Category Archives: Protective

Winter covers and colony survival

Synopsis : A recent study shows increased overwinter colony survival of ‘covered’ hives wrapped in Correx and with insulation under the roof. What provides the most benefit, and are the results as clear cut as they seem?

Introduction

A recent talk by Andrew Abrahams to the Scottish Native Honey Bee Society coincided with me catching up my ¹ backlog of scientific papers on honey bees. I’d been reading a paper on the benefits of wrapping hives in the winter and Andrew commented that he did exactly that to fend off the worst of the wet weather. Andrew lives on the island of Colonsay about 75 km south of me and we both ‘benefit’ from the damp Atlantic climate.

The paper extolled the virtues of ‘covered’ hives and the data the researchers present looks, at first glance, compelling.

For example, <5% of covered hives perished overwinter in contrast to >27% of the uncovered control hives.

Wow!

Why doesn’t everyone wrap their hives?

However, a closer look at the paper raises a number of questions about what is actually benefitting (or killing) the colonies.

Nevertheless, the results are interesting. I think the paper poses rather more questions than it answers, but I do think the results show the benefits of hive insulation and these are worth discussing.

Bees don’t hibernate

Hibernation is a physiological state in which the metabolic processes of the body are significantly reduced. The animal becomes torpid, exhibiting a reduced heart rate, low body temperature and reduced breathing. Food reserves e.g. stored fat, are conserved and the animal waits out the winter until environmental conditions improve.

However, bees don’t hibernate.

Winter cluster 3/1/21 3°C (insulation block removed from the crownboard)

If you lift the lift the roof from a hive on a cold midwinter day you’ll find the bees clustered tightly together. But, look closely and you’ll see that the bees are moving. Remove the crownboard and some bees will probably fly.

The cluster conserves warmth and there is a temperature gradient from the outside – termed the mantle – to the middle (the core).

If chilled below ~5.5°C a bee becomes semi-comatose ² and unable to warm herself up again. The mantle temperature of the cluster never drops below ~8°C, but the core is maintained at 18-20°C when broodless or ~35°C if they are rearing brood. I’ve discussed the winter cluster in lots more detail a couple of years ago.

The metabolic activity of the clustered winter bees is ‘powered’ by their consumption of the stores they laid down in the autumn. It seems logical to assume that it will take more energy (i.e. stores) to maintain a particular cluster temperature if the ambient temperature is lower.

Therefore, logic would also suggest that the greater the insulation properties of the hive – for a particular difference in ambient to cluster temperature – the less stores would be consumed.

Since winter starvation is bad for bees (!) it makes sense to be thinking about this now, before the temperatures plummet in the winter.

Cedar and poly hives

I’m not aware of many comparative studies of the insulation properties of hives made from the two most frequently used materials – wood and polystyrene. However, Alburaki and Corona (2021) have investigated this and shown a small (but statistically significant) difference in the inner temperature of poly Langstroth hives when compared to wooden ones.

Poly hives were ~0.5°C warmer and, perhaps more importantly, exhibited much less variation in temperature over a 24 hour period.

Temperature and humidity in poly and wood hives

In addition to the slight temperature difference, the humidity within the wooden hives was significantly higher than that of poly.

The hives used in this study were occupied by bees and the temperature and humidity were recorded from sensors placed in a modified frame in the ‘centre of the brood box’. The external ambient temperature averaged 0°C, but fluctuated over a wide range (-10°C to 20°C) during the four month study ³.

Temperature anomalies

Whilst I’m not surprised that the poly hives were marginally warmer, I was surprised how low the internal hive temperatures were. The authors don’t comment on whether the ‘central’ frame was covered with bees, or whether the bees were rearing brood.

The longitudinal temperature traces (not reproduced here – check the paper) don’t help much either as they drop in mid-February when I would expect brood rearing to be really gearing up … Illogical, Captain.

The authors avoid any discussion on why the average internal temperature was at least 5-8°C cooler than the expected temperature of the core of a clustered broodless colony, and ~25°C cooler than a clustered colony that was rearing brood.

My guess is that the frame with the sensors was outside the cluster. For example, perhaps it was in the lower brood box ⁴ with the bees clustered in the upper box?

We’ll never know, but let’s just accept that poly hives – big surprise 😉 – are better insulated. Therefore the bees should need to use less stores to maintain a particular internal temperature.

And, although Alburaki and Corona (2021) didn’t measure this, it did form part of a recent study by Ashley St. Clair and colleagues from the University of Illinois (St. Clair et al., 2022).

Hive covers reduce food consumption and colony mortality

This section heading repeats the two key points in the title of this second paper.

I’ll first outline what was done and describe these headline claims in more detail. After that I’ll discuss the experiments in a bit more detail and some caveats I have of the methodology and the claims.

I’ll also make clear what the authors mean by a ‘hive cover’.

The study was conducted in central Illinois and involved 43 hives in 8 apiaries. Hives were randomly assigned to ‘covered’ or ‘uncovered’ i.e. control – groups (both were present in every apiary) and the study lasted from mid-November to the end of the following March.

Ambient (blue), covered (black) and control (dashed) hive temperatures

There were no significant differences in internal hive temperature between the two groups and – notably – the temperatures were much higher (15°-34°C) than those recorded by Alburaki and Corona (2021).

All colonies, whether covered or uncovered, got lighter through the winter, but the uncovered colonies lost significantly more weight once brood rearing started February. The authors supplemented all colonies with sugar cakes in February and the control colonies used ~15% more of these additional stores before the study concluded.

I don’t think any of these results are particularly surprising – colonies with additional insulation get lighter more slowly and need less supplemental feeding.

The surprising result was colony survival.

Less than 5% (1/22) of the covered hives perished during the winter but over 27% (6/21) of the control hives didn’t make it through to the following spring.

(Un)acceptable losses

To put these last figures into context the authors quote a BeeI Informed Partnership survey where respondents gave a figure of 23.3% as being ’acceptable’ for winter colony losses.

That seems a depressingly high figure to me.

However, look – and weep – at the percentage losses across the USA in the ’20/’21 winter from that same survey ⁵.

Bee Informed Partnership 2021 winter colony losses (preliminary data)

This was a sizeable survey involving over 3,300 beekeepers managing 192,000 colonies (~7% of the total hives in the USA).

If hive covers reduce losses to just 5% why does Illinois report winter losses of 47%? ⁶

Are the losses in this manuscript suspiciously low?

Or, does nobody use hive covers?

I don’t know the answers to these questions, but I also wasn’t sure when I started reading the paper what the authors meant by a hive ‘cover’ … which is what I’ll discuss next.

Hive covers

The hives used in this study were wooden Langstroths and the hive covers were 4 mm black corrugated polypropylene sleeves.

This is what I call Correx … one of my favourite materials for beekeeping DIY.

These hive covers are available commercially in the USA (and may be here, I’ve not looked). At $33 each (Yikes) they’re not cheap, but how much is a colony worth?

Significantly more than $33.

I’ve not bothered to make the conversion of Langstroth Deep dimensions (always quoted in inches 🙁 ) to metric and then compared the area of Correx to the current sheet price of ~£13 … but I suspect there are savings to be made by the interested DIYer ⁷.

However, knowing (and loving) Correx, what strikes me is that it seems unlikely to provide much insulation. At only 4 mm thick and enclosing an even thinner air gap, it’s not the first thing I’d think of to reduce heat loss ⁸.

4 mm Correx sheet

Thermal resistance is the (or a) measure of the insulating properties of materials. It’s measured in the instantly forgettable units of square metre kelvin per watt m².K/W.

I couldn’t find a figure for 4 mm Correx, but I did manage to find some numbers for air.

A 5 mm air gap – greater than separates the inner and outer walls of a 4 mm Correx hive cover – has a thermal resistance of 0.11 m².K/W.

Kingspan

It’s not possible to directly compare this with anything meaningful, but there is data available for larger ‘thicknesses’ of air, and other forms of insulation.

An air gap of 100 mm has a thermal resistance of about 0.17 m².K/W. For comparison, the same thickness of Kingspan (blown phenolic foam wall insulation, available from almost any building site skip) has a thermal resistance of 5, almost 30 times greater.

And, it turns out, St. Clair and colleagues also added a foam insulation board on top of the hive crownboard (or ‘inner cover’ as they call it in the USA). This board was 3.8 cm thick and has somewhat lower thermal resistance than the Kingspan I discussed above.

It might provide less insulation than Kingspan, but it’s a whole lot better than Correx.

This additional insulation is only briefly mentioned in the Materials and Methods and barely gets another mention in the paper.

A pity, as I suspect it’s very important.

Perspex crownboard with integrated 50 mm Kingspan insulation

I’m very familiar with Kingspan insulation for hives. All my colonies have a 5 cm thick block present all year – either placed over the crownboard, built into the crownboard or integrated into the hive roof.

Two variables … and woodpeckers

Unfortunately, St. Clair and colleagues didn’t compare the weight loss and survival of hives ‘covered’ by either wrapping them in Correx or having an insulated roof.

It’s therefore not possible to determine which of these two forms of protection is most beneficial for the hive.

For reasons described above I think the Correx sleeve is unlikely to provide much direct thermal insulation.

However, that doesn’t mean it’s not beneficial.

At the start of this post I explained that Andrew Abrahams wraps his hives for the winter. He appears to use something like black DPM (damp proof membrane).

Hive wrapped in black DPM (to prevent woodpecker damage)

Andrew uses it to keep the rain off the hives … I’ve used exactly the same stuff to prevent woodpecker damage to hives during the winter.

It’s only green woodpeckers (Picus viridis) that damage hives. It’s a learned activity; not all green woodpeckers appear to know that beehives are full of protein-rich goodies in the depths of winter. If they can’t grip on the side of the hive they can’t chisel their way in.

When I lived in the Midlands the hives always needed winter woodpecker protection, but the Fife Yaffles ⁹ don’t appear to attack hives.

Here on the west coast, and on Colonsay, there are no green woodpeckers … and I know nothing about the hive-eating woodpeckers of Illinois.

So, let’s forget the woodpeckers and return to other benefits that might arise from wrapping the hive in some form of black sheeting during the winter.

Solar gain and tar paper

Solar gain is the increase in thermal energy (or temperature as people other than physicists with freakishly large foreheads call it) of something – like a bee hive – as it absorbs solar radiation.

On sunny days a black DPM-wrapped hive (or one sleeved in a $33 Correx/Coroplast hive ‘cover’) will benefit from solar gain. The black surface will warm up and some of that heat should transfer to the hive.

And – in the USA at least – there’s a long history of wrapping hives for the winter. If you do an internet search for ‘winterizing hives’ or something similar ¹⁰ you’ll find loads of descriptions (and videos) on what this involves.

Rather than use DPM, many of these descriptions use ‘tar paper’ … which, here in the UK, we’d call roofing felt ¹¹.

Roofing felt – at least the stuff I have left over from re-roofing sheds – is pretty beastly stuff to work with. However, perhaps importantly, it has a rough matt finish, so is likely to provide significantly more solar gain than a covering of shiny black DPM.

I haven’t wrapped hives in winter since I moved back to Scotland in 2015. However, the comments by Andrew – who shares the similarly warm and damp Atlantic coastal environment – this recent paper and some reading on solar gain are making me wonder whether I should.

Fortunately, I never throw anything away, so should still have the DPM 😉

Winter losses

Illinois has a temperate climate and the ambient temperature during the study was at or below 0°C for about 11 weeks. However, these sorts of temperatures are readily tolerated by overwintering colonies. It seems unlikely that colonies that perished were killed by the cold.

So what did kill them?

Unfortunately there’s no information on this in the paper by St. Clair and colleagues.

Perhaps the authors are saving this for later … ’slicing and dicing’ the results into MPU’s (minimal publishable units) to eke out the maximum number of papers from their funding ¹², but I doubt it.

I suspect they either didn’t check, checked but couldn’t determine the cause, or – most likely – determined the cause(s) but that there was no consistent pattern so making it an inconclusive story.

But … it was probably Varroa and mite-transmitted Deformed wing virus (DWV).

It usually is.

Varroa

There were some oddities in their preparation of the colonies and late-season Varroa treatment.

Prior to ‘winterizing’ colonies they treated them with Apivar (early August) and then equalised the strength of the colonies. This involves shuffling brood frames to ensure all the colonies in the study were of broadly the same strength (remember, strong colonies overwinter better).

A follow-up Varroa check in mid-October showed that mite levels were still at 3.5% (i.e. 10.5 phoretic mites/300 bees) and so all colonies were treated with vaporised oxalic acid (OA).

Sublimox vaporiser … phoretic mites don’t stand a chance

In early November, mite levels were down to a more acceptable 0.7%. Colonies received a second OA treatment in early January.

For whatever reason, the Apivar treatment appears to have been ineffective.

When colonies are treated for 6-10 weeks with Apivar (e.g. early August to mid-October) mite levels should be reduced by >90%.

Mite infestation levels of 3.5% suggest to me that the Apivar treatment did not work very well. That being the case, the winter bees being reared through August, September and early October would have been exposed to high mite levels, and so acquired high levels of DWV.

OA treatment in mid-October would kill these remaining mites … but the damage had already been done to the ’diutinus’ winter bees.

That’s my guess anyway.

An informed guess, but a guess nevertheless, based upon the data in the paper and my understanding of winter bee production, DWV and rational Varroa management.

In support of this conclusion it’s notable that colonies died from about week 8, suggesting they were running out of winter bees due to their reduced longevity.

If I’m right …

It raises the interesting question of why the losses were predominantly (6 vs 1) of the control colonies?

Unfortunately the authors only provide average mite numbers per apiary, and each apiary contained a mix of covered and control hives. However, based upon the error bars on the graph (Supporting Information Fig S1 [PDF] if you’re following this) I’m assuming there wasn’t a marked difference between covered and control hives.

I’ve run out of informed guesses … I don’t know the answer to the question. There’s insufficient data in the paper.

Let’s briefly revisit hive temperatures

Unusually, I’m going to present the same hive temperature graph shown above to save you scrolling back up the page ¹³.

Ambient (blue), covered (black) and control (dashed) hive temperatures

There was no overall significant difference in hive temperature between the control and covered colonies. However, after the coldest weeks of the winter (7 and 8 i.e. the end of February), hive temperatures started to rise and the covered colonies were consistently marginally warmer. By this time in the season the colonies should be rearing increasing amounts of brood.

I’ve not presented the hive weight changes. These diverged most significantly from week 8. The control colonies used more stores to maintain a similar (actually – as stated above – marginally lower) temperature. As the authors state:

… covered colonies appeared to be able to maintain normal thermoregulatory temperatures, while consuming significantly less stored food, suggesting that hive covers may reduce the energetic cost of nest thermoregulation.

I should add that there was no difference in colony strength (of those that survived) between covered and control colonies; it’s not as though those marginally warmer temperatures from week 9 resulted in greater brood rearing.

Are lower hive temperatures ever beneficial in winter?

Yes.

Varroa management is much easier if colonies experience a broodless period in the winter.

A single oxalic acid treatment during this broodless period should kill 95% of mites – as all are phoretic – leaving the colony in a very good state for the coming season.

If you treat your colonies early enough to protect the winter bees there will inevitably be some residual mite replication in the late season brood, thereby necessitating the midwinter treatment as well.

I’m therefore a big fan of cold winters. The colony is more likely to be broodless at some point.

I was therefore reassured by the similarity in the temperatures of covered and control colonies from weeks 48 until the cold snap at the end of February. Covered hives should still experience a broodless period.

I’m off for a rummage in the back of the shed to find some rolls of DPM for the winter.

I don’t expect it will increase my winter survival rates (which are pretty good) and I’m not going to conduct a controlled experiment to see if it does.

If I can find the DPM I’ll wrap a few hives to protect them from the winter weather. With luck I should be able to rescue an additional frame or two of unused stores in the spring (I often can anyway). I stack this away safely and then use it when I’m making up nucs for queen mating.

I suspect that the insulation over the crownboard provides more benefit than the hive ‘wrap’. As stated before, all my colonies are insulated like this year round as I’m convinced it benefits the colony, reducing condensation over the cluster and keeping valuable warmth from escaping. However, wrapping the hive for solar gain and/or weather protection is also worth considering.

References

Alburaki, M. and Corona, M. (2022) ‘Polyurethane honey bee hives provide better winter insulation than wooden hives’, Journal of Apicultural Research, 61(2), pp. 190–196. Available at: https://doi.org/10.1080/00218839.2021.1999578.

St. Clair, A.L., Beach, N.J. and Dolezal, A.G. (2022) ‘Honey bee hive covers reduce food consumption and colony mortality during overwintering’, PLOS ONE, 17(4), p. e0266219. Available at: https://doi.org/10.1371/journal.pone.0266219.

The gentle art of beekeeping

High summer.

The swarm season had been and gone. The June gap was over. Grafts made at the peak of the swarm season had developed into lovely big fat queen cells and been distributed around nucleus colonies for mating.

That was almost six weeks ago.

From eclosion to laying takes a minimum of about 8 days. The weather had been almost perfect for queen mating, so I was hopeful they’d got out promptly, done ‘the business’, and returned to start laying.

That would have been about a month ago.

Good queens

I’d spent a long morning in the apiary checking the nucs and the colonies they were destined for. In the former I was looking for evidence that the queen was mated and laying well. That meant looking for nice even frames of sealed worker brood, with some – the first day or two of often patchy egg laying – now emerging.

Brood frame with a good laying pattern

It was warming up. More significantly, it was getting distinctly close and muggy. I knew that thunderstorms were predicted late in the afternoon, but by late morning it already had that oppressive ‘heavy’ feel to the air. Almost as though there wasn’t quite enough oxygen in it.

Never mind the weather, the queens were looking good. 90% of them were mated and laying well.

Just one no-show. She’d emerged from the cell, but there was no sign of her in the nuc, and precious few bees left either.

Queenless nucs often haemorrhage workers to nearby queenright colonies (or nucs), leaving a pathetic remainder that may develop laying workers. There’s no point in trying to save a colony like that.

Actually, it’s not even a colony … it’s a box with a few hundred abandoned and rapidly ageing workers. Adding resources to it – a new queen or a frame of eggs and young larvae – is almost certainly a waste of resources. They’d better serve the colonies they were already in. The remaining workers were probably over a month old and only had another week or two before they would be lost, ‘missing in action’, and fail to return from a foraging flight.

If you keep livestock, you’ll have dead stock.

These weren’t dead stock, but they were on their last ~~legs~~, er, wings. I shook the workers out in front of a row of strong colonies and removed the nuc box so there was nowhere for them to return. The workers wouldn’t help the other colonies much, but it was a better fate than simply allowing them to dwindle.

Spare queens

Most of the nucs were going to be used to requeen production colonies. A couple had been promised to beginners and would be ready in another week or so.

Midseason is a good time to get a nuc to start beekeeping. The weather – the predicted (and seemingly increasingly imminent) afternoon thunder notwithstanding – is more dependable, and much warmer. The inevitably protracted inspections by a tyro won’t chill the brood and nucs are almost always better tempered than full colonies. In addition, the new beekeeper has the pleasure of watching the nuc build up to a full colony and preparing it for winter. This is a valuable learning experience.

Late season bramble

It’s too late to get a honey crop from these midseason nucs (usually, there may be exceptional years) but that’s probably also good training for the new beekeeper. An understanding that beekeeping requires a degree of patience may be a tough lesson to learn but it’s an easier one than discovering that an overcrowded nuc purchased in April, swarms in May, gets really ratty in June and needs a new queen at the beginning of July.

But, after uniting the nucs to requeen the production hives it turned out that I had one queen spare.

Which was fortunate as I’d been asked by a friend for an old leftover queen to help them improve the behaviour of their only colony. Rather than give them one of the ageing queens she could have the spare one from this year.

A queen has a remarkable influence over the behaviour and performance of the colony. Good quality queens head calm, strong colonies that are a pleasure to work with. But it’s not all good genes. You can sometimes detect the influence of a good new queen in a poor colony well before any of the brood she has laid emerges. I assume this is due to pheromones (and with bees, if it’s not genetics or pheromones I’m not sure what else could explain it – ley lines, phase of the moon, 5G masts nearby?).

Go west, young(er) man

My friend lived about 45 minutes away. I found the queen in the nuc, popped her into a marking cage and placed her safely in light shade at the back of the apiary while I rearranged the nuc for uniting over a strong queenright colony.

Handheld queen marking cage

A few minutes later I’d recovered the queen, clipped her and marked her with a white Posca pen. I alternate blue and white (and sometimes yellow if neither of those work or can be found) and rely on my notes to remind me of her age should I need to know it. I’m colourblind and cannot see – or at least distinguish – red and green, either from each other or from lots of other colours in the hive.

I transferred the marked queen into a JzBz queen cage and capped the exit tube. Of all the huge variety of queen introduction cages that are available these are my favourite. They’re also the only ones I was given a bucket of … something that had a big part to play in influencing my choice 🙂

JzBz queen cages

I put the caged queen in the breast pocket of my beesuit, extinguished the smoker and tidied up the apiary. It was warm, dark and humid in the pocket – for an hour or so she would be fine.

Actually, it was getting increasingly humid and the heaviness in the air was, if anything, getting more oppressive.

What I’d really like now would be a couple of large mugs of tea … I’d inspected a dozen large colonies and nearly the same number of nucs. The colonies that needed requeening had been united with the nucs (having found and removed the ageing queens) and I’d neatly stacked up all the empty nuc boxes in the shed. Finally, I’d retuned all the supers, some reassuringly heavy, and left everything ready for the next inspection in a fortnight or so ¹.

That’s a lot of lifting, carrying, bending, squinting, prising, turning, rearranging and then gently replacing the crownboard and the roof.

Not really hard work, but enough.

Actually, quite enough … I’d really like that cuppa.

Was that thunder? Way off to the west … a sound so faint I might have imagined it. There were towering cumulus clouds building along the horizon.

Threatening

Time to get a move on.

With the car packed I lock the apiary gate and set off.

West.

Leaving the flat agricultural land I climbed gently into low rolling hills. The land became more wooded, restricting my view of the thunderheads building, now strongly, in the direction I was heading. The sun was now intermittently hidden between the wispy clouds ahead of the storm front.

Could you do me a favour?

The bad weather was still a long way off. I’d have ample time to drop the queen off, slurp down a cuppa and be back home before any rain arrived. If my friend was sensible she’d just leave the new queen hanging in her cage in a super. The workers would feed her until the weather was a little more conducive to opening the hive and finding the old queen.

I pull into the driveway and my friend comes out to meet me. We share beekeeping chat about the weather, forage, the now-passed swarm season, the possibility of getting a nuc for next season ².

“Could you perhaps requeen the colony? I’m really bad at finding the queen and they’ve been a bit bolshy ³ recently. I’ll put the kettle on while you’re doing it.”

I did a quick mental calculation … weighing up the positives (kettle on) and the negatives (bolshy, the distant – but approaching – thunder) and was surprised to find that my yearning for a cuppa tipped the balance enough for me to agree to do it.

I returned to the car for my smoker and some queen candy which I used to plug the neck of the JzBz cage. At the same time I also found a small piece of wire to hang the cage between the frames from.

“They’re in the back garden on the bench by the gate to the orchard.”

I look through the kitchen window across the unkempt lawn (was the mower broken?). Sure enough, there was a double brooded National hive topped with two supers on a garden bench about 30 metres away.

“I’ll stay here if you don’t mind … they gave me a bit of a fright when I last checked them.”

Sure. No problem. I’ve done this a hundred times. White, no sugar and, yes, I’d love a cookie as well.

Be properly prepared

I stepped into the back garden and fired up the smoker. It was still warm from being used for my own bees and the mix of cardboard, woodshavings and dried grass quickly started smouldering nicely. A couple of bees had come to investigate but had just done a few laps of my head and disappeared.

But they returned as I walked across the lawn.

And they brought reinforcements.

By the time I was half way across the lawn I’d been pinged a couple of times. Not stung, but the sort of glancing blow that shows intent.

A shot across the bows, if you like.

I didn’t like.

I pulled the veil over my head and zipped it up quickly, before rummaging through my pockets to find a pair of gloves. Mismatched gloved. A yellow Marigold for my left hand and a thin long-cuff blue nitrile for my right. It’s an odd look ⁴ but an effective combination. The Marigold is easy to get on and off, and provides ample protection.

Nitriles …

The nitrile is a bit of a nightmare to get on when it’s still damp inside. Another couple of bees dive bomb my veil, one clinging on and making that higher pitched whining sound they make when they’re trying to get through. I brushed her off with the Marigold, turned the nitrile inside out, blew into it to inflate the fingers, and finally got it on.

Why two different gloves? Two reasons. I’d lost the other Marigold and because nitriles are thin enough to easily pick a queen up with, and that’s what I’d been doing most of the morning.

And hoped to do again shortly when I found the old queen in the agitated colony.

Opening hostilities

I approached the hive. It was a strong colony. Very strong. It was tipped back slightly on the bench and didn’t look all that stable ⁵. I gave them a couple of puffs of smoke at the entrance and prised the supers up and off, placing them propped against the leg of the bench.

I was faintly aware of the smell of bananas and the, still distant, sound of thunder. It probably wasn’t getting any closer, but it certainly wasn’t disappearing either.

The thunder that is.

The smell of bananas was new … it’s the alarm pheromone.

Actually, it’s one of the alarm pheromones. Importantly, it’s the one released from the Koschevnikov gland at the base of the sting. This meant that one or two bees had already pressed home a full attack and stung me. Felt nowt. Presumably they’d hit a fold in the beesuit or the cuff of the Marigold.

Or my adrenaline levels were sufficiently elevated to suppress my pain response.

I was increasingly aware of the number of really unpleasant bees that were in the hive.

And, more to the point, coming out of the hive.

But I was most aware that I was only wearing a single thickness beesuit in the presence of 50,000 sociopaths with a thunderstorm approaching. Under the suit I had a thin short sleeved shirt and a pair of shorts.

It might be raining in half an hour … this could get ugly.

It was late July, it was a hot day, my bees are calm. I wasn’t dressed appropriately for these psychos.

I felt I needed chain mail … and an umbrella.

Time for a rethink

I gave the hive a couple of larger puffs from the smoker and retreated back to the car, ducking under and through – twice – some dense overhanging shrubs to deter and deflect the bees attempting to hasten my retreat.

Ideally I’d have put a fleece on under the beesuit. That makes you more or less impervious to stings.

Did I mention it was a warm day in July? No fleece 🙁

However, I did have a beekeeping jacket in the car. This is what I wear for most of my beekeeping (unless I’m wearing shorts). I removed the jacket hood and put it on over the beesuit, remembering to transfer the queen to the outer jacket pocket. I also found another nitrile glove and put it on to be double gloved.

“The queen’s not marked”, my friend shouted to me as I walked back across the garden, “Sorry!”

Now you tell me …

I See You Baby

I returned to the hive. To reduce the immediate concentration of bees, I split the two brood boxes off the floor, placing each several metres away on separate garden chairs. I balanced the supers on the original floor to allow returning foragers and the increasing maelstrom of flying bees to have somewhere to return if needed.

And then I found the unmarked queen.

As simple as that.

Amazingly, it was on the first pass through the second brood box.

Each box was dealt with in the same way. I gently split the propolis sealing the frames together – first down one side of the box, then the other. I removed the outer frame, inspected it carefully and placed it on the ground leaning against the chair leg. With space to work I then methodically went through every frame, calmly but quickly.

I didn’t expect to find her so easily. I wasn’t sure I’d be able to find her at all.

It helped that she was huge and pale. It helped that she was calmly ambling around on the frame, clearly confident in the knowledge that there were 50,000 acolytes willing to lay down their lives to protect her.

Her confidence was misplaced 🙁

Veiled threat

And then a bee got inside the veil.

This happens now and then. I suspect they sneak through the gap where the zips meet at the front or the back. There are little Velcro patches to hold everything together, but it was an old suit ⁶ and the Velcro was a bit worn.

There are few things more disconcerting that 50,000 psychos encouraging a Ninja worker that’s managed to break through your defences and is just in your peripheral vision. Or worse, in your hair. With a calm colony you can retreat and deal with the interloper. You have to take the veil off. Sometimes you have to take the suit off.

Removing the veil would have been unwise. Perhaps suicidal. I retreated a few yards and dealt with the bee. It was never going to end well for one of us 🙁

Reassemble in the reverse order

Returning to the original bench, I removed the supers that were now festooned with thousands of bees, balancing them against the leg again. I found a pencil-thick twig and used it under one corner of the floor to stop everything wobbling. Both brood boxes were returned, trying to avoid crushing too many bees at the interface. A combination of a well aimed puff or two of smoke, brushing the bees away with the back of my hand and placing the box down at an angle and then rotating it into position reduced what can otherwise cause carnage.

I hung the new queen in her cage between the top bars of the central frames in the upper box, returned the queen excluder and the supers and closed the hive up.

It took 15 minutes to avoid and evade the followers before I could remove the beesuit safely. I’d been stung several times but none had penetrated more than the suit.

I finally got my cup of tea.

Confidence

This was several years ago. I took a few risks towards the end with the queen introduction but got away with it. The colony released the queen, accepted her and a month or so later were calm and well behaved.

I was lucky to find the queen so quickly in such a strong colony. I didn’t have to resort to some of the tricks sometimes needed to find elusive queens.

Ideally I’d have left the queen cage sealed to see if they were aggressive to her, only removing the cap once I was sure they’d accept her. This can take a day or two, but you need to check them.

There was no way I was going back into the hive and my friend definitely wasn’t.

The rain and thunder never arrived … like many summer storms it was all bluster but eventually dissipated as the day cooled.

This was the worst colony I’ve ever handled as a beekeeper. At least for out and out, close quarter, bare knuckle aggression. By any measure I’d have said they were unusable for beekeeping. I’ve had colonies with followers chase me 300 metres up the meadow, though the hive itself wasn’t too hot ⁷. This colony was an order of magnitude worse, though the followers were less persistent.

I suspect that aggression (or, more correctly, defensiveness) and following have different genetic determinants in honey bees.

Lessons

Knowing when to retreat is important. Smoking them gently before I returned to the car for a jacket helped mask the alarm pheromone in the hive and gave me both time to think and renewed confidence that I was now better protected.
Confidence is very important when dealing with an unpleasant hive. It allows you to be unhurried and gentle, when your instincts are screaming ‘get a move on, they’re going postal’.
Confidence comes with experience and with belief in the protective clothing you use. It doesn’t need to be stingproof, but it does need to protect the soft bits (my forearms, ankles and face react very badly when stung).
Indeed, it might be better if it’s not completely stingproof. It’s important to be aware of the reactions of the colony, which is why I prefer nitrile gloves to Marigolds, and why I never use gauntlets.
Many colonies are defensive in poor weather or with approaching thunderstorms. If I’d known just how defensive this colony were I’d have planned the day differently.
The unstable ‘hive stand’ would have agitated the bees in windy weather or during inspections.

Bad bees

It turned out the colony had been purchased, sight unseen, as a nuc the year before. By the end of the season it had become unmanageable. The supers had been on since the previous summer and the colony hadn’t been treated for mites.

They appeared healthy, but their behaviour was negatively influencing their management (and the upkeep of the garden). Beekeeping isn’t fun if you’re frightened of the bees. You find excuses to not open the hive, or not mow the lawn.

The story ended well. The new queen settled well and the bees became a pleasure to work with. My friend regained her confidence and is happy to requeen her own colonies now.

She has even started using proper hive stands rather than the garden bench … which you can now use for relaxing on with a mug of tea and a cookie.

While watching the bees 🙂

Ouch, that hurt

If you keep bees you’ll inevitably get stung.

Not necessarily often and not necessarily badly, but getting stung goes with the territory.

You’ll probably get stung more often if your bees are stroppy, or if you are clumsy. But even if you’re careful and the bees are calm there’s always the chance of being stung.

I moved a very feisty colony late one evening last week ¹. The hive was sealed, moved and re-located to an out apiary. Knowing they were, er, rather temperamental I let them settle for 15 minutes, then gently lifted the entrance block.

Out they boiled … as I beat a very hasty retreat 🙁

I thought I’d got away with it, but driving home 20 minutes later I was stung on the ankle by a stowaway in my boot.

Ouch! That hurt.

I’ve only been stung a few times all season. Most didn’t hurt much at the time and were forgotten within minutes. That sting on the ankle hurt like hell and was sore for a further 48 hours.

Why does it hurt when you’re stung? Furthermore, assuming stings are inevitable, which parts of the body hurt more when stung … and so deserve additional protection?

Why do bee stings hurt?

The honey bee sting is a hollow barbed tube used to deliver the venom. About 50% of bee venom by weight is the small protein mellitin.

It’s fair to say that mellitin is small but potent. It’s only 26 amino acids ² long and forms a tetramer in aqueous solution. The ‘noughts and crosses’ shape it adopts hides the hydrophobic parts of the peptide and therefore allows it to ‘dissolve’ in venom. However, the tetramer dissociates at or near cell membranes into which monomeric mellitin embeds itself.

Mellitin

And this is where the pain and damage start …

Membrane-association causes cell lysis ³. This results in the release of all sorts of cytokines from the cells which signal ‘damage’ to the body, leading to the inflammatory response usually associated with bee stings. That’s the long-term effect of a bee sting. However, simultaneously, mellitin triggers the expression of proteins known as sodium channels in pain receptor cells. These allow large amounts of sodium to flow across the membrane. It is this that is directly responsible for the pain sensation when you are stung.

So, if being stung is almost inevitable and if bees have evolved stings to cause pain (which they have), in which parts of the body is the pain sensation most marked?

Measuring pain

Pain is a subjective response. What’s painful to me might hardly be noticed by someone with a higher pain threshold. Two individuals receiving the same sensory input can experience very different sensory responses ⁴.

As an aside it’s well documented that there are differences in the pain felt by males and females ⁵. All the pain reported in this article is from studies – or personal experience – by males.

Therefore, to meaningfully determine how much pain a sting causes, from a particular insect or at a particular location for example, it’s essential that the studies are properly controlled. This includes taking account of variation between individuals and variation within an individual on a day to day basis.

These are not the sorts of studies that attract large numbers of volunteers 😉

Perhaps unsurprisingly, the scientific work in this field is often published in single author papers in which the author alone is the ‘volunteer’.

The Schmidt Sting Pain Index

Before discussing honey bees specifically a brief diversion must be made to introduce the seminal studies by Justin Schmidt.

Schmidt is an entomologist at the Carl Hayden Bee Research Centre in Arizona. He’s interested in haemolysis (the cell lysis caused by mellitin and other constituents of insect venom) and whether the evolution of sociality in hymenopterans (bees, ant and wasps) required the evolution of toxic and painful stings.

Over about twenty years Justin Schmidt published a number of papers on hymenopteran venoms and the pain that they cause. In his early papers he rated stings on a scale of 1 – 4 (actually 0 upwards, but 0 was totally painless to humans).

Only a very few insects scored 4, including bullet ants about which Schmidt comments “Paraponera clavata stings induced immediate, excruciating pain and numbness to pencil-point pressure, as well as trembling in the form of a totally uncontrollable urge to shake the affected part“.

You can’t fault his commitment, but you might question his sanity.

Schmidt published his magnum opus in 1990 in which he ranked stings by 78 hymenopteran species covering 41 genera ⁶. His descriptions of the pain induced are often entertaining. The aforementioned bullet ant is “pure, intense, brilliant pain…like walking over flaming charcoal with a three-inch nail embedded in your heel“.

Another sting scoring 4, that of Synoeca septentrionalis (the warrior wasp) is accompanied by the statement “Torture. You are chained in the flow of an active volcano. Why did I start this list?”.

Why indeed?

Standing on the shoulders of giants

Bees and wasps scored 2 on the Schmidt Sting Pain Index. What Schmidt didn’t investigate was the influence of the location of the sting on the pain experienced.

Which brings me to Michael Smith. In 2014 Smith published an entertaining paper entitled Honey bee sting pain index by body location. It’s published in the journal PeerJ and the full paper is available for download.

It’s a well controlled study written in an engaging style that most readers will appreciate.

Building on the landmark studies by Schmidt, Michael Smith rated the pain endured from honey bee stings in 25 different locations.

Some of these locations should really be protected with a bee suit.

Sting locations tested

Smith controlled the study by always including an “internal control” i.e. comparing two test locations with three stings to his forearm.

Every time.

All locations were tested in triplicate (randomly). This meant that Smith was stung a minimum of five times for 38 consecutive days. Ouch.

There are some excellent quotes in the paper … “Some locations required the use of a mirror and an erect posture during stinging (e.g., buttocks)“. Scientists involved in studies that require ethical approval will appreciate the comments made in the paper on self-experimentation.

And the results? To quote directly from the paper “The three least painful locations were the skull, middle toe tip, and upper arm (all scoring a 2.3). The three most painful locations were the nostril, upper lip, and penis shaft (9.0, 8.7, and 7.3, respectively)” ⁷. Interestingly, skin thickness did not correlate with the pain experienced.

My experience of stings is limited. Those I’ve had to the face (including the lower lip) have been relatively painless, but the subsequent inflammatory response has been dramatic. Smith only scored immediate pain … I think a follow-up study on inflammation and its duration is needed.

I’m not going to conduct it.

Points pain means prizes

You can’t fault the dedication shown by Justin Schmidt and Michael Smith ⁸. That sort of dedication should be recognised with prizes and honours.

And it was.

Schmidt and Smith shared the 2015 Ig Nobel prize for Physiology and Entomology. The Ig Nobels – a parody of the Nobel prizes – recognise unusual or trivial achievements in scientific research.

The list of Ig Nobel prizes awarded is eclectic and highly entertaining … Medicine (2013) “for treating “uncontrollable” nosebleeds, using the method of nasal-packing-with-strips-of-cured-pork“, Economics (2005) for the inventors of “Clocky, an alarm clock that runs away and hides, repeatedly, thus ensuring that people get out of bed, and thus theoretically adding many productive hours to the workday” and Psychology (1995) for “their success in training pigeons to discriminate between the paintings of Picasso and those of Monet” ⁹.

Sir Andre Geim received the Physics Ig Nobel in 2000 for levitating a frog by magnetism. Yes, really. Ten years later he was awarded the Nobel prize in Physics for his studies on graphene. He’s the only holder of a Nobel and Ig Nobel.

Marc Abrahams, the founder of the Ig Nobel awards, regularly tours giving talks on Improbable Research and the Ig Nobel prizes.

Go if you get the chance … it’s highly entertaining.

Shelter from the storm

The new bee shed is in an apiary with space for about a dozen additional hives around it. The apiary is fenced and heavily sheltered from cold easterly winds by a convenient strip of woodland. However, the site is open and exposed to westerlies. These can whip in across the fields and their impact is exacerbated by the apiary being elevated on a small mound a few feet above the low lying – and often flooded – adjacent land.

Laden foragers returning …

The bees occupying the hives in the shed are protected from the full force of the westerlies by the shed itself, which is angled slightly to deflect the wind. However, those outside in the apiary get the full impact, and the wire mesh security fencing provides no shelter.

We’ve had one summer gale that lifted a few polystyrene hive roofs and caused a bit of damage. Better preparation might have prevented this; I should have heeded the weather forecast and strapped the hives to the stands.

Inspection deflection

The major problem isn’t gales though. Instead, it’s the impact of the wind on returning foragers and the irritation it causes the bees during inspections on a blustery day.

Several of the hives face west so the bees often approach the entrance downwind. They can get a real buffeting and often have to make repeated crash-landings and attempts to reach the hive entrance.

A small mound of earth …

In marginal weather or on a cold day some inevitably get chilled and don’t make it back. The apiary has a compacted hardcore base and – unlike long grass – it’s easy to spot the bees ‘lost in action’.

Hive inspections are conducted from behind the hive. On a windy day – and it’s not always possible to inspect on calm days – the bees can show their disapproval when the crownboard is lifted. They’re not really aggressive, but can be a bit surly and are certainly less appreciative of the disturbance than those inside the shed.

It has become obvious that some additional shelter is needed.

Shelter belt

Herbage

As a long-term solution we’ve planted a double row of mixed native hedging plants (predominantly blackthorn but with a smattering of hazel, crab apples and dogwoods) mixed 1:2 with goat willow (Salix caprea). The latter is fast-growing and provides excellent early-season pollen at a time when colonies need it for brood rearing.

We planted 60-80cm ‘whips’, cut them back to ~35cm, wrapped them in perforated spirals to deter the rabbits and pretty-much left them to it. We’ve had a dry summer so have inevitably lost a few ¹. However, the majority are now at or well above the spirals.

We didn’t – but should have – used old carpet tiles or cardboard squares as a weed suppressor around each plant. This was due to lack of preparation on the day and lack of organisation subsequently. The plants would undoubtedly have done better if they’d been given a bit of help competing with the surrounding weeds.

The intention will be to cut this hedging back so that it provides a light screen and an abundance of pollen, rather than letting it develop into an impenetrable barrier around the apiary.

We’ll let it grow for another couple of years and then start staggered pruning as required.

In addition, and a little further from the apiary, we planted more willow which we’ll allow to grow larger – though probably still coppice it periodically. This will help landscape the otherwise rather unattractive earth mound and help it merge better with the trees to the east.

Windbreak

Although willow is relatively fast-growing, it’s not fast enough to provide protection from this autumn’s westerlies. Using the security fence as a support we’ve therefore installed a 2m high netting windbreak around part of the apiary.

Windbreak netting …

This netting was easily ‘zip’-tied to the fencing and is claimed to reduce windspeed on the lee side by 50%. From the outside – see above – it’s a bit of an eyesore. This is partly because the viewpoint is oblique and partly because it’s viewed against a dark backdrop.

And partly because it’s a bit ugly 😉

However, from inside the apiary – which is where I usually view things from – it’s far less obvious. We’ve had no strong winds since installing it but even with gentle westerlies the initial impression, in terms of the shelter provided, is positive. We’ll see how it performs in the winter gales.

Now you see me, now you don’t …

The netting has the added advantage of forcing all the bees ‘up and over’ as they exit the apiary, making them even less of a problem to passers-by ². The security fencing has ~15x5cm rectangular ‘holes’ in it and already forced most of the bees to fly above head height, but the addition of the netting reroutes them all.

I’ve previously discussed urban beekeeping and suggested engineering the flight lines of foragers by facing the hives up against a fence. As an alternative I’ve seen hives in a back garden encircled by a tall mesh net ³ that forced the bees up about ten feet before they set off foraging.

In that situation the net is present to protect the people outside. In my apiary it’s there to protect the bees inside … until the hedge grows.

The view from the west …

Colophon

Shelter from the storm is the title of track on the 1975 studio album Blood on the Tracks by Bob Dylan – Nobel Prize in Literature 2016 and University of St Andrews Honorary Doctorate in Music 2004. Widely regarded as being one of his greatest albums ⁴ it has been interpreted as recounting the turmoil in his life due to estrangement from his wife Sara. Although – perhaps inevitably – Bob Dylan has denied this, his son Jacob said it was “my parents talking”.

Two out of three ain’t bad

Beehives are full of things that get all over your hands – honey, propolis and bees. Most beekeepers therefore wear gloves.

Gloves provide protection from the sticky stuff that’s easy to remove (honey), the sticky stuff that is both hard to remove and gets everywhere else (propolis) and the sticking of stings into your delicate digits by the bees.

How to get stung

Perhaps surprisingly – at least for beginners – protection from stings is probably the least important thing that gloves provide.

Gauntlets …

Surely not? What about those huge leather welders gauntlets? Thick impenetrable leather, heavily stitched seams along the sides of the fingers, protection up to the elbows. You’re certainly not going feel the stings through those.

Yes … but you will get stung.

You’ll get stung because you’ll have “hands like feet” as my graduate students used to say of my laboratory skills. You will have little manual dexterity, no real tactile ability and – probably – poor grip as the leather becomes hardened with age.

You’re like a brain surgeon wearing mittens.

Consequently, the bees will sting the gloves (but not you) as you fumble about handling the frames, inadvertently squashing bees under your fingers, or the frame lugs. The alarm pheromone released will agitate the colony and you – or rather the gloves – will get stung again. And again.

What’s more, unless you carefully wash the gauntlets between inspections, the lingering alarm pheromone will agitate the next colony you inspect … before you’ve even had an opportunity to squash a few more bees.

How not to get stung

Paradoxically, I think the best way to avoid being stung is to use thin gloves. You’ll have better grip, much better dexterity and a hugely enhanced tactile awareness of what’s happening in and around your fingers.

You’ll be able to feel individual bees. Unsurprisingly, they buzz in an agitated way if you start to squash them. You probably won’t hear it above the noise of her 25,000 half-sisters that are also in the hive.

But you’ll feel it.

Consequently, you’ll be able to move your fingers slightly, allowing the bee to move before you lower the frame back into position.

Thin gloves aren’t enough

Of course, the other two things that help you not get stung is having well-tempered bees and learning how to carefully inspect a colony. These points should be self-evident. If your bees are naturally belligerent or you bash the frames about clumsily you are much more likely to get stung.

The combination of thin gloves, gentle bees and good beekeeping makes weekly inspections a real pleasure … for you and the bees ¹.

Marigolds

Marigold gloves …

Standard washing up gloves provide a good combination of protection and sensitivity. Buy them so they’re a reasonably snug fit. I usually buy the bright yellow “Extra Life” kitchen gloves which you can find for less than £2 a pair. With care and with minimal washing they’ll last half a season. Of course, there are hundreds of alternative kitchen ‘rubber’ gloves. Try several. I like the makes with the rolled cuff as they don’t ride down my arm as much, so protecting that super-sensitive (to stings) wrist area. The Lidl ones I’ve tried lack this rolled cuff and were a poor fit.

I strongly advise you do not buy the Marigold Extra Tough outdoor gloves. Yes, they’re thicker and so provide even more protection. But that extra thickness markedly reduces sensitivity. More importantly, they’re black so your hands look like the paws of a bear and the bees will give you a hammering anyway 😉

Bees can sting through standard Marigolds. However, the sting cannot usually get embedded into your skin. Consequently, you feel a tiny pinprick – a reminder that you’ve been a bit clumsy perhaps – but little else.

Nitrile and latex gloves

Nitriles …

Even better in terms of sensitivity are gloves made from latex or nitrile. These are very thin, provide excellent grip and still give some protection. Powder free nitrile are probably to be preferred as repeated use of latex gloves can lead to allergic reactions.

You can buy long cuff nitrile gloves in boxes of 50 or 100 for about £10 per hundred, or much cheaper if you arrange to buy in bulk through your association.

Do buy the long cuff versions. Some of the nitrile gloves sold through beekeeping suppliers are short cuff (and are much more expensive per pair if bought in small amounts). The longer cuffs pull over the cuffs of your beesuit and protect your wrists.

Nitrile gloves can be reused time and again, though they’re much less resilient than Marigolds. They eventually lose their slight stretch and either go super-baggy at the wrist, or you pull your hand through the glove when putting them on.

Propolis, apiary hygiene and sweat

Gloves get dirty. Propolis gets caked on the outside and, particularly on a sweltering hot midsummer day, you’ll fill them with sweat if you use them for prolonged periods. I rinse them in washing soda solution after use and then turn them inside-out to dry … usually stuffed into my beesuit pocket or dropped in the bee bag.

I use separate pairs for each apiary, not each hive. This probably isn’t ideal in terms of apiary hygiene, but I rationalise it because I’m aware of the very high level of drifting of bees between adjacent colonies.

It’s also much, much more difficult to pull on a new pair of nitriles if your hands are soaking wet with sweat … so not changing them is also a pragmatic decision.

If they’re heavily soiled with propolis it’s probably best to simply chuck them out, though you can freeze them and then easily peel it away.

Psycho bees

I’ve never worn gauntlets for beekeeping. I’ve tried them on many times. Since I can’t easily pick up a pen wearing them I’m not going to try picking up a frame by the lugs. In contrast, with nitriles you can easily pick up the queen, for example for marking. You can also usually pick her up with a bit of care when wearing Marigolds.

So, if thin gloves provide sensitivity with protection, what about the rare times when you want protection with protection? The times when the colony are truly psychotic.

Not my bees of course 😉

What about the colony you’re asked to requeen for a nervous beekeeper? The colony that dive bombs you from across the garden. The colony you’ve been warned is a bit ‘hot’. The colony you’ve donned a thick fleece under your beesuit for.

The colony that goes absolutely postal when you lift the crownboard ².

Under these circumstances I simply wear two pairs of Marigolds. I’ve never needed anything more. They’re effectively impenetrable to stings.

Colophon

Bat out of hell

Two out of three ain’t bad is a track by Meat Loaf from his 1977 album Bat out of hell. It seemed appropriate as two of the three types of gloves described “ain’t bad”. Bat out of hell, the first of a trilogy of albums that together have sold more than 50 million copies, was a collaboration between Meat Loaf and the lyricist Jim Steinman. It was produced by Todd Rundgren. It’s a great album to crank up loud and sing (badly) to driving back late at night from beekeeping talks.