Category Archives: Seasonal

Midseason mite management

The Varroa mite and the potpourri of viruses it transmits are probably the greatest threat to our bees. The number of mites in the colony increases during the spring and summer, feeding and breeding on sealed brood.

Pupa (blue) and mite (red) numbers

In early/mid autumn mite levels reach their peak as the laying rate of the queen decreases. Consequently the number of mites per pupa increases significantly. The bees that are reared at this time of year are the overwintering workers, physiologically-adapted to get the colony through the winter.

The protection of these developing overwintering bees is critical and explains why an early autumn application of a suitable miticide is recommended … or usually essential.

And, although this might appear illogical, if you treat early enough to protect the winter bees you should also treat during a broodless period in midwinter. This is necessary because mite replication goes on into the autumn (while the colony continues to rear brood). If you omit the winter treatment the colony starts with a higher mite load the following season.

And you know what mites mean

Mites in midseason

Under certain circumstances mite levels can increase to dangerous levels 1 much earlier in the season than shown in the graph above.

What circumstances?

I can think of two major reasons 2. Firstly, if the colony starts the season with higher than desirable mite levels (this is why you treat midwinter). Secondly, if the mites are acquired by the colony from other colonies i.e. by infested bees drifting between colonies or by your bees robbing a mite infested colony.

Don’t underestimate the impact these events can have on mite levels. A strong colony robbing out a weak, heavily infested, collapsing colony can acquire dozens of mites a day.

The robbed colony may not be in your apiary. It could be a mile away across the fields in an apiary owned by a treatment-free 3 aficionado or from a pathogen-rich feral colony in the church tower.

How do you identify midseason mite problems?

You need to monitor mite levels, actively and/or passively. The latter includes periodic counts of mites that fall through an open mesh floor onto a Varroa board. The National Bee Unit has a handy – though not necessarily accurate – calculator to determine the total mite levels in the colony based on the Varroa drop.

Out, damn'd mite ...

Out, damn’d mite …

Don’t rely on the NBU calculator. A host of factors are likely to influence the natural Varroa drop. For example, if the laying rate of the queen is decreasing because there’s no nectar coming in there will be fewer larvae at the right stage to parasitise … consequently the natural drop (which originates from phoretic mites) will increase.

And vice versa.

Active monitoring includes uncapping drone brood or doing a sugar roll or alcohol wash to dislodge phoretic mites.

Overt disease

But in addition to looking for mites you should also keep a close eye on workers during routine inspections. If you see bees showing obvious signs of deformed wing virus (DWV) symptoms then you need to intervene to reduce mite levels.

High levels of DWV

High levels of DWV …

During our studies of DWV we have placed mite-free 4 colonies into a communal apiary. Infested drone cells were identified during routine uncapping within 2 weeks of our colony being introduced. Even more striking, symptomatic workers could be seen in the colony within 11 weeks.

Treatment options

Midseason mite management is more problematic than the late summer/early autumn and midwinter treatments.

Firstly, the colony will (or should) have good levels of sealed brood.

Secondly, there might be a nectar flow on and the colony is hopefully laden with supers.

The combination of these two factors is the issue.

If there is brood in the colony the majority (up to 90%) of mites will be hiding under the protective cappings feasting on sealed pupae.

Of course, exactly the same situation prevails in late summer/early autumn. This is why the majority of approved treatments – Apistan (don’t), Apivar, Apiguard etc. – need to be used for at least 4-6 weeks. This covers multiple brood cycles, so ensuring that the capped Varroa are released and (hopefully) slaughtered.

Which brings us to the second problem. All of those named treatments should not be used when there is a flow on or when there are supers on the hive. This is to avoid tainting (contaminating) the honey.

And, if you think about it, there’s unlikely to be a 4-6 week window between early May and late August during which there is not a nectar flow.

MAQS

The only high-efficacy miticide approved for use when supers are present is MAQS 5.

The active ingredient in MAQS is formic acid which is the only miticide capable of penetrating the cappings to kill Varroa in sealed brood 6. Because MAQS penetrates the cappings the treatment window is only 7 days long.

I have not used MAQS and so cannot comment on its use. The reason I’ve not used it is because of the problems many beekeepers have reported with queen losses or increased bee mortality. The Veterinary Medicines Directorate MAQS Summary of the product characteristics provides advice on how to avoid these problems.

Kill and cure isn’t the option I choose 😉 7

Of course, many beekeepers have used MAQS without problems.

So, what other strategies are available?

Oxalic acid Api-Bioxal

Many beekeepers these days – if you read the online forums – would recommend oxalic acid 8.

I’ve already discussed the oxalic acid-containing treatments extensively.

Importantly, these treatments only target phoretic mites, not those within capped cells.

Trickled oxalic acid is toxic to unsealed brood and so is a poor choice for a brood-rearing colony.

Varroa counts

In contrast, sublimated (vaporised) oxalic acid is tolerated well by the colony and does not harm open brood. Thomas Radetzki demonstrated it continued to be effective for about a week after administration, presumably due to its deposition on all internal surfaces of the hive. My daily mite counts of treated colonies support this conclusion.

Consequently beekeepers have empirically developed methods to treat brooding colonies multiple times with vaporised oxalic acid Api-Bioxal to kill mites released from capped cells.

The first method I’m aware of published for this was by Hivemaker on the Beekeeping Forum. There may well be earlier reports. Hivemaker recommended three or four doses at five day intervals if there is brood present.

This works well 9 but is it compatible with supers on the hive and a honey flow?

What do you mean by compatible?

The VMD Api-Bioxal Summary of product characteristics 10 specifically states “Don’t treat hives with super in position or during honey flow”.

That is about as definitive as possible.

Another one for the extractor ...

Another one for the extractor …

Some vapoholics (correctly) would argue that honey naturally contains oxalic acid. Untreated honey contains variable amounts of oxalic acid; 8-119 mg/kg in one study 11 or up to 400 mg/kg in a large sample of Italian honeys according to Franco Mutinelli 12.

It should be noted that these levels are significantly less than many vegetables.

In addition, Thomas Radetzki demonstrated that oxalic acid levels in spring honey from OA vaporised colonies (the previous autumn) were not different from those in untreated colonies. 

Therefore surely it’s OK to treat when the supers are present?

Absence of evidence is not evidence of absence

There are a few additional studies that have shown no marked rise in OA concentrations in honey post treatment. One of the problems with these studies is that the delay between treatment and honey testing is not clear and is often not stated 13.

Consider what the minimum potential delay between treatment and honey harvesting would be if it were allowed or recommended.

One day 14.

No one has (yet) tested OA concentrations in honey immediately following treatment, or the (presumable) decline in OA levels in the days, weeks and months after treatment. Is it linear over time? Does it flatline and then drop precipitously or does it drop precipitously and then remain at a very low (background) level?

Oxalic acid levels over time post treatment … it’s anyones guess

How does temperature influence this? What about colony strength and activity?

Frankly, without this information we’re just guessing.

Why risk it?

I try and produce the very best quality honey possible for friends, family and customers.

The last thing I would want to risk is inadvertently producing OA-contaminated honey.

Do I know what this tastes like? 15

No, and I’d prefer not to find out.

Formic acid and thymol have been shown to taint honey and my contention is that thorough studies to properly test this have yet to be conducted for oxalic acid.

Until they are – and unless they are statistically compelling – I will not treat colonies with supers present … and I think those that recommend you do are unwise.

What are the options?

Other than MAQS there are no treatments suitable for use when the honey supers are on. If there’s a good nectar flow and a mite-infested colony you have to make a judgement call.

Will the colony be seriously damaged if you delay treatment further?

Quite possibly.

Which is more valuable 16, the honey or the bees?

One option is to treat, hopefully save the colony and feed the honey back to the bees for winter (nothing wrong with this approach … make sure you label the supers clearly!).

Another approach might be to clear then remove the supers to another colony, then treat the original one.

However, if you choose to delay treatment consider the other colonies in your own or neighbouring apiaries. They are at risk as well.

Finally, prevention is better than cure. Timely application of an effective treatment in late summer and midwinter should be sufficient, particularly if all colonies in a geographic area are coordinately treated to minimise the impact of robbing and drifting.

I’ve got two more articles planned on midseason mite management for when the colony is broodless, or can be engineered to be broodless 17.


 

Ready, Steady … Wait

Since you are reading an internet beekeeping site you are probably aware of the discussion fora like Beesource, BBKA, the Beekeeping Forum and Beemaster Forum.

Several of these have a section for beginners. The idea is that the beginner posts a simple beekeeping question and, hey presto, gets a helpful answer.

Of course, the reality is somewhat different 😉

The question might seem simple (“Should I start colony inspections this week?”), but the answers might well not be.

If there’s more than one answer they will, of course, be contradictory. The standard rule applies …

Opinions expressed = n + 1 (where n is the number of respondents 1)

… but these opinions will be interspersed with petty squabbles, rhetorical questions in return, veiled threats, comments about climate or location, blatant trolling and a long discourse on the benefits of native black bees/Buckfast/Carniolans or Osmia bicornis 2

Finally the thread will peter out and the respondents move to another question … “When should I put the first super on my hive?”

Climate and weather

Although it might not seem helpful at the time, the comment about climate and location refers to an important aspect of beekeeping often overlooked by beginners 3.

Climate and weather are related by time. Weather refers to the short term atmospheric conditions, whereas climate is the average of that weather.

Climate is what you expect, weather is what you get.

Climate and weather have a profound influence on our beekeeping.

We live on a small island bathed in warm water originating from the Gulf Stream. In addition, we are adjacent to a large land mass. The continent and the sea influence both our weather and climate.

For simplicity I’m going to only consider temperature and rainfall. The former influences the flowering period of plants and trees upon which the bees forage.

Mean annual temperature average 1981-2010

Mean annual temperature average 1981-2010

Both temperature and rainfall determine whether the bees can forage – if it’s too cold or wet they stay in the hive.

And adverse weather (strong winds, heavy rain) can make inspections an unpleasant experience for the bees … and the beekeeper 4.

Mean annual average rainfall 1981-2010

Mean annual average rainfall 1981-2010

The North – South divide (and the East – West divide)

Compare the mean temperature in Fife (marked with the red star) with Plymouth (blue star). The average annual temperature is 8-9°C in Fife and 10-11°C in Plymouth. Although this seems to be a very minor temperature difference it makes a huge difference to the beekeeping season 5.

As I write this (mid-April) I’ve yet to fully inspect a hive but colonies are swarming in the south of England, and have been for at least a week.

When I lived in the Midlands I would often start queen rearing in mid/late April 6 whereas here inspections might not begin until May in some years.

The 6° of latitude difference between Plymouth and Fife (~415 miles) is probably equivalent to 3-4 weeks in beekeeping terms.

In contrast to the oft-quoted view that ‘Scotland is wet’, Fife only gets about 66% of the rainfall of Plymouth (800-1000 mm for Fife vs. 1250-1500 mm for Plymouth).

However, there is an East – West divide for rainfall in parts of the country. I’m writing this in Ardnamurchan, the most westerly point of mainland Britain (yellow arrow), where we get about three times the annual rainfall as the arid East coast of Fife.

The rhythm of the seasons

The seasonal duties of the beekeeper are dependent on the weather and the climate. This is because the development of the colony is influenced by how early and how warm the Spring was, how many good foraging days there were in summer, the availability of sunny 20°C days for queen mating and the warmth of the autumn for late brood rearing.

And a host of other weather-related things.

All of which vary depending where your bees live.

And vary from year to year.

Which is why it’s impossible to answer the apparently simple question When should I put the first super on my hive?” using a calendar.

“Beekeeping by numbers (or dates)” doesn’t work.

You have to learn the rhythm of the seasons.

Make a note of when early pollen (snowdrop, crocus, hazel, willow) becomes available, when the OSR and rosebay willowherb flowers and when migratory birds return 7. The obvious ones to record are flowers or trees that generate most honey for you, but early- and late-season cues are also useful.

Most useful are the seasonal occurrences that precede key events in the beekeeping year.

Link these together with the recent weather and the development of your colonies. By doing this you will begin to know what to expect and can prepare accordingly. 

If the OSR is just breaking bud 8 start piling the supers on. If cuckoos are first heard a month before the peak of the swarming period in your area make sure you prepare enough new frames for your preferred swarm control method.

And preparation is pretty-much all I’ve been doing so far this year … though I expect to conduct my first full inspections over the Easter weekend.

Degree days

While doing some background reading on climate when preparing this post I came across the concept of heating and cooling degree days. These are used by engineers involved in calculating the energy costs of heating or cooling buildings.

Heating degree days are a measure of how much (in degrees), and for how long (in days), the outside air temperature was below a certain level. 

Conversely, cooling degree days are a measure of how much (in degrees), and for how long (in days), the outside air temperature was above a certain level.

You can read lots more about degree days on the logically-named degreedays.net , which is where the definitions above originated.

From a beekeeping point of view you can use this sort of data to compare seasons or locations.

Most ‘degree days’ calculations use 15.5°C as the certain level in the definitions above. This isn’t particularly relevant to beekeeping (but is if you are heating a building). However, degreedays.net (which have a bee on their BizEE Software Ltd. logo 🙂 ) can generate custom degree day information for any location with suitable weather data and you can define the level above or below which the calculation is based.

For convenience I chose 10°C. Much lower than this and foraging is limited.

The North – South divide (again)

So, let’s return to swarms in Plymouth and the absence of inspections in Fife … how can we explain this if the average annual temperate is only a couple of degrees different?

Heating and cooling degree days for Plymouth and Fife, April 2018 to March 2019

Heating and cooling degree days for Plymouth and Fife, April 2018 to March 2019

Focus on the dashed lines for the moment. September to November (months 9, 10 and 11) were very similar for both Plymouth (blue) and Fife (red). After that – unsurprisingly – the Fife winter is both colder and longer. From December through to March the Plymouth line rises later, rises less far and falls faster. In Plymouth the winter is less cold, is shorter and – as far as the bees are concerned – the season starts about a month earlier 9.

2018 in Fife was an excellent year for honey. After a cold winter (and the Beast from the East) colonies built up well and I harvested record amounts (for me) of both spring honey (in early June) and summer honey (in late July/early August).

I’ve no idea what 2018 was like for honey yields in Plymouth, but the cooling degree days (solid lines) show that it was warmer earlier, hotter overall and that the season lasted perhaps a month longer (though this tells us nothing about forage availability).

Of course it’s the longer, hotter summers and cooler, shorter winters that – averaged out – mean the average annual temperature difference between Plymouth and Fife is only a couple of degrees Centigrade.

Good years and bad years

As far as honey is concerned the last two years in Fife have been, respectively, sublime and ridiculous.

2018 was great and 2017 was catastrophic.

How do these look when plotted?

The 2017 and 2018 beekeeping season in Fife.

The 2017 and 2018 beekeeping season in Fife.

The onset of summer (solid lines – the cooling degree days – months 4-6) and the preceding winter (dashed lines – the heating degree days – months 9-11) were similar – the lines are nearly superimposed.

The 2016-17 winter was milder and shorter than 2017-18. The latter was extended by arrival of the Beast from the East and Storm Emma which brought blizzards in late February and continued unseasonably cold through March.

However, the harsh 2017-18 winter didn’t hold the bees back and the 2018 season brought bumper honey harvests.

In contrast, the 2017 season was hopeless. It was cooler overall, but the duration of the season was similar to the following year 10. Supers remained resolutely empty and my entire honey crop shared a single batch number 🙁

However, it wasn’t the temperature that was the main problem. It was the abnormally high rainfall during June.

June 2017 rainfall anomaly from 1981-2010

June 2017 rainfall anomaly from 1981-2010 …

Colonies were unable to forage. Some needed feeding. Queen mating was very patchy, with several turning out as drone laying queens later in the season.

Early June 2017 ...

Early June 2017 …

The spring nectar flows were a washout and the colonies weren’t at full strength to exploit the July flows.

Let’s see what 2019 brings …


 

Spring starvation

A very brief post this week to highlight the dangers of unseasonably warm weather early in the season. February 2019 has entered the record books as the first ‘winter’ month in which the temperature exceeded 20°C (on at least the 25th and 26th in the UK). It’s also been a record with the daily temperature (highs … we’ve had some hard frosts as well) exceeding the historic average daily temperature on almost every day of the month.

Fife temperatures, February 2019

Fife temperatures, February 2019

Even here in Fife on the East coast of Scotland, the weather has been very warm and sometimes even sunny. The graph above shows the daily maximum temperature compared to the monthly average (dashed line).

The contrast with this time last year is very striking. The big winter storm called Anticyclone Hartmut (aka the Beast from the East) arrived in the last week of February.

The Beast from the East ...

The Beast from the East …

We had six foot deep snow drifts blocking the road to the village and there wasn’t a bee to be seen.

Crocus and snowdrop

Fast forward exactly 12 months and the bees are piling in the pollen and flying well for an extended period. Around here this early pollen probably comes from crocus, snowdrop, hazel and alder, perhaps with a bit of gorse as well which flowers throughout the season.

Brood rearing will have started in earnest. The large amounts of pollen being collected is a pretty good indicator that all is well in the hive, that the queen is starting to ramp up her egg laying rate and the numbers of hungry larvae are increasing.

There’s no need to open the hive to check for brood. Indeed, hive inspections (here at least) are probably at least 6 weeks away.

However, don’t ignore the colonies. The increase in brood rearing is a time when stores levels can quickly get critically low. There’s not a huge range of nectar sources about at the moment and the combination of a warm spell, increasing amounts of brood and a subsequent deterioration in the weather can rapidly result in colonies starving.

Hefting or a sneak peak

If you’ve been regularly hefting the hive to check its weight you should have a reasonable ‘feel’ for what it should be, and whether it’s significantly lighter. More accurately, but also more trouble, you can use luggage scales to record the week-by-week reduction over the winter.

It’s possible to determine whether there are sufficient – or at least some – stores by looking through a perspex crownboard at the tops of the frames.

Emptied bag of fondant

Emptied bag of fondant

Many of my hives went into the winter with the remnants of the autumn-fed fondant still present on the top bars. With a perspex crownboard it’s a trivial task to check if these stores have been used and – if they have – to heft the hive to see if they need more.

Fondant topups

Several hives have already had a fondant topup of about a kilogram placed directly onto the top of the frames. Alternatively, the hives with the Gruyere-like Abelo crownboards 1 get a fondant block slapped directly over the hole above the most concentrated seams of bees.

Fondant absorbs moisture from the atmosphere so you need to protect the faces of the fondant block not accessed by the bees. There are all sorts of ways to do this. A strong plastic bag with a slot or flap cut in the bottom is more than adequate.

Better still is to dole out the fondant into plastic food containers you’ve diligently saved all year. These are reusable, come in a variety of sizes and – ideally – are transparent. You can then easily see when and if the bees need a further topup.

Time for another?

Time for another?

I usually slice up a block of fondant and fill these food containers in midwinter, wrap them in clingfilm and carry them around in the back of the car for my occasional apiary visits. If a hive needs more stores I remove the clingfilm and simply invert the container over the bees.

Do remove the clingfilm! Bees tend to chew it up and drag it down into the brood nest, often embedding it into brace comb. It can be a bit disruptive during cool weather early-season inspections to remove it … hence the suggestion to use a strong plastic bag earlier.

Continued vigilance

Most of my hives will have had at least a kilogram of fondant by the end of February this year. One or two are likely to have had significantly more. I’ll keep a note of these in my records as – all other things being equal – I’d prefer to have frugal bees that don’t need fussing with over the winter.

As the days get longer and the season continues to warm the queen will further increase her laying rate. Until there are both dependable foraging days and good levels of forage there remains the chance of starvation.

Colonies are much more likely to starve in early spring than in the middle of a hard winter. If the latter happens it’s either due to poor winter preparation or possibly disease. However, if they starve in early spring it is probably due to unseasonably warm weather, a lack of available forage, increasing levels of brood and a lack of vigilance by the beekeeper.

Don’t delay!

If a colony is worryingly light don’t wait for a warm sunny day to feed them. Adding a block of fondant as described above takes seconds.

Everynuc fondant topup

Everynuc fondant topup

If a colony needs stores add it as soon as possible.

If it’s cold the bees will be reasonably lethargic and you may not even need to smoke them. I’ve only fired up the smoker once … to topup a colony of psychotic monsters ‘on loan’ from a research collaborator who shall remain nameless.

I managed to add the fondant without using the smoker but they then chased me across the field to thank me 🙁


 

Winter chores

After two weeks of mites, their diets and pedantry we’ll take a break this week for some practical beekeeping.

Or at least as close as you can get to practical beekeeping when it’s been as cold as -8°C.

Midwinter is a time to prepare for the season ahead, to stock up on new equipment during the winter sales, build more frames, plan the strategy for swarm control and think about stock improvement.

And – if you’re anything like as disorganised as me – it’s also the time to tidy up after the season just finished.

Which is what we’ll deal with today.

Tidy the shed

The original research apiary and bee shed is now under an access road for a new school. Fortunately, we managed to rescue the shed which has now been re-assembled in the new apiary.

In the longer term these sheds could together accommodate at least a dozen full colonies. However, in the shorter term it has allowed me to rationalise the storage, giving much more space to work with the colonies in the larger shed.

Supers and brood in the storage shed have all been tidied (see below) and are in labelled stacks ready to use. The other side of the store contains stacks of floors, split boards, clearers and roofs.

It’ll get messier as the season progresses, but it’s a good start.

I also spent a couple of weekends making some minor improvements to the bee shed following the experience last season.

The lighting has been increased and repositioned so it is ‘over the shoulder’ when doing inspections. On a dull winter day it is dazzlingly bright 1 but I fear it will still not be enough. I’m looking at creating some reflectors to direct the light better.

I’ve also used a few tubes of exterior sealant to block up all the holes and cracks around the edge of the shed roof. Last season was a bad one for wasps and we were plagued with the little stripy blighters.

Tidy the frames

Two of the most valuable resources a beekeeper has are drawn super frames and capped stores in brood frames.

Look after them!

I often end up uniting colonies late in the season, but then overwinter the bees in a single brood box. This means I can end up with spare frames of sealed stores. These should be protected from wax moth and mice (or anything else) as they are really useful the following year for boosting colonies that are light on stores or making up nucs.

Drawn supers can be used time and time again, year after year. They also need to be protected but – if your extraction is as chaotic as mine – they also usually need to be tidied up so they are ready for the following season.

I load my extractor to balance it properly, rather than just super by super. Inevitably this means the extracted frames are all mixed up. Since frames are also often drawn out unevenly this leaves me with a 250 piece jigsaw with billions of possible permutations, but only a few correct solutions.

Little and large - untidy frames and a breadknife

Little and large – untidy frames and a breadknife

And that’s ignoring all the frames with brace comb that accumulate during a good flow.

So, in midwinter I tidy up all the cleared super frames, levelling off the worst of the waviness with a sharp breadknife, removing the brace comb, scraping down the top bar and arranging them – 9 to 11 at a time 2 – in supers stored neatly in covered stacks.

And, if you’ve got a lot, label them so you know what’s where.

An hour or two of work on a dingy midwinter day can help avoid those irritating moments when – in the middle of a strong flow – you grab a super to find it contains just five ill-fitting frames, one of which has a broken lug.

The wax removed during this tidying up is usually lovely and white. Save it for making soaps, cosmetics or top-quality candles.

Wax extraction

Brood comb has a finite life. After about three years of repeated brood rearing cycles it should be replaced. Old comb contains relatively little wax but what’s there can be recovered using a solar or steam wax extractor. This also allows the cleaned frames to be re-used.

Processing a few dozen brood frames with a solar wax extractor during a Scottish winter is an exercise in futility. For years I’ve used a DIY steam wax extractor which worked pretty well but was starting to fall apart. I therefore recently took advantage of the winter sales and purchased a Thorne’s Easi-steam 3.

The Easi-steam works well and with a little further processing generates a few kilograms of wax for making firelighters or trading in … and a large stack of frames for re-use.

Remember to keep a few old dark brood frames aside for using in bait hives

Keep an eye on your bees

In between all these winter chores don’t forget to check on your bees.

There’s not a lot to do, but these checks are important.

Make sure the entrances are clear, that the mouse guards 4 are in place and that the roofs are secure.

Storm Eric brought us 50-60 mph winds and a couple of my hives lost their roofs. These had survived a couple of previous storms, but the wind was from a different direction and lifted the roofs and the bricks stacked on top. I got to them the following day but we’ll have to wait until the season warms up to determine if there’s any harm done.

Fondant top up

Fondant top up

Finally, as the days lengthen and it gets marginally warmer colonies should have started rearing brood again. Make sure they have sufficient stores by regularly ‘hefting‘ the hive. If stores are low, top them up with a block or two of fondant. This should be placed directly over the cluster, either over a hole in the crownboard or on the top bars of the frames.


 

Mites equal viruses

Healthy bees are happy bees 🙂

Sounds good doesn’t it?

Actually, there’s no evidence that bees display or perceive most of the emotions often attributed to them 1.

Happy? Who knows? But certainly not healthy ...

Happy? Who knows? But certainly not healthy …

A more accurate statement might be “Healthy bees are more productive, they are less likely to die overwinter, less likely to be robbed out by wasps or neighbouring strong colonies and their parasites and pathogens cannot threaten the health of other honey bee colonies or, through so-called-pathogen overspill, the health of other pollinators.”

More accurate?

Yes … but it doesn’t exactly trip off the tongue 😉

Whether it makes the bees happy or not, beekeepers have a responsibility to look after the health of their livestock. This includes controlling Varroa numbers to reduce the levels of pathogenic viruses in the hive.

How well are virus levels controlled if mite levels are reduced?

I’ll get to that in due course …

Midwinter mite massacre

The 2018 autumn was relatively mild through until mid/late November. In the absence of very early frosts colonies continued rearing brood.

We opened colonies in mid-November (for work) and found sealed brood, though it was clear that the laying rate of the queen was much-reduced.

These are ideal conditions for residual mite replication. Any mites that escaped the late summer/early autumn treatment (the ideal time to treat to protect the overwintering bees) continue to replicate, resulting in the colony starting the following season with a disappointingly high level of mites.

I’ve noted before that midwinter mite levels are paradoxically higher if you treat early enough in the autumn to protect the all-important winter bees.

Consequently, to start the year with minimal mite levels, I treat in midwinter with a trickled or vaporised oxalic acid-containing (OA) treatment.

A combination of colder weather (hard frosts in late November) and brood temperature measurements 2 indicated mid-December was a good time to treat.

Midwinter mite massacre

Midwinter mite massacre

18th December

In one of my apiaries ten colonies were treated. Some were definitely broodless (based upon Arnia hive monitoring). Others may have had brood, but colonies were not routinely checked.

Over the four day period after vaporising these ten colonies dropped a total of 92 mites. More than 50% of these were from just one double-brooded colony. Overwintering nucs 3 dropped no mites at all in the 12 days following treatment.

This was very encouraging. These are lower midwinter mite levels than I’ve seen since returning to Scotland in 2015.

The one colony with ‘high’ mite levels received two further treatments (on the 22nd and 27th) in an attempt to minimise the mite levels for the start of the season. Going by the strength of the colony and the debris on the Varroa tray it was presumed that this colony was still rearing brood.

Mite drop following the third treatment was negligible 4.

Why are mite levels so low?

I think it’s a combination of:

  • Luck
  • Use of natural, organic, bee-centric and biodynamic beekeeping methods
  • Varroa-resistant bees
  • Very tight control of mite numbers in the 2017/18 season, primarily by correctly timing the winter and the late-season autumn treatments. This is simply good colony management. Anyone can achieve this.
  • A brood break midseason and/or a broodless period when splitting colonies (both give opportunities for more phoretic mites to be lost through grooming). Undoubtedly beneficial but season-dependent. I’ll be discussing ways to exploit these events in posts next year.
  • A low density of beekeepers in Fife, so relatively little drifting or robbing of poorly managed colonies from neighbouring apiaries. Geography-dependent. Much easier in Fife than Warwickshire … and easier still in Lochaber.

And what do less mites mean?

Varroa is a threat to bee health because it transmits pathogenic viruses when feeding on developing pupae.

The most important of these viruses is deformed wing virus (DWV).

Generally, the higher the level of infestation with mites, the higher the viral load 5. This has been repeatedly demonstrated by studies from researchers working in the UK, Europe and the USA.

It is well-established that colonies with high viral loads have an increased chance of dying overwinter, due to the decreased longevity of bees infected with high levels of virus.

DWV symptoms

DWV symptoms

In our work apiaries we regularly measure DWV levels. For routine screening our limit of detection is around 1,000 viruses per bee.

We don’t actually count the viruses. They’re too small to see without an electron microscope 6.

Instead, we quantify the amount of the virus genetic material present 7, compare it to a set of standards and express it as ‘genome equivalents (GE)’.

Many of the bees tested this year contained ~103 (i.e. 1000) GE, which is extremely low. Bees from Varroa-free regions (e.g. Colonsay) carry similar levels of DWV.

Most of our colonies were at or close to this level of virus much of the 2018 season. This is 100-1,000 times lower than we often see even in apparently perfectly healthy colonies in other years or other apiaries.

For comparison, using the same assay we usually detect about 1010 (ten billion) DWV GE per bee in symptomatic adult bees from heavily mite-infested colonies.

So, less mites means less viruses which means healthier bees 🙂

And they might even be happier bees 😉

And your point is?

It’s worth remembering that the purpose of treating a colony with miticides is to reduce the transmission of viruses between bees. This transmission results in the amplification of DWV. This is why the timing of treatments is so important.

Yes, it’s always good to slaughter a few (or a few thousand 🙂 ) mites. However, far better massacre them when you need to protect particular populations of bees.

This includes the overwintering bees, raised in September, that get the colony through to the Spring.

Remember also that it ‘takes bees to make bees’ i.e. the rearing of new brood requires bees. Therefore strong colony build-up in Spring requires healthy workers rearing healthy brood.

This is why it’s important to minimise mite levels in midwinter when colonies are broodless.

What do most beekeepers do?

Fifteen months ago I published a post on the preparation of oxalic acid solutions for trickling colonies in midwinter.

Whatever the vapoholics on the online forums claim, trickling remains the easiest, quickest and least expensive way to treat colonies in midwinter 8.

The best time to treat in the winter is when the colony is broodless. Here in Fife, and often elsewhere, I believe that this usually occurs earlier in the winter than many beekeepers treat (if it happens at all … or if they treat at all).

I usually treat between the end of the third week in November and mid-December, at the end of the first extended cold period.

Oxalic acid preparation recipe page views

Oxalic acid preparation recipe page views

Looking at the page views for these oxalic acid recipes it looks as though many beekeepers treat after Christmas 9 … which may be suboptimal if colonies had a broodless period and now started rearing brood again.

Mine have.

This winter has been quite mild (at least at the time of writing) so there may yet be opportunities to treat really effectively during a broodless period.

Or the chance may have gone …


 

2018 in retrospect

How was 2018 for you?

It was a good year here in Fife, with more of everything; more snow, more colonies, more honey (much more honey 🙂 ), more sheds, more wasps, more swarms and more dead Varroa.

Actually, the ‘more dead mites’ isn’t quite correct but I’ll return to that later.

The Beast from the East

There’s not much to say about the winter, but as we moved from February into March Storm Emma (also called the Beast from the East) arrived. The wind whipped the snow across the Howe of Fife (the largely flat centre of the county), dumping large drifts whenever it eddied over hedges or buildings. I had to dig us out of the house and the road from the village was impassable for 2-3 days.

The Beast from the East ...

The Beast from the East …

The colonies were all snug, if not warm, and weathered the storm without mishap. The reality is that if colonies are properly prepared for winter there’s almost nothing to do – or nothing you can do – until the weather picks up again in the Spring.

During the early part of the year I finished preparing our new bee shed. The bees were installed at the very end of March, soon followed by installation of a solar lighting system.

As I write this (early December 2018) the old apiary site has recently been bulldozed flat to make way for a new road. The contractors felled most of the beautiful trees in the well-established arboretum that surrounded the apiary.

All that’s left now is a muddy, ugly scar across the landscape waiting to be tarmac’d. Every time I drive past the line from The Last Resort by The Eagles, Some rich men come and raped the land”, comes to mind.

That’s progress 🙁

On a slightly brighter note, we did save the original shed and it’s recently been reassembled on the new apiary site. This will provide some much needed storage space. The new shed is bigger, but still a bit cramped when used for storage, work and bees.

In like a lion, out like a lamb

Well, almost. March continued cold but the weather had picked up by mid-April. I’d lost just two colonies in the winter, both due to failed queens. By the third week of April I’d started inspections 1 and colonies were all looking pretty good.

The weather got better and better, the oil seed rape (OSR) flowered and the bees started hammering it. Only one of my apiaries had OSR in range and they did really well.

Capped honey super frame ...

Capped honey super frame …

By the middle of June the OSR was over and the honey was all extracted. The high glucose content of OSR nectar means it crystallises fast and very hard. It needs to be extracted before this happens in the frames. Some find OSR honey rather bland or an acquired taste. However, I’ve just processed the first couple of buckets into soft set honey and it’s excellent on toast.

The June gap

In terms of beekeeping it was non-stop. June was frantically busy. Even before the the Spring honey was off the crowded colonies had started to make preparations for swarming.

Just as the bees were preparing to move house I was also busy moving into a new house. It was manic. As fast as I put split boards into colonies more queen cells would appear. I started to run out of frames and brood boxes. I managed to hold some colonies back by slicing out great slabs of drone comb. This takes just a few seconds using foundationless frames and gives the bees something to do rather than make swarm preparations.

And in between all this I was interminably packing, driving and unpacking rental vans doing my own move.

I know I lost a couple of swarms – from about 20 colonies in total 2 – which left me feeling a bit guilty. At least they left with very low Varroa levels so, for a time at least, they would not contribute to the mite levels in the local environment. To ‘compensate’ for colonies that might establish themselves somewhere unwanted I donned my beesuit and destroyed a huge wasps nest in a neighbours roof space.

I also gratefully received a good-sized swarm in a bait hive.

The ‘June gap’ refers to the dearth of nectar that often occurs at this time of year. This year – despite excellent weather – was no exception. I didn’t feed colonies but many around me did. A few were a bit light but were OK until the summer flow started … which it did in late June or early July.

The flow must go on

Lime, blackberry, clover, rosebay willow herb and goodness knows what else. It was excellent. Coupled with continued good weather, hives got taller and taller as more supers were added. I ran out of supers altogether.

With lots of nectar and great weather for inspections it was my best beekeeping year since I moved back to Scotland.

Laden foragers returning ...

Laden foragers returning …

The good weather also aided queen mating which helped with requeening and preparing nucs for overwintering. About 75% of my colonies were requeened this year, almost all through splits of one type of another.

And then it was all over

The flow eventually stopped and the extraction was interminable. Not that I’m complaining. Super after super after super looked like this:

Ready to extract

Ready to extract …

Wasps were a big problem in late summer. I lost a queenless colony and a nuc to the stripey blighters. Amazingly I managed to save the queen from the nuc 3 and she’s now heading a strong colony through the winter.

After a fortnight or so tidying, stock-taking (uniting colonies, cleaning cleared supers, making up a few additional nucs) and ‘final’ inspections it was time to start Varroa treatment and feeding colonies up for winter.

I’ve deliberately finished the season with fewer colonies than I started, but with more overwintering nucleus colonies for sale or making up losses. The absence of a work/life balance means I want to reduce my personal colony numbers by about a third for the next couple of years (to ~10), with another 6-8 overwintering for work. I’ll still be busy 🙁

Mite news

Mite levels have been extraordinarily low this season. For work we uncapped many hundreds to low thousands of individual pupae 4 and found no more than half a dozen mites all season. We’ve seen no evidence of DWV symptoms and irregular mite counts on the Varroa trays have yielded very low numbers.

All colonies were treated by sublimation with an oxalic acid-containing treatment in early September, with three applications at five day intervals. The mite drop was so low (<200 from eight colonies in total in one apiary) that I was concerned that the treatment had failed. I therefore followed it up with Apivar strips in half the colonies. One or two additional dead mites appeared, but that was all.

So, not more dead Varroa, but probably a much greater proportion of the mite population were killed.

The Apiarist in 2018

This is the 300th post over the last five years. Yes, I’m surprised as well. I missed only one Friday when my hosting service was either not hosting or not providing a service 🙁

A few weeks ago I moved the site to a cloud-based virtual server (Amazon LightSail) which, to me at least 5 appears faster and more stable. Processor load is 10% what it was and page response times seem much better. Tell me if it isn’t.

Unique visitor numbers and page reads continue to increase year on year with both up ~33% on last year. What is particularly reassuring is that articles I’ve written on disease management now feature as the most read over the course of the year (though several were written in previous years). The ‘top five’ are:

  1. When to treat? – the importance of correctly timing the early autumn Varroa treatment.
  2. Feeding fondant – quicker, easier and possibly better for the bees.
  3. Oxalic acid preparation – making Api-Bioxal solution properly for trickle treating.
  4. Vertical splits and making increase – manipulations for swarm control and expansion.
  5. Making soft set honey – making all that OSR honey look good and sell well.
"When to treat" monthly page views

“When to treat” monthly page views (5/2/16 to 13/12/18)

The composite page on ‘Equipment‘ also featured amongst this top five, but takes visitors off to all sorts of articles on bee sheds, DIY and hive reviews.

And the future …

This post is already too long. I’ve just checked and see I have 55 posts with working titles and scrawled notes in my drafts folder 6. That suggests there’s likely to be something written next year.

Until then … Happy New Year 


 

Know your enemy

What less appropriate time is there, as we enter the festive season of goodwill, to provide a brief account of the incestuous and disease-riddled life cycle of the Varroa mite?

Happy Christmas 🙂

Scanning electron micrograph of Varroa destructor

Scanning electron micrograph of Varroa destructor

Varroa is the biggest enemy of bees, beekeepers and beekeeping. During the replication cycle the mite transfers a smorgasbord of viruses to developing pupae. One of these viruses, deformed wing virus (DWV), although well-tolerated in the absence of Varroa 1replicates to devastatingly high levels and is pathogenic when transferred by the mite.

Without colony management methods to control Varroa, mite and virus replication will eventually kill the colony.

I’ve written extensively on ways to control Varroa. Most of these have focused on early autumn and midwinter treatment regimes. However, next season I’m hoping to discuss some alternative strategies and will need to reference aspects of the life cycle of Varroa … hence this post.

What is Varroa?

Varroa destructor is a distant relative of spiders, both being members of the class Arachnida … the joint-legged invertebrates (arthropods). It was originally (and remains) an external parasite (ectoparasite) of Apis cerana (the Eastern honey bee) and – following cross-species transfer a century or so ago – Apis mellifera, ‘our’ Western honey bee.

Apis cerana, having co-evolved with Varroa, has a number of strategies to minimise the detrimental consequences of being parasitised by the mite.

Apis mellifera doesn’t. Simple as that 2.

One hundred years is the blink of an eye in evolutionary terms and, whilst there are bees that have partial solutions – largely behavioural (small colonies and very swarmy) – they’re probably unable to collect meaningful amounts of honey 3.

Varroa-resistant honey bees will probably evolve (as much as anything is predictable in evolution) but not in my time as a beekeeper … or possibly not until Voyager 2 leaves the Oort Cloud 4.

And there’s no guarantee they’ll be any use whatsoever for beekeeping …

The replication cycle of Varroa

Varroa has no free-living stage during the life-cycle. The adult mated female mite exhibits two distinct phases during the life-cycle. It has a phoretic phase on adult bees and a reproductive phase within sealed (‘capped’) worker and drone brood cells. Male mites only ever exist within sealed brood cells.

I’m going to discuss phoretic mites in a separate post. I’ll concentrate here on the replication cycle.

The mated female mite enters a cell 15-50 hours before brood capping. Drone brood is chosen preferentially (at ~10-fold greater rates than worker brood) and entered earlier. Depending upon the time of the season and the levels of mites and brood, up to 70-90% of mites in the colony occupy capped cells.

The first egg is laid ~70 hours after cell capping. This egg is unfertilized and develops into a haploid male mite. Subsequent eggs are fertilised, diploid, and so develop into female mites. These are laid at ~30 hour intervals.

The replication cycle of Varroa

The replication cycle of Varroa

Worker and drone brood take different times to develop. Therefore a typical reproductive cycle involves five eggs being laid in worker brood and six in drone brood. Not all of these eggs mature, their development being curtailed by the bee emerging as an adult.

There are all sorts of developmental stages involved in getting from an egg to a mature unfertilised mite, but these are not important in terms of the overall outcome. Mite-geeks love this sort of detail 5, but we need to cut to the chase …

Keeping it in the family

The foundress ‘mother’ mite and her progeny all share a single feeding hole through the cuticle of the developing pupa.

What a lovely scene of family ‘togetherness’. 

Male and female mites take 6.6 and 5.8 days respectively to develop to sexual maturity. Therefore the male mite reaches sexual maturity before the first of his sisters.

He then lurks around the attractive-sounding “faecal accumulation site” and mates with each of the (sister) females in turn.

What a little charmer 😉

Male mites are short lived and the eclosion of the adult worker or drone curtails further mating activity, releasing the foundress mite and the mated mature daughters 6.

Reproductive rate (mites per cell)

The three day difference in the duration of worker and drone development means that more mites are produced from drone cells than worker cells. Depending on conditions the reproductive rate is 1.3 – 1.45 in worker brood and 2.2 – 2.6 in drone brood.

Remember that the foundress is also released from the cell. She can go on to initiate one or two further reproductive cycles (or up to 7 in vitro). Consequently, the average yield of mature, mated female mites from worker and drone cells is a fraction over 2 and 3 respectively.

Before entering a fresh cell containing a late stage (5th instar) larva the newly-mated mites need to mature. They do this during the phoretic phase which lasts 5-11 days. Therefore the full replication cycle of the mite probably takes a minimum of about 17 days.

Exponential growth

Two to three mites per infested cell doesn’t sound very much. However, under ideal conditions this leads to exponential growth of the mite population in the colony. Assuming 10 reproductive cycles in 6 months, a single mite would generate a population of >1,000 in worker brood and >59,000 in drone brood 7.

Fortunately (for our bees, not for the mites), ideal conditions don’t actually occur in reality.

Lots of things contribute to the reduction in reproductive potential. For example, only 60% of male mites achieve sexual maturity due to developmental mortality, drone brood is only available at certain times in the season, brood breaks interrupt the availability of any suitable brood and grooming helps rid adult bees of phoretic mites.

Out, damn'd mite ...

Out, damn’d mite …

However, these reductions aren’t enough. Without proper management mite levels still reach dangerously high levels, threatening the long-term viability of the colony.

In the next few months I will discuss some additional opportunities for reducing the mite population.

In the meantime, as we reach the winter solstice, colonies in temperate regions may well be broodless and – as emphasised last week – this is an ideal time to apply a midwinter oxalic acid-containing treatment. This will effectively reduce mite levels for the start of the coming season.

Happy Christmas … unless you’re a mite 😉


Colophon

Today is the winter solstice in the Northern hemisphere. This is actually the precise time when the Earth’s Northern pole has its maximum tilt away from the Sun. However, the term is usually used for the day with the shortest period of daylight and the longest period of night. In Fife, sunrise is at 08.44 and sunset at 15.37, meaning the day length is 6 hours and 53 minutes long.

With increasing day length queens will start laying again … but there’s a long way to go until winter is over.

 

Convenience or laziness?

It’s cold and dark and all is quiet in the apiary. Hives appear somnolent. Colonies are clustered 1 and, other than the odd corpse or two on the landing board, I’ve not seen a bee for at least a fortnight.

The apiary in winter ...

The apiary in winter …

Based upon previous experience I suspect colonies are – or very soon will be – broodless. I usually reckon that the first extended (2-3 weeks) period of cold weather 2 in the winter is the most likely time for the colony to be broodless.

In 2016/17 this was the first week in December.

In 2017/18 it was just a day or two later.

In both instances, when the hives were checked, they had no brood.

What’s all this about being broodless?

If a colony is broodless there are no capped cells in which the Varroa mite can ‘hide’. As a consequence it’s an ideal time to apply a miticide like a trickled solution of Api-Bioxal 3.

There are very good reasons why a midwinter OA treatment is necessary, particularly if you treated early enough in the autumn to protect the overwintering workers from the ravages of Deformed Wing Virus (DWV). High DWV levels reduce the lifespan of bees and contribute to many (possibly most) winter colony losses. I’ve even suggested here that “isolation starvation” might actually be due to Varroa-transmitted viral disease.

Time of treatment and mite numbers

Time of treatment and mite numbers

Early autumn treatment protects the winter bees but also leaves the long autumn for the residual mites to continue replicating.

And there will be residual mites. No treatment is 100% effective.

So, paradoxically, if you treated early enough in the autumn to really help protect the winter bees, your mite levels will be higher at the end of the year.

Which also means they’ll be higher at the beginning of next year.

Not a good start to the 2019 season 🙁

Convenience or laziness?

Many beekeepers, for convenience, laziness or historical precedent, choose to apply the winter OA treatment between Christmas and New Year. I suspect that this is often too late. If the queen starts laying again around the winter solstice there will be sealed brood – and therefore unreachable Varroa – by the end of the month.

I’d prefer to have a cold and damp afternoon in the apiary slaughtering Varroa now than the convenience of treating them less effectively during the Christmas holiday period.

The latter might be more convenient … the office will be closed, I’ll be replete with turkey and sprouts and it will be a good excuse to ‘escape’ visiting relatives and yet more mince pies 4.

But is it the best time for your bees?

We have the technology

We have a couple of hives with Arnia hive monitors fitted 5. These have a temperature probe inserted into the brood nest. Brood rearing temperature is around 34°C. Here is a trace of one colony over the last month.

Arnia hive monitor temperature

Arnia hive monitor temperature

The colony temperature was pretty stable (around 33-35°C) until about the 19th of November and has dropped about 10°C since then. Although I’ve not opened the colony I think that this is additional evidence that the colony is broodless 6.

Beekeeping by numbers

Keeping bees properly involves being aware of the seasons, the available forage and the state of the colony. This varies from month to month and year to year 7.

You can’t mechanically (‘by the numbers’) add supers on the 5th of May and harvest honey on the 15th of June. Sure, it might work some years, but is it the best time to do it?

Similarly, you can’t optimally treat a colony for Varroa on the 30th of December unless the climatic conditions and state of the colony coincide to make that the best time to treat.

It might be, but I suspect that generally it’s a bit late if there is a brood break.

If you’re going to the trouble of preparing the OA treatment, donning the beesuit and disturbing the colony you might as well do it at the right time for the bees.

I’ll be treating in between the predicted sleet showers and sunny periods this weekend.

Time to treat

Time to treat

Isn’t evolution a wonderful thing? This post started with a working title of Know your enemy” and was on a different topic altogether. I’ll save that for next week.


STOP PRESS

The above was written at the beginning of the week. Now the weekend is closer it’s clear the weather is going to be cold with heavy snow predicted. Unless the forecast is wrong (and how often does that happen?!) I’ll hold off treating until a) it’s over 5°C, and b) the roads are safe.

They think it’s all over!

We’re gently but inexorably segueing into early autumn after an excellent beekeeping season. The rosebay willow herb is almost over, the farmers are busy taking in the harvest and colonies are – or should be – crowded with under-occupied workers.

Rosebay willow herb

Rosebay willow herb

Drones are being ejected, wasps are persistently looking for access and there’s a long winter – or at least non-beekeeping period – ahead.

There’s a poignancy now in being in the apiary conducting the last few inspections of the season. Only a few short weeks ago, during late May and early June, the apiary was a scene of frenetic productivity … or complete turmoil, depending upon your level of organisation or competence.

Now there’s little activity as there’s not much forage available.

Colonies are busy doing nothing.

The most important time of the season

But that doesn’t mean that there’s nothing to do.

Rather, I’d argue that late August and early September is probably the most important period during the beekeeping year.

However well or badly the season progressed, this is the time that colonies have to be prepared for the coming winter. With good preparation, colonies will come through the winter well. They’ll build up strongly in spring and be ready to exploit the early season nectar flows.

In Fife, this is about 8 months away 🙁

This explains the poignancy.

There are some colonies inspected last weekend that probably won’t get properly opened again until mid/late April 2019. Queens I saw for the first time in August won’t get marked or clipped until next spring 1.

Au revoir!

Spot the queen ...

Spot the queen …

To survive the winter and build up well in the spring the colony has few requirements. But they are important. A lack of attention now can result in the loss of the colony later.

To appreciate their needs it’s important to understand what the colony does during the winter.

Suspended animation

Honey bees don’t hibernate in winter. In cold weather (under ~7°C) they cluster tightly to conserve energy and protect the queen and any brood in the colony.

At higher temperatures the cluster breaks but they largely remain within the hive. After all, there’s little or no forage available, so they use their honey and pollen stores.

The fat-bodied overwintering bees that are reared in autumn have a very different physiology to the ephemeral summer workers. The latter have a life-expectancy of 5-6 weeks whereas overwintering bees can live for many months 2.

But they’re not immortal.

Throughout the winter there’s a slow and steady attrition of these workers. As they die off the clustered colony gradually reduces in volume, shrinking from the size of a medicine ball, to a football, to a grapefruit … you get the picture.

Some brood rearing does occur. The queen often stops laying after the summer nectar flows stop 3 and laying might be sporadic through the autumn, dependent upon weather and forage availability.

Late summer brood frame from a nuc ...

Late summer brood frame from a nuc …

However, by the turn of the year she starts laying again. At a much reduced level to her maximum rate, but laying nevertheless and, with sufficient workers in the colony and as forage become available, this rate will increase.

The amount of brood reared during the winter period (late autumn to early spring) isn’t enough to make up for the losses that occur through attrition. This explains why colonies are much smaller in the spring than the early autumn.

Strong, healthy, well-provisioned and weathertight

Knowing what’s happening in the colony during the winter makes the requirements that must be met understandable.

  • Strong colonies start the winter with ample bees. Assuming the same attrition rate, a larger colony will get through the winter stronger than a smaller one. There will be more workers available to ‘reach’ stores (I’ll deal with this in the next week or two) and keep the queen and brood warm. Hence there will be more foragers to exploit the early crocus, snowdrop and willow.
  • Healthy colonies will have a lower attrition rate. The overwintering workers will live longer. High levels of deformed wing virus (DWV) are known to shorten the life of winter bees. To minimise the levels of DWV you must reduce the levels of Varroa in the colony. Critically, you must protect the overwintering bees from Varroa exposure. Treat too late in the season and they will already be heavily infected …
  • Well-provisioned colonies have more than enough stores to survive the winter. The clustered colony will have to move relatively short distances to access the stores. As a beekeeper, you won’t have to constantly meddle with the colony, lifting the lid and crownboard to add additional stores in midwinter.
  • Weathertight colonies will be protected from draughts and damp 4.The hive must be weathertight and, preferably, not situated in a frost pocket or damp location 5.

Winter preparation

Once the honey supers are off all activities in the apiary are focused on ensuring that these four requirements for successful overwintering are achieved in a timely manner.

Clearing bees from wet supers ...

Clearing bees from wet supers …

Weak colonies are united with strong colonies. At this stage in the season – other than disease – the main reason a colony is likely to be weak is because the queen isn’t up to the job. If she’s not now, what chance has the colony got over the winter or early spring? 6

Varroa treatment is started as early as reasonably possible with the intention of protecting the overwintering bees from the ravages of DWV. This means now, not early October. Use an appropriate treatment and use it correctly. Apiguard, oxalic acid (Api-Bioxal), Apivar etc. … all have been discussed extensively here previously. All are equivalently effective if used correctly.

All colonies get at least one block (12.5kg) of bakers fondant, opened like a book and slapped (gently!) on the tops of the frames. An eke or an empty super provides the ‘headspace’ for the fondant block. All of the Varroa treatments listed above are compatible with this type of feeding simultaneously 7.

Hopefully, hives are already weathertight and secure. Other than strapping them to the hive stands to survive winter gales there’s little to do.

They think it’s all over!?

It is … almost 🙂


Colophon

They think it’s all over! is a quote by Kenneth Wolstenholme made in the closing stages of the 1966 World Cup final. Some fans had spilled onto the pitch just before Geoff Hurst scored the the last goal of the match (England beat West Germany 4-2 after extra time), which Wolstenholme announced with “It is now, it’s four!”. This was the only World Cup final England have reached, whereas Germany have won four.

As Gary Lineker says “Football is a simple game; 22 men chase a ball for 90 minutes and at the end, the Germans win.”

Taking stock

It’s the middle of the season 1. Hopefully, the timely application of swarm control measures such as a vertical split or Pagden’s artificial swarm, have maintained strong colonies and created additional colonies headed by new queens.

July is the month I review my stocks with the goal of:

  • replacing ageing queens that are unproductive
  • removing bad tempered colonies (though most have already been dealt with)
  • preparing strong colonies to exploit late season nectar flows
  • making up nucleus colonies for overwintering, either as backups or for sale

Of course, this type of taking stock should be a continuous process through the season, but it’s easier to start it now for the winter, rather than leaving it to the shorter days, more variable weather and less dependable nectar flows of late summer.

Two into one does go

A small hole ...

A small hole …

Often the intention is to simply replace an old queen with a new queen. In a vertical split this is simplicity itself. Remove the queen that is unwanted and the split board, replacing the latter with a sheet of newspaper. Make one or two very small holes in the newspaper with the point of a hive tool and leave the colony to it.

Over the course of the next few days the workers will chew through the newspaper, unite amicably and set about building up the stores for winter.

A week or so after uniting I rearrange the frames, usually making space for the queen to lay in the top box with the brood below. If the colonies being united are smaller it’s sometimes possible to remove one box altogether.

There’s discussion online about quick ways to unite colonies by spraying both with air freshener. The smell – which is usually pretty awful 2 – masks the colony scent and so the colony does not fight. I’ve not done this so can’t recommend it (or, for that matter, criticise it).

Since I’ll be returning a week later to check the boxes and rearrange frames I’m happy to stick with newspaper uniting which rarely fails. Air freshener is also one less thing to carry in the bee bag.

Nucs for pleasure and profit

Five frame nucleus (nuc) colonies overwinter well if prepared properly 3. They are really useful in the early spring to make up for any winter losses, to replace colonies with failing queens 4 or to sell.

Everynuc

Everynuc …

Overwintered nucs are often appreciably more expensive than those imported later in the season, or in the glut of bees that follows the swarming season.

The queen has proved herself and the nuc is available when demand is highest … at the very beginning of the season.

Whilst I would – and have – argued that it might be better to start beekeeping later in the season working alongside your mentor, there are strong economic imperatives to overwinter nucs for sale.

Splits and nucs

With a successful split (or Pagden) you now have two queens, one strong colony and one building up fast. The latter – with the new queen – can be used to prepare a nuc for overwintering, with the remaining bees and brood strengthening the original colony for the late season nectar flow 5.

It’s easy to prepare a nuc colony to take away to a distant apiary – the new queen, a frame of stores, one or two of emerging brood and a mixed frame of eggs and brood, all with the adhering bees, together with a couple more frames of bees shaken in over the top. Make up to five frames with foundation, seal them up and ship ’em off to your out apiary.

If you don’t have access to an out apiary you should ensure that the majority of the older workers are omitted when preparing the nuc, and you should add in additional young bees to help the new queen get established.

It’s also worth stuffing the nuc entrance with dead grass for a few days to enforce the ‘new environment’ on the bees.

Stuffed

Stuffed …

You exclude the old foragers by giving each frame placed in the nuc a gentle shake before putting it into the box. The old bees fly off, the young ones cling on. Do the same with the ~3-4 additional frames of bees added on top before re-siting the the nuc in the apiary.

Nucs may need feeding, particularly if there’s a dearth of nectar or bad weather. Keep an eye on them. By excluding the old foragers you can feed them without the risk of robbing. However, it’s wise not to feed them for the best part of a week after making up the nuc to allow any carried-over stragglers to return. This is why it’s important to include a full frame of stores from the outset.

Variations

There’s still ample time in the season to rear new queens, so all sorts of other combinations of requeening/uniting and/or splits are still possible. For example, I’ve recently used a particular queen to requeen a colony and will split the box she came from into 2-3 nucs, all of which should build up well for overwintering.

By splitting the box after the new queen cells are raised I ensure they were produced by a well-balanced population of bees, with ample stores under ideal conditions. I think this is better than divvying up the frames from the recently queenless box and hoping to achieve the strong and balanced population in all the nucs. Inevitably some are stronger than others … or, more significantly in terms of queen cell production, weaker.

And in between all of this amateur dabbling I’ve been working with our friends and collaborators in Aberdeen on methods of Varroa control to minimise the levels of deformed wing virus (DWV) as well as starting our studies on chronic bee paralysis virus (CBPV) …

Hot day, hard work ...

Hot day, hard work …

… oh yes, and moving into a new house 😉 6