Synopsis : Swarmtastic! The first swarms of the season and a timely lesson on why swarm control is important and how clipping the queen really helps.
Temperatures have finally achieved a ‘typical’ mid-May average of low teens (°C), and on most days the bees are out foraging well. If anything this is making the discrepancy between the strongest hives and the also-rans even more marked. I’ve just put my fourth supers on some, whereas a few hives are struggling to do anything much with the first one.
The oil seed rape in Fife is going over in a few fields, but most still has 10-14 days to go 1 … and the forecast is fantastic, so I’m hoping to still have time to snatch beekeeping victory (or what masquerades as victory for a beekeeper which is full buckets of honey) from the jaws of defeat.
It’s not going to be a bumper spring crop, but it might just about manage average.
Of course, the combination of a good nectar flow and overcrowded colonies means that the bees are now busying themselves with swarm preparations. The post today is all about swarms, lost and found, the benefits of clipped queens and the importance of observation.
Or, to put it another way, more tales of slapstick beekeeping 😉 .
Synopsis : Where should bait hives be located to capture your own lost swarms? 1 Can you omit the old brood frame and still make the bait hive attractive?
Social media can be seriously misleading for beekeepers. For months now it seems like I’ve been reading about boxes bulging with bees, third supers being added, swarms swarming and the oil seed rape bonanza.
With luck they’ve resisted the temptation to go rummaging through the brood box. Twice, because they didn’t see the queen on the first run through. Or the second. Should they buy another queen ’just in case’? 3
Old lags, by contrast, give a resigned shrug knowing that the season will be along in due course.
There’s nothing to be gained by trying to force things. Why open the box, why search for the queen, why risk chilling the bees and brood? There’s pollen going in on the few days good enough for flying, the water carriers are water carrying, the hive has stores (or you’ve quickly added a kilo or two of fondant under the crownboard) and things are progressing much as they should be … though definitely not in lockstep with events reported by the Twitterati in warmer climes.
Synopsis : Are feral colonies recently lost swarms or a self-sustaining ‘wild’ honey bee population? The latter must reproduce faster than they perish. Measuring rates of colony loss and nest occupancy provides a good indicator of the likely origin and independence of feral populations.
Most colonies try to swarm every year. Most – not all – but if your colonies are strong and healthy they are likely to swarm. That’s why swarm prevention and subsequent swarm control are such important skills for the tyro beekeeper to master. Without swarm control the majority of the workforce is ‘lost’, the residual colony will be left temporarily queenless and the potential honey crop is probably much reduced.
A small swarm …
It is not difficult to become competent at swarm prevention and control. However, any beekeeper who claims to never lose swarms is probably being ‘economical with the actualité’ as the late Alan Clark once said.
What happens to those ‘lost’ swarms?
Some forward-thinking beekeepers set out bait hives. Any swarms that end up being attracted to these ‘swarm traps’ will eventually find their way back to a managed apiary. Some swarms end up in the church tower where ‘there have always been bees’, according to local parishioners.
Others move into the roof space above the entrance to the local nursery school, causing fascination, irritation and consternation in equal measure. Their fate depends upon whether the head teacher contacts a beekeeper or a pest controller … but their arrival reinforces the importance of swarm control and the use of bait hives.
A bait hive deployed in mid-April in good time for the swarming season ahead
And other swarms disappear over the apiary fence, across the field and into the local woods, eventually establishing a new colony in a suitable hollow tree.
No risk, no reward
Swarming is a risky business. The swarm leaves with the majority of the flying bees and the mated queen. However, it takes more than that to establish a functional colony. They need to draw comb, rear brood and collect sufficient stores to get through the winter.
That’s a tall order and most swarms fail.
Data from Thomas Seeley in The Lives of Bees suggests that only about 23% of swarms survive the winter.
In contrast, the swarmed colony has about an 80% chance of survival. They’ve got drawn comb, stores, eggs and larvae … ‘all’ they need to do is rear a new queen.
And then they’re likely to swarm again the following year 1. In fact, without swarm control, the average number of swarms produced by a colony is two per year – presumably a prime swarm (headed by the old queen) and a cast (headed by a virgin queen).
So, swarming is risky, but those swarms that succeed in establishing a new colony and overwintering can themselves attempt to reproduce again the following year.
That’s the reward.
Where are all these bees?
Even taking account of the exemplary swarm control by the UK’s ~25,000 beekeepers 2 I’m reasonably certain that a lot of swarms are lost every year.
Where do all these bees go?
I’ve been told of lots of churches or schools or trees with resident bees.
A swarm magnet … or just an old church?
However, it’s certainly not every church, or school or hollow tree that’s occupied. Even when there’s a surplus of suitable nest sites, those that are occupied by a colony are the exception, not the rule.
The main reason of course is Varroa.
In the absence of intervention to reduce the mite population, the developing winter bees get parasitised by Varroa, and the resulting high levels of deformed wing virus (DWV) reduces the longevity of these necessarily 3 long-lived bees.
Consequently the winter cluster shrinks in size, from that of a football (early October) to a honeydew melon (late December) to a large orange (early February).
And then it freezes to death during a cold snap 🙁 .
The apiary in winter …
Numerous studies have shown that untreated colonies, in the absence of any natural resistance or tolerance to Varroa or DWV (though the latter is rarely discussed, and even less frequently tested for), almost always perish within a year or two of Varroa infestation.
Look back at the recent post on Biological control with Varroa for a reminder of the devastation wreaked on an island population of honey bees after the introduction of mites.
Wild? They’re livid feral …
Technically, swarms lost by beekeepers (that become established in the environment) are probably best termed feral colonies.
Originally feral meant simply ‘wild or untamed’, but the more common usage these days means ’animals or plants that have lapsed into a wild form from a domesticated condition’.
Bees aren’t domesticated, but I think feral conveniently encompasses their origin.
However, I’m more than happy to accept that a colony, initially feral, that becomes well-established in the church tower and throws off a swarm or two every year, that requeens every two or three seasons, surviving without intervention or management, must be considered ‘wild’ at some point.
It’s not worth discussing when a colony transitions from feral to wild.
It’s semantics, though I think the distinction between ‘recently arrived from a swarmed managed colony’ and ‘self-sustaining’ is an important one.
Notwithstanding the ravages of Varroa, whether feral or wild, there are colonies in the environment – churches, schools, trees – and probably rather more than many beekeepers are aware of.
The missing bees
Periodically there’s a little flurry of interest in the press about ‘long lost’ or ‘missing’ wild bees discovered in the woods.
Late last summer there were articles in all the newspapers about bees found on Blenheim Estate. TheObserverreported this discovery with the headline ”No one knew they existed”: wild heirs of lost British honeybee found at Blenheim.
‘Blenheim bees’ article in the Observer, 7-11-21
As an aside – as this isn’t the real topic for discussion today – there are at least three challenging claims made in that headline; how can you be sure that no-one knew they existed? Is the British honey bee (it is not honeybee) actually lost? How do you know that these bees are their heirs?
Pedantic is my middle name.
But the 2500 hectare Blenheim Estate 4 isn’t the only location with apparently self-sustaining populations of honey bees. There are trees, churches and (I dare say) even nursery schools up and down the country that appear to have a ‘resident’ colony or two of bees.
Periodically they’re observed swarming. Sometimes things seem a bit quiet in the spring, but perhaps it’s too cold for the bees to be flying strongly anyway.
By May there’s a lot of activity so all must be well.
These wild/feral colonies are infrequent but widely distributed. They are therefore difficult for one person to regularly observe. As a consequence there are several ‘citizen science’ projects monitoring some of these sites. Magnus Peterson regularly reports inThe Scottish Beekeeper on the one he coordinates for the University of Strathclyde.
The criticism of these types of studies – certainly not Magnus’s specifically – but any study the largely relies upon infrequent observation by volunteers, is that stuff gets missed. A visit doesn’t happen because it’s raining hard. Or it does happen in heavy rain and no activity is observed and the colony is recorded as dead.
Or worse, recorded as alive, but not flying because of the heavy rain.
With more systematic observation, though not necessarily more frequent, you can have increased certainty that the site that was occupied last autumn is still occupied this spring.
The timing of these observations is important. Three per season is probably the minimum, early, mid and late, but they have to be at particular times of the season – see below.
So, let’s assume a colony is found in the autumn and the same hollow tree is occupied in late-April the following year … yippee, the colony is still alive.
Feral – or are they now wild? – bees living successfully with Varroa (at least presumably living with Varroa if they’re almost anywhere in mainland UK).
Perhaps they’ve evolved to have some interesting and useful trait(s) that renders the colony resistant to or tolerant of the dreaded parasitic mites?
These are valuable bees.
They are an important genetic resource.
They must be protected at all costs.
Perhaps it’s time to set up a web colony cam to record their activity? That’s going to cost a pretty penny, so some crowdfunding is needed.
A website is created … a dozen mini-nucs are purchased for the ambitiously planned queen rearing programme and – inevitably – there’s a misquoted article or two in the Guardian.
But hold on …
Are they really the same colony in April that were there the previous autumn?
How can you be sure?
How can you be certain that it’s not an unseasonably early swarm that was missed by the – usually eagle-eyed – local beekeepers? 5
It’s not unusual to find the odd charged queen cell during the first colony inspection of the season. At least, I’ve sometimes found queen cells during that first inspection. I’m sufficiently experienced to not go rummaging about in the boxes too early in the season, and so I am sometimes surprised at how well developed the colony is when I open the box.
Charged queen cell
But what if it had been raining, so I’d postponed the inspection?
On the next warm spring day – well before I was able to return to the apiary – the colony could swarm.
I’ve regularly seen April swarms in Scotland and there are many reports of even earlier swarms on social media every year.
Perhaps the active ‘overwintered’ colony is nothing of the sort.
Maybe it’s just been occupied by a very early swarm?
To be sure it’s the same colony you need to do some genetic testing. If the colony is the same the genetic testing will show identity. If the testing shows significant variation then it’s a different colony.
And, if you combine some genetic testing of overwintered colonies with three carefully-timed visits – late season, very early season and mid-season – to a large number of wild/feral colonies, or likely sites that they would occupy, you can determine their longevity and whether they are a self-sustaining population.
And I wouldn’t have given that long and rambling introduction if there wasn’t a recent scientific paper where they’ve done exactly that (Kohl et al., 2022). I’ll describe it briefly as it’s a nicely written and compelling story. The paper is open access, so you can read it if you want to check my interpretation of the data.
Importantly, I think it provides a very good guide to both the quality and quantity of data that are needed to be sure a population of bees are truly wild and self-sustaining 6 … or just regularly boosted by careless local beekeeping!
Feral colonies are few and far between. It’s hard work walking around the woods looking for hollow trees that may (but probably won’t) contain a colony. You find lots of trees with holes, but they need to lead to a suitably-sized cavity to be of any use to a colony of bees. Binoculars help (the holes are often 15 metres off the ground) … but perhaps there are better ways of doing this?
A bee tree?
Bee-lining – as described by Seeley inFollowing the Wild Bees – is an effective way of tracking down wild colonies, but needs good weather, good forage and ample time. It works well when locating a few colonies, but probably takes too long if you want 100+ to produce a statistically compelling set of results.
But what if you also wanted to record how many new nest sites are occupied? You would need to know where the empty cavities were before they were occupied. That’s not something you can determine by bee-lining, so you’re back to traipsing around the woods with a pair of binoculars.
But in Germany they have some very large woodpeckers.
The black woodpecker (Dryocopus martius) is a crow-sized bird that excavates correspondingly large holes for nest sites in old-growth forests. The average volume of a black woodpecker nest is about 10 litres, smaller than optimal for a swarm, but appreciably larger than most ‘natural’ tree cavities.
Conveniently, there are high-resolution maps of (historical) woodpecker nesting trees in old-growth forests in Swabian Alb, Weilheim-Schongau and the counties of Coburg and Lichtenfels. 98% of these woodpecker nest sites are in large beech trees, most are 10-12 metres above ground and with an entrance of ~10cm diameter (again, not optimal, but better than no nest site for a swarm).
Kohl and colleagues surveyed about 460 of these ‘cavity’ trees three times per season; in July (after the main May/June swarming season) to determine peak occupancy rates, in mid/late September to determine late summer survival and in early/mid April to determine winter survival.
‘Occupancy’ was determined by visual inspection and regular forager activity and/or pollen loads (i.e. they ignored scout bees checking empty cavities). In addition, for some colonies, a dozen or so workers were collected for genetic analysis.
With these data, the mathematical calculation of annual survival rates could be determined, as could the prediction of the annual numbers of swarms needed per colony for the population to be self-sustaining 7. In addition, it was possible to determine the average lifespan of a colony.
There were a bunch of perfectly reasonable assumptions made, based upon the known biology of honey bees – all are listed in the paper.
Yo-yoing colony numbers
The scientists counted colony numbers, but could also determine colony densities per km2. By making observations over a 3-4 year period it was strikingly obvious that the largest number of ‘cavity’ trees were occupied after swarming in summer, but that numbers dropped dramatically overwinter. This ’recurring temporal pattern of population fluctuations’ is very obvious in the major data figure in the paper.
Temporal population fluctuations of feral honey bee colonies in Germany; A) occupancy rates, B) population density
The average maximum occupancy rate and population density was 11% and 0.23 colonies per km2. This ‘dropped massively’ over the winter to just 1.4% and 0.02 colonies per km2.
The majority of nest sites (n = 112) occupied in late summer were unoccupied the following spring, before swarming started. 90% of colonies survived the summer (from July until late September), but only 16% of colonies survived the following winter.
The spring survival rate was calculated as 74% based upon genetic testing of colonies in early spring and mid-summer
Knowing the summer, winter and spring survival rates enables the annual survival rate to be calculated.
This was a sobering 10.6%.
Therefore, to maintain a stable population, each surviving colony would need to produce an average of 8.4 swarms per season.
That’s an unachievable amount of swarming.
The average lifespan of a feral colony in these three German forest regions was just 0.619 years … a little over 32 weeks.
Clearly, these honey bee populations are not self-sustaining.
Are these German forests typical?
There are two other regions where similar quality data exists for wild/feral honey bee populations. These are the Arnot forest in the USA, studied for decades by Thomas Seeley, and Wyperfield National Park in Australia.
There are striking differences between these two regions and the German forests, both in terms of colony lifespan and swarm numbers needed to be self-sustaining.
For the Arnot forest and Wyperfield National Park, lifespan was calculated as 1.34 and 1.53 years respectively (cf. 0.62 years for Germany), with annual survival of ~50% (cf. 11% in Germany). Annual swarm numbers per colony for the population to be self-sustaining was 0.94 and 0.85 for the the Arnot forest and Wyperfield National Park respectively (cf. 8.43 for the German forests).
Other than these obvious differences in the related figures for survival/longevity and ‘swarms needed’ the other significant difference between self-sustaining populations (like the Arnot forest and Wyperfield National Park) is the colony density.
In areas where feral/wild honey bees are self-sustaining the colony density is at least 1 per km2. In contrast, in Germany and a large number of other studied feral populations in other parts of Europe (including Ireland, Spain, Serbia, Poland and other regions of Germany), the colony density is usually much lower, at 0.1-0.2 per km2.
So, these German forests are seemingly typical of honey bee populations that are not self-sustaining. These are regions where the feral population is boosted annually (and is essentially dependent upon) an influx of swarms that become temporarily established in natural nest sites.
Environmental colony density
Where do all these swarms come from?
The average managed honey bee colony density in the areas of Germany studied is 4 per km2, appreciably higher than either the Arnot forest or Wyperfield National Park. Precise figures for these two were not quoted, but in both locations the feral colonies (remember, these were at ~1 per km2) outnumber managed colonies.
It therefore seems very likely that managed colonies from farmland areas surrounding the German forests acts as the source for swarms, and the latter – because of the paucity of suitable nest sites in the arable land (relatively few buildings, few mature trees etc.) – gravitate towards the forests looking for suitable nest sites.
Feral and managed colonies may therefore be spatially separated, though not very widely. In contrast, in urban environments – where nest sites are probably common – it might be expected that feral and managed colonies are intermixed in the environment.
A by-product of the study by Kohl and colleagues is that they could also calculate the difference in the relative attractiveness of woodpecker nests that had previously, or had never, been occupied by bees. When new colonies occupied woodpecker nest sites there was a strong preference of 5 to 15-fold for sites that had previously been occupied by bees.
This, of course, is why it makes sense to include a single old, dark comb in your bait hives.
That seems like a good place to stop …
I think this German study is interesting. It shows the quantity and quality of data needed to make a compelling case that a location has a self-sustaining population of feral/wild honey bees.
Such locations are likely to exhibit colony densities of at least 1 per km2 and to be physically separated from higher density managed colonies. This physical separation could be in the form of simple geographic isolation – just a long way from other apiaries – or something more complex like being surrounded by high hills or water etc.
Self-sustaining wild/feral populations are likely to exhibit >50% annual survival rates, to live for an average of ~1.5 years and to produce about 0.8-0.9 swarms per colony per year 8.
If survival rates are lower, or the life expectancy of a colony is much less, then the number of swarms needed to maintain the population rapidly becomes so high that they are unattainable.
In which case, large numbers of feral/wild colonies cannot be self-sustaining, but instead must be present because the area acts as a ‘sink’ for lost swarms from nearby managed colonies.
This post is already longer than my self-imposed-but-regularly-exceeded 3000 word limit so I’ll save further discussion of the Blenheim bees and other feral colonies for another post.
However, I hope the study shows that a healthy scepticism is perhaps sensible when considering any claims made about self-sustaining feral colonies.
That church tower in which ‘there have always been bees’ may well have had bees in it every year.
But that’s not the same as having the same bees in it.
In fact, with an ~90% attrition rate of feral colonies annually it’s very unlikely to be the same colony in successive years.
In the final stages of completing this post – very, very late at night – I re-discovered an article (Moro et al., 2018) on citizen science and feral colonies that I’ll return to sometime in the future.
Kohl, P.L., Rutschmann, B. and Steffan-Dewenter, I. (2022) ‘Population demography of feral honeybee colonies in central European forests’, Royal Society Open Science, 9(8), p. 220565. Available at: https://doi.org/10.1098/rsos.220565.
Moro, A. et al. (2021) ‘Using Citizen Science to Scout Honey Bee Colonies That Naturally Survive Varroa destructor Infestations’, Insects, 12(6), p. 536. Available at: https://doi.org/10.3390/insects12060536.
Synopsis : Bees don’t use a diary. Colony development is influenced by local environmental conditions. These are largely determined by latitude and longitude but also vary from year to year. Understanding these influences, and learning how to read the year to year differences, should help you judge colony development. You’ll be better prepared for swarm prevention and control, and might be able to to identify minor problems before they become major problems.
Writing a weekly post on beekeeping inevitably generates comments and questions. Over the last 5 years I’ve received about 2500 responses to posts and at least double that in email correspondence. That works out at ~30 comments or questions a week 1.
Every one of them – other than the hate mail and adverts 2 – has received a reply, either online or by email.
Some are easy to deal with.
It takes just seconds to thank someone for a ”Great post, now I understand” comment, or to answer the ”Where do I send the cheque? question.
Others are more difficult … and the most difficult of all are those which ask me to diagnose something about their hive.
I almost always prefix my response by pointing out that this sort of online diagnosis is – at best – an inexact art 3.
Patchy brood & QC’s …
Think about it … is your definition of any of the following the same as mine?
Engaging in to and fro correspondence to define all these things isn’t really practical in a week containing a measly seven 24 hour days.
However, having stated those caveats, there’s still the tricky issue of geography.
Many correspondents don’t mention where the hive is – north, south, east, west (or in a couple of instances that they are in the southern hemisphere 6).
Location has a fundamental impact on your bees. The temperature, rainfall, forage availability etc. all interact and influence colony development. They therefore determine the timing of what happens when in the colony.
And so this week I decided to write a little bit about the timings of, and variation in, environmental events that influence what’s going on inside the hive.
I’ll focus here on latitude and temperature as it probably has the greatest influence. My comments and examples will all be UK based as it’s where a fraction over 50% of the readers are, but the points are relevant in all temperate areas.
Temperate climates – essentially 40°-60° north or south of the equator – experience greater temperature ranges through the year and have distinct seasons (at least when compared with tropical areas). Whilst latitude alone plays a significant role in the temperature range – smaller nearer the equator – the prevailing wind, altitude, sea currents and continentality 7 also have an important influence.
For starters let’s consider the duration of the year during which foraging might be possible. I’ll ignore whether there’s any forage actually available, but just look at the temperature over the season at the northern and southern ends of mainland Great Britain.
I arbitrarily chose Thurso (58.596°N 3.521°W) and Penzance (50.119°N 5.537°W) for these comparisons. Both are lovely coastal towns and both are home to native black bees, Apis mellifera mellifera8.
The lowest temperature I have observed my native black bees flying on the west coast of Scotland was about 8°C 9. So, let’s assume that the ‘potential foraging’ season is defined by an average maximum daily temperature above 8°C.
How do Penzance and Thurso compare?
Thurso – average Max/Min temperatures (°C)
In Thurso there are eight months (November just squeezed in by 0.1°C) where the average maximum daily temperature exceeds 8°C.
Penzance – average Max/Min temperatures (°C)
In contrast, every month of the year in Penzance has an average maximum daily temperature exceeding 8°C.
Thurso and Penzance are just 950 km apart as the bee flies.
I don’t have information on the forage available to bees in Penzance or Thurso, but I’m sure that gorse is present in both locations. The great thing about gorse is that it flowers all year, or – more accurately – individual, genetically distinct, plants can be found every month of the year in flower.
Based upon the temperature it’s possible that Penzance bees could forage on gorse in midwinter and so be bringing fresh pollen into the hive for brood rearing.
The gorse is in flower … somewhere under there
However, further north, gorse might be flowering but conditions may well not be conducive for foraging.
Inevitably, warmer temperatures will extend the range of forage types available, so increasing the time during the year in which brood rearing can occur 10.
In reality, at temperatures below 12-14°C bees start to cluster 11 and bees chilled to 10°C cannot fly. It’s unlikely much foraging could be achieved at the 8°C used in the examples above 12.
The point is that different latitudes differ greatly in their temperature, and hence the forage that grows, the time it yields nectar and pollen, and the ability of the bees to access it.
The availability of forage has a fundamental impact on the ability of the colony to rear large amounts of new brood.
It’s not until foraging starts in earnest that brood rearing can really ramp up.
Similarly, low temperatures in autumn, reduce the availability of nectars and ability of bees to forage, so curtailing brood rearing 13.
And the ability to effectively treat mites in the winter is largely determined by the presence or absence of sealed brood. If there is sealed brood in the colony there will also be mites gorging themselves on the capped pupae. These mites are untouched by the ‘usual’ winter miticide, oxalic acid.
I’ve not kept bees in either of those locations, but I know my bees in Fife (56°N) are reliably broodless at some point between late October and mid-December. Varroa management is therefore relatively straightforward, and Varroa levels are under control throughout the season.
In contrast, when I kept bees in Warwickshire (52°N) there were some winters when brood was always present, and Varroa control was consequently more difficult. Ineffective control in the winter results in higher levels of mites earlier in the season.
Brood rearing models
To emphasise the differences here are two images generated from Randy Oliver’s online Varroa Model, just showing the amounts of brood in all stages and adult bees 14. The overall colony sizes and amount of brood reared are about the same, but the ‘hard winter’ colony (no foraging for five months) is broodless for a much greater period.
The brood and bee population in hives that experience ‘default’ and ‘hard’ winters
Without knowing something about the latitude and/or the likelihood of there being capped brood present in the hive, it’s impossible to give really meaningful answers to questions about winter mite treatment.
This also has a bearing on when you conduct your first inspections of the season.
It is also relevant when comparing what other beekeepers are discussing on social media – e.g. those ’8 frames of brood’ I mentioned last week. If it’s early April and they’re in Penzance (or Perigord) then it might be understandable, but if you’re in Thurso don’t feel pressurised into checking your own colonies as it may well be too early to determine anything meaningful.
Year on year variation
But it’s now approaching late April and most beekeepers will be starting to think/worry about swarm control.
When should you start swarm prevention and, once that fails, when must you apply swarm control?
Or, if you’d prefer to take a more upbeat view of things, when might you expect your bait hives to be successful and when should you start queen rearing?
Again, like almost everything to do with beekeeping, dates are pretty meaningless as your colonies are not basing their expansion and swarm preparations on the calendar.
They are responding to the environmental conditions in your particular locality and in that particular year.
Which brings me to year on year variation.
Not every year is the same.
Some seasons are warmer than others – the spring might be ‘early’ or there might be an ‘Indian summer’. In these instances foraging and brood rearing are likely to start earlier or finish later.
One way to view these differences is to look at the Met Office climate anomaly maps. These show how different the climate – temperature, rainfall, sunshine etc. – can be from year to year when compared to a 30 year average.
Met Office anomaly charts – spring temperatures 2020 and 2021 (compared to 30 year averages)
Here are the anomaly maps for the last two springs. For almost all of the country 2020 was unusually warm. Penzance was 1.5°C warmer than the 30 year average. In contrast, over much of the country, 2021 was cooler than the 1990-2010 average.
So when considering how the colony is developing it’s important to consider the local conditions.
Those Met Office charts are retrospective … for example, you cannot see how this spring compares with previous years (at least, not yet 15.).
And, while we’re on the subject of anomalies … here are the rainfall charts for the summers of 2012 and 2021.
Met Office anomaly charts – summer rainfall 2012 and 2021 (compared to 30 year averages)
I suspect that both were rather poor years for honey. 2012 was – with the exception of Thurso! – exceedingly wet. My records for that year don’t include honey yield 16.
Last year was generally dry, and very dry in the north and west 17. Since a good nectar flow often needs moisture in the soil it may have been poor for many beekeepers.
It was my first full season on the west coast and the heather honey yield was disappointing (but it’s not a great heather area and I’ve nothing to compare it with … perhaps I’ll be disappointed every year?). However, I managed a record summer honey crop in Fife from a reduced number of hives. Quite a bit of this was from lime which I always think of as needing rain to get a good flow from, so perhaps the little rain we did have was at the right time.
Local weather and longitude
If you really want to know what the weather has been doing in your area you probably need something more fine-grained and detailed than a Met Office chart. There are very large numbers of ‘personal weather stations’, many of which share the data they generate with websites such as windy.com or wunderground.com.
Find one by searching these sites and you’ll be able to access recent and historical weather data to help you determine whether colony build up is slow because it’s been colder and wetter than usual. Or – if the conditions have been ideal (or at least normal) but the colony is struggling – whether the queen is failing, if there’s too much competition for forage in the neighbourhood, or if there might be disease issues.
Of course, judgements like these mean you need to have good records year on year, so you know what to expect.
To emphasise the local influence of prevailing winds and warm sea currents it’s interesting to note that my west and east coast apiaries – which are at almost the same latitude 18 – experience significantly different amounts of rainfall.
We had >270 mm of rain in November 2021 on the west coast, compared to ~55 mm on the east. In July 2021 the figures were 43 mm and 7 mm respectively.
All of which I think makes a good argument for rearing local bees that are better adapted to the local conditions 19. That’s something I’ve discussed previously and will expand upon further another time.
Rainfall charts and meteorological tables are all a bit dull.
An additional way a beekeeper can observe the progression of the season, and judge whether the colony is likely to be developing as expected, or a bit ahead or a bit behind, is to keep a record of other environmental events.
This is phenology, meaning ‘the timing of periodic biological phenomena in relation to climatic conditions’.
Are frogs spawning earlier than normal?
When did the first snowdrops/crocus/willow flower?
Are the arrival dates of migrant birds earlier or later than normal?
I’m poor at identifying plants 20 so tend to focus on the animals. The locals – frogs, slow worms, toads, bats, butterflies, dragonflies – are all influenced by local conditions. Many don’t make an appearance until well into the beekeeping season.
Or perhaps I just don’t notice them?
In contrast, the avian spring migrants appear in March and April. These provide a good indication of whether the spring is ‘early’ or ‘late’.
For example, cuckoo arrived here in 2020 (a warm spring) on the 18th of April. In 2021, a cold spring, they didn’t make an appearance until the 24th.
This year, despite January to March being warmer than average, they have yet to arrive. The majority of GPS-tagged birds are still en route, having been held up by a cold start to April 21, though some have just 22 arrived in southern Scotland.
Wheatear are also several days later this year than the last couple of seasons, again suggesting that the recent cold snap has held things back.
You can read more about arrival dates of spring migrants on the BTO website.
Beekeeping is not just bees
Much of the above might not appear to be much to do with beekeeping.
But, at least indirectly, it is.
Your bees live and work in a small patch of the environment no more than 6 miles in diameter. That’s a very small area (less than 30 square miles). The local climate they experience will determine when they can forage, and what they can forage on. In turn, this influences the timing of the onset of brood rearing in the spring (or late winter), the speed with which the colony builds up, the time at which winter bees start to be reared and the duration of the winter when it’s either too cold to forage or there’s nothing to forage on (or both).
As a beekeeper you need to understand these events when you inspect (and judge the development of) your colonies. Over time, with either a good memory or reasonable hive records, you can make meaningful comparisons with previous seasons.
If your colony had ’8 frames of brood’ in mid-April 2020 (a warm year) and your records showed they swarmed on the 27th, then you are forewarned if things look similar this season.
Conversely, if spring 2020 and this year are broadly similar (and supported by your comprehensive phenological records 23 ) but your bees have just two frames of brood then something is amiss.
Of course, the very best way to determine the state of the colony is to inspect it carefully. Understanding the environmental conditions helps you know what to expect when you inspect.
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:
supersedure – in which the colony rears a new queen to eventually replace the current queen in situ.
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).
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 🙁
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 oriented3 worker cells which, should the need arise, are re-engineered to face vertically.
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.
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 …
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.
Queen cells can occur anywhere in the hive to which the queen has access.
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 …
… 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 notinvariably 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 …
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.
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.
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 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 …
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 onthe 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 🙂