More from the fun guy

Great fleas have little fleas upon their backs to bite ’em,
And little fleas have lesser fleas, and so ad infinitum.

Augustus de Morgan’s quote from A Budget of Paradoxes (1872) 1 really means that everything is preyed upon by something, which in turn has something preying on it.

The Flea, engraving from Robert Hooke’s Micrographia (1665)

As a virologist I’m well aware of this.

There are viruses that parasitise every living thing.

Whales have viruses and so do unicellular diatoms. All the ~30,000 named bacteria have viruses. It’s likely that the remaining 95% of bacteria that are unnamed also have viruses.

There are even viruses that parasitise viruses. The huge Mimivirus that infects amoebae 2 is itself parasitised by a small virophage (a fancy name for a virus that infects viruses) termed Sputnik.

Whether these interactions are detrimental depends upon your perspective.

The host may suffer deleterious effects while the parasite flourishes.

It’s good for the latter, but not the former.

Whether these interactions are detrimental for humans 3 also depends upon your perspective.

The deliberate introduction of rabbit haemorrhagic disease virus to Australia benefitted sheep farmers who were plagued with rabbits … but it was bad news for rabbit farmers 4.

Biocontrol

Beneficial parasitism, particularly when humans use a pathogen to control an unwanted pest, is often termed biocontrol, a convenient abbreviation for biological pest control.

There are numerous examples; one of the first and best known is control of greenhouse whitefly infestations with the parasitoid wasp Encarsia formosa.

Tomato leaf with whitefly nymphs (white) parasitized by E. formosa (black).

One of the benefits of biocontrol is its self-limiting nature. The wasp will stop replicating once it runs out of whitefly to parasitise.

A second benefit is the specificity of the interaction between the host and whatever is administered to control it; by careful selection of the biocontrol agent you can target what you want to eradicate without lots of collateral damage.

Finally, unlike toxic chemicals such as DDT, the parasitoid wasp – and, more generally, other biocontrol agents – do not accumulate in the environment and cause problems for the future.

And, with all those benefits, it’s unsurprising to discover that scientists have investigated biocontrol strategies to reduce Varroa mite infestation of honey bee colonies.

It’s too early for an aside, but I’ll make one anyway … I’ve discussed the potential antiviral activity of certain fungi a couple of years ago. That wasn’t really biocontrol. It was a fungal extract that appeared to show some activity against the virus. Although that story has gone a bit quiet, one of the authors – Paul Stamets – is also a co-author of the Varroa control paper discussed below.

Biocontrol of Varroa using entomopathogenic fungi

Entomopathogenic means insect killing 5. There are several studies on the use of insect killing fungi to control Varroa 6, with the most promising results obtained with a variety of species belonging to the genus Metarhizium

Metarhizium produces asexual spores termed mitospores. The miticidal activity is due to the adhesion of these mitospores to Varroa, germination of the spore and penetration by fungal hyphae 7 through the exoskeleton of the mite and proliferation within the internal tissues.

A gruesome end no doubt.

And thoroughly deserved 🙂

Although Metarhizium is entomopathogenic it has a much greater impact on Varroa than it does on honey bees. This is the specificity issue discussed earlier.

It is for this reason that scientists have continued to explore ways in which Metarhizium could be used for biocontrol of Varroa.

But there’s a problem …

Although dozens of strains of Metarhizium have been screened, the viability – and therefore activity – of the mitospores is significantly reduced by the relatively high temperatures within the colony.

The spores would be administered, they’d show some activity and some Varroa would be slaughtered. However, over time treatment efficacy would reduce as spores – either administered at the start of the study, or resulting from subsequent replication and sporulation of Metarhizium on Varroa – were inactivated.

As beekeepers you’ll be familiar with the limitation this would impose on effective control of mites.

Varroa spend well over half of their life cycle capped in a cell while it feeds on developing pupae. Anything added to kill mites must be present for extended periods to ensure emerging mites are also exposed and killed.

This is why Apiguard involves two sequential treatments of a fortnight each, or why Apivar strips must be left in a hive for more than 6 weeks.

In an attempt to overcome these limitations, scientists are using directed evolution and repetitive selection to derive strains of Metarhizium that are better able to survive within the hive, and so better able to control Varroa than the strains they were derived from.

Good news and bad news

Like many scientific papers on honey bees 8 those with even a whiff of ‘saving the bees’ get a lot of positive press coverage.

This often implies that the Varroa ‘problem’ is now almost solved, that whatever tiny, incremental advance is described in the paper represents a new paradigm in bee health.

This is both understandable and disappointing in equal measure.

It’s understandable because people (not just beekeepers) like bees. News publishers want ‘good news’ stories to intersperse with the usual never-ending menu of woe they serve up.

It’s disappointing because it’s a variant of “crying wolf”. We want the good news story to describe how the impact of Varroa can now be easily mitigated.

It gets our hopes up.

Unfortunately, reality suggests most of these ‘magic bullets’ are a decade away from any sort of commercial product.

They will probably get mired in licensing problems.

And they may not be any better than what we currently use.

You finally end up as cynical as I am. This might even force you to read the original manuscript, rather than the Gung ho press release or the same thing regurgitated on a news website.

And, if you do that, you’ll better understand some of the clever approaches that scientists are applying to the development of effective biocontrol for Varroa.

We’re not there yet, but progress is being made.

V e r y   s l o w l y.

The paper I’m going to discuss below is Han, J.O., et al. (2021) Directed evolution of Metarhizium fungus improves its biocontrol efficacy against Varroa mites in honey bee colonies. Sci Rep 11, 10582.

It’s freely available should you want to read the bits I get wrong 😉

Solving the temperature-sensitivity problem of mitospores

The strain of Metarhizium chosen for these studies was M. brunneum F52. This had previously been demonstrated to have some efficacy against Varroa. Almost as important, it can be genetically manipulated and there was some preliminary evidence that its pathogenicity for Varroa – and hence control potential – could be improved.

Genetic manipulation covers a multitude of sins. It could mean anything from selection of pre-existing variants from a population to engineered introduction of a toxin gene for destruction of the parasitised host.

In this study the authors used directed evolution of a population of Metarhizium to select for strains with more heat tolerant spores.

Directed evolution of Metarhizium to select mitospores with increased thermotolerance

This is not genetic engineering. They grew spores under stressful conditions and increasing temperatures. Hydrogen peroxide (H2O2) , a mild mutagen, was added in some cases. Nutritional stress also increases population variation. Spores selected using nutritional stress are better able to withstand UV and heat stress.

The optimal growth temperature for the strain of Metarhizium they started with was 27°C. By repeated selection cycles at increasing temperatures they derived spores that grew at 35°C, the temperature within a colony.

Ladders and snakes

A well known phenomena of repeated selection in vitro (i.e. in a test tube in the laboratory, though you actually grow Metarhizium on agar plates) is that a pathogen becomes less pathogenic.

It was therefore unsurprising that – when they eventually tested the thermotolerant spores – only about 3% of the Varroa that died did so due to Metarhizium infection.

Field selection after directed evolution of Metarhizium in the laboratory

They therefore modified the repetitive selection, but this time did it on Varroa-infested colonies in the apiary. Mites that died from Metarhizium mycoses 9 were used as a source to cultivate more Metarhizium.

They were therefore selecting for both thermotolerant (because the experiments were being conducted in hives at 35°C) and pathogenic fungi, because they only cultivated mitospores from Varroa that had died from mycoses.

And it worked …

Amplification of Varroa mycoses by Metarhizium. Black arrows indicate the treatment dates.

After four rounds of selection over 60% of the mites that died did so because they were infected with Metarhizium.

All very encouraging … but note I was very careful with my choice of words in that last sentence. I’ll return to this point shortly.

Before that, here’s the ‘proof’ that the strain selected by directed evolution (which they termed JH1078) possessed more thermostable spores.

Thermostable spores

They measured this by recording the percentage that germinated. At 35°C ~70% of JH11078 spores germinated compared to only ~45% of the M. brunneum F52 strain they started with.

But it’s not all good news

My carefully chosen “60% of the mites that died” neatly obscures the fact that you could get a significant increase in mites dying of Metarhizium, but still have almost all the mites in the hive surviving unscathed.

The authors continued repeated Metarhizium monthly treatments for a full season after the selection experiments described above. The apiary contained 48 colonies, 24 received Metarhizium JH1078 and the remainder received no treatment.

Did Metarhizium treatment stop the well documented increase in Varroa levels observed in colonies not treated with miticides?

Varroa levels in Metarhizium treated and untreated (control) colonies.

Er … no.

They describe this data (above) as showing a ‘delay’ in the exponential increase in Varroa … but acknowledge that it ‘did not totally prevent it’.

Hmmm … looking at the error bars in the last few timepoints I’d be hard pressed to make the case that there was any significant difference in Varroa increase caused by treatment.

And while we’re here look at the mite infestation rate … 10-25 mites per 100 bees.

These are catastrophically high numbers and, unsurprisingly, 42 (~88%) of the 48 colonies – whether treated or untreated – died by the end of 2018, succumbing to “Varroa, pathogen pressure and intense yellow jacket predation”

There was some evidence that colonies receiving Metarhizium treatment survived a bit longer than the untreated controls, but the end results were the same.

Almost every colony perished.

Metarhizium vs. oxalic acid

Typically a paper on a potential improved biocontrol method for Varroa would do a side-by-side comparison with a widely used, currently licensed treatment.

There’s only one comparative experiment between Metarhizium and dribbled oxalic acid treatment. It’s buried at the end of the Supplementary Data 10. In it they show ‘no significant difference’ between the two treatments.

Frankly this was a pretty meaningless experiment … it was conducted in June 2020 when colonies would have been bulging with brood. Consequently 90% of the mites would have been hidden under the cappings. They assayed mite levels only 18 days after a single application of Metarhizium or oxalic acid.

Although it showed ‘no significant difference’ – like the “60% of the mites that died” quote – it obscures the fact that most mites were almost certainly completely untouched by either treatment.

What does this study show?

This study involved a large amount of work.

The directed evolution in the laboratory is a very nice example of how the combination of phenotypic selection and natural variation can rapidly yield new strains with desirable characteristics.

Combination of this with in vivo selection for enhanced pathogenesis successfully produced a novel strain of Metarhizium with some of the features desirable for biocontrol of Varroa.

However, in the apiary-based studies the majority of the colonies, whether treated or not, died.

This shows that, although scientists might have made a promising start, they are still a very long way from having an effective biocontrol solution for Varroa.

Unmanaged Varroa replicates to unmanageable levels

One of the Supplementary Data figures illustrated the Varroa drop per month from colonies in the research apiary.

Cumulative mite drop per colony for the month of July 2018

This is relatively late in the study, July 2018. These hives were established from commercial packages of bees in April 2017. They were either treated with the experimental Metarhizium spores or were untreated controls for the 15 months between April 2017 and July 2018 11.

Look at those Varroa numbers!

This is the mite drop just after the peak of the season. Brood levels would be close to maximum in their short, warm summer 12. The majority of the mite population would have been safely tucked away feasting on developing brood.

This is not the mite drop after miticide treatment … it’s just the drop due to bee grooming, natural mite mortality and the general ‘friction’ in the hive.

The average is 2866 mites dropped per month per hive 😥

Maybe nothing could have saved hives as heavily infested as these? 13

Don’t wait for Metarhizium … be vigilant now

These numbers – of mites and dead colonies – are a stark warning of the replication potential of Varroa and the damage is causes our bees.

Left untreated, Varroa will replicate to very high levels.

Colony mortality – either directly due to the mite and viruses, or indirectly due to the weakened colonies succumbing to robbing – is a near-inevitable consequence.

I’ve discussed the importance of Varroa management repeatedly over the years. It’s a topic I’ll be returning to again – probably in August when it starts to become a necessity.

In the meantime, keep an eye on the mite levels in your own colonies as they get stronger during the season.

While you’re doing that think of the scientists who are looking for practical, effective and environmentally-friendly strategies to control Varroa. Understand that these studies are time-consuming, progress is glacial incremental … and they might not work anyway.

Of course, if we finally manage to develop a suitable Metarhizium-based mite control strategy then bees and beekeepers will not be the only beneficiaries.

Metarhizium has its own parasites. Some of the best characterised of these are small RNA viruses.

If beekeepers are sprinkling billions of Metarhizium spores over their colonies every year then these viruses will be having a great time 😉


 

Supering

Something short and sweet this week 1 … though perhaps ‘tall and sweet’ would be preferable as I’m going to discuss supering.

The noun supering means ‘the action or practice of fitting a super to a beehive’ and dates back to 1840:

Duncan, James. Natural History of Bees Naturalist’s Library VoI. 223   The empty story which is added, may be placed above, instead of below the original stock, and the honey will thus be of a superior kind. This mode of operating is called super-ing, in contra-distinction to nadir-ing.

I don’t quite understand the description provided by here. Adding a super underneath the colony (original stock) is unlikely to lead to it being used as a honey store. Bees naturally store honey to the side and above the brood nest.

And does James Duncan mean the honey is superior because it’s better? Or is he using superior in its zoological sense meaning ‘at or near the highest point’? 2

So … let’s get a few definitions out of the way first.

  • Supering – the addition of a super to a hive, which could be either:
    • Top-supering – adding a super to the top of a stack of existing supers, or
    • Bottom-supering – adding a super below any existing supers, but above the brood box(es) 
  • Nadiring – the addition of a super below an existing brood box (which won’t be mentioned again in this post 3.

Supering … click for legend

I prefer the term top- or bottom-supering as the alternative over- or under-supering could be misinterpreted as the amount of supers being excessive or insufficient.

Which is better – top- or bottom-supering?

Let’s get the science out of the way first.

There’s an assumption that bottom supering should be ‘better’ (in terms of honey yield) as it reduces the distance bees have to travel before they are relieved of their nectar. 

A study conducted two decades ago by Jennifer Berry and Keith Delaplane 4 showed that – in terms of the amount of honey stored – it makes no statistical difference whether top- or bottom-supering is used.

This study was conducted at the University of Georgia (USA). It used 60 hives – 3 different apiaries each containing 10 hives over two distinct nectar flows. 

Note the deliberate inclusion of the term ‘statistical’ above … the bottom-supered hives did end up with ~10% more honey in total but, considering the scale of the experiment, this was not statistically significant. 

To determine if this difference was real you’d need to do a much larger scale experiment.

This was not simply weighing a few hives with the supers added on top or below … each colony used was balanced in terms of frames of brood, numbers of bees and levels of stores in the brood box for each nectar flow. That’s not my idea of fun when it would involve a few thousand colonies 🙁   5.

The Berry & Delaplane study reached the same conclusion as earlier research by Szabo and Sporns (1994) who were working in Alberta, Canada 6. They had concluded that the failure to see a significant difference in terms of honey stored was because the nectar flows were rather poor. However, this seems unlikely as the Berry & Delaplane study covered two nectar flows, one of which was much stronger than the other (measured in terms of honey yield).

Before we leave the science there’s a minor additional detail to discuss about the Berry & Delaplane study. All their hives consisted of a single Langstroth brood box with a honey super on top underneath the queen excluder (refer to C. in the figure above).

This first honey super was termed the ‘food super’. The remaining supers were the ‘honey supers’. It’s not clear from the description in the paper whether the queen ever moved up to lay in the ‘food super’. I’m assuming she did not.

That being the case, the bottom supering employed by Berry & Delaplane is probably not quite the same as understood by most UK beekeepers.

When I talk about bottom-supering (here and elsewhere) I mean adding the super directly above the box that the queen is laying in (refer to A. in the figure above).

Whether ‘true’ bottom-supering leads to increased honey yields I’ll leave to someone much stronger than me. It’s an experiment that will involve a lot of lifting … and a lot of hives 😉

Which brings us to other benefits associated with where the super is added …

Benefits of bottom supering

I can think of two obvious ones.

The first is that the frames are immediately above the warmth of the broodnest. This might help get new foundation drawn a bit faster. However, if the flow is so good you’re piling the supers on it’s likely that the bees will draw comb for fun.

Note also the comments below about frame spacing and brace comb. I start new supers with 11 frames and subsequently reduce the number to 9. To avoid brace comb it’s easier to get undrawn supers built when there are no other supers on the hive. However, if that’s not possible I usually bottom-super them … it can’t do any harm. 

The second benefit is that by bottom-supering the cappings on the lowest supers always stay pristine and white. This is important if you’re preparing cut comb honey. It’s surprising how stained the cappings get with the passage of hundreds of thousands of little feet as the foragers move up to unload their cargo in top-supered colonies. 

Benefits of top supering

Generally I think these outweigh those of bottom-supering (but I don’t make cut comb honey and I’d expect the sale price of cut comb with bright white cappings trumps any of the benefits discussed below).

The first is that it’s a whole lot easier on your back 🙂

No need to remove the stack of supers first to slide another in at the bottom. This is a significant benefit … if the colony needs a fourth super there’s probably the best part of 50 kg of full/filling supers to remove first 7

Lifting lots of heavy supers is hard work. A decade ago I’d tackle three full supers at a time without an issue.

More recently, honey seems to be getting much denser 😉 … three full supers, particularly if on top of a double brood box, are usually split into two (or even three) for lifting. 

Secondly, because top-supering is easier it’s therefore much quicker.

Pop the crownboard off, add another super, close up and move on. 

Some claim an additional benefit is that you can determine whether the colony needs an additional super simply by lifting off the crownboard and having a peek. That might work with a single brood box and one super 8, but it’s not possible on a double brood monster hive already topped with four supers 9.

Of course, all of the benefits in terms of ease of addition and/or lack of lifting are null and void if you are going to be inspecting the colony and therefore removing the supers anyway.

Frame spacing in supers

Assuming a standard bee space between drawn, filled, capped honey stores, the more frames you have in the super the smaller the amount of honey the super will contain. 

This might never be an issue for many beekeepers.

However, those that scale up to perhaps half a dozen hives soon realise that more frames per super means more time spent extracting. 

That’s exactly what happened with me. My epiphany came when faced with about 18 supers containing almost 200 frames and a manual (hand cranked) three-frame extractor 🙁

By the next nectar flow I’d invested in an electric 9 frame radial extractor and started spacing my frames further apart.

That first ‘semi-automated’ honey harvest paid for the extractor and my physique became (just) slightly less Charles Atlas-like.

With undrawn foundation I start with a full box of 11 frames. However, once drawn I space the frames further apart, usually 9 per super. The bees draw out deeper comb and fill it perfectly happily … and I’ve got less frames to extract 🙂

I know some beekeepers use 8 frames in their supers. I struggle with this and usually find the bees draw brace comb or very uneven frames. This might be because our nectar flows aren’t strong enough, but I suspect I’ve spaced the frames too far apart in one go, rather than doing it gradually.

Frame alignment of supers

Speaking of brace comb … remember to observe the correct bee space in the supers. Adding a super with mismatched frame numbers will result in brace comb being built at the junction. The same thing happens if frames are misaligned.

Frame spacing and alignment in the supers.

Inevitably this brace comb ends up fusing the two supers together and causes a ‘right mess’ 10 when you eventually prize them apart.

And you’ll have to because they’re probably too heavy to lift together.

Brace comb

Brace comb …

The example above is particularly bad due to the use of misaligned foundationless super frames. The comb is, as always, beautiful … and unusually in this example the bees built from the bottom upwards.

Note that the frame alignment between adjacent boxes does not appear to apply to the brood box and the first super. At least, it doesn’t when you’re using a queen excluder. I presume this is because the queen excluder acts as a sort of ‘false floor’. It disrupts the vertical bee space sufficiently that the bees don’t feel the need to build lots of brace comb.

You can use castellations to space the frames in the supers. I don’t (and got rid of my stock of used and unused castellations recently) as they prevent re-spacing the frames as needed 11. The bees quickly propolise up the frame lugs meaning the frames are effectively immovable without the application of significant force.

Oops ...

Oops …

Like with a hive tool … or if you drop the super 🙁  12.

Caring for out of use supers

After drawn brood comb, drawn supers are probably the most valuable resource a beekeeper has.

You can’t buy replacement so it makes sense to look after it.

Of course, having written the sentence above I realised I was almost certainly wrong. A quick Google search turned up this Bad Beekeeping post from Ron Miksha who described commercially (machine) produced drawn comb.

Three Langstroth-sized combs are €26 😯 

There’s also this stuff … 

OK, so I stand corrected. You can buy replacement drawn comb, but a single super will cost you about €78 13 so they should be looked after.

Empty drawn supers should be stored somewhere bee, wasp and rodent-free. I store mine in a shed with a solid floor underneath the stack and a spare roof on top. 

Late November in the bee (storage) shed …

I have friends who wrap their supers in clingfilm … not 30 cm kitchen roll, but the metre wide stuff they use in airports to wrap suitcases 14.

Wax moth infestation of drawn supers is generally not a problem. They much prefer used brood frames. However, it makes sense to try and make the stacks as insect-proof as possible.

Caring for in use supers

If the supers are full of bees and honey then the drawn comb is only the third most important thing in the box.

Don’t just pile the supers on the ground next to the hive. The lower edges of the frames will be festooned with bees which will get crushed. You’ll also pick up dirt from the ground which will then be transferred to the hive.

Instead, use an inverted roof. Stand the super(s) on it, angled so they’re supported just by the edges of the roof. This minimises the opportunities for bees to get squashed.

If you’re removing a stack of supers individually (because they’re too heavy to lift together) do not stack them up in a neat pile as you’re very likely to crush bees. It’s better to support the super on one edge, propped up against the edge/corner of the first super I removed.

Again, this minimises the chances of crushing bees. It’s distressing for the beekeeper, it’s definitely distressing for the bee(s) and it’s a potential route for disease transmission.

The multi-purpose Correx hive roof

Once the supers are emptied of bees but full of capped honey you’ll need to transport them home from the apiary. I use spare Correx hive roofs to catch the inevitable drips that another more caring member of the household would otherwise discover 🙁

These Correx hive roofs aren’t strong enough to stack supers on. I always ensure there’s at least one or two conventional roofs in each apiary to act as temporary super stands during inspections.

Final thoughts

Tidy comb

At the end of the season it’s worth tidying the super frames before stacking them away for the year.

Before - brace comb

Super frames before tidying and storage

I use a hive tool to scrape off any bits of brace comb from the top and bottom bars of each frame. I also use a breadknife to level up the face of the comb. The combs are then arranged in boxes of nine and stored away for the winter.

A small amount of time invested on the supers saves time and effort doing much the same thing when you need them.

Drone foundation in supers

Over 50% of my supers are drawn from drone foundation.

There are two advantages to using drone foundation in the supers. The first is that there’s less wax and more honey; it takes less effort for the bees to build the comb in the first place and the larger cell volume stores more honey.

In addition, with less surface area in each cell, it’s at least theoretically possible to get a greater efficiency of extraction 15.

The second benefit is that bees do not store pollen in drone comb. In a strong colony you sometimes get an arch of pollen stored in the bottom super, and this is avoided by using drone comb.

Drone comb in super

That doesn’t mean that they’ll necessarily fill the comb with nectar. Quite often they just leave an empty arch of cells above the brood nest 🙁

The major problem with using drone comb in the supers occurs when the queen gets above the queen excluder. You end up with my million drones fiasco and a lot of comb to melt down and recycle.

The super frame shuffle

Bees often draw and fill the central frames in the super before those at the sides. This can lead to very unevenly drawn comb (which can be ‘fixed’ with a breadknife as described above), and grossly unbalanced comb when extracting.

Full super ready for extraction

Full super ready for extraction …

To avoid this simply shuffle the outer frames into the centre of the super and vice versa. The frames will be much more evenly filled.

Spares

If you have an out apiary, keep spare supers in an insect-proof stack in the apiary.

Spare supers … only one now, on hive #29

Alternatively, keep spares under the roof but over the crownboard. As a strong nectar flow tails off, or if the weather is changeable, it might save a trip back to base, or having to carry yet another thing on your rounds.


Note

I’ve now done the calculation … 11 National super frames have an area of ~5500 cm2 which would require 6.5 Langstroth-sized sheets of drawn commercial comb. At the prices quoted above (€26 for three) that would only cost about €56 … but you’d still have to slice’n’dice them into the frames.

Hmmm … almost 3000 words … not so short and sweet after all 🙁

Radar love

The average beefarmer in the UK is probably somewhere in their mid-60’s 1. This means that in 1973, when the Dutch rock band Golden Earring had their only notable chart success Radar love, they were about 18.

Bear with me …

As 18 year olds they probably wore denim flares and loud shirts with spearpoint collars. They would go to the local disco to meet similarly-attired members of the opposite sex (whose shorter hair may have been their only distinguishing feature).

They knew when and where to meet … the weekly Saturday night (obviously 2 ) disco.

There was no point in turning up at 10 in the morning … the disco was closed 🙁

Similarly, despite their ‘cool threads’, wearing them to the launderette would have resulted in almost certain disappointment … the dance partners they were seeking weren’t likely to be found doing the laundry 🙁

No, the disco was the place to go. 

Radar love would have been on the playlist. It reached the top 10 in the charts in many countries.

Hold that thought … we’ll return to Radar love in a few minutes … 3

The birds and the bees

Of course, these young beefarmers didn’t just go to the disco to dance

Oh no.

They had an ulterior motive 😉

They knew that they had a good chance of meeting a like-minded (and similarly attired) member of the opposite sex who was also ‘looking for love’.

These meetings were effectively ritualised … a particular time and place.

Let’s forget the bell bottoms and hippie shirts now … I only added that detail so that any readers who know an ageing beefarmers can have a little giggle imagining them dressed for the disco 😉 

OK, back to the disco … metaphorically.

The disco is not fundamentally dissimilar to the lek used by male grouse 4

Greater sage-grouse at a lek, with multiple males displaying for the less conspicuous females

A lek is defined as a location where males congregate to compete and mate with females. Importantly, there are no direct benefits – such as food or territory – that the females gain from attending the lek 5.

How do the males know where to congregate?

Grouse tend to live for several years 6. Older grouse know where the lek is because they attended last season. Juveniles probably tag along and learn from their elders despite the fact they are too immature to mate, or lack the social dominance (or plumage 7 ) to compete.

As a consequence of this male hierarchy the location of the lek is invariant.

The birds congregate at the same place each year.

One of the features of leks is that males show high levels of fidelity to a single lekking site.

So now we know something about the birds … what about the bees?

Drones congregate in particular – rather ill defined – landscape features called drone congregation areas (DCA’s).

These, like a black grouse lek, are stable from day to day and year to year.

The drones compete (for the queen, though not directly with each other by displaying) and offer the queen no territorial or food benefits … meaning that DCA’s are effectively insect leks 8

Drone congregation areas

There are studies going back well over 50 years on DCA’s. There are no hard and fast rules that define their location (at least to humans … thankfully virgin queens have no problems finding them). However, you can sometimes hear them; they sound like a small swarm, the noise caused by thousands of drones circling 5-40 metres above the ground in a swirling, traffic cone-shaped, perhaps a 100 metres or more in diameter.

How do drones know where to congregate? There is no male hierarchy 9. An individual drone lives for just a few weeks and perishes before winter. 

The location must be somehow ‘hard-coded’ in the environment. Effectively a set of features that – once located – attract the drones back repeatedly until they either mate with a queen, or die trying 10.

Many studies have attempted to identify DCA’s – geographic features on the ground, sheltered from strong winds, a dip in the horizon etc. These have tended to produce rather mixed results.

I don’t think we’re anywhere close to being able to point to an intersection of two hedges and say “Over there … that’s where drones will congregate”.

An alternative approach is to go fishing for DCA’s.

Literally. 

Having identified a number of potential DCA’s from landscape analysis, you can dangle a virgin queen from a helium balloon and sample the drone density in each of the areas.

It sounds a lot simpler than it is … there’s a nice account by Aude Sorel in Bee Culture if you’re interested.

By definition, the drone congregation areas are the ones you trap the most drones in.

Right?

Well, possibly not.

Perhaps the very method used to sample the drones attracted them there in the first place? 

It’s been known since the 1960’s that high concentrations of queen mandibular pheromone can attract drones to almost any location – in one notable example, even 800 metres out to sea 11.

If you use bait, how can you be certain that the areas you define are ‘real’. 

A better way to define a DCA would be to observe individual drones accumulating in a particular area … to watch them leaving the hive, fly the tens or hundreds of metres to the same place they flew to yesterday, and record them ‘strutting their funky stuff’.

Have you ever tried to follow a drone in flight?

They’re strong and fast. They need to be to outcompete other drones when chasing the queen.

It’s almost impossible to track them across the apiary, let alone over the hedge, across two fields and into the lee of a copse.

But scientists can now do exactly that … using a technique called harmonic radar tracking.

The title of this post should now make a bit more sense … it’s the use of radar to find where drones go ‘looking for love’ 😉

Harmonic radar tracking

A harmonic radar system emits a stimulus signal. This signal is picked up by a harmonic tag (the transponder) which uses the low frequency stimulus energy to generate a second harmonic which is then re-radiated back out to a receiving system.

The harmonic signal emitter/receiver is portable … if you’ve got a lorry.

Harmonic radar emitter and detector – with Rothamsted Manor in the background.

Fortunately, the transponder is tiny … small and light enough to be glued to the back of a bee.

Drone with harmonic radar transponder attached.

Harmonic radar has been used to study orientation flights in honey bees 12, to track Asian hornets, and to follow butterfly flight paths 13 (amongst other things).

And now it’s been used to map drone congregation areas by tracking the flights of individual drones from the hive.

Harmonic radar is a relatively short range system. You can’t track transponder-tagged insects flying miles away. The effective range is just a few hundred metres for most systems.

However, for drone congregation areas this shouldn’t be a major limitation. Drones generally fly shorter distances to mate than queens (an evolutionary mechanism to avoid inbreeding) and DCA’s have often been found near to apiaries 14.

Tracking drones by harmonic radar

The study, by Woodgate et al., was published a couple of weeks ago in iScience. The full reference is:

Woodgate et al., Harmonic radar tracking reveals that honeybee drones navigate between multiple aerial leks, iScience (2021), https://doi.org/10.1016/j.isci.2021.102499

It’s available under open access (i.e. free, for anyone) and I recommend you read it if you’re interested.

I’m just going to pick out a few highlights.

During two sequential seasons the authors tracked over 600 flights by at least 78 drones. These included 19 first flights (orientation flights) and – for four drones – 6-8 consecutive flights, including their first ever orientation flight.

Orientation flights were typically observed as multiple loops in different directions, centred on the hive from which the drone originated.

Drone orientation flights

The average duration of these orientation flights was ~13 minutes and the drones observed only took one or two before changing their flight pattern (see below) and seeking drone congregation areas.

Worker bees typically take more (~6) orientation flights than drones. Presumably foragers need to ‘map’ the hive location better because they may end up returning to it (and they’ve failed if they don’t) from any location.

As we’ll see in a minute, drones tend to use particular ‘flyways’ which are probably determined by landscape features. Drones also may return to a different hive to the one they set out from.

Identifying drone congregation areas by harmonic radar tracking

Scientists love ‘heat maps’.

These are a graphical way of depicting levels of activity of one kind or another.

If you overlay the flights by every transponder-tagged drone in each of the two years of this study you generate a map (like C and E shown below). In this study they used a ‘white to red’ scale where the paler the colouration, the more drones were detected in that particular point on the map.

You can easily see the hive location (points 1, 2 and 3) as all flights originated there.

Heat map of the landscape used by drones.

Actually, C and E are a bit confusing because they include the orientation flights which are centred on the hives. If you exclude these you end up with the heat maps D and F on the right.

From these the authors could detect particular areas where the drones tended to concentrate … these are proposed to be the drone congregation areas. There were four within range of the harmonic radar system – A-D above (confusingly labelled on images D and F).

There are a few obvious features of these proposed DCAs:

  1. They are in approximately (but not exactly) the same position in the two study years.
  2. The frequency with which they were visited changes. A is visited less frequently in the second year (panel F) than in the first (panel D).
  3. The most distant DCA (at least that could be mapped in this study) was ~600 metres from the hive. 
  4. Each DCA had a roughly symmetrical ‘core’ of 30-50 metres, significantly smaller than many drone trapping studies suggest..

One thing that was noticeable by comparison of the orientation flights and the proposed DCAs was that they did not overlap.

So how do the drones ‘find’ the DCA if they don’t discover them on an orientation flight?

Flyways, straight and convoluted flights

Heat maps are cumulative data.

It was also possible to look at the individual flight paths of drones on their way to and from a DCA (in exactly the same way as they mapped orientation flights).

Analysis of these showed that drones adopted two distinct types of flight – an approximately straight, direct flight interspersed with periods of convoluted, looping flight. There are lots of pictures of these in the paper but, rather than showing another published image, here’s my “no expense made spared” diagram of these two patterns of flight.

Drone flight paths showing distinct direct and convoluted elements.

The convoluted flight defines the drone congregation areas. In these the drones showed very distinctive behaviour – the further they were from the centre of the DCA the more strongly they accelerated back towards the centre. 

Drone flight paths (inevitably) overlapped in DCAs.

However, they also overlapped in the straight line flight. Drones tended to use particular flyways from the hives to, and between, the DCAs.

Scientists have previously identified (or at least suggested the existence of) these flyways that drones use to travel to and from the hive and the DCAs 15

However, what they had previously not identified was that drones often visit more than one DCA in a single (potential) mating flight.

In 20% of the flights analysed drones visited more than one DCA. 

Finally, drones tended to only spend about 2 minutes flying around very fast (at ~5 m/s rather than the sedate ~3 m/s they fly around the hive at 16 ) within the proposed DCA.

This suggests that drones might routinely patrol several DCAs in a single flight, moving on unless a queen is present.

Harmonic radar mapping the flights of virgin queens

I’ve often preceded the term ‘drone congregation area’ in the text above with the word ‘proposed’. A DCA has a very specific meaning that describes the places where drones congregate to attempt to mate with a virgin queen.

None of the studies above showed queen mating, or even the presence of a queen.

But, of course, the authors tried that as well.

They transponder-tagged queens (94 in total) and tracked their orientation flights and mating flights (26 in total). The orientation flights were remarkably similar to those of the drones; the average number of these flights was 3 and no queen went on more than 6 orientation flights.

Unfortunately the tracking of queen mating flights was less successful 17.

Queens flew out of range (I’ll return to this shortly), the transponder fell off, or parts of the flight were not picked up by radar. Some of the queens ‘followed’ (or for which tracking was attempted) did get mated, but not apparently in the DCAs identified during the flight tracking of drones.

This type of study clearly needs further work …

Conclusions

Drone congregation areas could be detected using harmonic radar tracking of transponder-tagged drones. Unlike other well-studied lekking areas, males (drones) did not display lek fidelity, but instead visited several in rotation 18.

The DCAs are a consequence of drones exhibiting a convoluted flight pattern in particular locations. The conservation of the flyways – the routes taken by the drones – between DCAs suggest they might contribute to the location of the DCAs.

Understanding what defines these flyways might allow better prediction of DCA locations.

Previous studies have shown that queens tend to fly further to DCAs than drones, presumably to avoid inbreeding. One possibility is that tagged queens in this study might have been more likely to visit the four DCAs identified if they were placed in mating nucs situated further away from this study site.

But, of course, they could have then flown off in a different direction altogether 🙁

Finally, it’s worth noting that a different pattern of queen mating activity had been described for dark, native (Apis mellifera mellifera) and near-native bees. This is apiary vicinity mating (AVM), and is nicely described by Jon Getty on his website

I now have some native black bees. I’m also experiencing the worst spring of my entire beekeeping career for queen mating. I am increasingly interested in AVM as a mechanism for saving the queen from drowning or freezing to death while attempting to reach a DCA 🙁


 

Hard graft

Regular readers will have seen this image before …

Swarmy weather? I don’t think so …

… as I used it (with the same legend) towards the end of the post last week. 

I spoke too soon 🙁

The temperature on the 17th and 18th briefly reached 17.5°C … which was enough.

Grrrr …

But I’m getting ahead of myself.

Good morning America Glenrothes

I’m fortunate to live in a stunningly beautiful and remote part of the country. I open the blinds in the morning to panoramic views of the Morvern hills across a narrow sea loch. There are no houses in direct sight and – even when it’s damp 1 – it’s an idyllic scene.

Good morning Morvern …

But although I live here, most of my bees still live in Fife, so I have a commute to look after them and stay in convenient 2 hotels.

Opening the curtains on these trips provides a somewhat less salubrious view.

Uninterrupted views of the Macdonald’s drive-in

But at least I don’t have to cook my own breakfast, which is but a short walk away 🙂

As you can see from the photo above, it’s been raining overnight.

To make these trips economically rational 3 it’s necessary to book them several weeks in advance.

Despite the use of supercomputers, the BBC’s medium to long-range weather forecasts seem little more than guesswork. It’s worth remembering that a weather forecast competition over several weeks was won by a team that predicted ‘tomorrow will be like today’ for the duration of the event 4.

And for beekeeping, there’s a significant difference between 12°C, light drizzle with strong winds and 13°C, intermittent sunshine and gentle breezes.

The latter makes opening hives a relatively straightforward proposition … careful and quick, but the bees will cope just fine.

In contrast, the former makes everything rather hard work.

And this morning we’ll graft delicate larvae no larger than a comma on a page …

And these are exactly the conditions that greeted me when I did my first round of grafting on the 10th of May.

The weather is probably the major problem of long distance beekeeping. You have to be prepared for anything.

Queenright cell raising – the Ben Harden system

I’ve discussed grafting and using the Ben Harden queenright cell raising system extensively before. 

My Ben Harden setup was in the bee shed.

As it turned out, this was a (disappointingly rare) stroke of genius.

A strong, double brood colony had been modified be the replacement of 7 frames in the upper box by two ‘fat dummies‘. These have the effect of concentrating the bees in the gap between them. 

In this space were two frames containing pollen, one frame of young larvae 5 and the cell bar frame, into which I would be grafting larvae.

Ben Harden setup and pollen patties

This box sits on top of a queen excluder, below which was a single brood box (containing the queen) literally overflowing with bees 6. Positively bulging at the seams.

Since I didn’t have frames with sufficient pollen in them I’d also supplemented the colony with pollen substitute (a pollen pattie) which they were happily devouring. 

The hive also had a couple of half-full supers. These contained lots of bees but rather disappointing amounts of nectar.

The queen providing the larvae was in a nuc box in the same apiary. I’d been feeding this colony syrup and pollen to ensure the young larvae were well fed 7.

Grafting

The day for grafting dawned cool, grey and drizzly.

Great 🙁

I ended up doing the grafting in the passenger seat of the car, wearing a headtorch. I kept the larvae warm and humid using a damp piece of kitchen paper draped over those I’d already transferred from the comb to the plastic cups in the cell bar frame.

After gently inserting the cell bar frame into the space in the centre of the Ben Harden setup and filling the feeder in the fat dummy with syrup, I added a clearer board and then replaced the two supers.

The intention was to empty the supers into the cell rearing box, guaranteeing a huge number of bees would be there to help raise the queens.

Ben Harden cell raiser with clearer and supers

After another evening of junk food and a disappointingly similar breakfast I checked the grafts the next day for ‘acceptance’.

10/10 …

You do this by – ever so gently – lifting the cell bar frame from the centre of the Ben Harden setup and looking for a 5-6mm collar of fresh wax built around the lower lip of the Nicot cup into which the larvae have been grafted.

Amazingly, considering the dodgy conditions and the fact that this was my first attempt at grafting for a couple of years, all the larvae appeared to have been accepted 8. I didn’t brush any of the bees off and I certainly didn’t prod about in the densely packed bees on the frame … but things looked good.

So I closed the hive up and went off to inspect some other colonies in the rain before driving back to the west coast.

Coffee mishaps and colony inspections

I returned to the east coast about 8-9 days later to add the queen cells to nucleus colonies.

The ~150 mile journey didn’t go well. In mid-slurp the lid came off my mug, depositing a lap-full of lukewarm coffee over me. 

Never mind. The route I take goes through some ‘modesty-ensuring’ remote countryside. It was a five minute task to leave the trousers drying over the boxes of frames in the back of the car.

Since I had no spares I donned my beesuit and continued on the journey.

The weather improved as I drove east. I checked an apiary in mid-Fife where all was well and finally arrived at my main apiary in mid-afternoon.

It was a lovely day 🙂

So lovely one of the colonies had swarmed 🙁

There were actually two small swarms hanging about a metre apart in the willow trees I’d planted around the apiary 9

I didn’t really have time to think about the swarm … we needed a few hundred early stage drone pupae for work so went through the colonies to find these first.

These were quick ‘n’ dirty inspections … I checked every frame, but not every cell or every nook and crannie … 

  • brood in all stages?
  • eggs?
  • stores?
  • any charged queen cells?
  • temper, behaviour, stable on the comb?
  • anything weird or strange? 10
  • next please …

I didn’t check the hive I’d set up for queen rearing, or any of the nucs on site that contained virgin queens. However, all of the other colonies were queenright as determined by the presence of eggs and the absence of (obvious 11 ) queen cells.

Drone brood was either present in relative abundance – in the strong colonies – or notable by its absence. This should not be unexpected to those of you who read the post on drones last week.

To the tune of ‘Ten green bottles’ … all together now, ‘Ten capped queen cells hanging on a frame …’

And I still had 10 queen cells in the cell raising colony, all now capped and ready to use the following day 🙂

And the swarm?

The swarm (either of them if there were actually two) wasn’t really big enough to be a prime swarm. These contain a mated queen and ~75% of the workforce from the hive. None of the hives appeared short of bees and I’d found no (obvious 12 ) charged queen cells.

However, I’d not checked the queen rearing colony – packed full of bees and fed copious amounts of syrup – and one of the colonies on the site was very bad tempered 13.

Poor temper is often a sign of a queenless colony.

Anyway, back to the swarm.

I dropped each clump of bees into a separate nuc box containing a frame of drawn comb and a couple of additional frames. I left these in the shade until late afternoon when I’d finished with the other colonies.

Two into one do go

By late afternoon most of the swarm bees from one of the nuc boxes had abandoned it and joined the other nuc box. It was pretty clear that there was only one ‘swarm’ and that it had got separated when settling at the bivouac.

The bees were leaving the queenless box and joining the queenright one.

I checked the willow where the swarm was found. 

Small amounts of wax where a swarm settled

There were small amounts of wax deposited on the leaves and stem of the willow. I suspect that the swarm may therefore have been there overnight 14 but can’t be sure.

I ended the afternoon by putting the hived swarm on a hive stand in the apiary.

Before leaving I checked the bad tempered colony (which I was intending to split into nucs the following day).

During my fumblings I managed to get a few bees into my beesuit pocket 15.

The one with the hole in it from my razor-sharp hive tool.

That opened onto my leg.

Which was unprotected by trousers due to my fumblings with the coffee 9 hours earlier 🙁

Ouch 🙁

Getting nuked

The weather the following day started bright but rapidly degenerated.

That lot is about 10 minutes away … and approaching fast

By the time I’d got the nuc boxes prepared – feeders, frames, stores, dummy boards, entrance blocks, labels, straps – it was 11°C and there was rain quickly approaching from the west.

The first four nucs were prepared from the ‘bad tempered’ hive (#6). I decided it was wise to get this over and done with before the heaven’s opened.

Despite going through the box twice I failed to find a queen. Perhaps she went with the smallest prime swarm ever?

I divided the frames (by brood and bees, not number of frames) into four approximately equal nucs and added a queen cell to each. 

Here’s one I produced earlier … or helped produce

Each queen cell was removed from the cell bar frame, the adhering bees gently brushed off (with a handful of weeds) and pressed into a thumb-sized indentation in the comb, just underneath the top bar of the frame.

I then carefully pushed the frames together (avoiding crushing the cell) and closed the nuc box up.

As I opened the next hive to be split the rain started …

I should design a beesuit with an integrated sou’wester

… and the wind lessened, meaning the rain stayed.

And it rained for most of the afternoon.

Rain did not stop play

In the words of the late Magnus Magnusson “I’ve started, so I’ll finish”.

And it was miserable.

For the second time in two days I was soaked.

As those of you who have hunched over open hives in the rain will know, it’s your back, shoulders and hood that catch the worst of it.

This time my trousers stayed mostly dry … 

Nucs in the rain

The high point of the afternoon (and, let’s face it, the bar was pretty low) was the realisation that housing the cell raiser in the bee shed was an inspired choice.

When adding queen cells to nucs you either have to detach them in advance from the cell bar frame and keep them warm somewhere convenient, or collect them in turn.

Five gone, five to go … queen cells reared in a Ben Harden cell raiser

I had nowhere to keep them warm, so was returning to the Ben Harden setup to retrieve them one at a time. Since it was warm and dry in the shed I could leave the frame balanced (as shown above) still festooned with bees and fetch each cell as needed.

Had they been outside I would have had to stop.

It was difficult enough making up the nucs in the rain, one hand holding a frame, the other lifting the roofs on and off. 

It would have been impossible to juggle the cell raiser and cell bar frame as well.

But I eventually finished and moved half a dozen of the nucs to another apiary 16. I put the Varroa trays underneath 17, filled the feeders with syrup and opened the entrances a half inch or so to allow the bees to fly.

Half a dozen nucs, all in a row

And then I returned to the main apiary to tidy up.

And the swarm?

I still don’t know where the swarm came from 18.

I checked it between downpours. 

Despite opening the box very gently, with almost no smoke, the bees ‘balled’ the queen and killed her. I found her in the middle of a golf ball-sized clump of bees on the floor. 

Queen being ‘balled’ … it didn’t end well

After dislodging some of the bees with my fingers I found her, laying on her side, as dead as a dodo. You can just see her in the photo above., slightly below the middle of the image by the edge of the mesh.

Why did they do this?

I’ve inspected dozens of swarms the day after hiving them and don’t ever remember having this happen before.

Perhaps it was the poor weather? Maybe my ‘very gently’ wasn’t gentle enough?

The queen was unmarked and (obviously) unclipped.

To me, she looked like a virgin queen, rather than a slimmed down mated queen 19

There were two nucs in the apiary containing virgin queens. I didn’t inspect either, but a quick peek through the plastic crownboard showed both still appeared to contain bees. The size of the swarm, although small (as swarms go) looked much larger than the size of these nucs.

I’ll check again next week …

I added a queen cell to the swarm and set off for home.

Chasing the setting sun

It’s a beautiful commute, across Rannoch and through Glencoe, chasing the setting sun. 

And my trousers were finally dry 😉


Note

I’ve already grossly exceeded my self-imposed word count this week. This is not meant as a practical guide to queen rearing 20. For those interested in queen rearing – the most fun you can have with a beesuit on 21 – there are lots of articles here with the nitty gritty practicalities. Try these for starters … queen rearing, an introduction to the Ben Harden system, setup and cell raising.

It’s a drone’s life

What has a mother but no father, but has both a grandmother and grandfather?

If you’ve not seen this question before you’ve not attended a ‘mead and mince pies’ Christmas quiz at a beekeeping association. 

Drone

Drone … what big eyes you have …

The answer of course is a drone. The male honey bee. Drones are produced from unfertilised eggs laid by the queen, so formally they have no father. Drones are usually haploid (one set of chromosomes), whereas queens and workers are diploid 1

Anyway, enough quiz questions. With the relaxation in Covid restrictions we may all be able to attend in person this Christmas 2, so I don’t want to spoil it by giving all the answers away in advance.

The long cold spring has been pretty tough for new beekeepers, it’s been a struggle for smaller colonies and it’s been really hard for drones.

Spring struggles

New beekeepers have had to develop the patience of Job to either acquire bees in the first place or start their inspections. Inevitably new beekeepers are bursting with enthusiasm 3 and the cold northerlies, unseasonal snow (!) and low temperatures have prevented inspections and delayed colony development (and hence the availability and sale of nucs).

Small colonies 4 are struggling to rear brood and to collect sufficient nectar and pollen.

This is an interesting topic in its own right and deserves a post of its own 5. In a nutshell, below a certain threshold of bees, colonies are unable to keep the brood warm enough and have sufficient foragers to collect nectar and pollen.

As a consequence, smaller colonies are low on stores and at risk of starvation. 

It’s a Catch-22 situation … to rear sufficient brood to collect an excess of nectar (or pollen) the colony needs more adult workers. 

I don’t know what the cutoff is in terms of adult bees, but most of my colonies with <7 frames of brood have needed feeding this spring.

One feature of these smaller colonies is that, unless they have entire frames of drone comb 6, there is little if any drone brood in the hive.

There might be drones present in the colony, but I don’t know whether they were reared there or drifted there from another hive.

And, for those of us attempting to rear queens, drones are an essential indicator that queen mating will be timely and successful.

On a brighter note …

But it’s not all gloom and doom.

Strong colonies are doing very well.

Several of mine have a box packed full of brood and I’m relying on a combination of …

  • lots of space by giving them more supers than they need
  • low ambient temperatures
  • crossed fingers

… as my swarm prevention strategy 😉

Beginners take note … one of these is likely to help (space), one is frankly pretty risky (chilly) and the last is not a proven method despite being widely used by many beekeepers 😉

I’m pretty confident that colonies will not swarm at 13-14°C.

I am inspecting colonies every 7 days and have only seen two with charged queen cells. One was making early swarm preparations; I used the nucleus method of swarm control and then split the colony into nucs a fortnight ago 7.

The other colony contained my first attempt at grafting this year, which seems to have gone reasonably well 8.

Lots of brood, nectar and drones

A typical brood frame from one of these strong colonies contains a good slab of sealed or open brood, some pollen around the sides and an interrupted arc of fresh nectar above the brood. 

In the photo above you can see pollen on the right hand side of the frame and glistening fresh nectar in the top left and right hand corners.

Typically these strong colonies also have partially filled supers, though it’s pretty clear that the oil seed rape is likely to go over before the weather warms enough (or the colonies get strong enough) to fully exploit it.

Spring honey is going to be in short supply and my fantastic new honey creamer is going to sit idle 🙁

Drones

What you probably can’t really see in the picture above is that these strong colonies also contain good numbers of drones.

Strong colonies … ample drones

I can count about a dozen in the closeup above. 

I like seeing drones in a strong, healthy colony early(ish) in the season 9.

Firstly, the presence of drones indicates that the colony (and presumably others in the neighbourhood which are experiencing a similar environment and climate) will soon be making swarm preparations. This means I need to redouble my efforts to check for queen cells to avoid losing swarms 🙁  … think of it as a long-range early warning system.

But it also means I can start thinking about queen rearing 🙂

Secondly, although these drones are unlikely to mate with my queens, you can be sure they’re going to have a damned good go at mating with queens from other local apiaries.

In addition to being strong and healthy, this colony is well-tempered, steady on the comb and pleasant to work with. The production of a few hundred thousand frisky drones prepared to lay down their lives 10 to improve the local gene pool is my small act of generosity to local beekeepers 11.

How many drones?

Honey bee colonies that nest in trees or other natural cavities produce lots of drone comb. Studies of feral colonies on natural comb show that about 17% of the comb is dedicated to rearing drones (but also used for storing nectar at other times of the season).

Foundationless triptych ...

Foundationless triptych …

Similarly, beekeepers who predominantly use foundationless frames regularly see significantly greater amounts of drone comb (and drone brood and drones) in their colonies. With the three-panel bamboo-supported frames I use it’s not unusual for one third of some frames to be entirely drone comb.

In contrast, beekeepers who only use standard worker foundation will be used to seeing drone comb occupying much less of the brood nest. Under these circumstances it’s usually restricted to the edges or corners of frames.

However, given the opportunity e.g. a damaged patch of worker comb or if you add a super frame into the brood box, the workers will often rework the comb (or build new brace comb) containing just drone cells.

The bees only build drone comb when they need it.

A newly hived swarm will build sheet after sheet of new comb, but it will all be for rearing worker brood. If you give them foundationless frames they only build worker comb and if you provide worker foundation they don’t rework it to squeeze in a few drone cells.

The colony will also not build new drone comb late in the season. Drone comb is drawn early in the season because the drones are needed before queens are produced.

The timing of drone production

Studies in the late 1970’s 12 demonstrated that drone brood production peaks about one month before the the main period of swarming. Similar studies in other areas have produced similar results.

Why produce all those drones when there are no queens about?

The timing is due to the differences in the development time (from egg to eclosion) of drones and queens, together with the differences in the time it takes before they are sexually mature.

Drones take 50% longer to develop than queens – 24 days vs. 16 days. After emergence the queen take a few days (usually quoted as 5-6) to reach sexual maturity before she embarks on her mating flight(s).

In contrast, drones take from 6-16 days to reach sexual maturity.

Swarming tends to occur when charged queen cells in the hive are capped. These cells will produce new virgin queens about a week later and – weather permitting – these should go on mating flights after a further six days. 

Therefore a colony that swarms in very early June will need sexually mature drones available 12-14 days later (say, mid-June) to mate with the newly emerged queen that will subsequently return to head the swarmed colony. These drones will have to have hatched from eggs laid in the first fortnight of May to ensure that they are sexually mature at the right time.

Decisions, decisions

How does the colony know to produce drones at the right time? Is it the workers or the queen who makes this decision?

I’ve recently answered a question on this topic for the Q&A pages in the BBKA Newsletter. In doing some follow-up reading I’ve discovered that (inevitably) it’s slightly more complicated than I thought … which was already pretty complicated 🙁

The workers build the comb and therefore determine the amount of drone vs. worker comb the brood nest contains.

I don’t think it’s known how the workers measure the amount of brood comb in the nest, but they clearly can. We do know that bees can count 13 and that they have some basic mathematical skills like addition and subtraction.

Perhaps these maths skills 14 include some sort of averaging, allowing them to sample empty cells, measure them and so work out the proportion that are drone or worker.

Whatever form this ‘counting’ takes, it requires direct contact of the bees with the comb. You cannot put a few frames of drone comb in the hive behind a mesh screen and stop the bees from building more drone comb. It’s not a volatile signal that permeates the hive.

However they achieve this, they are also influenced by the amount of capped drone brood already present in the colony. If there’s lots already then the building of additional drone comb is inhibited 15.

Colonies therefore regulate drone production through a negative feedback process.

So … does the queen simply lay every cell she comes across, trusting the worker population has provided the correct proportions of drone and worker comb?

Not quite

Studies by Katie Wharton and colleagues 16 showed that the queen could also regulate drone production.

Wharton confined queens on 100% drone or worker comb in a frame-sized queen ‘cage’ for a few days.

Frame sized queen ‘cage’ …

She then replaced the comb in the cage with 50:50 mix of drone and worker comb and recorded the number of eggs laid in drone or worker cells over a 24 hour period (and then allowed the eggs to develop).

Queens that had only been able to lay worker brood for the first four days of confinement laid significantly more drone brood when given the opportunity.

The scientists showed reasonably convincingly that this was a ‘decision’ made by the queen, rather than influenced by the workers e.g. by preparing biased number of drone or worker cells for eggs to be laid in, by preferentially ‘blocking’ certain cell types with honey or by selectively cannibalising drone or worker eggs.

Interestingly, queens initially confined on worker comb laid significantly (~25%) more eggs on the 50:50 comb than those confined on drone comb. I’m not sure why this is 17.

Wharton and colleagues conclude “these results suggest that the regulation of drone brood production at the colony level may emerge at least in part by a negative feedback process of drone egg production by the queen”.  

So it seems likely that drone production in a colony reflects active decisions made by both workers and the queen.

Why has this spring been really hard for drones?

To be ready for swarming, colonies therefore need to start drone production quite early in the season – at least 4-5 weeks before any swarms are likely.

Late May ’21 forecast. Swarmy weather? I don’t think so …

But with consistently poor weather, these drones are unlikely to be needed. Colonies will not have built up enough to be strong enough to swarm.

Producing drones is a high energy process – they are big bees and require a lot of carbohydrate and protein during development.

Under natural conditions 18 a colony puts as many resources into drone production over the season as it does into swarms.

Thomas Seeley has a nice explanation of this in The Lives of Bees – if you take the dry weight of primary swarms and casts produced by a colony it’s about the same as the dry weight of drones produced throughout the season. 

Rather than waste energy in drone production the workers remove unwanted drone eggs and larvae. The queen lays them, but the workers prevent them being reared.

How do the workers decide the drones aren’t going to be needed?

Do workers have excellent long-range weather forecasting abilities?

Probably not 19

If the weather is poor the colony will be unable to build up properly because forage will be limited. As a consequence, the colony (and others in the area) would be unlikely to swarm and so drones would not be needed for queen mating.

Free and Williams (1975) demonstrated that forage availability was the factor that determined whether drones were reared and maintained in the colony. 

Under conditions where forage was limited, drone eggs and larvae were rejected (cannibalised) and adult drones were ejected from the hive.

Unwanted drone ejected from a colony in early May

Beekeepers are familiar with drones being ejected from colonies in the autumn (again, a time when forage becomes limiting), but it also happens in Spring.

And at other times when nectar is in short supply …

Those of you currently enjoying a good nectar flow from the OSR should also look at colonies during the ‘June gap’. With a precipitous drop in nectar available in the environment once the OSR stops yielding, colonies can be forced to eject drones.

It’s tough being a drone … which may explain why one of my PhD students has the name @doomeddrone on Twitter 😉


 

No risk, no reward

“April showers bring May flowers”, or something close to that, is a poem that has its origins in the General Prologue of Chaucer’s Canterbury Tales.

It means that the Atlantic low pressure systems that roll in from the west during April, often bringing rain, also account for the abundance of flowers that bloom in May.

Not much sign of any April showers last month …

April 2021 sunshine anomaly compared to 1981 – 2010

Most of the country was bathed in spring sunshine, with Scotland and the north of England getting 150-170% of the average seen over the last 30-40 years. 

Unsurprisingly, with that amount of sunshine, rain was in short supply. Much of the country experienced only 20-33% of the usual April rainfall.

Which should be great for beekeeping, right?

Well, not if it’s accompanied by some of the lowest temperatures seen for half a century.

April 2021 average temperature anomaly compared to 1981 – 2010

The entire country was significantly colder than normal, with the bit of Fife my bees are in being 3°C colder than the average over the last decade, with frosts on ~60% of the nights during the month 1.

And, for those of us interested in queen rearing, this sort of start to the season can cause frustrating delays … or encourage a bit of risk taking.

The heady mix of strong colonies, drones and good weather

Queen rearing needs three things to occur at more or less the right time – which doesn’t mean simultaneously.

  1. The colony needs to be strong enough to rear new queens. Good queens – whether reared from grafted larvae or naturally under the swarming or emergency impulse – require lots of nurse bees in the hive to lavish the developing larvae with attention. Three or four frames of brood isn’t enough. The hive really needs to be bursting with bees. A long winter, cold spring or bad weather can hold the colony back. 
  2. Drones need to be available to mate with the virgin queens. Drones take 24 days to develop from egg to emerged adult. However, before they can mate, drones need to reach sexual maturity and learn about the environment around the hive. Sexual maturity takes 6 – 16 days and, at the same time, the drones embark on a number of orientation flights which start a week or so after emergence. 
  3. Good weather for queen mating. After emerging the queen also needs to reach sexual maturity. This takes 5-6 days. She then goes on one or more mating flights, before returning to the hive for a lifetime of egg laying 2. Bad weather – either temperatures significantly below 20°C, rain or strong winds – all prevent these mating flights from taking place. 

With no drones, a weak colony, or lousy weather there’s little chance of producing high quality, well-mated queens.

Or perhaps of producing any queens at all 🙁

Second impressions

My Fife colonies were first inspected in mid-April. Most were doing OK, with at least 5-7 frames of brood and some fresh nectar in the brood box. 

Despite the low temperatures they were making the most of the sunshine and foraging whenever possible.

A week later, at their second inspection on the 25th, the majority of colonies had 1-2 supers 3 and were building up well. All had drone brood and some had adult drones.

By this time I’d identified – from my records, the overwinter performance (stores used, strength and build-up) and their behaviour when inspected under frankly rubbish conditions – which colonies I would be using for queen rearing.

I also knew which colonies would need to be requeened.

My ‘rule of thirds’

My colony selection for stock improvement is simple and straightforward.

Colonies that I consider form the worst third of my stocks are always requeened 4. Furthermore, I do my best to avoid these bees contributing to the gene pool. I don’t use larvae from them for grafting and I don’t split them and allow them to rear their own queens 5.

Ideally (in terms of the gene pool, not in terms of their fate 🙁 ) I’d also remove all drone brood from these colonies. These drones will most likely mate with queens from other hives 6, but if their genes aren’t good enough for me they probably aren’t good enough for the unsuspecting virgin queens in the neighbourhood either.

Colonies I consider in my top one third of stocks are used as a source of larvae for grafting, and can be split and allowed to rear their own new queens.

The ‘middle’ third are requeened if I have spare queens, which I usually do.

It’s surprising how quickly this type of selection results in stock improvement. By focusing on a series of simple traits I favour (e.g. frugal with winter stores, calm when inspected in persistent rain) or dislike (e.g. running on the comb, following, stroppiness) in my bees I’ve ended up with stocks that are pretty good 7.

Queen cells … don’t panic

On April 25th many colonies had play cups but only one had charged queen cells

Considering the 10 day weather forecast, my overall level of preparedness to start queen rearing (!) and the relatively early stage of development of the cells (24-48 hour larvae) I nearly squidged the cells and closed the hive up for another week.

It still felt too early and far too cold.

know that knocking back queen cells is not swarm control (and have suggested this is engraved on all hive tools sold to beginners).

However, swarming also requires good weather. If it’s 9-11°C the colony will not swarm … and I was pretty confident that the weather wasn’t going to warm up significantly in the week until the next inspection.

So, in my typical Do as I say, don’t do as I do” style, I reckoned it was a safe bet to destroy the queen cells and check again a week later.

I would have expected to find more queen cells then, but I’d have been astounded if the colony had swarmed in the intervening period.

Second thoughts

But this was a lovely colony. 

It has always been good, had overwintered on a single 12.5 kg block of fondant and was already on 10 frames of brood in all stages 8. And that was a full box as it’s a Swienty brood box that only takes 10 National frames. To give them more room I would have had to add another brood box.

Not only that, but the bees were calm when inspected under miserable conditions. They didn’t run about on the comb and they weren’t aggressive.

The colony was comfortably near the top of my top third …

If the colony had swarmed, despite the queen being clipped, there’s a good chance I’d have lost her. The apiary is ~140 miles from home and that’s not the sort of journey you can make to ‘quickly check the hives’

So, how could I ensure that I didn’t lose the queen and take advantage of the quality of the stock and its apparent readiness to reproduce?

Plan B

Looking after the queen was straightforward. 

I prepared a 3 frame nucleus colony containing the frame the queen was on and a couple of frames of emerging brood. I added a frame of sealed stores and a new frame of foundation.

A frame of sealed stores … perfect for feeding nucs

I stuffed the entrance of the nuc with grass, wedged the frames together with a foam block and pinned a travel screen over the top.

The travel screen really wasn’t necessary. I had to transport the bees to another apiary and, although there was now weak sunshine the temperature was only just double digits (°C) and my beesuit was still damp from an earlier shower. I didn’t fancy driving for 40 minutes with the windows open to keep the bees cool, so opted to ventilate them better and keep me a bit warmer 😉

This is the nucleus method of swarm control. It’s almost foolproof 9.

It is possible to get it wrong, but you have to try quite hard. 

In my experience it’s the most dependable method and has the added advantage of using the minimal amount of additional equipment.

The queen was safe in a new box. She had space to lay and lots of young bees to support her. The queenless colony had ample stores and 7 frames of brood in all stages. 

This nucleus colony will be used as a source of larvae for grafting in mid/late May. I can easily regulate the strength of this colony – to prevent them swarming – by stealing a frame or two of brood periodically. If replaced by a foundationless frame (or a frame with foundation) they will draw lovely new comb with the help of the nectar flow from the oil seed rape.

The original, and now queenless, colony was given three new frames and closed up.

One week later

In early May the cold, sunny weather was replaced by very cold, very wet weather 🙁

On the 3rd of May I drove through snow and heavy rain to get to the apiary. The following day I started inspecting the colonies in intermittent light drizzle and a temperature of 7°C. 

Not ideal 🙁

The weather gradually improved. By the time I finished in the apiary it had reached a balmy 11°C.

Notwithstanding the conditions, the bees were well behaved. 

With some bees, if you open the hive in poor weather they rush out mob-handed.

Before you get a chance to think “Can I smell bananas?” you’ve collected half a dozen stings and they’re recruiting reinforcements 10.

You know it’s going to be a long and painful day …

However, perhaps because the bees were sick and tired of the low temperatures this spring they just sat on the comb looking mournful … you could almost see their little faces as row upon row of upside down smilies 🙁 🙁 🙁 🙁 

This ‘calmness in the face of adversity’ (!) makes these bees easy and tractable to deal with in poor conditions. It’s a byproduct of selection from the ‘best’ third of my stocks year after year.

I don’t actively select bees for bad weather beekeeping, but it’s a nice bonus when it happens.

The queenless colony now contained 7 frames of sealed brood, many of which also contained queen cells. They had almost completely drawn the new frames I’d added the previous week when I made up the nuc.

More nucs

I prepared 3 two frame nucs from the hive, leaving the remaining frames – with some new ones – in the dummied down brood box.

Doing this sort of manipulation in poor weather takes preparation and planning. You do not want to be rushing back to the shed for an extra frame, or searching around for entrance blocks, or doing anything that leaves the bees exposed for longer than necessary.

Ready to go …

The poly nucs were all set up, with the entrances sealed, a frame of capped stores, two new frames and a dummy board. The foam travel blocks (to hold the frames tightly together), plastic crownboards, lids and hive straps were piled up within easy reach.

Making up two frame nucs

All of this was done before I’d even opened the queenless hive 11.

The queen cells were all sealed (as would be expected from the timing of the last inspection, 8-9 days earlier) and had been produced in a busy hive, with lots of nurse bees to attend to them.

The majority would have been reared under the emergency impulse.

I quickly and carefully transferred two frames from the queenless hive to each nuc. I ensured that each nuc received a frame containing a good queen cell.

In practice, the nucs and the colony remnants probably all ended up with several queen cells.

Not another “Do as I say, don’t do as I do?” situation?

I usually leave only one queen cell in a hive to ensure a strong colony doesn’t produce multiple casts.

However, this time I did not thin out any of the queen cells. 

This was a pragmatic decision largely based upon the weather. It was too cold to be searching across every frame to select the best cell. The bees would have been distressed and disturbed, and there was a risk of chilling the brood 12.

It was also a rational decision considering the strength of the colonies I was setting up. With a much-reduced population of bees it’s very unlikely the colony will allow all the queens to emerge. I expect most of the cells to be torn down by the workers.

The nucs were all transferred to an apiary over three miles away. This avoids any risk of them reducing in strength due to flying bees returning to the original site.

These nucs were relatively small colonies so will require some TLC. I’ll check them soon after the new queens emerge. If they look understrength I’ll add a frame of emerging brood (harvested from one of the bottom ‘third’ of colonies. They might not be good enough to split but they are still very useful bees 🙂 ).

I’ll then leave them for at least 2-3 weeks hoping that the weather improves significantly for queen mating.

This is the ‘taking a risk’ bit of the whole process. Mid/late May should offer some suitable days for queen mating, but if this weather continues it’s not guaranteed. 

Somewhere between ~26-33 days after emergence the virgin queen becomes too old to mate successfully.

For these queens, that will take us to the week beginning the 3rd of June.

If we’ve not had any good queen mating days by then things will be getting a bit desperate 🙂

Active queen rearing begins soon

Splitting a colony into nucs containing queen cells is one way of rearing new queens. The quality of the resulting colony is dependent – at least partially – on the quality of the colony you start with.

With a high quality starting stock it is effectively ‘passive’ queen rearing … very little effort with potentially good rewards. 

What’s not to like?

Preliminary setup for Ben Harden queen rearing

But with the weather slowly but inexorably improving (really!) it’s time to start thinking about ‘active’ queen rearing – cell starters, grafting, cell finishers, mini-nucs etc.

With the good quality queen busily laying away in her nuc box it was time to set up a colony for queen rearing using the Ben Harden approach.

In this instance the quality of the colony is largely immaterial. It needs to be strong and healthy, but its genetics will not contribute to the quality of the resulting queens. 

My final task before leaving the apiary was to add the fat dummies and additional frames in preparation for queen rearing using selected grafted larvae.

And that’s what I hope to be doing next week 🙂


 

Acting on Impulse

Men just can’t help acting on Impulse … 

This was the advertising strapline that accompanied the 1982 introduction of a new ‘body mist’ perfume by Fabergé. It was accompanied by a rather cheesy 1 set of TV commercials with surprised looking (presumably fragrant) women being accosted by strange men proffering bouquets of flowers 2.

Men just can’t help acting on Impulse …

And, it turns out that women – or, more specifically, female worker honey bees – also act on impulse

In this case, these are the ‘impulses’ that result in the production of queen cells in the colony.

Understanding these impulses, and how they can be exploited for queen rearing or colony expansion (or, conversely, colony control), is a very important component of beekeeping.

The definition of the word impulse is an ‘incitement or stimulus to action’.

The action, as far as our bees are concerned, is the development of queen cells in the colony.

If we understand what factors stimulate the production of queen cells we can either mitigate those factors – so reducing the impulse and delaying queen cell production (and if you’re thinking ‘swarm prevention‘ here you’re on the right lines) – or exploit them to induce the production of queen cells for requeening or making increase.

But first, what are the impulses?

There are three impulses that result in the production of queen cells – supersedure, swarm and emergency.

Under natural conditions i.e. without pesky meddling by beekeepers, colonies usually produce queen cells under the supersedure or swarm impulse.

The three impulses are:

  1. supersedure – in which the colony rears a new queen to eventually replace the current queen in situ
  2. swarm – during colony reproduction (swarming) a number of queen cells are produced. In due course the current queen leaves heading a prime swarm. Eventually a newly emerged virgin queen remains to get mated and head the original colony. In between these events a number of swarms may also leave headed by virgin queens (so-called afterswarms or casts).
  3. emergency – if the queen is lost or damaged and the colony rendered queenless, the colony rears new queens under the emergency impulse.

Many beekeepers, and several books, state that you can determine the type of impulse that induced queen cell production by the number, appearance and location of the queen cells.

And, if you can do this, you’ll know what to do with the colony simply by judging the queen cells.

If only it were that simple

Wouldn’t it be easy?

One or two queen cells in the middle of frame in the centre of the brood nest? Definitely supersedure. Leave the colony alone and the old queen will be gently replaced over the next few weeks. Brood production will continue uninterrupted and the colony will stay together and remain productive.

A dozen or more sealed queen cells along the bottom edge of a frame? The colony is definitely  in swarm mode and – since the cells are already capped – has actually already swarmed. Time to thin out the cells and leave just one to ensure no casts are also lost.

But it isn’t that simple 🙁

Bees haven’t read the textbooks so don’t necessarily behave as expected.

I’ve found single open queen cells in the middle of a central frame, assumed it was supersedure, left the colony alone and lost a swarm from the hive a few days later 🙁

D’oh!

Or I’ve found loads of capped queen cells on the edges of multiple frames in a hive, assumed that I’d missed a swarm … only to subsequently find the original marked queen calmly laying eggs as I split the brood box up to make several nucleus colonies  🙂

Not all queen cells are ‘born’ equal

It’s worth considering what queen cells are … and what they are not. And how queen cells are started.

There are essentially two ways in which queen cells are started.

They are either built from the outset as vertically oriented cells into which the queen lays an egg, or they start their life as horizontally oriented 3 worker cells which, should the need arise, are re-engineered to face vertically.

Play cup or queen cell?

Play cup or are they planning their escape …?

Queen cells started under the supersedure or swarming impulse are initially created as ‘play cups‘. A play cup looks like a small wax version of an acorn cup – the woody cup-like structure that holds the acorn nut. In the picture above the play cup is located on the lower edge of a brood frame, but they are also often found ‘centre stage‘ in the middle of the frame.

Play cups

A colony will often produce many play cups and their presence is nothing to be concerned about. In fact, I think it’s often a rather encouraging sign that the colony is sufficiently strong and healthy that it might be thinking of raising a new queen. 

Before we leave play cups and consider how emergency queen cells start life it’s worth emphasising the differences between play cups and queen cells.

Play cups are not the same as queen cells

Until a play cup is occupied by an egg it is not a queen cell.

At least it’s not as far as I’m concerned 😉

And, even if it contains an egg there’s no guarantee it will be supported by the workers to develop into a new queen 4.

However, once the cell contains a larva and it is being fed by the nurse bees – evidenced by the larva sitting in an increasingly thick bed of royal jelly – then it is indisputably a queen cell.

Charged queen cell ...

Charged queen cell …

And to emphasise the fundamental importance in terms of colony management I usually refer to this type of queen cell as a ‘charged queen cell’.

Once charged queen cells appear in the colony, all other things being equal, they will be maintained by the workers, capped and – on the 16th day after the egg was laid – will emerge as a new queen.

And it is once charged queen cells are found in the colony that swarm control should be considered 5.

But let’s complete our description of the queen cells by considering those that are produced in response to the emergency impulse.

Emergency queen cells

Queen cells produced under the emergency impulse differ from those made under the swarm or supersedure impulse. These are the cells that are produced when the colony is – for whatever reason – suddenly made queenless. 

Without hamfisted beekeeping it’s difficult to imagine or contrive a scenario under which this would occur naturally 6, but let’s not worry about that for the moment 7

The point is that, should a colony become queenless, the workers in the colony can select one or more young larvae already present in worker cells and rear them as new queens.

So, although the eggs are (obviously!) laid by the queen 8, they have been laid in a normal worker cell. To ensure that they get lavished with attention by the nurse bees, feeding them a diet enriched in Royal Jelly, the cell must be re-engineered to project vertically downwards.

Location, location

Queen cells can occur anywhere in the hive to which the queen has access.

Queen cell on excluder

Queen cell on underside of the excluder …

But they are most usually found on the periphery of the frame, either along the lower edge …

Queen cells ...

Queen cells …

… or a vertical side edge of the frame …

Sealed queen cells

… but they can also be found slap, bang in the middle of a brood frame.

Single queen cell in the centre of a frame

And remember that bees have a remarkable ability to hide queen cells in inaccessible nooks and crannies on the frame … and that finding any queen cells is much more difficult when the frame is covered with a wriggling mass of worker bees.

Location and impulses

Does the location tell us anything about the impulse under which the bees generated the queen cell?

Probably not, or at least not reliably enough that additional checks aren’t also needed 🙁

Many descriptions will state that a small number (typically 1-3) of queen cells occupying the centre of a frame are probably supersedure cells. 

Whilst this is undoubtedly sometimes or even often true, it is not invariably the case.

The workers choose which larvae to rear as queens under the emergency impulse. If the only larvae of a suitable age are situated mid-frame then those are the ones they will choose.

In addition, since generating emergency cells requires re-engineering worker cells, newer comb is likely more easily manipulated by the workers.

Some beekeepers ‘notch’ comb under suitably aged larvae to induce queen cell production at particular sites on the frame 9. The photograph shows a frame of eggs with a notch created with the hive tool. It’s better to place the notch underneath suitably aged larvae, not eggs. Clearly, the age of the larvae is more critical than the ease with which the comb can be reworked. Those who use this method [PDF] properly/extensively claim up to a 70% ‘success’ rate in inducing queen cell placement on the frame. This can be very useful if the plan is to cut the – well separated – queen cells out and use them in mating nucs or for requeening other colonies.

Eggs in new comb ...

Eggs in new comb …

Comb at the bottom or side edges of the frame often has space adjacent and underneath it. Therefore the bees might favour these over sites mid-frame (assuming ample suitable aged larvae) simply because the comb is easier to re-work in these locations.

And don’t forget … under the emergency impulse the colony preferentially chooses the rarest patrilines to rear as new queens 10.

Not all larvae are equal, at least when rearing queens under an emergency impulse.

Active queen rearing and the three impulses

By ‘active’ queen rearing I mean one of the hundreds of methods in which the beekeeper is actively involved in selecting the larvae from which a batch of new queens are reared.

This doesn’t necessarily mean grafting , towering cell builders and serried rows of Apidea mini nucs.

It could be as simple as taking a queen out of a good colony to create a small nuc and then letting the original colony generate a number of queen cells.

Almost all queen rearing methods use either the emergency or supersedure impulses to induce new queen cell production 11.

For example, let’s consider the situation described above.

Active queen rearing and the emergency impulse

A strong colony with desirable traits (calm, productive, prolific … choose any three 😉 ) is made queenless by removing the queen on a frame of emerging brood into a 5 frame nucleus hive. With a frame of stores and a little TLC 12 the queen will continue to lay and the nuc colony will expand.

Everynuc

Everynuc …

But the, now queenless, hive will – under the emergency impulse – generate a number of new queen cells. These will probably be distributed on several frames if the queen was laying well before she was removed.

The colony will select larvae less than ~36 hours old (i.e. less than 5 days since the egg was laid) for feeding up as new queens.

If the beekeeper returns to the hive 8-9 days later it can be split into several 5 frame nucs, each containing a suitable queen cell and sufficient emerging and adherent bees to maintain the newly created nucleus colony 13.

Active queen rearing and the supersedure impulse

In contrast, queenright queen rearing methods such as the Ben Harden system exploit the supersedure impulse.

Queen rearing using the Ben Harden system

In this method suitably aged larvae are offered to the colony above the queen excluder. With reduced levels of queen pheromones present – due to the physical distance and the fact that queen cannot leave a trail of her footprint pheromone across the combs above the QE – the larvae are consequently raised under the supersedure impulse.

Capped queen cells

Capped queen cells produced using the Ben Harden queenright queen rearing system

I’m always (pleasantly) surprised this works so well. Queen cells can be produced just a few inches away from a brood box containing a laying queen, with the workers able to move freely through the queen excluder. 

Combining impulses …

Finally, methods that use Cloake or Morris boards 14 use a combination of the emergency and supersedure impulses.

Cloake board ...

Cloake board …

In these methods the colony is rendered transiently queenless to start new queen cells. About 24 hours later the queenright status is restored so that cells are ‘finished’ under the supersedure response.

The odd one out, as it’s not really practical to use it for active queen rearing, is the swarming impulse. Presumably this is because the conditions used to induce swarming are inevitably rather difficult to control. Active queen rearing is all about control. You generally want to determine the source of the larvae used and the timing with which the queen cells become available.

Environmental conditions can also influence colonies on the brink of swarming … literally a case of rain stopping play.

Acting on impulse

If there are play cups in the colony then you don’t need to take any action 15, but if there are charged queen cells present then your bees are trying to tell you something.

Precisely what they’re trying to tell you depends upon the number and position of the queen cells, the state or appearance of those cells, and the state of the colony – whether queenright or not.

What you cannot do 16 is decide what action to take based solely on the number, appearance or position of the queen cells you find in the colony. 

Is the colony queenright?

Are there eggs present in the comb?

Does the colony appear depleted of bees?

If there are lots of sealed queen cells, no eggs, no sign of the queen and a depleted number of foragers then the colony has probably swarmed. 

Frankly, this is pretty obvious, though it’s surprising the number of beekeepers who cannot determine whether their colony has swarmed or not.

But other situations are less clear … 

If there are a small number of charged queen cells, eggs, a queen and a good number of bees in the hive then it might be supersedure.

Or the colony might swarm on the day the first cell is sealed 🙁

How do you distinguish between these two situations? 

Is it mid-May or mid-September? Swarming is more likely earlier in the season, whilst supersedure generally occurs later in the season.

But not always 😉

Is the queen ‘slimmed down’ and laying at a reduced rate?

Much trickier to determine … but if she is then they are likely to swarm.

Decisions, decisions 😉 … and going by the number of visits to my previous post entitled Queen cells … don’t panic! there are lots of beekeepers trying to make these decisions right now 🙂


 

Winter losses

I lost 10% of my colonies this winter.

It’s always disappointing losing colonies, but it’s sometimes unavoidable.

I suspect the two I lost were unavoidable … though, as you’ll see, they weren’t completely lost.

April showers frosts

Late April may seem like mid-season for many beekeepers based in southern England. While they were adding their second super, the bees here in Scotland were only just starting to take their first few tentative flights of the year.

This April has been significantly cooler in Fife 1 than any year ‘since records began’.

However, the records I’m referring to are from the excellent Auchtermuchty weather report 2 which only date back to about 2013 … I like it because it’s local, not because it’s historically comprehensive 😉

The average April temperate has only been 5.5°C with 15 nights with frost in the first three weeks of the month. In contrast, the same month in 2019 and 2020 averaged over 9°C with only 3-4 nights with frosts 3

In both 2019 and 2020 swarming started at the end of April. Several colonies had queen cells when I first inspected them and I hived my first swarm (not lost from one of my colonies 😉 ) on the last day of the month.

First inspections and winter losses

Unsurprisingly, with appreciably lower temperatures, things are less well advanced this season. None of the colonies I inspected on the 19th were making swarm preparations. Instead, most were 2-4 frames of brood down on the strength I’d expect them to have before they started thinking about swarming.

Nevertheless, most were busy on a lovely spring day … lots of pollen (mainly gorse and some late willow by the looks of things) being delivered by heavily-laden foragers, and fresh nectar in some of the brood frames.

Fresh nectar glistening in a brood frame

The first inspection of the season is an opportunity to not only check on the strength and behaviour of the colony, but also to do some ‘housekeeping’. This includes:

  • swapping out old, dark brood frames (now emptied of stores) and replacing them with new foundationless frames
  • removing excess stores to make space for brood rearing
  • removing the first sealed drone brood in the colony to help hold back Varroa replication

And, as the winter is now clearly over, it’s the time at which the overall number of winter losses can be finally assessed.

Winter losses

Winter losses generally occur for one of four reasons:

  • disease – in particular caused by deformed wing virus (DWV) vectored by high levels of Varroa in the hive. DWV reduces the longevity of the diutinus winter bees, meaning the colony shrinks in size and falls below a threshold for viability. There are too few bees to thermoregulate the colony and too few bees to help the queen rear new larvae. The colony either freezes to death, dwindles to the size of an orange, or starves to death because the cluster cannot reach the stores 4.
  • queen failure – for a variety of reasons queens can fail. They stop laying altogether or they only lay drone brood. Whatever the reason, a queen that doesn’t lay means the colony is doomed.
  • natural disasters – this is a bit of a catch-all category. It includes things like flooded apiaries, falling trees and stampeding livestock. Although these things might be avoidable – don’t site apiaries in flood risk areas, under trees or on grazing land – these lessons are often learnt the hard way 5.
  • unnatural disasters – these are avoidable and generally result from inexperienced, or bad 6 , beekeeping. I’d include providing insufficient stores for winter in this category, or leaving the queen excluder in place resulting in the isolation of the queen, or allowing the entrance to be blocked. These are the things that the beekeeper alone has control over. 

The BBKA run an annual survey of winter losses in the UK. This is usually published in midsummer, so the graph below is from 2020.

BBKA winter survival survey

Over the 13 years of the survey the average losses were 18.2% 7. Long or particularly hard winters result in higher levels of losses.

Lies, damn lies and statistics

I’ve no idea how accurate these winter loss surveys are.

About 10% of the BBKA membership reported their losses, and the BBKA membership is probably a bit over 50% of UK beekeepers. 

I would expect, with precious little evidence to back it up, that the BBKA generally represents the more ‘engaged’ beekeepers in the UK 8. It also probably represents a significant proportion of new beekeepers who were encouraged to join while training.

So, like Amazon reviews, I treat the results of the survey with quite a bit of caution. I suspect beekeepers who have low losses complete it enthusiastically to ‘brag’ about their success (despite its anonymity), while those with large losses either keep quiet or are happy to share their grief. 

Unlike Amazon reviews, I’d be surprised if there are many fake submissions to the BBKA and I’m not aware there’s a living to be made from selling fake colony survival reviews in bulk online.

For comparison, the Bee Informed Partnership in the USA runs a similar survey every year.

Bee Informed Partnership loss and management survey

This survey covers about 10% of the colonies in the USA. Again it is voluntary and likely subject to the same inherent biases that may affect the BBKA survey.

The USA winter colony losses average ~28% over the same 13 year survey period.

Are US beekeepers less good at keeping their colonies alive than beekeepers in the UK?

Perhaps the US climate is less suited to honey bees?

Or, possibly, US beekeepers are simply more honest than their UK counterparts?

I doubt it 9.

Running on empty

My two colony losses were due to queen failures.

Old winter bees and no brood

In the first colony there was no evidence the queen had laid any brood since the previous autumn. There were about 6 seams of bees in the hive, but the outer 2-3 frames were solid with untouched winter stores.

Unused winter stores

This is usually a dead giveaway … literally. The colony hasn’t used the stores because they’ve not had any hungry mouths to feed. With no new brood the colony is doomed.

This queen appears to have simply run out of sperm and stopped laying. She was present (a 2019 marked queen and the same one I’d seen in August last year) and ambling around the frame, but she wasn’t even going through the pretence of inspecting cells before laying.

I removed the queen and united what remained of the colony over a nearby strong colony.

Strong colony ready for uniting

Assuming the queen stopped laying at the end of year all the bees in the hive – and there were a good number – were old, winter bees. These won’t survive long, but will provide a temporary boost to the colony I united them with. 

Every little bit helps 🙂

Even more valuable than the bees were the frames they were on.

Most of the comb in the colony with the failed queen was relatively new. By uniting them I can quickly swap out the old comb (from the stronger hive #34) when I next inspect the hive. At the same time I’ll rescue the frames of sealed stores for use when making up nucs during queen rearing.

Drone laying queen

The second failure was a drone laying queen (DLQ).

These are usually unmistakeable … the brood is clustered, with drone pupae occupying worker brood cells. If the queen has been drone laying for some time there may be lots of undersized ‘runt’ drones present in the hive as well.

Drone laying queen ...

Drone laying queen …

Again, this colony was doomed. With no new queens available and a lot of pretty old bees in the hive they could not be restored to a functioning colony.

However, many of the bees could be saved …

The colony wasn’t overrun with drones. Going by the amount of stores consumed it had probably been rearing worker brood since the winter solstice.

The queen was unmarked and unclipped. I strongly suspect she was a late-season supersedure queen who was very poorly mated.

The 3-4 weeks of drone brood rearing 10 had wrecked quite a few of the frames, but the bees were worth saving.

Under these circumstances I decided to shake the colony out.

When I do this I like to move the original hive and the stand it’s on. If you don’t move the stand the displaced bees tend to cluster near the original hive entrance, festooned from the hive stand. 

In poor weather, or late in the afternoon, this can lead to lots of bees unnecessarily perishing.

However, the stand was shared with two other colonies, so couldn’t be removed. It was also late morning and the weather was excellent.

I moved the hive away and shook the bees out. 

Sure enough … they returned to their original location.

They then marched along the hive stand to the entrance of the adjacent hive.

This way sisters!

And, by the time I left the apiary in mid-afternoon there were only a few diehard bees clustered near where the original hive entrance was.

Why didn’t I just unite them as I’d done with the other failed queen?

Drone brood is a Varroa magnet

Varroa replicate when feeding on developing pupae. The longer development time of drone pupae (when compared with worker pupae) means that you get ~50% more Varroa from drone brood 11

Unsurprisingly perhaps (or not, because that’s the way evolution works) Varroa have therefore evolved to preferentially infest drone brood. When given the choice between a drone or worker pupa to infest, Varroa choose the drone about 10 times more frequently than the worker.

And that ~10:1 ‘preference ratio’ increases when drone brood is limiting … as it is early in the season.

What this means is that the first burst of drone brood production in a colony is very attractive to Varroa.

Unless there are compelling reasons to keep this very early drone brood – for example, a colony with stellar genetics I’d like to contribute as much as possible to the local gene pool – I often try and remove it.

Drone-worker-drone

Drone-worker-drone …

If you use foundationless frames this is often as easy as simply cutting out a single panel of drone brood.

But, in the case of this drone laying queen, it meant that the logical action was to discard all of the drone brood to ensure I discarded the majority of the Varroa also present in the colony 12.

Which is why I shook the colony out, rather than uniting them 🙂

Boxes of bees

Several colonies in one apiary went into the winter on double brood colonies. Inevitably, with the loss of bees during the winter months, the colony contracts and the queen almost invariably ends up laying in the upper box.

The first inspection of the season is often a good time to remove the lower box. It can be removed altogether, or replaced (above the other box) for a Bailey comb change if the weather is suitable.

At this stage of the year the lower box is often reasonably empty of bees and totally empty of brood. 

Emptying a box of bees

If the comb in the lower box is old and dark (see the picture above) I place the upper box on the original floor and add an empty super on top. I then go through the lower box, shaking the bees into the empty super. Good frames are retained, the rest are destined for the wax extractor and firelighters.

Using an empty super helps ‘funnel’ the bees into the brood box.

Sometimes the queen has already laid up a frame or so in the lower box. Under these circumstances – particularly if the comb is relatively new – I’ll simply reverse the boxes, placing the lower box on top of the upper one. This results in the queen quite quickly moving up and laying up the space in the upper brood chamber.

It’s then time to add a queen excluder and the first super.

The beekeeping season has definitely started 🙂


Notes

I commented a fortnight ago about the apparent lateness of the 2021 spring. I’m adding this final note on the afternoon of the 23rd and have still yet to see or hear either cuckoo or chiffchaff on the west coast. Last year they were here in the middle of the month. This, combined with the temperature data (see above) show that everything is a week or two behind events last year.

Which means I can expect to start doing some sort of swarm prevention and control in the next fortnight.

A no competition, competition

Unless you’re in an unseasonably warm part of the country, mid-April is usually early enough to put out your bait hives. This year, because of the unusually cold snap in the last week or so, it might still be a bit early. However, colonies are developing well and as soon as the weather properly warms up they will start thinking about swarming.

Regular readers, look away now

I’ve written a lot about bait hives in previous years. Anyone who assiduously follows this site and – unlike me 😉 – remembers what’s been written before can skip ahead to the next section.

But for those who need an aide memoire

The purpose of a bait hive is to attract a swarm that you (surely not?) or someone else has temporarily misplaced i.e. lost 1. When a colony swarms it settles in a temporary bivouac from which the scout bees fly to survey the area for a suitable new nest site.

The two stage process of swarming

The scout bees have very particular requirements.

They’re looking for cavities of about 40 litres volume with a small, clearly visible, south facing, entrance near the base.

Evolution and fussy house hunters

Bees have evolved to nest in trees – not quaint cartoon churches as shown above – and cavities in trees come in all shapes and sizes.

This is why they don’t care what shape the cavity is. However, cavities with small entrances are easier to defend, which is why they prefer them 2.

In addition, bees favour cavities situated more than 5 metres above ground level. Again, this makes evolutionary sense. It’s not just Winnie the Pooh that likes honey. The higher up a tree they nest, the less likely they would be detected by a bear 3 on the ground. And if the nest remains undetected (or unreachable by a climbing bear) there’s a chance the colony will thrive and reproduce (swarm) to pass on the ‘high altitude’ nest site preference gene.

And if you’ve evolved to nest in a tree cavity in a wood filled with other trees, it again makes evolutionary sense for the entrance to be clearly visible. If it wasn’t, bees on their orientation flights would inevitably get confused (and therefore lost).

Finally, bees have a strong preference for cavities that smell … of bees.

A cavity that’s already heavily propolised, or contains used drawn comb, offers distinct advantages to the incoming swarm. They will have less work to do and so more chance of building up before winter arrives.

The ideal bait hive

And you can reproduce these requirements by offering a used single brood box National hive with a solid floor and an entrance reducing block in place … facing south and situated well off the ground.

I discussed the evolutionary selection pressures that have shaped the preference for a 40 litre box rather than that convenient spare nuc box I’m repeatedly asked about a smaller box a few weeks ago.

In that post I also discussed why I ignore the preference for bait hives located 5 metres above the ground:

  • I want to be able to watch scout bee activity. This is tricky if they’re a long way off the ground 4.
  • It’s a lot safer retrieving a bait hive from a hive stand at knee level than it is when climbing a ladder. I usually move occupied bait hives late in the evening (when the bees are all in residence) and prefer not to do this balanced precariously on top of a ladder.
  • And – though not listed last time – my knee level bait hives are sufficiently successful I don’t need to increase their attractiveness. I don’t doubt they’d be more efficient located at altitude 5 but they work well enough that I don’t  feel the need to risk altitude sickness or a broken leg …

But, what I’ve not really discussed before is the location where bait hives should be sited and the importance of appreciating the ‘competitive‘ aspects of bait hives.

Natural competition

When you place a bait hive in the environment, whether it’s in your garden or the corner of a field or 5 metres up an oak tree 6, you are providing a potential nest site that will be judged in competition with other natural sites in the area.

And ‘the area’ is probably about 25 square kilometres.

If you struggle to visualize that then it’s the area covered by this circle centred on the roof of Fortnum & Mason’s, where there are some hives. London Zoo to Battersea Power Station and the Round Pond to Southwark Bridge … a large area 7.

Fortnum & Mason, 181 Piccadilly, London … scout bee range (in theory at least)

Scout bees survey over 3 km from their nest site, though swarms rarely relocate that far 8.

Why don’t they move ‘that far’?

Again, evolution may have selected bees that choose not to move away from the environment in which the swarming colony has flourished and built up strongly enough to be able to swarm.

Scout bees find nests, they don’t survey the available forage around those nests. So it makes sense to stay in the general area where forage is proven to be good enough (to allow swarming).

However, I suspect a compelling reason that swarms don’t move far from their original nest site is that there are plenty of alternative nest sites available.

Church towers 9, roof spaces, chimneys, tree cavities 10, compost bins, abandoned sheds etc.

Choices, choices

Think about the environment near your hives. Whether urban or rural, there are bound to be thousands of potential cavities within 3 km.

Some will be too small, some will be poorly defendable 11 and some will be unsuitable for other reasons.

But there are very likely to be some that are ideal, or pretty close to it.

Mature woodland and older man made environments are likely to have ample choices.

Occupied bait hive

Occupied bait hive …

And then there’s your lonely bait hive.

Chance in a million?

How can it possibly compete with all those natural cavities in the environment?

Bait hive ...

Bait hive …

The first thing to do is to ensure it adheres as close as is practically possible (and safely achievable) to the idealised requirements determined by Martin Lindauer, Thomas Seeley and others.

  • a 40 litre cavity = National brood box 
  • a small entrance of 10-15cm2 = entrance block, solid floor
  • south facing
  • shaded but in full view
  • over 5m above ground level 12
  • smelling of bees = one old, dark comb against the sidewall (no stores!)

Secondly, locate it within ~500 metres of your own apiary (to hopefully re-capture your own ‘lost’ swarms 13 ) or, more speculatively, anywhere in an environment in which there are other managed or feral colonies.

Which does not mean over the fence from another beekeeper’s apiary!

Be courteous … don’t poach 🙂

The density of bees throughout much of the UK is very high. Look at Beebase to see the numbers of apiaries within 10 km of your own. When I lived in Warwickshire it was ~180-220, in Fife it was ~35-40 14.

In the talks I’ve given on bait hives this winter – where I customise the presentation to the audience location – few areas with active BKAs have under 100 apiaries within 10 km of their teaching apiary.

In both Fife or Warwickshire I never failed to attract swarms to bait hives in my garden every single year … and in several years up to three swarms to a single bait hive location.

And, with one or two exceptions, these weren’t swarms I had lost 15.

The density of managed colonies in the UK means that a suitable bait hive just about anywhere stands a chance of being occupied.

So, that’s how to win the competition with the natural nest sites that are available.

No competition

But do not put out multiple bait hives in one area.

I have recently re-read an old paper by Thomas Seeley and Kirk Visscher on quorum sensing by scout bees. Quorum sensing is a term for a decision making process where enough bees agree on the same choice, rather than the majority.

Seeley and Visscher (2004) Quorum sensing experiment

Like many good experiments it has an elegant simplicity.

They reasoned that if you provided a bivouacked swarm with a choice of suitable nest sites it would reduce the numbers of scouts that favoured each nest site, and in doing so, would increase the time to reach a decision as to which was best.

And it does.

More potential nest sites leads to an increase in time taken to reach a decision

Unsurprisingly, with more nest box sites to choose between, the scout bees per box were reduced in number (top panel), dancing to advertise preferred nest sites was delayed (second panel), and piping – the ‘prepare for take-off’ signal (third panel) for the bivouacked swarm – was also delayed.

I’ll discuss how this favours a quorum sensing mechanism (and some other aspects of the study) if and when I get time in the future.

For the moment the key take home message is ‘more choice = slower decision making’ by the swarm.

And, if you delay the decision making, there’s a chance it’ll start raining, or the swarm will be collected by another beekeeper … or they’ll opt to move into the old tower of that quaint cartoon church.

One area?

I started the last subsection with the sentence ‘But don’t put out multiple bait hives in one area’.

What is one area?

I was being deliberately vague because I don’t know the answer.

Since I don’t know where the bees might come from 16, I don’t know what’s within range of the bivouacked swarm.

Widely separated bait hives (black) are likely to be within reach of more swarms than clustered bait hives (white)

In practical terms this means I space my bait hives at least 500 metres apart. Widely separated bait hives are likely to be within reach of more swarms than clustered bait hives.

More importantly, clustered bait hives are likely to lead to competition between scout bees from the same swarm, resulting in reduced scout bee attention..

Until recently I’ve not kept bees in my garden. I would always place a bait hive in the garden and one near my out apiaries. With permission, I’d locate them in other places as well.

Having moved, I now have much more space and have bees in the ‘garden’. When my bait hives go out 17 they will be placed in likely spots on opposite sides of our bit of scrubby wooded hillside 18 .

But what’s a likely spot?

Ley lines

And if you thought that last bit was slightly vague … brace yourself.

Over the years I’ve noticed that some bait hive locations are much more successful than others.

Under offer ...

Under offer …

My tiny courtyard garden in Fife was a magnet for swarms. I placed a bait hive in a warm corner of the garden on the day we moved in, and within 10 days a swarm had arrived.

Planting tray roof …

Every year, without fail, multiple swarms would occupy bait hives 19 in that corner of the garden. I even had two swarms competing for one bait hive in 2019.

A sheltered south-east facing hedgerow in Warwickshire was equally effective.

Bait hive

Smelling faintly of propolis and unmet promises

As was a south-west facing spot sheltered next to my greenhouse in a previous garden.

Des Res?

Des Res?

But other locations have been far less successful.

Of course, this is a positive reinforcement exercise. I’m more likely to site a bait hive in a location I’ve previously been successful in.

But what else might account for this differential success rate? And can it be exploited in the rational location of bait hives?

Is it, as some suggest, that bait hives work best when they are located at the intersection of ley lines? This, and the possibility of creating Varroa-resistant bees by exploiting geopathic stress lines, surely deserves a post of its own 20.

Call me sceptical

However, as a scientist – and knowing others have been more than a little sceptical about the existence of ley lines – I think there’s a more prosaic explanation.

Without exception, my most successful sites for bait hives have been well sheltered to the north, and – in most cases – to the north-east and north-west directions as well.

For example, the bait hive is situated on the south face of a wall running east-west (Under offer, above), or in a corner sheltered to the north and east (Planting tray roof, above), or facing south-east in a very dense hedgerow running north-east to south-west (Smelling faintly etc., above), or sheltered by surrounding walls or outhouses but with a clear entrance facing south-west (Des res?, above).

And … since I’ve been aware of this for at least five years, and probably subconsciously aware of it for much longer, that’s exactly the type of location I choose to site my bait hives.

Which is, of course, another example of positive reinforcement 🙂

However, it works for me. I choose sites that are well sheltered to the sides and back of the bait hive, and I try and orientate the bait hive to face south (ish).

At knee level 😉

Give it a try.


 

First impressions

There’s always a slight feeling of trepidation when I lift a roof for the first hive inspection of the season.

What’s in the box?

Is the colony going to be thriving or just hanging on?

I know they’ve got sufficient stores and that the bees have been flying on good days, but that’s not the same as the reassurance that comes from finding 3-4 frames of brood in all stages, well-tempered bees, and a marked queen with a good laying pattern.

Iffy weather

It takes bees to make bees, the saying goes. The colony cannot rear large slabs of brood without large numbers of nurse bees to feed them and clean them and cap the cells.

After a midwinter brood break (which we get, but you may not if you live further south than my 56°N) the queen lays a small patch of eggs which eventually develop and emerge. Over the next few weeks the amount of brood slowly but inexorably increases. The numbers of new bees in the hive increases.

But remember that the total number of bees in the hive is actually still decreasing as the winter bees continue to die off.

And, although brood rearing can (and does) continue like this for weeks – through January and February at least – it needs the better weather, warmer temperatures and early forage to really start ramping up.

So the further north your bees are, the later in the season that things get going.

Unlike last year, the weather this spring has been decidedly ‘mixed’. I barely saw a bee until the penultimate day of February and, with average temperatures of ~6.5°C March wasn’t a whole lot better.

And since then it’s got colder …

I’m writing this after four days of ‘sunny periods’. These sunny periods were interspersed with snow, hail and bitingly cold northerly winds.

Sunny periods … but 4°C with squally snow showers being driven down the Sound of Mull

Although the average temperature is under 5°C the bees are busy foraging when the sun is out. I spent some time yesterday trying to (unsuccessfully) photograph pollen-laden foragers returning to the hive in a snow shower.

Shirtsleeve weather

The usual advice is to not rush the first hive inspection. Wait until it’s a warm spring day. Often it’s recommended to choose a day with ‘shirtsleeve weather’.

Which here might mean July … 🙁

Actually, that’s a bit harsh. We often have excellent weather in late April through until early June.

However, this is my first season with bees on the west coast and I was very keen to see how they were progressing. I also wanted to remove the nadired super and check the levels of pollen.

It certainly wasn’t shirtsleeve weather, but I needed no more than one fleece under my beesuit and I haven’t had to wear long johns since mid-March 😉

Ribes ...

Ribes …

The other advice you’ll often hear is that a good time to conduct the first inspection is when the ornamental currant (Ribes sanguineum) is flowering.

Treat this advice 1 with some caution. In St Andrews there’s a large amount of these flowering currants near the bus station that would always be in full bloom by mid/late March, whatever the weather.

We have no Ribes on the west coast. If we had, the deer would eat them all.

But we did have an unseasonably warm day on the first of the month.

So I had a quick look.

Very disturbing

A hive inspection inevitably disturbs the colony.

However gentle you are the activities of the bees are interrupted, the humidity of the hive changes and the temperature decreases.

The odours and pheromones, so critical for the organised functioning of the colony are also affected.

For these reasons alone there must be a good reason to inspect a colony.

And that’s before you consider the increased opportunities for robbing 2, potential damage to the queen, or a myriad of other reasons.

But none of this means that hive inspections should not be conducted if and when they are needed.

What it does mean is that you need to have a plan in mind when conducting a hive inspection. In addition, you need to have all the things you might need close to hand, and have a mental checklist (your hands will be full) of the order you’re going to execute the plan.

All of which sounds very contrived.

It doesn’t need to be.

What you don’t want to be doing is realising half way through the inspection that you need a clearer board … and it’s at home in the shed 3. Or that your queen has been superseded and the new queen needs to be marked … with the non-existent Posca pen which you lost at the end of last season 🙁

Be prepared

So, although I was only having a ‘quick look’ I did make sure I had everything I needed before I removed the hive roof. This included a:

  • smoker with sufficient fuel to last the duration
  • clearer board to allow the simple removal of the nadired super
  • queen marking kit and snips
  • hive tool with a wide blade to clear the floor
  • spare frame or two
  • pollen pattie 4
  • wrapped fondant block ‘just in case’ 5

All this needs to be close to hand but not so close you trip over it. The roof of an adjacent hive is as good a place as any for the small stuff.

Since I was going to rearrange the boxes I kept space immediately adjacent to the hive free to give me room to work.

Ready, steady … Go!

The hives I inspected were single brood Nationals with a nadired 6 super containing (or not containing?) honey from last season.

Nadired super and single National poly hive

Immediately over the top bars of the frames was the remnants of a block of fondant in a ‘carry out’ food container, with the headspace over the hive provided by one of my inverted deep-rimmed perspex crownboards. This was topped by a block of insulation and the roof 7.

The colonies were installed in these hives from 5 frame nucs in July last year. They had built up reasonably well and collected a half super of heather honey.

However, most of the old, dark frames from the nuc were still in the box as I’d not managed to finish rotating them out of the hive before the season ended.

Corpses and accumulated debris

I removed the roof and the insulation. I then lifted both the nadired super and the brood box together and carefully moved them aside.

This gave me access to the floor.

Sometimes the floor is clear at this time in the spring. At other times you can find a thick accumulation of corpses, or a scattering of mummified larvae with chalkbrood.

Rarely you’ll find a dead mouse … or a live one 8. It’s not at all unusual to find slugs in the hive. These appear to particularly like the damp environment underneath the frame lugs in Abelo poly hives.

Old floors …

Old floors …

Usually I’d choose to replace the floor with a recently cleaned one.

One spare is all you need. You place the new floor down, complete the inspection, close the hive and then scrape clean and blowtorch the old floor before using it as a replacement for the next hive in the apiary.

However, despite my careful planning (!) I had no spares as they were all back in the bee shed, 150 miles away. D’oh! At least I was aware of this before I started which is why I’d made sure I had a wide-bladed hive tool with me.

I scraped the floor clean of a few bee corpses and checked that the entrance channel was clear before putting the floor back in its original location.

I gently separated the brood box from the nadired super. During this process I checked the amount of bees in the super, making an immediate judgement whether the brood nest extended that far down in the hive.

Had the super contained a lot of bees (and therefore potentially brood) there would be a risk that the queen was also ‘down below’. This would have necessitated a quick rethink.

As it was, the super had just a couple of hundred bees in it and it was clear – just by looking down the seams between the frames – that there was no brood present.

It was safe to proceed.

Elbow room and the queen

Only now did I remove the crownboard, lifting one edge first and giving the bees a gentle puff from the smoker to encourage them to stay put.

I removed the fondant block and left it nearby. The bees would return to the hive unaided, or I’d shake the last few in before closing the hive.

The colony inspection was brief and focused. The first few frames contained no bees and so were ignored. Other than the outer dark frame – see below – they weren’t even removed from the hive.

Ready for inspection

I quickly and carefully went through the frames occupied by bees, checking for:

  • sufficient stores (there were still stores on some of the frames I’d not lifted from the hive as well)
  • levels of pollen
  • brood in all stages – eggs, larvae and sealed brood
  • the queen (was she the same I’d last seen in the box over 7 months ago?)

which took no more than a minute for each of the 4-5 frames. Each frame was lifted, inspected on each side and – with one exception – replaced in the same position it had come from.

The brood nest was off-centre, pushed up against one of the side walls of the hive. This isn’t unusual with poly hives as they are so well insulated. However, it means that expansion of the brood nest can only go in one direction.

Giving them a little more elbow room

So, the exception was a frame, with some stores but mainly nice empty comb. I placed this between the brood nest and the side wall of the hive. This gives the expanding colony the option of growing in two directions.

Later in the season, when it’s warmer and the colony is growing faster, you can expand the brood nest further. However, this early in the year 9 just giving them the option to go in either direction is a start.

Marked, laying queen

The marked, clipped queen was easy to spot. I managed to disturb her while laying an egg which you can just see at the tip of her abdomen in the picture inset above.

Replacement of dark frames

Unfortunately the queen was laying up one of the old dark frames in the hive. I couldn’t therefore move this to the outside of the brood nest, but made a mental note to in a month or so.

On the opposite side of the hive were a couple of old dark frames that had been largely cleared of stores.

Old dark frames rotated out of the hive and replaced

These were removed and replaced with new frames. In a few weeks I’ll move these close to the centre of the hive. With abundant spring nectar, and warmth, they will draw fresh comb for the expanding brood nest.

Both the frames above show slight signs of mould. This isn’t unusual to see on frames at the end of the winter, and is generally nothing to worry about. The hive is a humid environment and the outer frames often get very little attention from the bees.

Emptying the super

The super contained a few hundred bees. It also clearly contained a bit of residual honey.

On a warm day I might have simply shaken the bees out. Quick and easy and all over in a single visit. However, it was not warm and this would have been even more disruptive. I therefore added a clearer board and placed the super on top of that. I replaced the crown board, the roof and strapped everything up securely.

Clearer boards

Clearer boards …

The warmth and odours of the hive quickly draw the bees down to join their nest mates, leaving the super empty. This was removed the following day.

The super still had a bit of capped honey in it, as well as a frame or two of uncapped ‘nectar’.

This wasn’t fresh nectar. There’s precious little about at the moment and any the bees are collecting is being secreted around and above the brood nest so that it’s immediately available. Remember, this super had been underneath the brood box since mid-September.

Much of the nectar could be shaken out of these frames. I assume it was uncapped from last year and that it has absorbed moisture from the atmosphere 10. It didn’t have the wet bubbly, yeasty smell and appearance that fermenting stores have … presumably because it’s been too cold 🙁

Thriving or just hanging on?

The two colonies I inspected were doing OK.

More brood than I’d feared, but less than I’d hoped for.

Beekeeping is greatly influenced by the climate, the geography and the local flora. This was my first west coast spring inspection, so there’s lots new to me. It feels like a colder spring than 2020, but I didn’t have bees here then, so have nothing to compare it with.

Once the spring migrants start arriving I’ll have a better idea how it compares.

All of which emphasises the importance of the final part of the inspection. Writing up the hive records. Comparison of notes about both the bees and the environment will, over time, mean I have a much better idea of what’s happening when. And whether the colonies are doing well or badly considering the state of the season.

Black throated diver (Gavia arctica) in full summer breeding plumage

The sand martens are already here, and there are black throated divers on the hill loch. I expect blackcap, cuckoos and wheatear in the next 7-10 days. Much longer than that and it will officially be a cold, late spring.

I’ll be checking my east coast colonies, including half a dozen that have luxuriated in the bee shed overwinter, in the next fortnight or so.

Fife has been warmer and drier, so I expect those colonies to be further advanced.

I hope I’m not too late 🙁