Tag Archives: Covid-19

2020 in retrospect

Almost exactly a year ago I wrote my retrospective review of the 2019 season.

At the time I was thinking “What a nightmare! If I never again have a year like that it’ll be too soon.”.

This was due to a major fire in my research institute which terminated a 30 year research programme and drowned me in a tsunami of administration.

The little beekeeping I did in 2019 kept me sane. Insurance issues and a new research facility took every waking hour. There was no ‘active’ queen rearing and my swarm control involved littering half of Fife with bait hives.

I piled on the supers, crossed my fingers and hoped for the best.

And got away with it 🙂

But by February 2020, the anniversary of the fire, it was looking as though those problems were just the hors d’oeuvres.

Coronavirus (Google Trends search terms, 12 months to mid-December 2020)

‘Coronavirus’ was a word transitioning from white-coated virology nerds with expansive foreheads to everyday, and then every minute, usage.

Covid and stockpiling

The word ‘Covid’ was first used in 1686. For its first 333 years it referred to an Anglo-Indian unit of linear measurement 1. On the 11th of February it appeared as a hashtag on Twitter and today it features a dozen times on the BBC homepage.

By early March it was clear that major societal changes were going to be needed to control virus transmission. A couple of days after spring talks to Oban beekeepers, Edinburgh and District BKA and the SNHBS the country went into lockdown …

The wild west

… by which time I was jealously guarding my panic-bought toilet rolls 2 on the remote west coast of Scotland.

The national beekeeping associations negotiated travel arrangements for animal husbandry purposes and the rest, as they say, is history.

I’ve already written about the practicalities of the small amount of long distance beekeeping I did in 2020. I won’t rehash the gory details here, but will make a few more general comments.

Highs and lows

It was a pretty good beekeeping start to the year. The spring was significantly drier than the 30 year average. This meant that the bees could get out and exploit the oil seed rape (OSR).

Spring 2020 rainfall anomaly

Consequently the honey yield per colony was the best I’ve had in the five years I’ve been back in Scotland. I think it would have been even better had I been present to add the supers in a more regulated manner … and to remove them before they crystallised.

In contrast, the summer was characterised by a series of lows … low pressure systems, bringing more rain than usual.

This probably reduced the time available for foraging, but perhaps was compensated by better nectar flows. My two main production apiaries performed very differently.

One generated almost no honey per hive, the other again generated record yields of outstandingly flavoured summer honey.

Summer honey

Guess which apiary contained more production hives?

Typical 🙁

Putting the control into swarm control

Swarm control usually involves careful observation of colony development coupled with a timely intervention to split the colony and prevent swarming.

The timely intervention is often at different times for different colonies, even in the same apiary.

There was none of that this year.

With only about four inspections all season I implemented swarm control  in the majority of colonies well before queen cells developed.

The method should be termed something like split and hope 😉

In practical terms it involved preemptive application of the nucleus method of swarm control.

The only decision I made for each colony was whether to apply swarm control or not.

I then made up the queenright nucs all on the same day. The nucs were made significantly weaker than usual to delay the time when I’d have to expand them up to a full colony.

Overall the approach worked very well, at least in terms of swarm control, as none of my colonies swarmed 🙂

The colonies that weren’t split were given lots of room and a combination of inspired judgement a long June gap and some iffy midsummer weather meant they stayed together.

Hieroglyphics

I need to go back through my notes to determine how individual colonies performed in terms of honey production. Other than the absence of any summer honey from one apiary, were there differences in terms of the amount nectar collected between colonies that were split or not?

Unfortunately, the (frankly) manic beekeeping that resulted from compressing everything into a few inspections over the season meant my notes are, in places, rather sparse 3.

Too weak to split

+3 supers Q+ good

WMCLQ WTF?

Grrr 4

Deciphering my hieroglyphics will necessitate a large glass of shiraz and a long winter night – two other things, along with the loo roll, I have an abundance of at the moment.

Varroa management

The other reason I need to review my notes is to look at the relationship (if any) between the in-season colony management 5 and end-of-season mite levels.

I do have some reasonably good counts of the mite drop during late summer and midwinter treatments 6. These are particularly reliable for the colonies in the bee shed because the floors I use have a tightly fitting Varroa tray, meaning that anything that drops, stays dropped 7.

Cedar floor and plywood tray …

In addition, I’m confident that the colonies received their ‘midwinter’ treatment – in mid/late November – when totally broodless.

There were significant differences between the mite drops of colonies in the bee shed. Some dropped 250-500 8 while others dropped less than 75. Those figures are totals over 8-9 weeks with Apivar plus the fortnight or so after oxalic acid treatment.

All other things being equal I’ll use the colonies with lower mite levels for queen rearing next season. For whatever reason, those colonies appear better able to manage their Varroa levels. Perhaps this is due to increased grooming or better defence (e.g. turning away potentially mite-laden drifting workers 9). If their temperament is good and they overwinter well they will be a good choice to rear queens from.

Inevitably all things will not be equal, but at least I’ll have tried.

And I’m hoping to be doing a reasonable amount of queen rearing in 2021 … though after a devastating fire and a global pandemic I wouldn’t be surprised if the Earth was obliterated by an asteroid just as I start grafting 🙁

Going Varroa free

I’ve spent almost all year on the west coast, and will be spending increasing amounts of time here in the coming years. The area is remote, very sparsely populated and Varroa free.

It also has spectacular sunrises …

Red sky in the morning …

… and scenery …

View from Ben Laga to Mull

Actually, until I imported 10 a couple of colonies, it appeared to be completely honey bee free. I’ve sourced Varroa-free colonies from an island off the west coast of Scotland.

I’ve often written about the importance of being ‘in tune’ with the local beekeeping environment. It’s already clear that the east and west coasts of Scotland 11, despite being separated by only ~120 miles, have distinct climates, nectar and pollen availability.

What? No oil seed rape?

On the west coast there’s no OSR. In fact, there’s almost no arable farming at all. I’ll be interested to see what the bees access for spring and mid-season nectars. With mixed woodland, and more being planted, and lots of native flowers they should have a good selection.

Early season primroses

There are some huge lime trees just down the road. These need rain to generate good levels of nectar, and rain is something else we have in abundance 😉

The main source of nectar is the heather. This is something 12 I have almost no experience of. In the Midlands I was always too busy to transport hives to Derbyshire for the heather. Fife, despite being in Scotland, has very little heather moorland and most beekeepers have to take their hives to the Angus Glens. I never bothered.

Now there’s acres of the stuff just up the hill at the back of the house. Not particularly good quality heather moorland, but lots of it.

I’ll return to this when I discuss planning for the season ahead, sometime in the New Year.

The Apiarist – online and offline

This is the 51st post of the year.

Regular as clockwork

With a bit of luck I’ll also scribble something for the 25th, so completing a ‘full house’ for 2020. It’s too soon to look at any year-end statistics, but it’s clear that lots of people had lots more time for lots more reading this year.

I wonder why?

Everything came to a grinding halt in mid-June when a post featured on one of the Google news sites. In one afternoon the server was inundated with people eager to read about the June gap.

Thousands and thousands of them 🙁

Since most of them didn’t look elsewhere on the site I suspect the topic was a bit too niche for the majority of the internet illiterati.

After a couple of hiccups and a faltering stagger the server collapsed under the onslaught. I spent an afternoon moving it to a host with four times the capacity (at four times the cost) and it’s hung on gamely ever since.

Not only have beekeepers been doing lots more reading, they’ve also doing lots more listening and watching.

Online beekeeping talks

Many beekeeping associations – both local and national – have developed online winter talk programmes.

I’ve attended lively SBA Q&A sessions, BIBBA webinars by Adam Tofilski on preserving native bees, and I spent yesterday evening learning all about distinguishing Apis mellifera mellifera from ligustica or carnica or Buckfast or mongrels, care of the SNHBS.

And I’ve delivered more talks to bigger audiences this winter than in all of the last few years combined.

These talks – not mine specifically, but all of those available – fill the void between September and April. Although perhaps not the easiest way to establish new friendships 13 they are an excellent way to keep in contact with people from all over the country. In that regards they’re much better than ‘in person’ evening talks, and much more akin to the annual beekeeping conventions.

Though, unlike the conventions, my wallet doesn’t return emaciated from an hour or two going round the trade stalls.

Online talks are also good for keeping in contact with people on the other side of the county, let alone the country. It’s not unusual for my talk to be sandwiched by friendly banter between beekeepers separated by both distance and Covid.

Will this continue? I expect so. I don’t expect in person talks will start until 2022 at the earliest. However, I think – just as remote working will increase – online talks will be a regular feature of the winter beekeeping calendar. The benefits outweigh the slightly impersonal format, and many people appreciate the convenience of not having to travel 14.

Science aside

The enforced downtime, with labs closed and staff furloughed, has enabled me to finally write up a backlog of papers on honey bee virus research. A few of these have featured on this site already, in discussions of whether DWV replicates in Varroa, or in bumble bees, and in the inexorable rise of chronic bee paralysis virus as an emerging pathogen of honey bees.

I’ve yet to find time to write about our green bees because I want to include a really elegant experiment we have yet to complete. These bees are infected with a virus that expresses a green fluorescent protein from a jellyfish. When visualised under UV illumination the individual cells and tissues in which the virus replicates are easily detected. More about this next year.

Green bees

Several more papers are in the pipeline or in preparation, on rescuing hives with catastrophically high mite loads, on competition between different variants of DWV and on the landscape-scale control of Varroa.

Lessons learned

Considering the paucity of beekeeping this year I’ve still managed to learn a few new tricks and improve a few old ones.

I’ve learned how little intervention is required to manage colonies adequately (defined by good health and no swarms, though undoubtedly at the cost of maximising the honey yield).

‘Adequately’ because I also learned how unrewarding it was keeping bees without beekeeping.

For the first time I used air freshener to unite lots of colonies during a particularly busy long weekend when I requeened the majority of my hives. It’s a new trick to me, though widely used by others. Having used it, I’m now confident it works. I’ll use it again if I’m similarly rushed for time, but expect to usually rely on uniting over newspaper.

I’ve gained more confidence in accurately guesstimating how weak I can make up nucs, without them succumbing to robbing, wasps or starvation. Undoubtedly I was aided with reasonable weather and good nectar and pollen availability, but it will be a skill I’ll be able to use again in future years.

I also learned  – or at least reinforced my appreciation of (as I’ve done this previously) – how to hold back the nucs, so preventing them swarm, by removing lots of brood 15. The brood was used to boost honey production colonies which were requeening themselves. With some good judgement, and a big slice of luck, this all went very well.

The importance of regularly checking bait hives was also emphasised when I found this …

Just when you thought it was safe to go back in the bee shed …

This season was unusual as I didn’t attract a single swarm to a bait hive, probably the first time that’s happened for a decade. Partly this was because I set so few out, but presumably it also reflected my dalliance with waspkeeping.

Finally, I’ve learned there are quicker ways to prepare spreadable ‘soft set’ honey that the interminable Dyce method. I’ve recently acquired a new honey creamer and the first fifty jars have been distributed to friends and family for Christmas. I expect very positive feedback 16 due to the extensive product testing and quality control applied during its preparation 😉

 

Long distance beekeeping

This post was originally entitled ‘lockdown beekeeping’. I changed it in the hope that, at some point in the future, we’ve all forgotten lockdown and are back to the ‘old normal‘. Instead, long distance beekeeping, better summarises the topic and might rank better in future Google searches …

But before I start, here’s some general advice …

Don’t do as I do, do as I say (elsewhere on this site 😉 )

I don’t think what I’m going to describe below was anything like ideal. In the end it worked out pretty well, but probably as much from luck as judgement. I’d do it again if I had to, but I’d prefer not to. I don’t think it is a workable solution for effective beekeeping in anything other than exceptional circumstances.

But 2020 has been an exceptional circumstance …

Mid-March madness

It was abundantly clear in very early March that a lockdown was inevitable 1 to restrict the spread of Covid-19. All the numbers were going in the wrong direction and other countries were already imposing quite draconian restrictions to control virus transmission 2.

I had speaking engagements with Oban & District BKA on the 12th and at the SNHBS event at Kinross on the 14th and, on the following day, I disappeared to my bolthole on the remote west coast of Scotland. 

The wild west

I decided to simply abandon the bees in Fife for at least a month while the country came to terms with movement restrictions, supermarket food deliveries, protecting the NHS and ‘working from home’.

On the day I left I checked that colonies were not too light, that the entrances were clear and that the roofs were secure and everything was strapped down.

March is too early to do anything with bees in Fife and my first inspections are usually not until mid/late April in a normal year, and even early May if there’s been a cold Spring. I therefore had a month to plan for the season ahead, with the expectation that I would have to manage the bees with the minimum possible number of visits for the next few months.

Planning

The beekeeping season contains a number of ‘moveable fixtures’.

By that I mean that certain things happen every season, but the time when they happen is not fixed. The timing depends upon the weather which, in turn, influences forage availability. It depends upon the strength of the colony, the location of the apiary and – for all I know – the phase of the moon.

Warm springs can lead to swarming by the end of April. Conversely, cold springs delay events. Dry summers generally put paid to the lime nectar and a protracted June gap can leave colonies starving in the middle of the season.

In the previous post I called these moveable fixtures the unknown knowns.

The variable timing of these moveable fixtures influences colony management by the beekeeper; this includes the spring honey harvest, swarm control and the summer honey harvest. In addition, it includes more mundane things like comb exchange, feeding the colony up for winter and Varroa management.

Bees and beekeeping are influenced by the environment, not the calendar 3.

The UK government imposed a nationwide lockdown on the 23rd of March 2020. Movement restrictions were imposed, including the distance you could travel from where you live.

Exemptions were made for allowed activities and, after lobbying from national associations and others, beekeeping was included as an exempt activity. Notwithstanding this, it was not going to be practical to conduct the usual weekly inspections from April until late July.

First inspections

I returned to Fife to conduct the first inspections in the third week of April. The spring was well advanced and the strong colonies were really booming. The overwintered nucs had built loads of brace comb in the space over the top bars and urgently needed to be moved to a full hive.

Overwintered nuc with brace comb

There were about 20 colonies spread between my two main apiaries. All were checked for space/strength, temper and the presence of a laying, marked and clipped queen 4. I didn’t have time to mollycoddle any weak colonies so these (having checked they were healthy) were united with nearby strong colonies.

Safely back in the hive

In addition, I didn’t have the luxury of time to see if poorly behaved colonies might pick up later in the season. To be frank, I had more colonies than I needed (or could easily cope with). With the need for swarm control looming, I decided to reduce colony numbers by uniting de-queened aggressive colonies with others in the same apiary. There were only a couple of these (identified the previous season and seemingly unimproved after the winter) … but every little bit helps.

United colonies, three supers, strapped up well … 25th April 2020

Finally, with the oil seed rape about to flower, I added three supers to the majority of the colonies. In a normal season these would have been added incrementally as needed. This year I had to assume (or hope) they might need them.

Swarm control

On my return to the west coast the spring was warming up. The primroses were looking fantastic and we had several weeks of outstanding weather.

Primroses – late April 2020

I enjoyed the good weather and spent the time fretting about the timing of swarm control.

My colonies tend to make swarm preparations between mid-May and the first week of June – a good example of a moveable fixture.

A priority this year was not to lose any swarms.

I did not want to inconvenience other beekeepers (or ‘civilians’ 5) with swarms I managed to lose by ineptly doing my beekeeping from the other side of the country.

With most people trying to keep themselves isolated, 30,000 bees moving into a chimney would be a lot more than unwelcome.

Even in a normal year I do my very best not to lose swarms, and this was anything but a normal year.

I therefore decided to conduct pre-emptive swarm control on every colony in the third week of May. ‘Pre-emptive’ meaning that, whether the colonies showed any signs of swarming or not, I’d remove the queen and let them rear another.

Colonies do not swarm every year. Every now and again a strong colony of mine will show no inclination to swarm. These are great … I just pile another super or two on top and am thankful not to have to intervene.

However, strong colonies are more than likely to swarm and I didn’t feel I had the luxury of waiting around to find which wanted to and which didn’t.

A swarm in May (and how I avoided it … )

With the exception of a couple of our research colonies that seemed to be on a ‘go slow’ I treated all my colonies in the same way.

I used the nucleus method of swarm control. I removed the queen and one frame of emerging brood and put them into a 5 frame nuc box with a frame of foundation or drawn comb and a frame of stores. To ensure there were sufficient bees in the box I then shook in another frame of bees before sealing them up for transport.

All the nucs were moved to distant apiaries so there was no risk of bee numbers being depleted as they returned to the original hive.

And then there were three … nucs for pre-emptive swarm control

The parental colonies were left for 6 days and then checked for queen cells.

Ideally this should have been 7 days. By this time there would be no larvae young enough to generate additional queen cells from. However, there was a large storm moving in from the west and it was clear that there would be no possibility of doing any beekeeping while it moved through.

I therefore checked on the sixth day, knocked back all the queen cells, leaving just one good one, and then scarpered back to the west coast (meeting the storm en route).

However, before I disappeared I also checked all the nucs. All were doing fine. There was a good nectar flow and they had already drawn and laid up the frame out I’d given them. I therefore added two foundationless frames flanking the central frame. With frames either side these are usually drawn straight and true.

New comb with queen already laying it up

If you give the bees lots of foundationless frames together, particularly if the hive isn’t perfectly level, they will often make a real mess of drawing the comb out. By interleaving the new frames with those that were already drawn the bees are forced to maintain the required bee space on either side, so usually draw the frame out satisfactorily.

Getting the timing right … at least partly

When I left Fife on the 22nd of May the OSR was in full flower. It would finish sometime in early June.

My next dilemma was to time the following visit for the spring honey harvest. Too soon and the frames wouldn’t be capped. Too late and, being OSR, it might start to crystallise in the comb.

But I also wanted to deal with all the requeening colonies during the same visit and all of the nucs.

I’ve previously discussed the time it takes for a new queen to develop, emerge, mature, mate and start laying. It always takes longer than you’d like. The absolute minimum time is about two weeks, but it usually takes longer. Ideally I wanted to go through all the requeening colonies, find, mark and clip the queens or re-unite (with the nuc) those that had failed.

At the same time, with a strong nectar flow and a strongly laying queen, there was a real risk that the nucs were going to get overcrowded very fast. The longer they were left, the more chance that they would think about swarming.

I employed a number of local spies (beekeeping friends in the area) and queried them repeatedly 6 about the state of the OSR. Shortly after it finished, I returned to take off the spring honey.

A minor catastrophe

It was the 10th of June; this was exactly 20 days since leaving the requeening colonies with a single freshly-sealed queen cell.

I’ve previously mentioned that one of my apiaries is rather exposed to strong westerlies. Despite the wind-reduction netting and the rapidly growing willow hedge, this apiary had been really hammered by the storm on the 22nd/23rd of May.

Nuked nucs

Two nucs had lost their lids and crownboards and a full strapped-up hive had been blown over, denting the fence on its descent but remaining more or less intact.

How is the queen supposed to find the entrance?

The apiary hadn’t been checked since my last visit, so I’m assuming the damage happened during the storm in late May. That being the case, the nucs would have been open to the elements for about 18 days. Amazingly, both still contained laying queens and – despite looking a little the worse for wear – eventually recovered.

In contrast, the strapped up hive was not ‘open to the elements’. It had fallen entrance-first onto the ground. I think a few bees could fly from a gap where the ground didn’t quite block the entrance, but I was more concerned about getting them upright again to check too carefully.

Despite my best efforts I failed to find a queen in this hive. My frames are arranged ‘warm way’, so all the frames had slid together when the hive fell and it’s possible the queen didn’t survive 7.

Spring honey, nucs and queens

The spring honey harvest went well. The OSR frames were mostly capped. Those that weren’t could still be extracted as the honey would not shake out of the frame.

A fat frame of spring honey

It was my best year for spring honey since returning to Scotland in 2015. With the exception of that one big storm the weather had been pretty good and the bees had had ample opportunity to be out foraging.

However, although a few of the colonies had newly mated and laying queens, the majority did not. In most of them I found evidence that there would be a laying queen sometime soon … I usually infer this from the presence of ‘polished’ cells in the centre of the one or two of the central frames in the hive. This gave me confidence that there was likely to be an unmated, or just mated, queen in the box. There’s nothing much to be gained from actually finding her, so I would have to be a bit more patient.

Just as these things cannot be rushed, an overcrowded nuc cannot be ignored.

Almost all the nucs were fast running out of space. I therefore removed 2-3 frames of brood from each and replaced them with fresh frames. I used the frames of brood to boost the honey production colonies that were ‘busy’ requeening.

Mid-June and the foxgloves are in flower

By the 14th of June I was back on the west coast.

Late June rearrangements

I returned a fortnight later for a very busy couple of days of beekeeping.

By this time the summer nectar flow was starting. The nucs, even those ‘weakened’ by removing brood, were busy filling spaces with brace comb.

Comb in feeder

All of the requeening colonies were checked for a laying queen. A handful had failed, disappeared or whatever and now looked queenless. These were requeened by uniting them with a nuc containing the ‘saved’ queen from earlier in the season.

What could be simpler? That’s one of the main attractions of this method of swarm control.

The colonies with the first of the new laying queens were doing really well, with lovely fresh frames of wall-to-wall brood. It’s only after a queen has laid up a full frame or two that you get a proper impression of her quality. I can never properly judge this in the tiny little frames of a mini-mating nuc, so – despite the extra resources (bees, frames, boxes) needed – prefer to get queens mated and laying in hives with full-sized frames.

Good laying pattern

The remaining ‘unused’ nucs were all expanded up to full hives and given a super. All the strong colonies in the apiaries were again given three supers and left to get on with things.

Expanded nucs on the left, production hives on the right

It was a backbreaking few days, particularly because I spent the evenings jarring honey 8, but it left the apiaries in a good state for the summer nectar flow.

Summer honey

The only beekeeping I did in July was on the west coast of Scotland. I moved a couple of nucs up to full hives and, since the heather wasn’t yet in full flower, I gave them each a gallon or so of thin syrup to encourage the bees to draw comb to give the queen space to lay.

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

I finally returned to Fife to take the summer honey off in late August. I’ve recently posted a brief description of clearing supers during Storm Francis so won’t repeat it here.

In four days I removed all the supers and extracted the honey, fed and treated the bees for the winter, and left the colonies strapped up securely for … goodness knows when.

The summer honey harvest was unusual. One of my apiaries did fantastically well, more than the last two seasons combined, and by far my best year since 2015.

The other apiary was just slightly worse than … utterly pathetic.

This second apiary is usually very reliable. The forage in the area has been dependable and, in some years, the lime has yielded very well. However, not this year and, since I wasn’t about, I don’t know why.

I did it my way … but it wasn’t very satisfying

That last paragraph rather neatly sums up the 2020 beekeeping season.

Overall the season must be considered a success; I didn’t lose any swarms, the majority of colonies were requeened successfully, all of the colonies are going into the winter strong, fed and treated, and the overall honey crop was very good.

However, it’s all been done ‘remotely’, both literally and figuratively. I’ve not felt as though I’ve been able to watch the season and the colonies develop together. I don’t feel as though I was ‘in tune’ with what was happening in the hives. I can’t explain why some things worked well and other things – like the apiary with no honey 🙁 – failed miserably.

My notes are perfunctory at best, “+3 supers, Q laying well”, and contain none of the usual asides about what’s happening in the environment. There’s no indication of what was flowering when, whether the year was ‘early’, ‘late’, or ‘about normal’, when the migrant birds arrived or left.

I’ve done less beekeeping this year than in any year in at least a decade. Since I rather like beekeeping, this means it has been a bit of a disappointment. Since I’ve spent less time with the bees, and I’ve been so rushed when I have been working with them, I feel as though I’ve learnt less this year than normal.

What didn’t get done?

With irregular and infrequent visits some things were simply ignored this season.

I did very little Varroa monitoring. With the Apivar strips now in it’s clear that some hives have higher Varroa counts than I’ve seen in the last few years 9. However, not all of them. Some colonies appear to have extremely low mite loads.

We finally managed to check the levels of deformed wing virus in our research colonies quite late in the season once the labs partially reopened. The levels were reassuringly low. This strongly suggests that the mite levels are not yet at a point threatening the health of the colonies.

I’ve singularly failed to do much in the way of brood comb exchange this season. This means I’m going to have to take a bit more care next year to cycle out the old, dark frames and replace them with brand new ones.

Here’s one I did manage to replace

Again, not the end of the world, but ‘bad beekeeping’ all the same.

As I’m putting the finishing words together for this post the government is re-introducing further curfews and restrictions … maybe next year will be more of the same?

 

Barcoding bees

Every jar of honey I prepare carries a square 20mm label that identifies the apiary, batch, bucket and the date on which is was jarred. The customer can scan it to find out about local honey … and hopefully order some more.

The label looks a bit like this:

Scan me!

This is a QR code.

You’ll find QR codes on many packaged goods in the supermarket, on bus stop adverts, on … well, just about anything these days.  QR codes were first used in 1994 and are now ubiquitous.

QR is an abbreviation of quick response.

It’s a machine-readable two-dimensional barcode that is used to provide information about the thing it’s attached to.

QR codes contain positional and informational content. In the image above the three corners containing large squares allow the orientation to be unambiguously determined.

Within the mass of other, much smaller, black and white squares are several alignment points, an indication of the encoding 1 and the ‘information payload’. 

Large QR codes can contain more information and more error correction (so they can be read if damaged 2 ). Conversely, small QR codes contain reduced amounts of information and less error correction, but can still be used to uniquely identify individual things in a machine-readable manner.

A barcoded bee and barcode diagram.

And those ‘things’ include bees.

I am not a number 3

I had intended to write a post on how pathogens alter honey bee behaviour. This has been known about in general terms for some time, but only at a rather crude or generic level. 

To understand behavioural changes in more detail you need to do two things:

  • observe bees in a ‘natural setting’ (or at least as natural as can be achieved in the laboratory)
  • record hundreds or thousands of interactions between bees to be able to discriminate between normal and abnormal behaviour. 

And that isn’t easy because they tend to all look rather similar.

Lots of bees

How many of the bees above are engaging in trophallaxis?

Does the number increase or decrease over the next five minutes? What about the next hour?

And is it the same bees now and in an hour?

And what is trophallaxis anyway? 

I’ll address the last point after describing the technology that enables these questions to be answered.

And, since it’s the same technology that has been used to monitor the behavioural changes induced by pathogens, I’ll have to return to that topic in a week or two. 

Gene Robinson and colleagues from the University of Illinois at Urbana–Champaign have developed a system for barcoding bees to enable their unique identification 4.

Not just a few bees … not just a couple of dozen bees … every bee in the colony.

Though, admittedly, the colonies are rather small 😉

Each barcode carries a unique number, readable by computer, that can be tracked in real time.

So, unlike Patrick McGoohan, these bees are a number.

bCode

The scientists designed a derivative of the QR code that could be printed small enough to be superglued to the thorax of a worker bee. They termed these mini-QR-like codes bCodes 5. The information content of a bCode was limited by its size and the reference points it had to carry that allowed the orientation of the bee to be determined.

In total the bCode could carry 27 bits of data. Eleven bits (each essentially on or off, indicated by a black or white square) encoded the identification number, allowing up to 2048 bees to be uniquely numbered. The remaining 16 bits were the error-correction parity bits that had to be present to ensure the number could be accurately decoded.

If you’re thinking ahead you’ll realise that the maximum number of bees they could therefore simultaneously study was 2048. That’s about 1/25th of a very strong colony at the peak of the season, or the number of bees covering both sides of a two-thirds full frame of sealed brood.

It’s enough bees to start a one frame nucleus hive, which will behave like a mini-colony 6 and, in due course, expand to be a much larger colony.

And if you’re thinking a long way ahead you’ll realise the every barcode must be affixed to each bee in the same orientation. How otherwise would you determine whether the bees were head to head or abdomen to abdomen?

Labelling bees

This is the easy bit.

Each bCode was 2.1mm square and weighed 0.6mg i.e. ~0.7% of the weight of a worker bee. Honey bees can ‘carry’ a lot more than that. When they gorge themselves before swarming they ingest ~35mg of honey. 

The bCode therefore should not be an encumbrance to the bee (and they confirmed this in an exhaustive series of control studies).

A single frame of sealed brood was incubated and the bees labelled within a few hours of emergence. Typically, two batches of ~700 bees each were labelled from a single frame for a single experiment.

Each bee was anaesthetised by chilling on ice, the bCode glued in place (remember … in the same orientation on every bee) and the bee allowed to recover.

Labelling a single bee took 1-2 minutes.

Labelling 1400 bees takes several people a long time.

I said it was easy.

I didn’t say it was interesting.

Smile for the camera

I’ve not yet discussed the goal of the study that needed barcoded bees. It’s not really important while I’m focusing on the technology. Suffice to say the scientists wanted to observe bees under near natural conditions.

Which means a free-flying colony, on a frame of comb … in the dark.

Free-flying because caged bees do not behave normally.

On a frame of comb because they were interested in the interactions between bees under conditions in which they would normally interact.

And in the dark because that’s what it’s like inside a beehive (and it’s one of the features that scout bees favour when selecting a site for a swarm).

Camera and hive setup.

The scientists used an observation hive with a difference. It had an entrance to allow the bees to fly and forage freely and it contained a single sided, single frame. In front of the frame was a sheet of glass separated by 8mm from the comb. This prevented the bees from clambering over each other, which would have obscured the bCodes 7. Behind the frame was an 850nm infrared lamp to increase contrast, and the front was illuminated by several additional infrared lamps.

Bees cannot see light in the infrared range, so they were effectively in the dark.

The camera used (an Allied Vision Prosilica GX6600 … not your typical point and shoot) recorded ~29MP images every second. A typical experiment would involve the collection of about a million images occupying 4-6 terabytes of hard drive space 8.

The recorded images were processed to determine the temporal location of every bee with a visible (and readable) bCode. This was a computationally interesting challenge and involved discarding some data – e.g. barcodes that moved faster than a bee can walk or barcodes that fell to the bottom of the hive and remained motionless for days (i.e. dead bees). About 6% of the data was discarded during this post-processing analysis.

Trophallaxis

Which finally gets us to the point where we can discuss trophallaxis. 

Honey bees and other social insects engage it trophallaxis.

It involves two insects touching each other with their antennae while orally transferring liquid food. It occurs more frequently than would be required for just feeding and it has been implicated in communication and disease transmission. 

bCoded bees and trophallaxis

So, if you are interested in trophallaxis, how do you determine which bees are engaging in it, and which are just facing each other head to head?

In the image above the two bees in the center horizontally of the insert 9 are engaged in trophallaxis. The others are not, even those immediately adjacent to the central pair.

Image processing to detect trophallaxis – head detection.

This required yet more image processing. The image was screened for bees that were close enough together and aligned correctly. An additional set of custom computer-vision algorithms then determined the shape, size, position and orientation of the bees’ heads. To be defined as trophallaxis the heads had to be connected by thin shapes representing the antennae or proboscis.

And when I say the image … I mean all million or so images.

Bursty behaviour

And after all that the authors weren’t really interested in trophallaxis at all.

What they were really interested in was the characteristics of interactions in social networks, and the consequences of those interactions.

This is getting us into network theory which is defined as “Well out of my depth”. 

Transmission of things in a network depends upon interactions between the individuals in the network.

Think about pheromones, or honey, or email … or Covid-19.

It’s only when two individuals interact that these can be transmitted between the individuals. And the interaction of individuals is often characterised by intermittency and unpredictable timing. 

Those in the know – and I repeat, I’m not one of them – call this burstiness. 

If you model the spread of ‘stuff’ (information, food, disease) through a bursty human communication network it is slower than expected.

Is this an inherent characteristic of bursty networks?

Are there real bursty networks that can be analysed.

By analysing trophallaxis Gene Robinson and colleagues showed that honey bee communication networks were also bursty (i.e. displayed intermittent and unpredictable interactions), closely resembling those seen in humans.

However, since they had identified every trophallaxis interaction over several days they could follow the spread of ‘stuff’ through the interacting network.

By simply overlaying the real records of millions of interactions over several days of an entire functional community with an event transmitted during trophallaxis they could investigate this spread..  

For example, “infect” (in silico) bee 874 in the initial second and follow the spread of the “infection” from bee to bee through the real network of known interactions.

In doing this they showed that in a real bursty network, interactions between honey bees spread ‘stuff’ about 50% faster than in randomised reference networks. 

Why isn’t entirely clear (certainly to me 10, and seemingly to the authors as well). One obvious possibility is that the topology of the network i.e. the contacts within it, are not random. Another is that the temporal features of a bursty network influence real transmission events. 

Scientists involved in network theory will have to work this out, but at least they have a tractable model to test things on …

… and at a time when some remain in lockdown, when others think it’s all a hoax, when social distancing is 2m 11, when some are wearing masks and when prior infection may not provide protective immunity anyway, you’ll appreciate that ‘how stuff spreads’ through a network is actually rather important.

Stay safe

 

Time to deploy!

It’s early April. The weather is finally warming up and the crocus and snowdrops are long gone. Depending where you are in the UK the OSR may start flowering in the next fortnight or so.

All of which means that colonies should be expanding well and will probably start thinking of swarming in the next few weeks.

So … just like any normal season really.

Except that the Covid-19 pandemic means that this season is anything but normal.

Keep on keeping on

The clearest guidelines for good beekeeping practice during the Covid-19 pandemic are on the National Bee Unit website. Essentially it is business as usual with the caveats that good hygiene (personal and apiary) and social distancing must be maintained.

Specifically this excludes inspections with more than one person at the hive. Mentoring, at least the really useful “hands-on” mentoring, cannot continue.

A veil is no protection against aerosolised SARS-CoV-2. Don’t even think about risking it.

This means that there will be a lot of new beekeepers (those that acquired bees this year or late last season) inspecting colonies without the benefit of help and advice immediately to hand.

Mistakes will be made.

Queen cells will be missed.

Colonies will swarm 1.

Queen cells

Queen cells …

It’s too early to say whether the current restrictions on society are going to be sufficient to reduce coronavirus spread in the community. It’s clear that some are still flouting the rules. More stringent measures may be needed. For beekeepers who keep their bees in out apiaries, the most concerning would be a very restrictive movement ban. In China and (probably) Italy these measures proved to be effective, although damaging to beekeeping, so the precedent is established.

Many hives and apiaries are already poorly managed 2. I would expect that additional coronavirus-related restrictions would only increase the numbers of colonies allowed to “fend for themselves” over the coming season.

Which brings me back to swarming.

Swarmtastic

The final point of advice on the NBU website is specifically about swarms and swarm management:

You should use husbandry techniques to minimise swarming. If you have to respond to collect a swarm you need to ensure that you use the guidelines on social distancing when collecting the swarm. If that is not possible, then the swarm then should not be collected. Therefore trying to prevent swarms is the best approach. 

Collecting swarms can be difficult enough at the best of times 3. And cutouts of established colonies are even worse.

In normal years I always prefer to reduce the swarms I might be called to 4 by setting out bait hives.

Swarm recently arrived in a bait hive with a planting tray roof …

Let the bees do the work.

Then all you need do is collect them once they’re all neatly tucked away in a hive busy drawing comb.

This year, with who-knows-what happening next, I’ll be setting out more bait hives than usual with the expectation that there may well be additional swarms.

If they’re successful I’ll have more bees to deal with when the ‘old normal’ finally returns. If they remain unused then all I’ve lost is the tiny investment of time made in April to set them out.

Not just any dark box

I’ve discussed the well-established ‘design features’ of a good bait hive several times in the past. Fortunately the requirements are easy to meet.

  • A dark empty void with a volume of about 40 litres.
  • A solid floor.
  • A small entrance of about 10cm2, at the bottom of the void, ideally south facing.
  • Something that ‘smells’ of bees.
  • Ideally located well above the ground.

I ignore the last of these. I’d prefer to have an easy-to-reach bait hive to collect rather than struggle at the top of a ladder. If I wanted to do some vertically-challenging beekeeping I’d go out and collect more swarms 😉

So, ignoring the final point, what I’ve described is the nearly perfect bait hive.

Those paying attention at the back will realise that it’s also a nearly perfect description of a single brood National hive.

How convenient 🙂

All of my bait hives are either single National brood boxes or two stacked National supers. The box does need a solid floor and a crownboard and roof. If you haven’t got a spare solid floor you can easily build them from Correx 5 for a few pence.

Inside ...

Bait hive floor

Alternatively, simply tape down a piece of cardboard or Correx over the mesh of an open mesh floor 6. In some ways this is preferable as it’s convenient to be able to monitor Varroa levels after a swarm arrives.

Do not be tempted to use a nuc box as a bait hive. You can easily fit a small swarm into a brood box, but a really big prime swarm will not fit in a 5 frame nuc box.

Big swarms are better 🙂 7

More to the point, bees are genetically programmed to search for a void of about 40 litres, so many swarms will simply overlook your nuc box for a more spacious nest site.

What’s in the box?

No, this has nothing to do with Gwyneth Paltrow in Se7en.

How do you make your bait hive even more desirable to the scout bees that search out nest sites? How do you encourage those scouts to advertise the bait hive to their sister scouts? Remember, that it’s only once the scouts have reached a democratic consensus on the best local nest site that the bivouacked swarm will move in.

The brood box ideally smells of bees. If it has previously held a colony that might be sufficient.

Bait hive ...

Bait hive …

However, a single old, dark brood frame pushed up against one sidewall not only provides the necessary ‘bee smell’, but also gives the incoming queen space to immediately start laying 8.

You can increase the attractiveness by adding a couple of drops of lemongrass oil to the top bar of this dark brood frame. Lemongrass oil mimics the pheromone produced from the Nasonov gland. There’s no need to Splash it all over … just a drop or two, replenished every couple of weeks. I usually soak the end of a cotton bud, and lay it along the frame top bar.

Lemongrass oil and cotton bud

The old brood frame must not contain stores – you’re trying to attract scouts, not robbers.

The incoming swarm will be keen to draw fresh comb for the queen to lay up with eggs. Whilst you can simply provide some frames and foundation, this has two disadvantages:

  • the vertical sheets of foundation effectively make the void appear smaller than it really is. The scout bees estimate the volume by walking around the perimeter and taking short internal flights. If they crash into a sheet of foundation during the flight the box will seem smaller than it really is.
  • foundation costs money. Quite significant amounts of money if you are setting out half a dozen bait hives. Sure, they’ll use it but – like putting a new carpet into a house you’re trying to sell – it’s certainly not the deal-clincher.

No foundation for that

Rather than filling the box with about £10 worth of premium foundation, a far better idea is to use foundationless frames. Importantly these provide the bees somewhere to draw new comb whilst not reducing the apparent volume of the brood box.

If you’ve not used foundationless frames before, a bait hive is an ideal time to give them a try.

There are two things you should be on the lookout for. The first is that the bait hive is horizontal 9. Bees draw comb vertically down, so if the hive slopes there’s a good chance the comb will be drawn at an angle to the top bar.

And that’s just plain irritating … because it’s avoidable with a bit of care.

Bamboo foundationless frames

Bamboo foundationless frames

The second thing is that the colony needs checking as it starts to draw comb. Sometimes the bees ignore your helpful lollipop stick ‘starter strips’ and decide to go their own way, filling the box with cross comb.

Beautiful … but equally irritating 🙂

Final touches

For real convenience I leave my bait hives ready to move from wherever they’re sited to my quarantine apiary (I’ll deal with both these points in a second).

Wedge the frames together with a small block of expanded cell foam so that they cannot shift about when the hive is moved.

Foam block ...

Foam block …

And then strap the whole lot up tight so you can move them easily and quickly when you need to.

Bait hive location and relocation

Swarms tend to move relatively modest distances from the hives they, er, swarmed from. The initial bivouac is usually just a few metres away. The scout bees survey a wide area, certainly well over a mile in all directions. However, several studies have shown that bees generally choose to move a few hundred yards or less.

It’s therefore a good idea to have a bait hive that sort of distance from your own apiaries.

Or even tucked away in the corner of the apiary itself.

I’ve had bees move out of one box, bivouac a short distance away and then occupy a bait hive on a hive stand adjacent to the original hive.

It’s probably definitely poor form to position a bait hive a short distance from someone else’s apiary 😉

But there’s nothing stopping you putting a bait hive at the bottom of your garden or – whilst maintaining social distancing of course – in the gardens of friends and family.

If you want to move a swarm that has occupied a bait hive the usual “less than 3 feet or more than 3 miles” rule applies unless you move them within the first couple of days of arrival. Swarms have an interesting plasticity of spatial memory (which deserves a post of its own) but will have fully reorientated to the bait hive location within a few days.

So, if the bait hive is in grandma’s garden, but grandma doesn’t want bees permanently, you need to move them promptly … or move them over three miles.

Or move grandma 😉

Lucky dip

Swarms, whether dropped into a skep or attracted to a bait hive, are a bit of a lucky dip. Now and again you get a fantastic prize, but often it’s of rather low value.

The good ones are great, but even the poor ones can be used.

But there’s an additional benefit … every one that arrives self-propelled in your bait hive is one less reported to the BBKA “swarm line” or that becomes an unwelcome tenant in the eaves of a house 10.

As long as they’re healthy, even a bad tempered colony headed by a queen with a poor laying pattern, can usefully be united to create a stronger colony to exploit late season nectar.

Varroa treatment of a new swarm in a bait hive…

But they must be healthy.

Swarms will potentially have a reasonably high mite count and will probably need treating within a week of arrival in the bait hive 11. Dribbled or vaporised oxalic acid/Api-Bioxal would be my choice; it’s effective when the colony has no sealed brood 12 and requires a single treatment.

But swarms can bring even more unwelcome payloads than Varroa mites. If you keep bees in an area where foulbroods are established be extremely careful to confirm that the arriving swarm isn’t affected. This requires letting the colony rear brood while isolated in a quarantine apiary.

How do you know whether there are problems with foulbroods in your area? Register your apiary on Beebase and talk to your local bee inspector.

My bait hives go out in the second or third week of April … but I’m on the cool east coast of Scotland. When I lived in the Midlands they used to be deployed in early April. If you’re in the balmy south they should probably be out already 13.

What are you waiting for 😉 ?