter.

Oxalic acid is, er, acidic. For trickle treating it’s mixed with thin syrup to make a 3.2% solution. The combination of syrup and acidity means that HMF can be produced if stored – for a long time – in unsuitable conditions (under which there is an obvious colour change).

Stored OA solution and colour change

Stored OA solution and colour change …

So, if you’re preparing OA solutions for trickle treating either:

  • use it immediately and safely dispose of the excess
  • store it at 4°C and use then it as soon as possible (before safely disposing the excess)

Fondant

But what about fondant?

The HMF levels in commercially available fondant have recently been discussed on the Beekeeping Forum. I’m grateful to ‘loyal listener reader’ (to use Radio 4’s More or Less definition) Archie McLellan for bringing this to my attention.

The thread started with the challenging title The truth behind fondants.

Like all discussion groups, the contributions are many and varied.

Some wander off-topic.

Others use it as an opportunity to get a little dig in at the opposition.

Or a great big dig 😉

Novices and the naive ask simple questions and hope for straightforward answers 10.

Usernames often give no indication of who the poster actually is.

Is the poster a manufacturer or distributor of BeeCentric fondant™ “The best fondant for bees and a whole lot better than that cr*p they sell for ice buns”

Does the poster use 5 tonnes of fondant a year and buys anything s/he can get as long as it’s cheap enough?

Or does the contributor have a £576,000 Orbitrap MALDI-TOF mass spectrometer in their basement and a damned good idea of exactly how much HMF is present in every commercial source of fondant?

On the internet, nobody knows you’re a dog

Who knows?

I certainly don’t know all of the contributors to these threads.

But I know some of them 😉

Read the thread. It’s now 12 pages long and you’ll do well not to get lost or to disappear down a few cul-de-sacs

If you’ve ‘got a life’ and want to cut to the chase then have a look at this post in particular.

What do I do?

I use standard Baker’s fondant. It costs about £8-12 for 12.5 kg depending how much you need. I’ve used this type of fondant for a decade for 90% of my colony feeding (and 100% of my autumn feeding).

I’ve never seen any adverse effects from using this type of fondant for my bees.

I simply do not believe some of the negative marketing that is used to promote BeeCentric fondant™ costing £36 for 12.5 kg. It’s not that I can’t afford this 11 and it’s certainly not because I don’t care about my bees. I simply choose to trust experience over carefully-worded marketing ‘information’.

To convince me they’d need to publish the HMF levels in their products. They might be lower than bog-standard Baker’s fondant.

And I’d also want to know the HMF levels in standard Baker’s fondant 12.

If they were significantly higher 13, are they anywhere near high enough to damage my bees?


Note

A version of this article appeared in the November 2021 edition of An Beachaire – The Irish Beekeeper.

Winding down

Here in Scotland the season is rapidly drawing to a close. All of the summer nectar sources – the lime, blackberry and heather – have stopped yielding and the bees are noticeably less busy, other than in the warmest parts of the day.

Inside the hive the colony is segueing from summer to winter bee production. Brood rearing is still ongoing and there’s lots of pollen still going in, but the rate at which the queen is laying is very much reduced.

And, as the bees transition from summer to autumn behaviour, my own beekeeping activities are also changing. No more queen rearing, uniting or even colony inspections. The risk of swarming ended months ago.

Instead, with the winter ahead, the number of evening talks is increasing and several winter beekeeping projects are starting to occupy my mind.

But the season’s not over yet and there are still a few last minute tasks before active beekeeping stops. Here is what has been keeping me busy over the last week or two …

Talk, talk

Beekeepers are a sociable bunch and the pandemic has had a significant impact on the amount of digestive biscuits consumed and tea slurped in church halls across the country.

However, in addition to being sociable 1 they are also adaptable and inventive. Zoom and GoToMeeting talks, attended from the comfort of the sofa with a glass of red wine, have become the new normal. 

Early forays into the world of ‘virtual’ beekeeping were plagued with dodgy connections or noisy feedback.

Q&A sessions were stilted due to the lack of familiarity with the need to unmute the microphone before talking.

Some were more like a Marcel Marceau tribute act than Beekeeper’s Question Time.

But all that has changed.

I’ve experienced some excellent hosting, lively and interactive Q&A sessions and entertaining pre- or post-talk chat with beekeepers across the country. 

‘Virtual’ beekeeping talks

Increasingly this format appears to have been widely accepted. There may not be face-to-face meetings with tea and biscuits, but there’s also no need to drive half way across the county on a filthy, wet winter night.

Long distance talks – imagine the travel expenses being saved

I live in one of the most westerly locations in the UK (I’m about 15 km west of Land’s End) and have used the title ‘Go West young man’ a couple of times in previous posts. Later this winter I’ll be ‘virtually’ going west a further 7000 km and talking to beekeepers in British Columbia, Canada. They may be half way across the world, but their climate (reasonably mild and wet) is not dissimilar to the west of Scotland, and bees are bees 🙂 

It should be interesting.

Zoom and GoToMeeting

About 95% of the talks I give (or attend) use Zoom. It works well. The interface is logical and I can see some/all of the audience. Questions are often handled through the ‘Chat’ function. At least a couple of associations have invested in an add-on 2 that allows questions to be upvoted, so moving the most popular or relevant topic 3 to the top of the pile. 

‘Seeing’ the audience in the talk isn’t really necessary, and can be a bit distracting 4. But I find it really helps during the Q&A session, and certainly makes the ‘virtual’ interaction just that little bit more realistic. 

At the very least I can guesstimate the age and experience of the beekeeper asking the question, so allowing me to tailor my answer if appropriate. Of course, this sometimes goes wrong, but people are usually too polite to point out my error.

GoToMeeting is less intuitive (possibly because I’ve used it less) and I don’t think offers me a view of the audience 5. However, I think it’s more suited to larger audiences and coped admirably with ~250 who attended a recent talk to the Welsh BKA.

OK, enough virtual beekeeping … what about the real thing?

Heather honey

In the six years I lived in Fife (on the east coast of Scotland) I never moved my bees outside a 20 mile corridor in the centre of the county. The arable farmland, mixed woodland and low, rough grazing contained no (worthwhile) heather.

Therefore, despite living in Scotland, I’ve no previous experience with heather, considered by many to be the ultimate honey. However, on the west coast we have patchy heather on the hill behind the house, so the bees have almost no choice but to forage there.

After a record-breaking honey yield in Fife, anything extra in the west was a bonus.

I was singularly ill-equipped to extract it. A few of the frames I put through the extractor collapsed spectacularly, so I was reduced to scraping the frames back to the midrib and crushing and straining the honey out.

As I’ve said before, there’s always something new to learn.

Crushed and strained … I was, but I got there eventually

And I learnt that this can be a messy and exhausting process 🙁

One of many few … my first jars of Ardnamurchan honey

But, by golly, it was worthwhile 🙂

I now have to buy a larger shed to store a compressed air-driven fruit press as extracting anything more than half a dozen supers of heather honey will probably drive me round the bend.

Based on the price of these fruit presses and the likely honey yield per year I reckon I’ll break even in about 29 years 🙁  6

The heather here on the west coast goes on yielding long after the bees in Fife have packed up and gone home.

At least, usually. 

Feeding and forage

The summer honey came off the hives in Fife in mid-August. All the colonies were treated with Apivar strips and received a full block of fondant on the same couple of days I removed the supers.

It was hard work, not least because there was a lot of honey. All the supers were brought back home for extracting, and subsequently returned for storage.

As described a couple of weeks ago, I only feed fondant in the autumn. Having checked the colony is queenright I simply plonk a block of fondant on the hive and leave them to get on with it 7.

When I checked the colonies earlier this week all had completely finished their 12.5 kg fondant block.

All gone

Although I didn’t do a full colony inspection, I did have a peek in a couple of hives to check the level of stores and brood. They were wall-to-wall with capped stores except for 2-3 frames in the centre of the brood box which contained about a hands-breadth of brood. Much of this brood was capped and there was still a little bit of space for the queen to lay … but not much.

However, several boxes also had brace comb in the super above the empty bag of fondant. None of this contained brood as I always support the block of fondant on a queen excluder. 

Bees don’t draw comb on fondant … or do they?

I suspect this comb building was triggered by the availability of ivy nectar. In previous years I’ve not seen comb drawn when feeding fondant. However, it’s been quite mild and the bees have probably been taking advantage of the warm weather to supplement the fondant.

Avoiding another sticky mess

I don’t want to leave the bees with a third of a super of ivy honey, particularly when the rest of the super is a big empty space they would have to heat. However, I also don’t want to mess about cutting it all away or – worse – wasting all their efforts.

A small hole

Therefore, having removed the queen excluder and the empty fondant wrapper I placed a new crownboard and empty super back on the hives with brace comb. I modified the crownboard to reduce the hole to about a single bee width.

Regular readers will know that modified almost always means either gaffer tape or Correx.

I’ve branched out this time and instead used the side of a cardboard box of fondant for one hive. If this works I’ll claim it was a well thought out experiment. If it doesn’t I’ll claim I was pushed for time and had no Correx or gaffer tape with me 8.

Having done all this I added back the original crownboard with the attached brace comb and closed the hive up securely.

The intention here was to make the stores in the brace comb appear as though it was outside the hive. I expect the bees to relocate the nectar from the brace comb – none of it was capped yet – to the brood box, as and when space become available.

No top ventilation please

Finally, reinforcing the point I made recently about the dislike bees have for top ventilation, every single Abelo crownboard “vent” was gummed up solidly with propolis. 

I’ve got the message loud and clear. No matchsticks needed here.

Scratch and sniff reposition

Apivar strips need to be placed in the edges of the brood nest, at least two frames apart and in diametrically opposing corners of the hive.

But in mid-August the brood nest is a lot larger than it is a month later. As the brood nest shrinks, the strips get further and further away from the main concentration of the bees in the hive.

In an active hive stuffed with bees this probably isn’t a major issue. However, to achieve maximum exposure of the bees – particularly the young bees that Varroa like to hang out with and that are concentrated around the brood nest – it makes sense to reposition the strips midway through the treatment period.

Apivar strip placement as the brood nest shrinks

Apivar treatment takes 6-10 weeks. The actual wording is something like “The larger the brood is, the longer the strips should be left in the limit of 10 weeks”. I usually treat for 9-10 weeks; my colonies are all pretty strong at the end of the summer.

But strips left for that long in the hive often get gummed up with propolis and wax.

Apivar strip efficacy is probably impaired by all that propolis and wax

I therefore spend a few minutes scraping the strips clean of gunk 9 and then reposition them in the hive, adjacent to the – now shrunken – brood nest.

There are studies showing that this scratching and repositioning of the Apivar strips marginally increases the devastation wreaked on the mite population.

Apivar scratch and sniff repositioning studies

And that can only be a good thing™.

More heavy lifting

I returned to the west coast after two long days of driving, beekeeping and meetings 10 having collected a further 125 kg of fondant en route. 

The following day a pallet of jars were delivered from C Wynne Jones. I get the square jars I like – and, more importantly, my customers like – from there. Because of my remote location the ‘free delivery’ comes with a hefty surcharge, so it makes sense to buy a reasonable number at once.

Unfortunately the courier transported them on a 36 ton artic, and there was slightly less than no chance whatsoever that it would be able to negotiate our ~300 metre, 1 in 5 driveway.

I’d had a barely decipherable call (wrong mobile network) from the driver in the morning as he arrived on the peninsula but heard nothing more. I presumed he was still negotiating the ~18 miles of single track road to get here.

Either that or he’d got no phone reception.

I was right on both counts.

He knocked at the door having been unable to call me, but had abandoned the lorry in the road and walked up the hill to the house. 

What a star.

With thanks to Palletline

In exchange for a jar of honey – to restore his flagging blood sugar levels – he unloaded the pallet in the road and I made four trips by car to collect the boxes.

Beekeeping is a high-volume pastime 11 … everything takes up a lot of space.

I think I need to find another location for the canoe that occupies one side of the shed.

In between all the heavy lifting …

And canoeing with the dolphins in the loch is the other thing I’ve been enjoying now the majority of the beekeeping is winding down for the year.


 

Beekeeping fantasy vs. reality

There have been a couple of stories in the press recently that have made me think about the idealised version of beekeeping that is often promoted … with the reality of a lot of amateur beekeeping 1.

Most recently was the announcement of the new CBBC show titled Show Me the Honey! which will be available at the end of this month on iPlayer.

Information is a bit limited at the moment. It’s clearly a programme featuring and for children. According the The Guardian it “features five children and their families taking part in a series of weekly challenges to create the best hive and tastiest honey, with the winner taking home the beekeeper of the year trophy”.

Undoubtedly this will increase interest in beekeeping. This isn’t in itself a bad thing, though the timing is a bit off. The seven week series will end with much of the winter left to run.

Not the best time to start beekeeping

Will those watching who are captivated by the thought of keeping bees go for the ‘quick fix’ of an expensive mid-March nuc thinking “What can be so difficult? One of those kids became the ‘Beekeeper of the Year’ in just seven weeks”.

Or, will they do their homework, attend a Start beekeeping course with a local association, go to a couple of ‘bee handling’ sessions in the association apiary, find a mentor … and only then order a locally sourced nuc?

I’m pretty sure I know which route is more likely to produce a future ‘beekeeper of the year’ 😉

Competitive beekeeping

Just like Show Me the Honey!, my beekeeping often involves a set of ‘weekly challenges’.

  • Where is my bloody hive tool?
  • Your mission, should you choose to accept it, is “To find, mark and clip the queen in this double brood monster of a hive, bulging with psychopathic bees … before the rain starts”.
  • Can I lift these three full supers together without causing permanent damage? 

The concept of competitive beekeeping grated a bit when I first read about it, but the reality is that beekeeping can be competitive.

Think about the annual honey shows.

A bit of lighthearted entertainment for the end of the season?

Or a cutthroat affair, with lashings of deviousness and skulduggery to produce the best 1 oz wax blocks?

That sort of competition I can cope with, although I no longer partake as I’m a very bad loser.

And I lost … a lot 🙁

But think about what’s happened to climbing, and the huge success it was at the Olympics. The speed climbing event is probably now the fastest non-gravity-assisted 2 Olympic sport. 

Perhaps the inevitable adult or celebrity spin-offs of Show Me the Honey! will involve speed inspections?

3 … 2 … 1 … GO!

With Martha Kearney doing the commentary … 3

The best hive

So let’s return to that quote from The Guardian … ‘the best hive’.

Are they going to start with a Thorne’s Bees on a Budget flatpack cedar hive, a mismatched pile of nails, a hammer and a set of IKEA-ish hieroglyphic 4 instructions?

Is the winner the one who gets everything square and true? Does beespace matter? What about injuries? 5

Or perhaps it will be to dream up ‘the best’ new hive design … and there’s lots of competition for that.

How about the urban-friendly 6 B-Box the first ever beehive designed for home beekeeping’.

The B-BOX

Hang on a sec … I’m currently at home.

Let me just check what’s in that blue and yellow box by the shed.

Don’t do this at home … this beehive is designed for other locations

Yep … just as I thought. Bees. It’s a beehive. 

Am I doing something wrong? Have I got a hive designed for beekeeping somewhere other than home? 

There are some grand claims made for the B-BOX and the website is awash with buzzwords 7. I’m not sure the 16 small honey ‘supers’ would be sufficient during a strong nectar flow from the lime trees found in many cities.

These hives are about €480 (plus an extra €580 or so if you want a ‘swarm’ of bees with it … and I think they probably do mean swarm from the description. Yikes!).

Or what about this Philips design – another Urban beehive – that “consists of two parts, a tinted glass shell that houses the honeycomb frames and a flower pot with an entry passage to the glass vessel. You can then harvest the honey produced, simply pull on the smoke actuator chain to calm the bees before it is opened”

Philips Urban beehive

Wow. 

I was sure that bees draw comb in a vertical plane? 

This one is a ‘concept’ hive, so is effectively priceless. 

Which would also be my reaction if I had to do a shook swarm on it 😉

Smart hives

I’m not sure that last hive is entirely practical. 

Instead, how about this ‘robotic’ hive – or Beehome as they call it – from Israeli startup Beewise? This is a container 8 housing 24 colonies which are constantly monitored.

The Beewise ‘Beehome’ robotic beehive

The technology is clearly pretty clever as they appear to be able (or claim) to:

  • provide climate and humidity control
  • monitor brood development on every frame of every hive
  • apply pest control (non-chemical, but it’s not clear what) to control Varroa
  • deliver swarm prevention by ‘changing the conditions in the hive’
  • automatically harvest honey … when the 100 gallon tank is full the Beehome calls you to come and collect

When you think of some of the manipulations needed for successful swarm control you wonder – well, I wonder – how on earth a robot could do it by simply ‘changing the conditions in the hive’

Their website shows a screenshot of an app displaying digital images of frames, together with schematics of the distribution of the various types of brood (capped/uncapped) and stores within the hive.

Very clever … though I do wonder whether the robot takes quite as much care as I do returning frames to the hive without crushing or rolling bees in the process.

What?

I thought you’d never ask … $400.

A month.

At least, that’s the price quoted on the website. I’ve no idea if that’s ‘all in’, or if there are hidden costs involved, like custom frames, software licenses. If it is ‘all in’ and every hive generates a good crop of honey each season it seems very reasonable.

But, and this is a biggy as far as I’m concerned, it seems to to rip the soul out of all that is special about keeping bees.

It’s more like factory farming.

Save the bees

But, inevitably, it ‘saves the bees’ … so that’s OK then 🙁  9

Hives in reality

So those are the fantasy hives that the public read about in the newspapers and that adorn press releases.

Super-clean and shiny and described in glowing terms as bee friendly, bee-centric, sustainable, healthier or a nature-based solution.

In many ways these are what shape their expectation and understanding of beekeeping.

The reality is that bees do just fine in almost any relatively secure container.

Like a hollow tree.

Or a dustbin.

Or a variety of beehive types …

Gaffer tape apiary

Gaffer tape apiary …

… including some that appear to consist mainly of gaffer tape.

Aesthetically perhaps less attractive, but perfectly functional.

I’ve discussed the concept of the ‘the best’ hive previously 10.

The 12-13 pages of different hive types in the Thorne’s catalogue describe a plethora of different sizes and designs. As long as they have the correct bee space and the boxes are broadly compatible – which really means flat interfaces – I’d be happy to keep bees in any of them.

Sure, some might suit my beekeeping a little better than others, but I reckon I’d do OK with them all. 

But, of course, I’d want more than one … which is where the compatibility becomes critical. I’d inevitably end up mixing ‘n’ matching different boxes during swarm control, autumn uniting or simply when running out of equipment.

Uniting with newspaper ...

Uniting with newspaper …

And it’s this reality that never appears in that glossy advertising on promotional websites. The ‘cobbling stuff together’ to make something that’ll do. In the picture above I’m uniting a queenless double hive with a queenright poly hive.

The poly hive is actually a bait hive built from two stacked supers. They are the Paradise/ModernBeekeeping design with an overhanging lip on the lower face, hence the thin, wide, wooden shim between the boxes.

And the crownboard is a piece of thick polythene.

All perfectly functional, but not quite as glossy, organised and coordinated as is often displayed in print or online 11.

But this neat, clean and pristine presentation doesn’t stop with the hives … 

Suits you Sir!

What about the protective clothing?

If you look at the photos above you’d think you could harvest honey (from the B-BOX) wearing a T-shirt and jeans, or inspect your Philips urban hive in a slinky Christian Dior LBD.

The reality is a little less flattering. 

Bees can sting, and agitated bees – with dodgy parentage or through sloppy handling 12 – can sting quite a lot. 

As a quick aside, I note that one of the presenters of Show Me the Honey! has apparently been ‘keeping bees for 15 years and has never been stung’.

And now back to reality 😉

Beesuits aren’t particularly flattering.

Does my bum look big in this? … doesn’t even come close. 

Everything … looks big in a beesuit.

And usually the beesuits are completely pristine, not stained with propolis, held together with gaffer tape or with pockets hanging off from hive tool damage 13.

Angelina Jolie and some slightly grubbier beekeepers

The beesuit Angelina Jolie is wearing is what they typically look like in ‘fantasy beekeeping world’. No broken zips, no propolis staining, no pockets bulging with emptied queen cages and old gloves.

Those worn by the beekeepers around her are probably a bit more normal, though I also have a sneaking suspicion they’ve worn their ‘Sunday best’ beesuits for the photo op.

As another aside, Angelia Jolie is promoting the UNESCO programme ‘Women for Bees’. This teaches beekeeping and entrepreneurship to women in UNESCO designated biosphere reserves around the world. Further details also in National Geographic.

And it doesn’t stop there

I’ve had a great beekeeping year.

There have been some notable successes – in queen rearing and mating, in preparing nucs and in a really excellent honey crop.

Show me the Honey!

However, it wasn’t all the clean, neat and tidy affair depicted in the press.

And, to be honest, parts of it could best be described as an omnishambles.

I’m being polite there.

Here are just a few examples where my beekeeping reality didn’t quite match the glossy, propolis-free, beautifully ordered and presented world of beekeeping fantasy.

  • Wrenching my back during the spring honey harvest by trying to carry too many supers. I walked hunched over for a month and spent quite a lot of time lying flat on my back.
  • Glenrothes – my base when beekeeping on the east coast. Underwhelming 14

Good morning Glenrothes

  • Installing a ‘lively’ nuc in a full hive before securing my veil. No stings, but a pretty close call with several bees agitatedly struggling to escape the space they’d seemingly so easily entered.
  • Lifting three supers off a hive in late July and carelessly 15 tripping over a hive roof. I dropped the lot and fell flat on my face. A very sticky mess but the bees were extraordinarily tolerant of my clumsiness.
  • Sweating so much during July inspections that my gloves filled with perspiration and my wrinkly fingers stopped ‘unlocking’ the phone.

Ewwww

  • Consequently dropping more queens in the grass than ever before. I was so cackhanded that it became unusual not to drop them on the ground before getting them into the marking cage.
  • Watching a much-needed virgin queen fly off out of sight while – stupidly – trying to get her into an introduction cage with the shed door open. D’oh!
  • Chasing another virgin queen around the shed – after closing the door 16 – for five minutes before getting her into a cage. 
  • Going half crazy trying to keep wasps out of cleared supers before stacking them in the car.
  • The hole in the hive pocket and no trousers debacle. Enough said 🙁
  • More lifting, more sweating, more wasps …
  • The long evening drive back to the west coast, tired, dehydrated and smelling of smoke and propolis 17.

Go west young man …

That’s the reality of a beekeeping season.

It’s been fantastic.

I wouldn’t have it any other way 🙂


 

Cut more losses

This is a follow-on to the post last week, this time focusing on feeding and a few ‘odds and sods’ that failed to make it into the first 3000 words on reducing overwintering colony losses.

Both posts should be read in conjunction with one (or more 1 ) of my earlier posts on disease management for winter. Primarily this involves hammering down the mite levels before the winter bees are produced, so ensuring their longevity.

But also don’t forget to treat your colonies during a broodless period in midwinter to mop up mites that survived the autumn treatment, or have reproduced since then.

Why feed colonies?

All colonies need sufficient stores to get the colony through the winter until suitable nectar sources and good enough weather make foraging profitable the following spring.

How much the colony needs depends upon the bees themselves – some strains are more frugal than others – and the duration of the winter. If there is no forage available, or the weather is too poor for the bees to fly, then they will be dependent upon stores in the hive.

A reasonable estimate would probably be somewhere around 20 kg of stores, but this isn’t a precise science.

It’s better for the colony to have too much than too little. 

If the colony has stores left over at winter’s end you can always remove them and use them when you make up nucs later in the season. Just pull out the frames and store them safely until needed.

Unused winter stores

In contrast, if the colony starts the winter with too few stores there are only two possible outcomes:

  • the colony will starve to death, usually in late winter/early spring (see below)
  • you will spend your winter having to regularly check the colony weight and opening the hive to add “emergency rations” to get them through the winter

Neither of these is desirable, though you should expect to have to check the colony periodically in winter anyway.

Feeding honey for the winter … and meaningless anecdotes

By the end of the summer the queen has reduced her laying rate and the bees should be backfilling brood comb with honey stores. If you assume there’s about 5 kg of stores 2 in the brood box then they’ll need about another 15 kg. 

15 kg is about the amount of honey you can extract from a well-filled super. 

Convenient 😉

Some beekeepers leave a full super of honey on the hive, claiming the “it’s better for the bees than syrup”

Of course, it’s a free world, but there are two things wrong with doing this:

  • where is the evidence that demonstrates that honey is better than sugar-based stores?
  • it’s an eye-wateringly expensive way to feed your colonies

By evidence, I mean statistically-valid studies that show improved overwintering on honey rather than sugar.

Not ‘my hive with a honey super was strong in spring but I heard that Fred lost his colony that was fed syrup’ 3.

That’s not evidence, that’s anecdote.

If you want to get this sort of evidence you’d need to start with a lot of hives, all headed by queens of a similar age and provenance, all with balanced numbers of brood frames/strength, all with similar mite levels and other pathogens.

For starters I’d suggest 200 hives; feed 50% with honey, 50% with sugar … and then repeat the study for the two following winters.

Then do the stats 4.

The economics of feeding honey

If I were a rich man …

The 300 supers of honey used for that experiment would contain honey valued at about £80,000.

That’s profit, not sale price (though it doesn’t include labour costs as I – and many amateur beekeepers – work for free).

The honey in a single full super has a value of £250-275 … that’s an expensive way to feed your bees 5.

Particularly when it’s not demonstrably better than a tenner or so of granulated sugar 🙁

But there are more costs to consider

The economic arguments made above are simplistic in the extreme. However, there are other costs to consider when feeding colonies.

  • time taken to prepare and store whatever you will be feeding them with 6
  • feeders needed to dispense the food (and storage of these when not in use)
  • energetic costs for the colony in converting the food to stores

Years ago I stopped worrying (or even thinking much) about any of this and settled on feeding colonies fondant in the autumn.

Fondant mountain ...

Fondant mountain …

Fondant is ~78% sugar, so a 12.5 kg block contains about 9.75 kg of sugar.

This year I’m paying £11.75 for fondant which equates to ~£1.20 / kg for the sugar it contains.

In contrast, granulated sugar is currently about £0.63 / kg at Tesco.

The benefits of fondant

Although my sugar costs are about double this is a relatively small price I’m (more than) prepared to accept when you take into account the additional benefits.

  • zero preparation time and no container costs. Fondant comes ready-wrapped and stores for years in the box it is purchased in
  • no need for jerry cans, plastic buckets or anything to prepare or store it in before use
  • no need for expensive Ashforth-type feeders that sit around for 95% of the year unused When I last checked an Ashforth feeder cost £66 😯 
  • it takes less than 2 minutes to add fondant to a colony
  • no risk of spillages – in the kitchen, the car or the apiary 7.
  • fondant is taken down more slowly than syrup, so providing more space for the queen to continue laying. In addition, in the event of an early cold snap, fondant remains accessible whereas bees often stop taking syrup down

Regarding the energetic costs for the colony in storing fondant rather than syrup … I assume this is the case based upon the similarity of the water content of fondant to capped stores (22% vs. 18%), whereas syrup contains much more water and so needs to be ripened before capping to avoid fermentation.

Fondant block under inverted perspex crownboard – insulation to be added on top.

Whether this is correct or not 8, the colony has no problem taking down the fondant over a 2-4 week period and storing it.

What are the disadvantages of using fondant? 

The only one I’m really aware of is that the colony will not draw fresh comb when feeding on fondant (or at least, not enthusiastically). In contrast, bees fed syrup in the autumn and provided with fresh foundation will draw lovely worker brood comb. 

Do not underestimate this benefit.

They fancied that fondant

Brood frames of drawn comb are a very valuable resource. Every time you make up a nuc, or shift a nuc to a full-sized box, providing drawn comb significantly speeds up the expansion of the resulting colony.

Nevertheless, for me, the advantages of fondant far outweigh the disadvantages …

Finally, in closing, I’ve not purchased or used invert syrup for feeding colonies. Other than no prep time this has the same drawbacks as syrup made from granulated sugar. Having learnt to use fondant a decade or so ago from Peter Edwards (Stratford BKA) I’ve never felt the need to look at other options.

Let’s move on …

Ventilation and insulation

Bees can withstand very cold temperatures if healthy and provided with sufficient stores. In northern Canada bees may experience only 120 frost-free days a year, and cope with 3-4 week periods in winter when the temperature is -25°C (and colder if you consider the wind chill).

That makes anywhere in the UK look positively balmy.

Margate vs. the Maldives … a similar temperature difference to Margate vs. Manitoba in the winter

I’ve overwintered colonies in cedar or poly boxes for a decade and not noticed a difference in survival rates. Like the honey vs. sugar argument above, if there is a difference it is probably minor. 

However, colony expansion in poly boxes in the spring is usually better in my experience, and they often fill the outer frames with brood well before cedar boxes in the same apiary get there.

Whether cedar or poly I take care with three aspects of their insulation/ventilation:

  • the colonies have open mesh floors and the Varroa tray is only in place when I’m actively monitoring mite drop
  • all have insulation above the crownboard in the form of a 50 mm thick block of Kingspan (or Recticel, or Celotex), either integrated into the crownboard itself, placed above it or built into the roof
  • I ensure there is no upper ventilation – no matchsticks under the crownboard, no holes etc.
  • excess empty space in the brood box is reduced to minimise the dead air space the bees might lose heat to

In my experience bees actively dislike ventilation in the crownboard. They fill mesh with propolis …

Exhibit A … are you getting the message?

… and block up the holes in those over-engineered Abelo crownboards …

Exhibit B … ventilated hole in an Abelo crownboard

Take notice of what the bees are telling you … 😉

Insulation over the colony

I’ve described my insulated perspex crownboards before. They work well and – when inverted – can just about accomodate a flattened 9, halved block of fondant.

Perspex crownboard with integrated insulation

Finally, if it’s a small colony in a brood box 10 then I reduce the dead space in the brood box using a fat dummy

Fat dummy with integral feeder

Fat dummy …

I build these filled with polystyrene chips.

You don’t need this sort of high-tech solution … some polystyrene wrapped tightly in a thick plastic bag and sealed up with gaffer tape works just as well.

Insulation ...

Insulation …

I’ve even used bubblewrap or that air-filled plastic packaging to fill the space around a top up block of fondant in a super ‘eke’ before now.

However, remember that a small weak colony in autumn is unlikely to overwinter as well as a strong colony. Why is it weak? Would you be better uniting it before winter starts?

Nucleus colonies

Everything written above applies equally well to nucleus colonies.

A strong, healthy nuc should overwinter well and be ready in the spring for sale or promoting to a full colony.

Here's one I prepared earlier

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

Although I have overwintered nucs in cedar boxes I now almost exclusively use polystyrene. This is another economic decision … a well made cedar nuc costs about double the price of the best poly nucs

I feed my nucs fondant in preparation for the winter, typically by adding 1-2 kg blocks to the integral feeder.

Everynuc fondant topup

Everynuc fondant topup

Because of the absence of storage space in the nuc brood box it’s not unusual to have to supplement this several times during the autumn and winter.

You can even overwinter queens in mini-mating nucs like Apidea’s and Kieler’s.

Kieler mini-nuc with overwintering queen

This deserves a post of its own. Briefly, the mini-nuc needs to be very strong and usually double- or triple- height. I build fondant frame feeders for Kieler’s that can be quickly swapped in/out to compensate for the limited amounts of stores present in the brood box.

Kieler mini-nuc frame feeders

My greatest success in overwintering these was in winters when I provided additional shelter by placing the nucs in an unheated greenhouse. A tunnel provided access to the outside. However, I know several beekeepers who overwinter them without this sort of additional protection (and have done so myself).

Just because this can be done doesn’t mean it’s the best thing to do.

I’d always prefer to overwinter a colony as a 5 frame nuc. The survival rates are much better, their resilience to long periods of adverse weather is significantly greater, and they are generally much more useful in the spring.

Miscellaneous musings

Hive weight

A colony starting the winter with ample stores can still starve if the bees are particularly extravagant, or if they rear lots of brood but cannot forage.

The rate at which stores are used is slow late in the year and speeds up once brood rearing starts again in earnest early the following spring (though actually in late winter).

Colony weight in early spring

As should be obvious, this is a Craptastic™ sketch simply to illustrate a point 😉

The inflection point might be mid-December or even early February.

The important message is that, once brood rearing starts, consumption of stores increases. Keep checking the colony weight overwinter and supplement with fondant as needed.

I’m going to return to overwinter colony weights sometime this winter as I’m dabbling with a weather station and set of hive scales … watch this space.

An empty super cuts down draughts

Periodically it’s suggested that an empty super under the (open mesh) floor of the hive ‘cuts down draughts’, and is therefore beneficial for the colony.

It might be.

But like the ‘overwintering on honey’ (and being a pedant scientist) I’d always want to see the evidence.

There are two claims being made here:

  • a super under the floor cuts down draughts
  • fewer draughts benefits the colony which consequently overwinters better

Really?

There are ways to measure draughts but has anyone ever done so? Remember, the key point is that the airflow around the winter cluster would be reduced if there are fewer draughts. 

Does a super reduce this airflow significantly over and above that already caused by the sidewalls of the floor?

And, even if it does, perhaps the colony ‘reshapes’ itself to accommodate the draught from an open mesh floor.

What shape is the winter cluster?

For example, in an uninsulated hive (including no insulation over the cluster) with a solid floor the cluster is likely to be roughly spherical. They minimise the surface area.

With an open mesh floor are they more ellipsoid, so avoiding draughts from below? If so, is this improved much by an empty super below the open mesh floor? Does the cluster change shape or position? I don’t know as I’ve not compared cluster shapes in solid vs. open mesh floors plus/minus a super underneath.

And anyway, an open mesh floor looks very like a baffle to me … how much better can it get? How draughty is it in the first place?

Is this example 8,639 for my ‘Beekeeping Myths’ book?

I do know that top insulation tends to flatten the cluster against the warm underside of the crownboard.

Midwinter cluster

A strong colony in midwinter

Having worked out that draughts are (or are not) reduced … you still need another couple of hundred hives to test whether overwintering success rates are improved!

More winter bees

Finally, always remember that the survival of the colony is dependent upon the winter bees. All other things being equal (stores, disease etc.), a colony with lots of winter bees will overwinter better than one with fewer.

This is one of the reasons I stopped using Apiguard for mite control in autumn. Apiguard contains thymol and quite regularly (30-50% of the time in my experience) stopped the queen from laying, particularly in warmer weather. 

Apiguard works well for mite control, but I became wary that I was potentially stopping the queen at a time critical for late-season colony development. I worried that, once treatment was finished, a cold snap would shut down brood rearing leaving it with suboptimal numbers of winter bees.

I never checked to see whether the queen ‘made good’ any shortfall after removal of the treatment … instead I moved to Scotland where it’s too cold to use Apiguard effectively 🙁


 

Cut your losses

The stats for winter losses in the UK, Europe and USA can make for rather sobering reading.

In the UK, losses over the last 12 years have fluctuated between 9% and 34%. This self-selecting survey includes responses from about 10% of the British Beekeepers Association membership (primarily England and Wales, despite the name). The average number of hives maintained by a BBKA member is about 5, meaning – all other things being equal 1 – that most beekeepers should expect to lose about 1 hive every winter.

BBKA winter losses survey

About 30 countries, mainly Northern hemisphere, contribute to the COLOSS survey which is significantly larger scale. The most recent 2 data published (for the ’16/’17 winter) had data from ~15,000 respondents 3 managing over 400,000 hives. Of these, ~21% were lost for a variety of reasons. COLOSS data is presented as an unwieldy table, rather than graphically. Further details, including recently published results, are linked from their website.

In the USA the Bee Informed Partnership surveys losses – both winter and summer – and claims to have results that cover ~10% of all the colonies in the country (so probably between 250,000 and 275,000 hives). Winter losses in the USA are rarely reported at less than 20% and were as high as 35% in the ’18/’19 winter 4.

Bee Informed Partnership annual colony losses

Are these figures to be trusted?

Who knows?

Each survey is accompanied by a variety of statistics. However, since they all appear to be based upon voluntary reporting by a subset of beekeepers, there are opportunities for all sorts of data to be included (and even more to be missed entirely). 

The problem with surveys

Is the successful beekeeper who managed to get all her colonies through the winter more likely to respond?

A form of ‘bragging rights’.

What about the beekeeper that lost all his colonies?

Does he respond out of a sense of responsibility?

Or does he keep quiet because he doesn’t want to be reminded of those cold, quiet, mouldy boxes opened on the first warm day of spring?

One and two year beekeepers

What about the high level of annual ‘churn’ amongst beekeepers? They buy a nuc in May, filled with enthusiasm about the jars of golden honey they’ll have for family and friends in late summer.

To say nothing of all the “saving the bees” they’ll be doing.

But by late summer the colony is queenless and has an unpleasant temperament

Beekeeping should be enjoyable ...

Beekeeping should be enjoyable …

Psychopathic you might say … if you were feeling uncharitable.

Consequently the Varroa treatment goes on far too late,. Or is quietly forgotten. The winter bees have high viral loads and ‘die like flies’ 5, resulting in the colony succumbing by the year end.

But this colony loss is never recorded on any surveys.

The once enthusiastic beekeeper has moved on and is now passionate about growing prize-winning vegetables or cheesemaking or keeping chickens. 

Beekeeping associations train lots of new beekeepers and – although membership numbers are increasing – it’s well below the rate they’re trained at.

Some may not be ‘joiners’ and go their own way.

Many just quietly stop after a year or two.

How many people have you met that say “Oh yes, I used to keep bees”

Did you ask them whether they ever completed a winter losses survey?

I’m not sure any of the surveys listed above do much ‘groundtruthing’ to establish whether the data they collect is truly representative of the population actually surveyed. With large numbers of respondents spread across a wide geographic and climatic range it’s not an easy thing to do.

So, treat these surveys with a healthy degree of scepticism.

Undoubtedly there are high levels of winter losses – at least sometimes – and the overall level of losses varies from year to year.

Losses and costs

The direct financial cost of these colony losses to beekeepers is very high.

Ignoring time invested and ‘consumables’ like food, miticides and foundation these costs in ’16/’17 for just Austria, the Czech Republic and Macedonia were estimated at €56 million 😯  

These figures simply reflect lost honey production and the value of the lost colonies. They do not include the indirect costs resulting from lost pollination.

But, for the small scale beekeeper, these economic losses are irrelevant.

Most of these beekeepers do not rely on bees for their income.

The real cost is emotional 🙁

It still saddens me when I lose a colony, particularly when I think that the loss was avoidable or due to my incompetence, carelessness or stupidity 6.

Little snow, big snow. Big snow, little snow.

Your hives should be quiet in winter, but it hurts when they are silent in spring.

Anatomy of a death

The COLOSS surveys give a breakdown of winter losses in three categories:

  • natural disasters
  • queen problems
  • dead colonies

Natural disasters are things like bears, honey badgers, flooding or falling trees.

We can probably safely ignore honey badgers in the UK, but climate change is increasing the weather extremes that causes flooding and falling trees.

Moving to higher ground ...

Moving to higher ground …

Don’t assume that poly hives are the answer to potential flooding.

They do float, though not necessarily the right way up 🙁

Queen problems cover a variety of issues ranging from reduced fecundity to poor mating (and consequent drone laying) to very early or late – and failed – supersedure 7.

Beekeepers with a lot more experience than me report that queen problems are increasing.

Drone laying queen ...

Drone laying queen …

Perhaps the issues with fecundity and drone laying are related to toxic levels of miticides in commercial foundation? It’s certainly known that these residues reduce drone sperm fertility significantly. I intend to return to this topic sometime during the approaching winter … perhaps in time to encourage the use of some foundationless frames for (fertile) drone production 😉

In the ’16/’17 COLOSS data, natural disasters accounted for 1.6% of all overwintered colonies (so ~7.5% of losses), queen problems resulted in the loss of 5.1% of colonies (i.e. ~24% of losses) and the remainder (14.1% of colonies, ~68% of losses) just died.

Just died?

We’ll return to natural disasters (but not bears or honey badgers) and queen problems shortly. What about the majority of losses in which the colony ‘just died’?

If you discuss colony post-mortems with beekeepers they sometimes divide the ‘just died’ category (i.e. those not readily attributable to failed queens, marauding grizzlies or tsunamis) into four groups:

  • disease
  • isolation starvation
  • starvation
  • don’t know 

The most important disease associated with overwintering colony losses is high levels of Deformed wing virus (DWV). This results from uncontrolled or inadequately controlled Varroa infestation. For any new readers of this site, please refer back to many of the articles I’ve already written on Varroa management 8.

I strongly suspect that a significant proportion of the reported isolation starvation is actually also due to disease, rather than isolation per se.

A consequence of high levels of DWV is that winter bees die prematurely. Consequently, the colony shrinks faster than it would otherwise do. It starts the size of a basketball but (too) rapidly ends up the size of a grapefruit … or an orange.

Isolation starvation and disease

The small cluster is then unable to remain in contact with stores, and so starves. 

Yes, the colony died from ‘isolation starvation’, but the cause was the high levels of Varroa and the viruses it transmits.

Isolation starvation ...

Isolation starvation …

What about regular starvation?

Not because the cluster became isolated from the stores, but simply because they had insufficient stores to get through the winter.

Whose fault was that?

And the last category, the “don’t knows”?

I bet most of these are due to high levels of Varroa and DWV as well 🙁

Yes, there will be other reasons … but probably not a huge number. 

What’s more … if you don’t know the reason for the colony loss there’s very little you can do to mitigate against it in future seasons.

And, other than wild and increasingly vague speculation, there’s little I can write about if the reason for the loss remains unknown 9.

Avoiding winter losses

So, let’s rationalise those earlier lists into the probable (known) major causes of overwintering colony losses:

  • natural disasters
  • queen problems
  • starvation
  • disease (but probably mainly DWV and Varroa

As the long, hot days of summer gradually shorten and cool as early autumn approaches, you should be thinking about each of these potential causes of overwintering colony loss … and doing what you can to ensure it doesn’t happen to you (or, more correctly, your bees).

Ardnamurchan autumn

Ardnamurchan autumn

Some are easier to deal with than others.

Here’s a whistle-stop tour of some more specific problems and some practical solutions 10. Some, all or none may apply to your bees – it depends upon your location, your climate, your experience and future plans as a beekeeper. 

Natural disasters

These fall into two broad groups:

  • things you can do almost nothing about (but might be able to avoid)
  • things you can relatively easily solve

Flooding, falling trees, lightning, landslides, earthquakes, volcanoes, meteor strikes etc. all fall into the first group.

If you can avoid them, do. 

Your local council will have information on areas at risk from flooding. There are also searchable maps available from SEPA. Do not underestimate the severity of some of the recent flooding. Some parts of Scotland and Northern England had 600 mm of rain in two days in 2015.

You might be surprised (and from an insurance aspect, devastated) at the classification of some areas now ‘at risk’. 

Where did Noah keep his bees? In his Ark hive.

Where did Noah keep his bees? In his Ark hive.

Consider moving hives to higher ground before the winter rains start. One consequence of climate change is that heavy rainfall is now ~20% heavier than it was a few decades ago. This means that floods occur more frequently, are more extensive and the water levels rise faster. You might not have a chance to move the hives if flooding does occur,

More rain and stronger winds (particularly before leaf fall) mean more trees will come down. You might be able to identify trees potentially at risk from falling. It makes sense to remove them (or site your hives elsewhere). 

No risk of this larch tree falling on my hives

Lightning, earthquakes, volcanoes, meteor strikes … all a possibility though I would 11 probably worry about Varroa and woodpeckers first 😉

Solvable natural disasters

The ‘solvable’ natural disasters include preventing your colonies being robbed by other bees or wasps. Or ransacked by mice or woodpeckers after the first hard frosts start. A solution to many of these are ‘reduced size entrances’ which either enable the colony to better defend itself, or physically restricts access to critters.

The L-shaped ‘kewl floors‘ I use prevent mice from accessing the brood box. They are also easier for the colony to defend from bees/wasps, but can also easily be reduced in size with a narrow piece of hardwood. If you don’t use these types of floor you should probably use a mouseguard.

Polyhives and polythene

Polyhives and polythene …

Woodpeckers 12 need to cling onto the outside of the hive to hammer their way through the side. You can either place a wire mesh cage around the hive, or wrap the box in something like damp proof membrane (or polythene) to prevent them gaining purchase on the side walls.

Keep off Woody

Keep off Woody

Doing both is probably overkill though 😉

Strong colonies

Before we move onto queen problems – though it is related – it’s worth emphasising that an even better solution to prevent robbing by bees or wasps is to maintain really strong colonies.

Strong colonies with a well balanced population of bees can almost always defend themselves successfully against wasps and robbing bees.

Nucs, that are both weaker and – at least shortly after being made up – unbalanced, are far less able to defend themselves and need some sort of access restriction.

By ‘balanced’ I mean that the numbers and proportions of bees fulfilling the various roles in the nucleus colony are reflective of a full hive e.g. nurse bees, foragers, guard bees. 

Reduced entrance ...

Reduced entrance …

But the benefits of strong colonies are far greater than just being able to prevent wasps or robbing bees. There is compelling scientific evidence that strong colonies overwinter better

I don’t mean strong summer colonies, I mean colonies that are strong in the late autumn when they are fully populated with the winter bees.

Almost the entire complement of bees in the hive are replaced between late summer and late autumn. Remember that a really strong summer colony may not be strong in the winter if Varroa and virus levels have not been controlled.

How do you ensure your colonies are strong?

  1. Minimise disease by controlling Varroa levels in early autumn to guarantee the all-important winter bees are reared without being exposed to high levels of DWV.
  2. Try and use a miticide treatment that does not reduce the laying rate of the queen.
  3. Avoid blocking the brood nest with stores where the queen should be laying eggs.
  4. Requeen your colonies regularly. Young queens lay more eggs later into the autumn. As a consequence the colonies have increased populations of winter bees.
  5. Unite weak colonies (assuming they are disease-free) with stronger colonies. The former may well not survive anyway, and the latter will have a better chance of surviving if it is even stronger – see below. 
  6. Use local bees. There’s good evidence that local bees (i.e. reared locally, not imported from elsewhere) overwinter better, not least because they produce stronger colonies.

Uniting – take your losses in the autumn

My regular colony inspections every 7-10 days during May and June are pretty much abandoned by July. The risk of swarming is very much reduced after the ‘June gap’ in my experience. 

I still check the colonies periodically and I’m usually still rearing queens. However, the rigour with which I check for queen cells is much reduced. By July my colonies are usually committed to single-mindedly filling the supers with summer nectar.

They are already making their own preparations for the long winter ahead.

Although the inspections are less rigorous, I do keep a careful watch on the strength of each colony. Often this is directly related to the number of supers I’ve had to pile on top.

Colonies that are underperforming, and – more specifically – understrength are almost always united with a stronger colony.

An Abelo/Swienty hybrid hive ...

An Abelo/Swienty hybrid hive …

Experience has taught me that an understrength colony is usually more trouble than it’s worth. If it’s disease-free it may well overwinter reasonably well. However, it’s likely to start brood rearing more slowly and build up less well. It may also need more mollycoddling 13 in the autumn e.g. protection from wasps or robbing bees.

However, a colony that is not flourishing in the summer is much more likely to struggle and fail during the winter. Perhaps the queen is not quite ‘firing on all cylinders’ and laying at a really good rate, or she might be poorly mated.

Far better that the workforce contributes to strengthening another hive, rather than collect an underwhelming amount of honey before entering the winter and eventually becoming a statistic.

My winter losses are low and, over the last decade, reducing.

That’s partly because my Varroa management is reasonably thorough.

However, it’s probably mainly due to ensuring only strong colonies go into the winter in the first place.

Newspaper

I’ve dealt with uniting in several previous posts.

It’s a two minute job. 

You remove the queen from the weak colony, stack one brood box over the other separated by a sheet or two of newspaper with a very small (~3mm) hole in the middle. Add the roof and leave them to get on with things.

I don’t think it makes any difference whether the strong colony goes on the top or the bottom.

I place the colony I’m moving above the box I’m uniting it with. My – wildly unscientific – rationale being that the bees in the top box will have to negotiate the route to the hive entrance and, in doing so, will help them orientate to the new location faster 14.

If you unite colonies early or late in the day most foragers will be ‘at home’ so not too many bees will return to find their hive missing.

If there are supers on one or both hives you can separate them with newspaper as well. Alternatively, use a clearer the day before to empty the supers prior to uniting the colonies. You can then add back the supers you want and redistribute the remainder to other hives in the apiary.

Successful uniting ...

Successful uniting …

Don’t be in too much of a hurry to check for successful uniting.

Leave them a week. The last thing you want is for the queen to get killed in an unseemly melee caused by you disturbing them before they have properly settled.

Done properly, uniting is almost foolproof. I reckon over 95% of colonies I unite are successful.

That’s all folks … more on ‘Cutting your losses’ next week 🙂


Notes

At just over 3000 words this post got a bit out of control … I’ll deal with more significant queen problems, feeding colonies, the weather and some miscellaneous ‘odds and sods’ next week.

Absconding

One of the few principles I have ( 😉  ) is that the posts here should be based upon practical experience. When I write about swarm control I describe the methods that I use. When I write about Varroa management I discuss Apivar and oxalic acid in detail as I have a lot of experience using these compounds. I’ve not written about MAQS as I don’t use it.

For the same reasons, you won’t see a discussion about top bar hives or the Bee Guardian piezoelectric gadgets that causes the varroa mites stop to reproduce and go away from the hive” 1.

The topic today is absconding. My qualification to write about this is extremely limited, but just about sufficient. I think I’ve had only one colony abscond in the last decade. It’s not something I take any notice of (or precautions against) in my regular beekeeping. However, it’s an interesting subject as there’s some relevant science associated with absconding and honey bee migration, so it’s worth discussing.

And perhaps more science to do …

But first some definitions

Colony reproduction involves swarming. The colony rears one or more new queens. Once the queen cells are capped, the current queen and up to 75% of the adult bees leave the hive as a swarm. Prior to leaving, scout bees have scoured the environment for suitable new nest sites. These scouts lead the swarm to the chosen new location 2.

The swarm leaves behind all the brood and most of the stores. Together with the adult bees that remain, this colony has a good chance of survival (~80%) which is probably a reflection on queen mating success rates 3.

‘Most of the stores’ because the swarming bees gorge themselves on honey prior to leaving the hive (or nest site if it’s a feral colony). Something like 40% by weight of the swarm is honey stores. They need these stores to survive – to build new comb, to tide them over a period of bad weather and while they scout the environment for forage. Swarming is a risky business, only about 20% of natural swarms survive.

Absconding is very different. During this process the entire colony – the queen and all the flying bees – leave the nest site (hive). They usually leave behind almost nothing. There may be very limited amounts of capped brood/larvae or eggs remaining, but the stores are usually gone. Absconding therefore does not involve colony reproduction. There are no queen cells produced. You start with one colony and end with one.

However, although absconding is very different, it’s not completely different. It still involves scout bees and it still involves waggle dances to communicate distance and direction.

Like swarming, it’s also a completely natural process. In certain parts of the world there are annual cycles of absconding and colony migration.

In the discussion that follows I’m going to try and make a distinction between absconding by managed and unmanaged colonies. 

The consequences of either type of colony absconding are probably the same. 

The drivers that result in the colony absconding are sometimes different.

My experience

Let’s get this out of the way … 4

To my knowledge the only colony I have ever had abscond was from a Kieler mini-nuc. The mini-nuc had been primed with a mugful of bees and a queen cell a week or so earlier. The queen had emerged and may (or may not?) have gone on a mating flight 5.

An Apidea mini-nuc ‘catching a few rays’

One baking hot June afternoon I turned up at the apiary just as a small swirling mass of bees disappeared over the fence. 

Never to return 🙁

The mini-nuc was low on stores (but far from empty) and devoid of bees (or brood). There was drawn comb so the queen would have been able to lay (if she had been mated). I can’t remember whether there were eggs present … this was several years ago 6.

‘Natural’ absconding and colony migration

This mini-nuc wasn’t the one pictured, but it was similarly exposed. In full sun these can rapidly overheat and there is a real risk of the small colony absconding. I now always site my mini-nucs out of the heat of the full sun – even in Scotland – in dappled shade, at the bottom of a hedge or somewhere similar.

Of course, I don’t know that overheating caused this little colony to abscond, but it seems like a reasonable assumption.

Bees living in temperate and tropical regions exhibit gross behavioural differences that reflect the climate and availability of forage. Those in temperate climates swarm annually, coinciding with the predictable period of forage availability, and are quiescent over ‘winter’.

In contrast, bees in tropical climates have no ‘winter’ to survive as the temperature is high enough all year for brood rearing and comb building. What differs though is the availability of forage and water. If these are limiting the bees migrate to other areas.

This annual migration involves the colonies absconding … and it has been quite well studied by scientists.

Adverse environmental conditions are one of the recognised drivers of absconding. In addition to overheating, these include a dearth of resources during the wet season. 

The other major driver of absconding is disturbance, for example by predators such as ants (or beekeepers). Disturbance is a lot less predictable than environmental factors, and it is the latter that has been better studied.

Preparing to migrate

Absconding and migration appear to be a characteristic of strong, healthy colonies. Prior to absconding the colony reduces brood rearing drastically although the queen continues to lay a very limited number of eggs until the bulk of the worker brood has emerged 7.

Colonies tended to abscond within a day of this worker brood emerging, leaving almost nothing in the original nest site. 

So, this isn’t a spur of the moment decision, it’s a protracted process taking at least a fortnight from the near-cessation of brood rearing. This means the colony benefits from the resources they have invested in rearing brood, rather than leaving behind slabs of capped brood that would otherwise be doomed.

How does the colony know where to go when it absconds?

Actually, these preparations probably take more than a fortnight. Analysis of the waggle dances for several weeks prior to absconding show that the foraging area and distances were both increasing and becoming more variable. 

Schneider and McNally 8 showed that these waggle dances regularly communicated distances of up to 20 km from the nest site.

However, these weren’t typical dances … the distance component was variable, the dance occurred during periods of little flight activity and the dance was not associated with forage sources. They interpreted this as a generalised signal to fly for a long (but unspecified) distance in a particular direction, rather than to a specific location.

I’m not aware of follow-up studies to these. Do the bees go through the same sort of decision-making process to ‘agree’ on the final direction as the scout bees do when a colony swarms? I suspect not, the distance component was very variable and there was no direct evidence that the dancing bees ever made the entire journey anyway.

Perhaps these waggle dances simply indicate “Things are better a long way south of here. When we go, that’s the direction to take”.

Stopovers

If a colony absconds due to adverse environmental conditions – such as a lack of forage, or overheating – it seems unlikely that things would be much better only 20 km away. “environment” is local, but not necessarily that local.

In reality, colonies abscond and migrate much further than this when necessary, restoring in temporary stopover locations when necessary. In the case of Apis mellifera I’m not aware of any studies of these sites. However, in the Giant honey bee (Apis dorsata) some of these stopover locations appear to be re-used annually. 

Apis dorsata migrates up to 200 km and has even been reported crossing 50 km of open water between Sumatra and Malaysia. These long migrations take up to a month and the bees bivouac on trees, resting and replenishing their stores (by foraging locally) 9.

Giant honey bee (Apis dorsata) temporary stopover bivouac

Analysis of scout bee dancing activity on the surface of these bivouacked colonies show that this again determines the direction (and possibly distance) of the next stage of the journey. 

Absconding and managed colonies

I think it’s reasonable to assume that at least some of the factors that induce colonies to abscond in tropical regions also trigger absconding in our managed colonies in the UK. 

Very small colonies – like the mini-nuc described above – are poor at thermoregulation. There are simply too few bees present to cool the colony in very hot weather.

Although I’m aware that colonies may abscond due to disturbance – from wax moth, Varroa or small hive beetle infestation – I’ve no experience of this 10.

What about disturbance by beekeepers managing colonies? It’s a possibility I suppose. Clearly the regular weekly inspections are not sufficient disturbance to trigger absconding, but perhaps a daily rummage through the brood box might not be tolerated 11.

Absconding swarms

In temperate climates most beekeepers associate absconding with recently hives swarms.

Here’s a typical scenario …

The beekeeper is called out to a bivouacked swarm hanging – conveniently and precariously, just out of reach – in a tree.

By the time they’ve collected the ladder, the skep, the white sheet and the secateurs it’s late afternoon. Never mind … A swarm in May is worth a bale of hay etc.

A spring swarm in a skep

They drop the swarm into the skep, avoid toppling off the ladder, allow the flying bees to join the queen, wrap everything in the sheet and return triumphantly to their apiary 12.

In time honoured tradition they assemble a new hive, prop the entrance open and build a sheet-covered ramp onto which they unceremoniously dump the collected swarm.

'Walking' a swarm into a hive

‘Walking’ a swarm into a hive

And the bees calmly walk up the slope into the hive.

It’s one of the great sights in beekeeping … and one I now never bother to do.

I just dump the swarm into the hive and close it up. 

Boring, but quick 😉

Back to the absconding swarm scenario …

The beekeeper returns late the following morning to find the swarm has gone 🙁

Is this typical absconding?

Other than one or two typical circumstances such as a freshly painted (and still smelly) hive, I think that these swarms may abscond because they have already chosen an alternative nest site

The scout bees from the bivouacked colony (collected a day or two previously) had been busy surveying the environment for suitable nest sites. This process can take several days until a sufficient number of the scouts are convinced of the benefits of a particular site.

Once that decision is made the colony leaves the bivouac and flies to the new nest site. However, this flight tends to happen in the middle of the day, not late in the afternoon.

The beekeeper who hived our hypothetical swarm in the scenario above may have actually interrupted this process, which simply continued the following morning.

I don’t know if scout bees conduct waggle dances overnight to reinforce nest site choices (but the normal waggle dance for forage resources can occur during the night). If they do, this might account for the bees disappearing soon after being hived.

How do you stop hived swarms absconding?

There are three methods I’m aware of.

One is foolproof and I use every season. The other two are reported to work with variable levels of success, but which I have never used.

Adding a frame of open brood is reported to help stop the colony absconding. Alternatively, placing a queen excluder under the brood box (but above the floor) ‘traps’ the queen and prevents the colony leaving.

The first of these provides brood to care for, brood pheromones and the general ‘pong’ of a hive, all of which are likely to be beneficial. As I’ve not used this method I’m unsure how effective it is.

The queen excluder seems a heavy-handed and rather crude solution. The colony may well still try and abscond, but the queen will remain trapped. This seems like a great way to induce considerable stress in the colony.

And it’s unlikely to be successful long-term if the swarm is a cast with a virgin queen 😉

And the totally foolproof method?

Swarm arriving at bait hive ...

Swarm arriving at bait hive …

Bait hives.

I’ve never had a swarm that voluntarily arrived in a bait hive abscond. Even if I move the bait hive to another apiary, they still happily stay 🙂

Citizen science

I almost never hive bivouacked swarms these days as I am sufficiently successful in attracting swarms with bait hives 13.

I’m therefore unable to conduct the following experiment that I think would be quite interesting.

I’ve predicted above that a swarm collected from a bivouac that absconds may have already decided on the new nest site. By ‘hiving’ the swarm all the beekeeper is doing is moving the bivouac.

That being the case, I’d expect that collected swarms would be less likely to abscond if they’re moved to an area the scout bees have no knowledge of.

Scout bees survey the environment at least 3 km from the original nest site although swarms tend to occupy new nest sites well within this distance.

There are two things that would be interesting to monitor:

  1. Are swarms hived over 8 km from the location the swarm is collected less likely to abscond?
  2. Is the delay between hiving a swarm and it absconding related to the distance between the original bivouac and the initial location it is hived in?

I’ve chosen 8 km because you cannot always be certain where the bivouacked swarm came from (and because it’s a convenient 5 miles for these post-Brexit times). If you assume that the bivouac is always within a few dozen metres of the original nest site this ‘removal’ distance could be decreased to about 4 km.

The time delay addresses a slightly different question. I’m assuming here that the scout bees have yet to reach a quorum decision and are continuing to survey the environment. The further you move them, the more the environment changes, so potentially necessitating a longer decision making period.

As the 2021 season starts to wind down that’s something to think about for the year ahead.


Note

Please don’t email me with all the gruesome details of swarms you’ve had abscond in the past. It’s not that I’m not interested … I’m just completely swamped with correspondence.

If there’s sufficient interest in this post over the next few months (and as a bit of ‘Citizen Science’ experiment which are all the rage) – determined by page accesses and comments – I’ll create a simple web form to log everything to a database. No individual beekeeper is likely to collect sufficient swarms to generate a meaningful amount of data. I doubt even if an entire association could do so. However, the thousands of readers a week are surely able to have enough hived swarms abscond to test the hypothesis?

Growing old (dis)gracefully

… but in this world nothing can be said to be certain, except death and taxes.

So wrote Benjamin Franklin in 1789 1.

Taxes are a subject that I’ve not previously covered. Furthermore, I have no intention of writing about them in the future. My once a year late-night wrestle with the HMRC website is a distressing enough experience and one I’d prefer not to be reminded about.

So this week I’ll deal with that other certainty … death.

Eilean Fhianain burial ground, Loch Shiel

Sooner or later it will happen to us all.

No ifs or buts, and – unlike taxes – it really is a certainty.

What’s interesting about death is the ‘sooner or later’ element.

Some die young, due to bad luck, poor health or overindulgence.

Others live to a ripe old age, outliving their peers by many years or even decades.

Talking the talk

Beekeeping has been a relatively solitary pastime for the last 16 months. The restrictions imposed by lockdowns and social distancing have meant that beekeeping meetings have all been ‘virtual’. 

I’ve written about these recently and it seems likely that many associations are going to continue (at least some of the time) with Zoom talks.

A caffeine-fueled Q&A session

Whether in person, or online, one of the things that’s noticeable is that all beekeeping audiences are – how can I put this delicately? – not as young as they used to be.

By which I mean the individual beekeepers are not callow youths, but are instead older, wiser, and – of course – better looking. 

In my experience, giving talks over the last decade or so, beekeeping audiences have always had an older average age than a cross-section of society.

In addition, as I briefly mentioned recently, the average age of beefarmers in the UK is about 66 years old.

Why is this?

It seems there are two possibilities:

  1. Since beekeeping takes a reasonable amount of time, it’s largely people who have more spare time who start or stick with the hobby. At least at the start, beekeeping also costs quite a bit of money. Again, those who are a bit older probably have more disposable income (or fewer distractions like mortgages or kids to spend it on).
  2. Beekeepers live longer. The relatively high average age of a beekeeping audience – when compared with a similarly-sized cross-section of society – reflects their increased longevity.

Of course, both of those are rather simplistic explanations, but it’s a start.

Do beekeepers live longer?

When you start beekeeping you tend to be interested in honey and swarm control and pathogens.

Or just honey 😉

But after a few years of successful beekeeping you probably produce quite a bit of honey. Your success in honey production is partly due to your understanding and implementation of swarm control, and by your interventions that minimise disease.

And so your interests in beekeeping expand.

Some produce award-winning candles or wax flowers, some rear hundreds of queens a season, some explore esoteric hive designs, and some become interested in the history of beekeeping.

And one of the things that’s noticeable about the history of beekeeping is that several well known beekeepers lived to a remarkably old age.

With improvements in nutrition and healthcare, the average life expectancy of the population has been increasing for the last 150 years or so. 

UK life expectancy (from birth) 1765-2020

If you were born in the 18th Century you’d be expected to live (on average) about 40 years. However, in the last third of the 19th Century, life expectancy started to increase.

I was going to say ‘inexorably increase’ were it not for that little blip around 1918-1920. That wasn’t the First World War. It was the last significant global viral pandemic, the so-called Spanish ‘flu 2. Only recently has this increase in life expectancy started to plateau, and actually reverse.

Well known historical (old) beekeepers

My knowledge of the history of beekeeping is rather patchy so I did a quick search for ‘famous beekeepers‘.

Don’t bother with the first couple of hits 3, but the third is the ever-dependable and enjoyable Bad Beekeeping Blog by Ron Miksha.

Here’s a few picked at anything-but-random ( 😉 ) to support my hypothesis that beekeepers live longer. 

In no particular order:

  • François Huber (1750-1831, 81 years), Swiss, ~40 years 4. Huber was an extraordinary individual 5. Despite being blind his ‘observations’ worked out many details of the life cycle of the queen and he developed one of the first observation hives.
  • Lorenzo Langstroth (1810-1895, 85 years), US, ~40 years. Langstroth combined an understanding of ‘bee space’ with the movable frame ‘leaf hive’ (developed by Huber) to develop and patent the first removable frame hive.
  • Brother Adam (1898-1996, 98 years), German (lived in UK), ~47 years. Brother Adam (Karl Kehrle) was an authority on bee breeding and the developer of the Buckfast strain of honey bees. He resigned his post of beekeeper at Buckfast Abbey at the age of 93.
  • Charles Dadant (1817-1902, 85 years), French (lived in US), ~40 years. Dadant invented the Dadant hive, ran thousands of hives (after failing as a vintner) and founded the – still flourishing – Dadant & Sons beekeeping business.
  • Eva Crane (1912-2007, 95 years), UK, ~52 years. Eva Crane was a mathematician/physicist who spent much of her (long) life doing research on bees. She founded the Bee Research Association (still flourishing as the International Bee Research Association) and wrote hundreds of papers, and notable books, on bees and beekeeping.
  • Harry Laidlaw (1907-2003, 96 years), US, ~51 years. Harry Laidlaw was one of the pioneers of studies on bee genetics and optimised methods for instrumental insemination of queens. 
  • Karl von Frisch (1886-1982, 96 years), German, ~39 years. Karl von Frisch deciphered the waggle dance of honey bees and received the Nobel Prize in 1973.

And there are many others … including many much less famous but equally old 6

Correlation not causation

Just because (some) beekeepers live a long time doesn’t mean that beekeeping is responsible for their longevity. 

Perhaps they’ve just got ‘good genes’ and they’d have lived into their 80’s or 90’s whether they’d been beekeepers or BASE jumpers.

BASE jumping, Half Dome, Yosemite

Maybe it takes that long to become an acknowledged expert at beekeeping? 

How many famous beekeepers can you name who died young?

If Harry Laidlaw had only lived to his mid-60’s (still older than the average for his year of birth) perhaps he’d have been unknown?

Unlikely … he published his first book at the age of 25, was elected a fellow of the American Association for the Advancement of Science at 48 and was the first Associate Dean for Research in UC Davis in his late 50’s.

All of the individuals listed enjoyed a near-lifelong association with bees and were clearly exceptional beekeepers well before they also achieved an exceptional age (considering the year that they were born).

So perhaps there is something about bees or beekeeping that makes beekeepers live longer?

One possibility is that honey is good for you. 

Although some beekeepers don’t like honey 7, most undoubtedly do. Honey has a host of antimicrobial, antiviral, antiparasitic, anti-inflammatory and antioxidant effects, as well as being a guaranteed ( 😉 ) way to prevent hay fever.

Or perhaps it’s bee stings? 8

Caveat

Treat most of what I’ve written above with some caution.

My selection of famous (old) beekeepers is extremely selective. 

The reason audiences in beekeeping association meetings have a high average age is almost certainly due to spare time and disposable incomes … and because all the young ones are out partying.

It’s not my sort of science, but a proper study of the association between longevity and beekeeping would be quite interesting. 

Do beekeepers actually live longer than non beekeepers? 

Is there a causative association? Is it associated with beekeeping per se, or do non-beekeepers who eat honey also live longer? How many hive/years do you need to keep bees to increase your longevity? If it’s bee stings that are beneficial, do beekeepers who keep stingless bees also live long and healthy lives?

There is literally a certain finality about studying the age at death. Are there perhaps other markers of longevity that could be investigated a little earlier in a beekeeper’s life?

There certainly are …

Chromosomes and DNA replication

We (beekeepers) have 23 pairs of chromosomes 9 that consist of DNA and proteins and contain the majority of our genetic material 10

The chromosomes are in nucleus of the cell.

Cells associate to form tissue (like muscle or nerves) which associate to form organs (like the heart or brain).

As humans grow – from egg, to embryo, to foetus, to adult – these cells have to divide. And the chromosomes have to be duplicated to ensure that all cells end up with the required 23 pairs. 

Chromosomes are not circular but are essentially linear strands of DNA. This introduces a problem. 

The enzymes that copy and make new DNA (the DNA polymerase) only ‘work’ in one direction. Since DNA consists of two antiparallel strands this means that the polymerase copies one strand directly to make one continuous product, but it copies the other strand in small pieces, and then joins them together. 

The details really don’t matter … but the consequences do. 

The small piece synthesised at the very end of the discontinuously copied strand isn’t quite at the very end of the strand 11

Frankly, this is a bit of a design flaw 🙁

Telomeres

As a consequence of this discontinuous copying, one of the strands of the DNA molecule gets a little bit shorter every time it is copied.

The DNA of chromosomes contains all the genes that make all the proteins that makes all the cells that get together to form all the tissues that create the organs that make beekeepers.

Phew!

So, if the little bit of the chromosome that’s lost during replication happened to contain an essential gene, things would go very seriously wrong™.

But chromosomes have a sort of ‘get out of jail card’.

The ends of the chromosome contain a region of highly repetitive and non-coding 12 DNA called telomeres. You can imagine the telomere as a sort of ‘cap’ at the end of the chromosome.

During replication, little bits of this cap are lost – the cap gets shorter – but this truncation does not result in the loss of any essential genes.

Telomere shortening and cell division

And all this telomere shortening is rather predictable.

As cells divide – during growth or tissue repair – the telomeres shorten. Therefore, if you measure telomere length you can get an idea of how many division it has undergone and therefore how old it is.

Telomere length is therefore a measure of biological age.

Except it’s not quite that simple

There are a bunch of things that also influence telomere length.

For example, the age of the father influences the length of the child’s telomeres. 

Telomeres also accumulate damage – and so shorten – through oxidative stress. This is a process that results from the excess production of oxidants such as peroxides, free radicals and reactive oxygen species. These are chemical intermediates in normal biochemical processes. The cell can cope with small amounts of oxidants. However, the protection mechanisms become swamped if they are in excess, resulting in cellular damage.

Some diets are rich in antioxidants which can (or at least are hypothesised to) reduce oxidative stress. 

Honey can contain high levels of polyphenols, these are well known antioxidants that are also found in some fruits, vegetables and olive oil.

Finally … we’re getting somewhere 😉

There are studies that demonstrate that eating honey every day increases the levels of antioxidants 13. However, I’m not aware that these or other studies were extended to investigate whether the test cohort also exhibited a reduced rate of telomere shortening.

This isn’t surprising … the inherent variation between individuals and the relatively slow rate at which telomeres shorten means thousands of individuals would need to be analysed. Potentially over many years.

But there is also a study of telomere length in beekeepers … which is the reason for the 2,200 word introduction above.

Beekeepers and telomeres

A Malaysian research team 14 have measured telomere length in 30 beekeepers and the same number of age-matched non-beekeepers.

The beekeepers chosen had all been keeping bees for at least five years. The non-beekeepers didn’t just not keep bees 15, they also did not consume any bee products (honey, propolis 16 or royal jelly 17 ). In addition to being age-matched (average age ~42 years) both groups excluded individuals with known disease.

And I wouldn’t have been telling you all this unless the telomere length did differ significantly. The non-beekeeper’s had telomeres that were ~30% shorter.

Chronologically they were the same age, but biologically they were older.

This small study also investigated whether there was a correlation between the period of beekeeping, the number of bee products consumed, or the period or frequency of bee product consumption, and telomere length.

Telomere length only correlated with the frequency and duration of consumption of bee products, not with the types of products or the number of years of beekeeping.

The significance of these sorts of population-based studies is related to the scale of the study. This is a small study, and the only one I’m aware of that specifically investigates telomere length in beekeepers.

It has only been cited 7 times and has not been repeated.

It remains firmly in the ‘interesting observation’ rather than ‘acknowledged fact’ category. 

So all those afternoons hunched over the hive appear to make no difference 18, but having honey every day on your porridge might actually make you younger.

Biologically younger … you’ll still look old 😉