Winter bee production

There are big changes going on in your colonies at the moment.

The summer foragers that have been working tirelessly over the last few weeks are slowly but surely being replaced. As they die off – whether from old age or by being eaten by the last of the migrating swallows – they are being replaced by the winter bees.

Between August and late November almost the entire population of bees will have changed. The strong colonies you have now (or should have) will contain a totally different workforce by the end of the year.

Forever young

The winter bees are the ones responsible for getting the colony from mid/late autumn through to the following spring. They are sometimes termed diutinus bees from the Latin for “long lived”.

These are the bees that thermoregulate the winter cluster, protecting the queen, and rearing the small amounts of brood during the cold, dark winter to keep the colony ticking over.

Midwinter cluster

A midwinter colony

Physiologically they share some striking similarities with so-called hive or nurse bees 1 early in the summer.

Both hive bees and winter bees have low levels of juvenile hormone (JH) and active hypopharyngeal glands. Both types of bee also have high levels of vitellogenin, high oxidative stress resistance and corpulent little bodies.

But early summer nurse bees mature over a 2-3 week period. Their JH levels increase and vitellogenin levels decrease. This induces additional physiological changes which results in the nurse bee changing into a forager. They sally forth, collecting nectar, pollen and water …

And about three weeks later they’re worn out and die.

Live fast, die young

And this is where winter bees differ. They don’t age.

Or, more accurately, they age   v  e  r  y    s  l  o  w  l  y.

In the hive, winter bees can live for 6 months if needed. Under laboratory conditions they have been recorded as living for up to 9 months.

They effectively stay, as Bob Dylan mumbled, forever young.

Why are winter bees important?

Although not quite eternal youth … staying forever young is useful as their longevity ensures that the colony does not dwindle and perish in the middle of winter.

With little or no nectar or pollen available in the environment the colony reduces brood rearing, and often stops altogether for a period.

But what about the kilograms of stores and cells filled with pollen in the hive? Why can’t they use that?

Whilst both are present, there’s nothing like enough to maintain the usual rate of brood rearing. If they tried the colony would very quickly starve.

Evolution has a very effective way of selecting against such rash behaviour 🙁

If you doubt this, think how quickly hives get dangerously light during the June gap. With no nectar coming in and thousands of hungry (larval) mouths to feed the colony can easily starve to death during a fortnight of poor weather in June.

The winter bees ‘hold the fort’, protecting the queen and rearing small amounts of brood until the days lengthen and the early season pollen and nectars become available again.

And, just as the winter bees look after the viability of the colony, the beekeeper in turn needs to look after the winter bees … we rely on them to get the colony through to spring.

Lots of bees

Can you identify the winter bees?

But before we discuss that, how do you identify and count the winter bees? How can you tell they are present? After all, as the picture above shows 2, all bees look rather similar …

Counting the long lived winter bees

The physiological changes in winter bees, such as the JH and vitellogenin levels, are only identifiable once you’ve done some rather devastating things to the bee. These have the unfortunate side effect of preventing it completing any further bee-type activities 🙁

Even before you subject them to that, their fat little bodies aren’t really sufficiently different to identify them visually.

But what is different is their longevity.

By definition, the diutinus or winter bees are long lived.

Therefore, if you record the date when the bee emerged you can effectively count back and determine how old it is. If it is more than ~6 weeks old then it’s a winter bee.

Or the queen 😉

And, it should be obvious, if you extrapolate back to the time the first long lived bees appear in the hive you will have determined when the colony starts rearing winter bees.

The obvious way to determine the age of a bee is to mark it upon emergence and keep a record of which marks were used when. Some scientists use numbered dots stuck to the thorax, some use combinations of Humbrol-type paint colours.

I’m not aware that anyone has yet used the barcoding system I discussed recently, though it could be used. The winter bee studies I’m aware of pre-date this type of technology.

Actually, some of these studies date back almost 50 years, though the resulting papers were published much more recently.

This is painstaking and mind-numbingly repetitive work and science owes a debt of gratitude to Floyd Harris who conducted many of the studies.

Colony age structure – autumn to winter

Here is some data showing the age structure of a colony transitioning from late summer into autumn and winter. There’s a lot in this graph so bear with me …

Colony age structure from August to December - see text for details

Colony age structure from August to December – see text for details

The graph shows the numbers and ages of bees in the colony.

The ages of the bees is indicated on the vertical axis – with eggs and brood (the youngest) at the bottom, coloured black and brown respectively. The adult bees can be aged between 1 and ~100 days old 3. The number of bees is indicated by the width of the coloured bar at each of the nine 12 day intervals shown.

All of the adult bees present in the hive at the end of August are coloured blue, irrespective of their age. There are a lot of these bees at the end of August and almost all of them have disappeared (died) by mid-November 4.

The remaining colours indicate all the bee that emerge within a particular 12 day interval. For example, all the bees that emerge between the 31st of August and the 12th of September are coloured yellow.  Going by the width (i.e. the numbers of bees of that age) of the yellow bars it’s clear that half to two-thirds of these bees die by mid October, with the rest just getting older gracefully.

But look at the cohort that emerge between the end of September and early October, coloured like this 5. The number of these bees barely changes between emergence and early December. By this time they are 72 days old i.e. an age that most summer bees never achieve.

Brood breaks and climate

In the colony shown above the queen continued laying reduced numbers of eggs – the black bars – until mid-October and then didn’t start again until the end of November. During this period the average age of the bees in the colony increased from ~36 days to ~72 days and the strength of the colony barely changed.

The figure above comes from a BeeCulture article by Floyd Harris. The original data isn’t directly referenced, but I suspect it comes from studies Harris conducted in the late 70’s in Manitoba, some of which was subsequently published in the Journal of Apicultural Research. In addition, Harris co-authored a paper presenting similar data in a different format in Insectes Sociaux which describes the Manitoban climate as having moderate/hot summers and long, cold winters.

My hives in Scotland, or your hives in Devon, or Denmark or wherever, will experience a different climate 6.

However, if you live in a temperate region the overall pattern will be similar. The summer bees will be replaced during the early autumn by a completely new population of winter bees. These maintain the colony through to the following spring.

The dates will be different and the speed of the transition from one population to the other may differ. The timing of the onset of a brood break is likely to also differ.

However, the population changes will be broadly similar.

And, it should be noted, the dates may differ slightly in Manitoba (and everywhere else) from year to year, depending upon temperature and forage availability.

Colony size and overwintering survival

Regular readers might be thinking back to a couple of posts on colony size and overwintering survival from last year.

One measured colony weight, showing that heavier colonies overwintered better 7. A second discussed the better performance of local bees in a Europe-wide study of overwintering survival. In this, I quoted a key sentence from the discussion:

“colonies of local origin had significantly higher numbers of bees than colonies placed outside their area of origin”

I can’t remember when during the season those studies recorded colony size, but I’m well aware that large colonies in the winter survive better.

The colonies that perish first in the winter are the pathetic grapefruit-sized 8 colonies with ageing queens or high pathogen loads.

In contrast, the medicine ball-sized ‘boomers’ go on and on, emerging from the winter strongly and building up rapidly to exploit the early season nectar.

But what the graph above shows is that the bees in a strong colony in late summer are a completely different population from the bees in the colony in midwinter.

The strength of the midwinter colony is determined entirely by when winter bee rearing starts and the laying rate of the queen, although of course both may be indirectly influenced by summer colony strength.

The influence of the queen

Other than this potential indirect influence, it’s possibly irrelevant how large the summer colony is in terms of winter colony size (and hence survival).

After all, even if the summer bees were three times as numerous, their fate is sealed. They are all going to perish six weeks or so after emergence.

Are there ways that beekeepers can influence the size of the overwinter colony to increase its chances of survival?

I wouldn’t pose the question if the answer wasn’t a resounding yes.

It has been known for a long time 9 that older queens stop laying earlier in the autumn than younger queens. As explained above, the longer the queen lays into the autumn the more winter bees are going to be produced.

Mattila et al., 10 looked at the consequences of late season (post summer honey harvest) requeening of colonies. In these they removed the old queen and replaced her with either a new mated or virgin queen, or allowed the colony to requeen naturally.

Using the ’12 day cohort’ populations explained above, the authors looked at when the majority of the winter bees were produced in the colony, and estimated the overall size of the winter colony.

The influence of new queens on winter bee production.

The influence of new queens on winter bee production. Note shift to the right in B, C and D, with new queens.

With the original old queen, 53% of winter bees were produced in the first two cohorts of winter bees. With the requeened colonies 54-64% of the winter bees were produced on average 36 days later, in the third and fourth cohorts of winter bees.

This indicates that young queens produce winter bees later into the autumn.

This is a good thing™.

In addition, though the results were not statistically significant, there was a trend for colonies headed by new queens to have a larger population of bees overwinter.

Perhaps one reason the requeened colonies weren’t significantly larger was that the new queens delay the onset of winter bee rearing. I’ll return to this at the end.

The influence of deformed wing virus (DWV)

Regular readers will know that this topic has been covered extensively, and possibly exhaustively, elsewhere on this site … so I’ll cut to the chase.

DWV is the most important virus of honey bees. When transmitted by Varroa destructor there is unequivocal evidence that it is associated with overwintering colony losses. The reason DWV causes overwintering losses is that it reduces the longevity of the winter bees.

The virus might also reduce the longevity of summer bees but,

  1. there’s so many of them to start with
  2. there’s loads more emerging every day, and
  3. they only survive a few weeks anyway,

that this is probably irrelevant in terms of colony survival.

Dainat et al., (2012) produced compelling evidence showing that DWV reduces the longevity of winter bees 11. The lifespan was reduced by ~20%.

A consequence of this is that the winter bees die off a little faster and the colony shrinks a little more. At some point it crosses a threshold below which it cannot thermoregulate the cluster properly, further limiting the ability of the colony to rear replacement bees (assuming the queen is able to lay at a low rate).

This colony is doomed.

Even if they stagger through to the longer days of spring they contain too few bees to build up fast. They’re not dead … but they’re hardly flourishing.

Winter bees and practical beekeeping

I think there are three ways in which our understanding of the timing of winter bee production should influence practical beekeeping:

Firstly … The obvious take-home message is that winter bees must be protected from the ravages of DWV. The only way to do this is to minimise the mite population in the colony before the winter bee rearing starts.

The logical way to do this is to treat using an approved miticide as soon as practical after the summer honey is removed 12.

I discuss the importance of the timing of this treatment in When to treat?, which remains one of the most-read posts on this site.

Secondly … Avoid use of miticides (or other colony manipulations) that reduce the laying rate of the queen in early autumn.

When I used to live at lower latitudes I would sometimes use Apiguard. This thymol-containing miticide is very effective if used when the temperature is high enough. However, in my experience a significant proportion of queens stop laying when it is being used. Not all, but certainly more than 50%.

I don’t know why some stop and others don’t. Is it genetic? Temperature-dependent?

Whatever the reason, they stop at exactly the time of the season you want them to be laying strongly.

Thirdly … consider requeening colonies with young queens after the summer honey is removed. This delays the onset of winter bee production and results in the new queen laying later into the year. The later start to winter bee production gives more time for miticides to work.

A win-win situation.


 

Footnotes

  1. i.e. bees that stay in the hive and have yet to develop foraging activity.
  2. And you’re probably already aware as this is a site for beekeepers!
  3. Data collection stopped at this point … if it had continued, the bees would have been shown to live longer.
  4. The few shown as remaining may be a graphing artifact. Numerically they’re a tiny component and we can safely ignore them.
  5. I’m colourblind, so can match the colour digitally, but can’t name it!
  6. Unless you live in Manitoba, and about 3% of the readership of this site are from Canada, so it might be rather similar for you.
  7. But there was also a relationship with colony size – large colonies collect more nectar and so weigh more.
  8. Or smaller.
  9. For example, Cale, G.H. (1956) In The Pink For Winter. American Bee Journal. 96:397 – 400.
  10. Matilla et al., (2001) Timing of production of winter bees in honey bee (Apis mellifera) colonies. Insectes soc. 48:88–93
  11. See also van Dooremalen C et al. (2012) Winter Survival of Individual Honey Bees and Honey Bee Colonies Depends on Level of Varroa destructor Infestation. PLoS ONE 7: e36285.
  12. There may be other ways to do this but I’ve seen no compelling evidence that other methods are at least as efficient and have as little detrimental effect on the bees.

19 thoughts on “Winter bee production

  1. John Swan

    I live in Cyprus. The part I live in is classified as sub tropical. I found this article very interesting but was wondering if winter bees will be produced here? I’ve just got into beekeeping having wanted to do it for ages. Retired and now have time!! I used to live in Dunfermline Fife so your piece would have been very apt. Finally, can you recommend sources which give guidance to beekeeping in Cyprus/ sub tropical areas.
    Thank you for the time you take to write your articles/posts… I really benefit from them

    Reply
    1. David Post author

      Hello John

      The bottom line is I don’t know anything about beekeeping in semi-tropical countries … there’s been no need because no amount of global warming is going to make Fife semi-tropical 😉 My guess would be that the bees rear brood year-round if there’s forage available. That being the case, there would be no need for winter bees. The physiology of the winter bee has evolved to get the colony through periods when it’s cold and there’s no forage available. You won’t have the former and you may not have the latter.

      Cyprus isn’t that much further south than parts of southern Spain I know where the beekeeping (and the honey) is rather good.

      Andalucian apiary

      You might want to have a look at the Beemaster Forum which is an international discussion forum for beekeepers. There are some commercial queen rearing operations in Cyprus I’m aware of, but that’s about the limit of my knowledge.

      Good luck
      David

      Reply
    2. Arnaud Ludet

      Hi John You probably know Dominique ? A wellknown french beekeeper in Chyprus (near Nicosia) who has been doing this for the past 30 years.

      Reply
  2. vince poulin

    David – many bee keepers fail to learn the principles you talk about due to not informed or simply casual bee keepers. They have one hive, love bees and hope for a little honey but not so into the hobby as to endlessly test or apply strategies we learn from mentors. I have two friends who spend much less time at their hives than I do. One returned from holiday to find his 2 hives empty of bees. Long before I kept suggesting he begin mite testing. Another only recently started treating mites but reluctant to use miticides. He’s trying sugar dusting. I’ve stressed to both the importance of assessing and treating mites. I began mite treatments on 6-August followed by the remainder of hives on 14-August. Drone uncapping and mite board counts suggested I treat ASAP. I was surprised as all hives were treated in spring and all super strong all summer. Without question had I not begun the treatments my hives would have been at significant risk. Mites killed to date range from 908 to 2,990 depending on the hive. Without treatment those mites would have been inside cells feeding on winter bees. All hive retained good numbers of eggs, larvae and capped brood except one. That hive became queen less 3-days into Treatment 2. I re-queened the colony with a new 2020 queen and she is doing what young queens do – filling frames with eggs and new larvae. There is one option you did not mention in your post which could have been – “Fourthly”, augmenting colonies with frames of winter bee brood from other colonies or combining hives entirely. I’m sure you’ve said this in many previous posts but worth repeating. Cheers.

    Reply
    1. David Post author

      Hi Vince

      I’ve covered some of the first part of your comment in a long and rambling post called Principles and practice. Lots of people take up beekeeping as they like the idea of a hive at the bottom of the garden and the odd jar of honey. They have no idea that regular care and attention of the colony is needed – the inspections, the swarm control, the feeding, the mite management. They ignore it, or forget it, or do it at entirely the wrong time and the colony suffers, and often perishes. They transition from being beekeepers to being beehadders.

      I’ve lost count of the number of people who I met – at dinner parties, during county-fair demonstrations, when they came buy honey – who say something like “I used to keep bees”. I stopped asking “Why did you stop?” as the answers were usually a version of ‘they died in the winter’, ‘they swarmed when I went sailing for a month in the Med’ or ‘I got stung too many times’.

      Boosting colonies with late season brood from another hive might work but it’s not something I’d attempt. Firstly, you’d have to be sure it was winter bees. There’s no point in transferring summer bees (they’re all going to die pretty soon). To be sure they’re winter bees means you’re depleting a colony at a critical time of the season when brood rearing is decreasing. It would also be quite late in the year. I’d worry about weakening the donor hive to a point when it might become non viable.

      Of course, uniting is a much better option. It’s one I use regularly for any colonies with late-season queen problems or that look weak but healthy. In the post last week (about the last colony checks, miticide treatment and feeding) I wrote:

      “If the colony is queenless (how did that happen without me noticing earlier?) I simply unite the colony with a strong, healthy queenright colony. I don’t bother testing it with a frame of eggs … time is of the essence.”

      The colonies must be healthy and I only consider uniting a weak colony with a strong colony. Two weak colonies are very unlikely to unite and produce a strong colony.

      So … I’m a big fan of uniting, even quite late in the season. Far better that than the colony perishes overwinter. If the colony is strong and builds up well the following spring you can almost always generate a nuc without denting honey production by the hive.

      Cheers
      David

      Reply
  3. Karen Alexander

    I like the idea of re-queening after the summer honey crop has been removed, but unless you have new queens ready, the emergency queen will take about a month to Be mated and start laying. This will be well into the time when the number of drones are reducing. I know that we have a milder climate down here in Devon, but what time do you think would be best to try requeening with emergency cells yet still get good mating. I guess you would ‘Bank’ the queen you remove in case the new queen is unsuccessful as there would be no recovery if the new queen got lost/eaten/ failed.

    Reply
    1. David Post author

      Hello Karen

      An impossible question I’m afraid … it all depends upon your climate and the particular weather that year. When I lived in Warwickshire I would often manage to get a few queens mated in September … but not so reliably that I’d want to depend upon it. Here in Scotland that’s not really something worth attempting 🙁

      A far better option is to rear queens in the middle of the season when the weather and forage are more dependable, keeping them in nucs over the summer. If they get too strong you can always hold them back by removing frames of brood (often several times, replacing them with foundation which nucs draw for fun if there’s a good nectar flow) and use it to boost honey production colonies. Then, as autumn approaches, you have two options – overwinter the nucs for the following season (relatively easy and reliably profitable if you want to sell them on) or uniting them with colonies from which you’ve removed the old queen. I discussed this recently in Bigging up nucs.

      This strategy would always be my preferred option – even if I lived in balmy Devon. Everything about it is a lot more certain – the likelihood of successful queen mating and the availability of queens exactly when you need them. You’d need to invest in a few nucleus hives but they pay for themselves if you ever sell a nuc colony and provide a large amount of flexibility to your beekeeping.

      Cheers
      David

      Reply
  4. MR Nigel Hurst

    Hi David ,
    Forgive me if you have covered this already but In connection to this article, I am curious as to the mechanism in the bee behaviour that triggers the removal of the drone population. I have spent some time watching and even filming workers expending a lot of time and energy escorting drones from a garden observation hive, it seems to be individual workers that pick a drone and work pretty hard at getting them to the entrance. Other drones seem to wander about unmolested while the chosen ones are wrestled fairly roughly to the door. Just recently I watched a powerful looking drone march up the outside of a hive with a worker hanging on for bravely but rather inefectively.
    I wonder when the decision to get them out starts? In my hives this year the actual start to laying drones seemed to start later than previously. At what point does the queen go into drone mode?

    Reply
    1. David Post author

      Hello Nigel

      You’ve not missed it because I’ve not written about it. Colonies may chuck drones out during a dearth of nectar, so the nectar flow (or absence of it) is likely one trigger. I don’t know why they choose some drones, but apparently ignore others.

      Drone laying by the queen and the ratio of drone brood in the colony is something that has been studied. I’ve got a couple of PDF’s tucked away somewhere and should read them up and write about it in the future.

      Here’s a September drone who is likely in for a rude shock soon … 🙁

      It's a drone's life

      Cheers
      David

      Reply
  5. Elaine Robinson

    Hi David
    another thought provoking blog! I inspected all my colonies this week, the majority have this year’s queens. Interesting how some are in full brood rearing mode with up to 9 combs of brood in all stages, to the other extreme of one colony, with only a few patches of sealed brood though it had 7 frames of brood in all stages, just 2 weeks ago.

    This particular colony was in the the same position last year, looking back at my records, headed by the mother of the current (blue) queen. By 13 September last year, very little sealed brood & no open brood. Lots of bees in the hive, plenty of stores. This queen & progeny came through winter strong & didn’t seem to suffer from the fact that she appeared to stop brood rearing early September. I didn’t inspect in Oct or Nov, so I don’t know whether she started brood rearing again. Interesting that her daughter queen seems to be following the same pattern. Forage wise, they’re still collecting balsam & plenty of pollen still available.

    I’m feeling a bit more relaxed about this colony this year, despite the Bee Inspector who came on my visits this week, remarking “I’d keep an eye on this colony”, due to the lack of open brood. So, I’m wondering if some colonies produce their winter bees far earlier than others & whether this trait is genetic?

    Thanks again for a thought provoking post!
    Best wishes
    Elaine

    Reply
    1. David Post author

      Hi Elaine

      I’m sure there is some variation in the onset of the timing of winter bee rearing, and it may be genetic. However, I’d be surprised if there was a huge difference. It’s also worth noting that production of winter bees isn’t an all or nothing event. It’s not like throwing a switch. If you look at the yellow bar in the graph further up the page – some of these bees survive a long time, but many don’t. This early in the autumn I’d expect colonies would still be producing some short-lived summer bees, gradually transitioning to the longer lived winter bees over the next 2-4 weeks.

      From a beekeeping perspective you’d really want lots of winter bees produced as late as possible. That gives miticides a chance to work their magic and slaughter all the mites before the winter bees start being reared, but still leaves you with a good population well before winter proper starts. Here in Scotland the main crop for many beekeepers is heather honey and on the west coast the flow has only just finished in the last week or so. That potentially causes a problem for achieving both effective mite treatment and a population of winter bees largely free of mites. This is one situation where young queens should be a real benefit.

      Cheers
      David

      Reply
  6. Janey Bolton

    Hi David,
    Many thanks for another informative, useful and timely post. Having just inspected all our colonies we find ourselves in a very similar situation to Elaine. Some colonies don’t seem to have noticed that it’s Autumn, but in some there is very little open brood. One colony in particular is causing concern. There are 11 frames of bees and in mid August had 9 frames of brood. We treated with MAQS on the 19th of August. There is now no brood at all and no eggs. The queen is still there and is this years queen. We assume the MAQS put her off lay but the MAQS was removed two weeks ago. Is it too late to hope she will start laying in time to produce enough winter bees.
    We are considering uniting but are reluctant to destroy what was a very productive and very calm queen. Also if we unite at this stage will all the current bees not die off anyway in the next few weeks?
    Thanks again.
    Janey

    Reply
    1. David Post author

      Hello Janey

      You can unite much later in the season if necessary. I’d just leave them. However, I’ve no experience with MAQS so can’t comment directly whether it might be responsible. It’s certainly not too late for her to start laying again. One possibility is that there’s no nectar coming in and she’s stopped laying (or not re-started) for that reason. I’d probably look on a warm day at the end of the month and unite then if there’s still no brood.

      We usually have brood through until at least early/mid October (we do open hives for our experiments). Remember that the study I quoted above was in Manitoba – for comparison, their average highs and lows in October are 10oC and 0oC whereas for Fife it’s 12oC and 4oC. That’s a significant difference in terms of colony clustering and daytime flying.

      Hope things work out,
      David

      Reply
  7. Simon Rice

    Hi David,
    Thank you for another interesting, thought provoking article.
    Do you know if the longer brood laying period by the queen into the autumn is reproduced in feral colonies? If it was evolutionary beneficial wouldn’t a feral colony not replace its queen annually or biannually? Yet don’t feral colonies keep them queens longer than managed bees?

    Reply
    1. David Post author

      Hello Simon

      I’d be pretty certain that no-one has ever looked. Feral colonies, either because they’re in trees or other inaccessible locations, would be almost impossible to check for brood at any time in the season, let alone late into the autumn. If feral colonies have older queens on average it’s more likely that’s because beekeepers either a) choose to replace them early, b) run stronger colonies which swarm and are therefore replaced, or c) inadvertently damage the queen during an inspection so that she’s again replaced. I don’t know of any evidence that formally shows this. There’s a lot of misinformation about feral colonies. I think many are recently lost swarms from nearby managed colonies. There is some evidence to support this but I think it’s yet to make it to a peer-reviewed journal.

      It might be worth looking in The Lives of Bees by Tom Seeley. It’s probably the most complete account of free-living honey bees. I’d check but my copy is on a shelf on the other side of Scotland!

      Cheers
      David

      Reply
  8. Sandra Wilson

    Hi there

    A little aside.. just wondering if the photos are of one of your hives in winter? It seems to have some insulation around it. Would you advocate this?

    Reply
    1. David Post author

      Hi Sandra

      No insulation around the sides of the hive. The hive is wrapped in DPM (the stuff they put under the floor when building houses – damp proof membrane) which is pinned to the cedar box. It stops woodpeckers from clinging on to the hive and ‘breaking in’ during the coldest months of the year. Green woodpeckers learn how to do this and not all of them can. Where I live now they can’t and they’re uncommon, but that photo was from ~7 years ago and I lived somewhere else then where the woodpeckers knew the trick about the goodies inside the box.

      All my hives have top insulation on all year round, even those in the bee shed. A simple 2 inch thick block of Kingspan. This is really important with a perspex or glass crownboard. About 50% of my hives are poly, the rest are cedar. I don’t see a difference in overwintering success between the two but acknowledge that the sample size is too small to be statistically meaningful.

      Thank you for the coffee 😉
      David

      Reply

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