Category Archives: Miscellaneous

Apivar (amitraz) resistance

Apivar is a widely used acaricide (a pesticide that kills mites and ticks) used to control Varroa.

The active ingredient of Apivar 1 is amitraz, a synthetic chemical discovered and developed almost 50 years ago.

Amitraz

Amitraz …

Amitraz has multiple molecular targets. I previously discussed the mechanism of action and summed it up with the words:

Essentially, amitraz binds and activates receptors that are critically important in a range of important aspects of the Varroa activity and behaviour … amitraz changes [this] behaviour and so exhibits miticidal activity. It has additional activities as well … these multiple routes of action may explain why resistance to amitraz is slow to develop.

I made the point in a subsequent post that amitraz resistance was very well documented … in cattle ticks 2 but that there was only anecdotal or incompletely documented evidence of resistance in Varroa in the USA, Argentina and Europe.

Apivar strip – fit and (don’t) forget

Amitraz has been used for mite control in honey bees for over twenty years. Considering its widespread use, the concentrations it is used at, and the relatively high replication rate of Varroa it is surprising that there has not been better evidence of resistance.

But that is no longer the case 🙁

Do you want the good news or the bad news first?

The bad news

A very recent paper 3 has clearly documented amitraz resistant Varroa in several commercial beekeeping operations in the USA.

I’ll discuss the key results of this paper first and then make some general comments on the implications for beekeepers and beekeeping.

The study had three components:

  1. Determine the sensitivity of Varroa never treated with amitraz to the chemical. This forms the baseline sensitivity against which field samples from commercial beekeepers could be tested.
  2. Screen Varroa from hives maintained by commercial beekeepers (with a multi-year history of Apivar usage) for amitraz resistance.
  3. Validate that the reduced efficacy of Apivar correlates with the observed amitraz resistance.

Essentially it involved harvesting live Varroa from colonies by a large-scale dusting with icing sugar 4. The Varroa were then tested to determine whether they showed resistance to amitraz, and the sensitivity was compared with the baseline sample of mites from colonies never treated.

Finally, an Apivar sensitivity test was conducted to determine the proportion of mites killed in a standardised assay in a set time period, again compared with the control (baseline sample).

The results of the study

You should refer to the paper for the primary data if needed.

Not all the apiaries tested yielded sufficient mites to screen for Apivar resistance. This is part of ‘the good news’ which I’ll get to shortly … but first the science.

Of those apiaries that did, Apivar resistance (determined by LC50 – the Lethal Concentration required to kill 50% of the mites) ranged from similar to that seen in the baseline samples to ~20-fold greater than the controls.

Two apiaries had an over 10-fold increase of the resistance ratio (the observed LC50 divided by the baseline LC50), with some individual colonies having high levels of Varroa infestation despite an active application of amitraz.

Apivar kills mites very quickly. Using a known number of mites trapped in a cage with a single small square of Apivar it is possible to ‘count the corpses’ and plot a kill curve over time. Sensitive mites from the control colonies were all killed within 3 hours.

Time course of Apivar efficacy in amitraz-susceptible Varroa

Using this as the baseline control it was then possible to determine the efficacy of Apivar in killing the mites (in the same 3 hour timeframe) from apiaries exhibiting resistance.

Apivar efficacy in commercial beekeeping apiaries.

Two apiaries (B and C, above) contained mites that exhibited high levels of resistance to Apivar, reflected in a low level of Apivar efficacy (above). In these apiaries, an average of less than 80% of mites were killed within the 3 hour assay.

Finally, the author demonstrated a correlation between Apivar efficacy and amitraz resistance. Unsurprising, but a necessary concluding point for the experimental data.

Within apiary variation

It was interesting that the author notes that the range of Apivar efficacy was much greater in colonies from apiaries with clear evidence of amitraz resistance.

For example, apiary B exhibited a range of Apivar efficacy in colonies from 28% to 97%, with an average (plotted above) of 68%. Whilst this is clearly an unacceptably low level, it is interesting that some of the colonies within the same apiary had mites killed at an efficacy similar or better (>90%) to apiaries A2 and A4 in the graph above.

I’ve re-plotted the primary data of Apivar efficacy vs. mite counts from individual colonies to emphasise this point.

Variation of Apivar efficacy vs mite infestation levels in individual colonies from commercial apiaries

Apiaries B and C (red markers) could be considered as ‘failing apiaries’ as the average Apivar efficacy of each was below 80% (see bar chart). Together the average mite load and Apivar efficacy for these two apiaries was 6.75 mites/100 bees and 72% respectively.

However, of the 16 colonies screened from these two apiaries (8 from each):

  • One colony had insufficient detectable mites to be included in the the full analysis.
  • Eight dropped less than 3 mites/100 bees during the sugar dusting analysis (the average over the 63 colonies screened was 5.33 mites/100 bees).
  • Four colonies exhibited ≥90% Apivar efficacy.
  • One colony from apiary B was a clear outlier, with >50 mites/100 bees ( 😯 ) and only ~28% Apivar efficacy. Inevitably this sample skews the averages …

Clearly the average figures presented in the bar chart above hides a very significant level of within-apiary variation.

Weird

I commented recently on the variation in mite levels during midwinter treatment of colonies with OA/Api-Bioxal. I attributed this – with little supporting evidence (!) – to different rates of late-season brood production. Colonies brooding late into the autumn were expected to have higher midwinter mite levels.

However, the variation seen here is different.

With the exception of that one heavily infested colony from apiary B, the mite levels in the ‘failing apiaries’ (B and C) are actually less than the average of the remainder of the study group (3.88 vs. 4.85).

What differs is the efficacy of Apivar treatment, not the resulting mite levels.

Frankly, this is a bit weird … on two counts:

  1. If Apivar treatment had been failing for a long time in apiaries B and C I would have expected much higher than average mite levels.
  2. Considering the amount of drifting and robbing that goes on between juxtaposed colonies I would have also expected Apivar-resistant mites to be very widely distributed within the ‘failing apiaries’.

Caveat on the mite counts – Apiaries in Louisiana, New York and South Dakota were analysed in this study. Louisiana apiaries were sampled in April, the others in July and August. I don’t know enough about the climate or mite-replication kinetics in these states to know how much this would have influenced the mite infestation levels (or prior or ongoing treatment regimes, which would also influence mite numbers). Unfortunately, the locations of the apiaries (A, B, C etc.) are not provided, other than the control apiary which is in Baton Rouge, LA. If the study had been done in the UK mite drops in April and August would have been wildly different depending upon the location.

Idle speculation

Apivar resistance does appear to have arisen in some of these colonies, but it does not appear to have become widely distributed within the apiary.

Why not?

I don’t actually think we have enough information to work with. The paper contains almost no additional background details – Apivar treatment history, use of other treatments, colony loss data etc.

But that won’t stop me speculating a little bit 😉

Do Apivar-resistant mites stop bees from drifting? Probably not, but it would explain why resistance was not widespread in the apiary 5.

More sensibly, perhaps Apivar resistance is detrimental in the absence of selection.

In the colonies in which resistance evolves it gives the mites a significant advantage. The ongoing infestation could encourage prolonged or repeated treatment, so selecting for yet more resistant mites. Eventually the colony succumbs to the resulting high viral load.

In other colonies, treatment is withdrawn (or forgotten … remember, we have zero information here!) and the Apivar-resistant mites are then at a disadvantage to their sisters.

This isn’t unheard of.

Apistan resistance appears to be detrimental in the absence of selection. There are some relatively straightforward molecular explanations for this type of phenotype.

You would have to assume differential colony treatments within apiaries B and C for this to be part of the explanation (and to account for drifting). Let’s hope the colony records are less shambolic than mine many beekeepers keep 😉

Until a clearer picture emerges of the management history of these colonies all we’re left with is the slightly (or very) confusing observation that Apivar resistance is a hive-specific phenomenon.

As the author states:

This colony level resolution suggests that each colony may act an island of resistance with its own distinct Varroa population. Beekeepers have reported inconsistency in amitraz treatment efficacy among colonies within an apiary and this variation seems to support those anecdotal observations.

And the good news?

I think there are two ‘encouraging’ observations in this paper (though of course I’d be happier if there was no resistance).

  1. About half of the commercial apiaries surveyed (5 of 11 that had a long history of Apivar usage) had too few mites detectable to screen for amitraz resistance. Clearly Apivar works, and often works very well indeed.
  2. Apivar resistance is not widespread in the apiaries within which it had arisen. For whatever reason, resistant mite populations appear restricted to individual colonies.

And these, in turn, have implications for practical beekeeping.

Implications for practical beekeeping

How does Apivar resistance evolve? Classically, misuse or overuse of treatments results in their eventual failure. Antibiotics are a good example of this.

I’ve been told by commercial beekeepers that some use a half dose of Apivar midseason to knock mite levels back sufficiently for the late season nectar flows. This is a typical example of misuse. It may not result in the development of resistance and it may not be a strategy used by the beefarmers managing apiaries B and C, but it is not the correct way to use Apivar.

What about overuse? Mites still dropping after 6 weeks of Apivar? Go on, slip another couple of strips in for another month or two. An (expensive) example of overuse.

Used Apivar strips

Or what about the Apivar strip found lying on the bottom of the hive at the first spring inspection? Again, overuse as there are likely to be lingering traces of Apivar present in the colony all winter 6.

So the first implication for practical beekeeping is to use Apivar correctly to help avoid the development of resistance. Don’t overdose or underdose, remove after 6-10 weeks, do not leave in over the winter.

Secondly, use alternate treatments to knock back the mite population. This is again a classic strategy to avoid selecting for resistance.

For example, use Apivar in late summer and Api-Bioxal in midwinter.

The mechanism of action of these two treatments is fundamentally different, so resistance to one will not confer resistance to the other (and there are no documented cases of oxalic acid resistance I’m aware of).

If you don’t treat midwinter (and you probably should 7) then use Apiguard one year and Apivar the next. Again, totally different mechanisms of action.

Finally, do not rely on individual colonies within an apiary being indicative of all colonies. I know some beekeepers who only conduct mite drop counts in one colony as a ‘sentinel’ 8.

If the drop is high then treatment is needed.

Or vice versa … no mites, so no treatment needed.

There’s a lot of colony to colony variation so it’s worth monitoring them all 9. And this is probably even more important with the colony level Apivar resistance reported in this paper.

Just something else to worry about … 🙁


 

“Start beekeeping” courses

It’s mid-January. If you are an experienced beekeeper in the UK you’re being battered by the remnants of Storm Brendan and wondering whether the roofs are still on your hives.

If my experience is anything to go by, they’re not 🙁

But if you’re a trainee beekeeper you may well be attending a course on Starting Beekeeping, run by your local beekeeping association. Typically these run through the first 1- 3 months of the year, culminating in an apiary visit in April.

Trainee beekeepers

Trainee beekeepers

Sometimes a not-really-warm-enough-to-be doing-this apiary visit in April 🙁

Beekeeping, just like driving a car

Many years ago I attended the Warwick and Leamington Beekeepers Introduction to Beekeeping course. It was a lot of fun and I met some very helpful beekeepers.

But I learnt my beekeeping in their training apiary over the following years; initially as a new beekeeper, and subsequently helping instruct the cohort of trainees attending the course and apiary sessions the following year(s).

Teaching someone else is the best way to learn.

The distinction between the theoretical and practical aspects of the subject are important. You can learn the theory in a classroom, refreshed with tea and digestive biscuits, with the wind howling around outside.

Plain chocolate are preferable

However, it is practical experience that makes you a beekeeper, and you can only acquire these skills by opening hives up – lots of them – and understanding what’s going on.

Some choose never to go this far 1, others try but never achieve it. Only a proportion are successful – this is evident from the large number who take winter courses compared to the relatively modest growth in beekeeper numbers (or association memberships).

Beekeeping is like driving a car. You can learn the theory from a book, but that doesn’t mean you are able to drive. Indeed, the practical skills you lack may mean you are a liability to yourself and others.

Fortunately, the consequences of insufficient experience in beekeeping are trivial in comparison to inexperienced drivers and road safety.

Theoretical beekeeping

What should an ‘introduction to beekeeping’ course contain?

Which bits are necessary? What is superfluous?

Should it attempt to be all encompassing (queen rearing methods, Taranov swarm control, Israeli Acute Paralysis Virus) or pared back to the bare minimum?

Who should deliver it?

I don’t necessarily know, but for a variety of reasons I’ve been giving it some thought(s) … and here they are.

The audience and the intended outcome

You have to assume that those attending the course know little or nothing about bees or beekeeping. If you don’t there’s a good chance some of the audience will be alienated before you start 2.

When I started I had never seen inside a beehive. I don’t think I even knew what a removable frame was. Others on the course had read half a dozen books already. Some had already purchased a hive.

Some even had bees (or ‘hoped they were still alive’ as it was their first winter) 😯

I felt ignorant when others on the course were asking Wouldn’t brood and a half be better? or I’ve read that wire framed queen excluders are preferable.

Framed wire QE ...

Preferable to what?

What’s a queen excluder?

By working from first principles you know what has been covered, you ensure what is covered is important and you keep everyone together.

Some on the course like the idea of keeping bees, but will soon get put off by the practicalities of the discipline. That doesn’t mean they can’t still be catered for on the course. It can still be interesting without being exclusive 3.

But, of course, the primary audience are the people who want to learn how to keep bees successfully.

For that reason I think the intended outcome is to teach sufficient theory so that a new beekeeper, with suitable mentoring, can:

  • acquire and house a colony
  • inspect it properly
  • prevent it swarming, or know what to do if it does
  • manage disease in the colony
  • prepare the colony for winter and overwinter it successfully

The only thing I’d add to that list is an indication of how to collect honey … but don’t get their hopes up by discussing which 18 frame extractor to purchase or how to use the Apimelter 😉

Course contents

I’m not going to give an in-depth breakdown of my views of what an introduction to beekeeping course should contain, but I will expand on a few areas that I think are important.

The beekeeping year and the principles of beekeeping

I’d start with an overview of a typical beekeeping year. This shouldn’t be hugely detailed, it simply sets out what happens and when.

It provides the temporal context to which the rest of the course can refer. It emphasises the seasonality of beekeeping. The long periods of inactivity and the manic days in May and early June. It can be quite ‘light touch’ and might even end with a honey tasting session.

Or mead … 😉

‘Typical’ means you don’t need to qualify everything – if the spring is particularly warm or unless there’s no oil seed rape near you – just focus on an idealised year with normal weather, the expected forage and the usual beekeeping challenges.

The normal beekeeping challenges

But this part of the course should also aim to clearly emphasise the principles and practice of beekeeping.

Success, whether measured by jars of honey or overwintered colonies, requires effort. It doesn’t just happen.

Hive inspections are not optional. They cannot be postponed because of family holidays 4, weekend breaks in Bruges, or going to the beach because the weather is great.

Great weather … good for swarming and swimming

Quite the opposite. From late April until sometime in July you have to inspect colonies at weekly intervals.

Whatever the weather (within reason).

Not every 9-12 days.

Not just before and when you return from a fortnight in Madeira 🙁

Andalucian apiary

While you’re looking at these Andalusian hives your colony might be swarming.

And hive inspections involve heavy lifting (if you’re lucky), and inadvertently squidging a few bees when putting the hive back together, and possibly getting stung 5.

The discussion of the typical year must mention Varroa management. This is a reality for 99% of beekeepers and it is our responsibility to take appropriate action in a timely manner (though the details of how and when can be saved for a later discussion of disease).

Finally, this part of the course should emphasise the importance of preparing colonies properly for the winter. This again necessitates mentioning disease control.

By covering the principles and practice of a typical year in beekeeping the trainee beekeepers should be prepared from the outset for the workload involved, and have an appreciation for the importance of timing.

We have to keep up with the bees … and the pace they go (or grow) at may not be the same every year, or may not quite fit our diaries.

Bees and beekeeping

There is a long an interesting history of beekeeping and an almost limitless number of fascinating things about bees. Some things I’d argue are essential, others are really not needed and can be safely ignored.

Bee boles in Kellie Castle, Fife, Scotland … skep beekeeping probably isn’t an essential course component.

Of the essential historical details I’d consider the development of the removable frame hive is probably the most important. Inevitably this also involves a discussion of bee space – a gap that the bees do not fill with propolis or wax. Of course, bee space was known about long before Langstroth found a way to exploit it with the removable frame hive.

The other historical area often covered is the waggle dance, but I’d argue that this is of peripheral relevance to beekeeping per se. However, it could be used to introduce the concept of communication in bees.

And once the topic turns to bees there’s almost no limit what could be included. Clearly an appreciation of the composition of the colony and how it changes during the season is important. This leads to division of labour and the caste system.

It also develops the idea of the colony as a superorganism, which has a bearing on swarm preparation, management and control.

Queen development

Queen development …

Probably most important is the development cycle of the queen, workers and drones. A proper understanding of this allows an appreciation of colony build-up, the timing of swarming and queen replacement, and is very important for the correct management of Varroa.

As with the beekeeping year, sticking to what is ‘typical’ avoids confusion. No need to mention laying workers, two-queen hives, or thelytokous parthenogenesis.

Keep on message!

Equipment

What a minefield?!

As long as the importance of compatibility is repeatedly stressed you should be OK.

An Abelo/cedar hybrid hive ...

An Abelo/cedar hybrid hive …

A little forethought is needed here. Are you (or the association) going to provide your beginners with bees?

I’d argue, and have before, that you really should.

Will the bees be on National frames? 14 x 12’s? One of several different Langstroth frames? Smiths?

Or packages?

I said it was a minefield.

Beginners want to be ready for the season ahead. They want to buy some of that lovely cedar and start building boxes. They need advice on what to buy.

What they buy must be influenced by how they’re going to start with bees. One of the easiest ways around this is to allocate them a mentor and let them lead on the specifics (assuming they’ll be getting bees from their mentor).

One thing that should be stressed is the importance of having sufficient compatible equipment to deal with swarming (which we’ll be coming to shortly).

Dummy board needed ...

5 frame poly nucleus hive needing a dummy board …

My recommendation would be to buy a full hive with three supers and a compatible polystyrene nucleus hive. In due course beginners will probably need a second hive, but (if you teach the simplest form of swarm control – see below) not in the first year. A nuc box will be sufficient.

Swarming and swarm control

Swarming is often considered to be confusing 6.

It doesn’t need to be.

The life cycle of the bee and the colony have been covered already. Swarming and queen cells is just honey bee reproduction … or it’s not swarming at all but an attempt to rescue the otherwise catastrophic loss of a queen 🙁

Deciding which is important and should influence the action(s) taken.

The determinants that drive swarming are reasonably well understood – space, age of the queen etc. The timing of the events, and the importance of the timing of the events leading to swarming is very well understood.

Preventative measures are therefore easy to discuss. Ample space. Super early. Super often.

It’s swarm control that often causes the problem.

And I think one of the major issues here is the attempts to explain the classic Pagden artificial swarm. Inevitably this involves some sort of re-enactment, or an animated Powerpoint slide, or a Tommy Cooper-esque “Glass, bottle … bottle, glass” demonstration 7.

Often this is confounded by the presenters’ left and right being the audiences right and left.

Confused? You will be.

Far better to simply teach a nucleus hive-based swarm control method. Remove the old queen, a frame of emerging brood, a frame of stores and a few shakes of bees. Take it to a distant apiary (or block the entrance with grass etc. but this adds confusion) and leave a single open charged queen cell in the original hive.

This method uses less equipment, involves fewer apiary visits, but still emphasises the need for a thorough understanding of the queen development cycle.

And, to avoid confusion, I wouldn’t teach any other forms of swarm control.

Yes, there are loads that work, but beginners need to understand one that will always work for them. Hopefully they’ve got dozens of summers of beekeeping ahead of them to try alternatives.

I think swarm control is one area where the KISS principle should be rigorously applied.

Disease prevention and management

Colony disease is a reality but you need to achieve a balance between inducing paranoia and encouraging complacency.

This means knowing how to deal with the inevitable, how to identify the possible and largely ignoring the rest.

The inevitable is Varroa and the viruses it transmits. And, of at least half a dozen viruses it does transmit, only deformed wing virus needs to be discussed. The symptoms are readily identifiable and if you have symptomatic bees – and there can be no other diagnosis – you have a Varroa problem and need to take action promptly.

Worker bee with DWV symptoms

Worker bee with DWV symptoms

In an introductory course for new beekeepers I think it is inexcusable to promote alternate methods of Varroa control other than VMD-approved treatments.

And, even then, I’d stick to just two.

Apivar in late summer and a trickle of Api-Bioxal solution in midwinter.

Used properly, at the right time and according to the manufacturer’s instructions, these provide excellent mite management.

Don’t promote icing sugar shaking, drone brood removal, small cell foundation, Old Ron’s snake oil or anything else that isn’t documented properly 8.

Almost always there will be questions about treatment-free beekeeping.

My view is that this has no place in a beginners course for beekeepers.

The goal is to get a colony successfully through the full season. An inexperienced beekeeper attempting to keep bees without treatment in their first year is a guaranteed way to lose both the colony and, probably, a disillusioned trainee beekeeper from the hobby.

To lose one may be regarded as a misfortune, to lose both looks like carelessness. 9

Once they know how to keep bees alive they can explore ways to keep them alive without treatment … and they will have the experience necessary to make up for the colony losses.

In terms of other diseases worth discussing then Chronic Bee Paralysis Virus (CBPV) is rapidly increasing in prevalence. Again the symptoms are pretty characteristic. Unlike DWV and Varroa it’s not yet clear what to do about it. Expect to see more of it in the next few years.

Nosema should probably be mentioned as should the foulbroods. The latter are sufficiently uncommon to be a minor concern, but sufficiently devastating to justify caution.

By focusing on the things that might kill the colony – or result in it being destroyed 🙁 – you’re obviously only scratching the surface of honey bee pests and pathogens. But it’s a start and it covers the most important things.

Most beginners have colonies that never get strong enough for CBPV to be a problem. Conversely, their weakness means that wasps might threaten them towards the end of the season, so should probably be discussed.

And, of course, the Asian hornet if you’re in an area ‘at risk’.

My beekeeping year

By this time the beginners have an overview of an idealised beekeeping year, an appreciation of the major events in the year – swarming, disease management, the honey harvest and preparation for winter.

Sounds easy, doesn’t it?

But an ideal wrap-up session to a starting beekeeping course would be the account of a real first year from a new beekeeper.

What were the problems? How did they attempt to solve them? What happened in the end?

This asks a lot of a relatively inexperienced beekeeper. Not least of which is good record keeping (but of course, they learnt this on the course the previous year 😉 ).

However, the comparison between the ‘textbook’ account delivered during the course with the ‘sweating in a beesuit’ reality of someone standing by an open hive feeling totally clueless is very enlightening.

Sweating in a beesuit

With sufficient preparation you could even turn it into a quiz to test what the trainees have understood.

I’ve seen several ‘starting beekeeping’ courses. All have had some of the things described above. None have had all of them. Most have included superfluous information, or in some cases, dangerous misinformation.

Which brings neatly me to the question of who should teach the course?

If you can do, if you can’t teach

Ensuring that everything is covered at the right time, avoiding duplication and maintaining the correct emphasis takes skill for one person. For a group of individuals it requires a lot of preparation and strict instructions not to drift off topic.

You might have noticed that many experienced beekeepers like to talk.

A lot.

A course handbook becomes an essential – both to help the students and as a guide to keep “on message” for the tutors.

Often it is some of the most experienced beekeepers who teach these courses.

Some are outstanding. Others less so.

Their years of experience often means they take for granted the subtleties that are critical. The difference between play cups and a 1-2 day old queen cell. A reduced laying rate by the queen. How to tell when there is a nectar flow on, and when it stops.

All of this, to them, is obvious.

They forget just how much they have learned from the hundreds of hives they have opened and the thousands of frames they have examined. They’ve reached the stage when it looks like they have a sixth sense when it comes to finding the queen.

Queen rearing course

Listen up Grasshopper!

As Grasshopper says to the old, blind master 10 “He said you could teach me a great knowledge”.

Possibly.

But sometimes they’ve retained some archaic approaches that should have been long-forgotten. They were wrong then, they still are. Paint your cedar hives with creosote. Use matchsticks to ventilate the hive in winter. Apistan is all you need for Varroa control.

 

Matchless matches

If any readers of this post have had these suggested on a course they are currently attending then question the other things that have been taught.

Get a good book that focuses on the essentials. I still think Get started in beekeeping by Adrian and Claire Waring is the best book for beginners that I’ve read 11.

Get a good mentor … you’re going to need one.

And good luck!


 

Resolutions

It’s that time of the year again. The winter solstice is long passed. Christmas has been and gone. The New Year is here.

Happy New Year 🙂

And New Year is a time to make resolutions (a firm decision to do or not to do something).

There is a long history of making resolutions at the turn of the year. The Babylonians promised to pay their debts and return borrowed objects at their New Year. Of course, their year was based on a lunar calendar and started with the first crescent moon in March/April, but the principle was the same.

Many New Year’s resolutions have religious origins … though the more recent trend to resolve to “drink less alcohol” or “lose weight are somewhat more secular.

About 50% of people in the western world make New Year’s resolutions. This figure is up from ~25% in the 1930’s. Perhaps success increases uptake?

Popular resolutions include improvement to: health (stop smoking, get fit, lose weight), finance or career (reduce debt, get a better job, more education, save more), helpfulness (volunteer more, give more to charity) or self (be less grumpy, less stressed, more friendly) etc.

But since this is a beekeeping website it is perhaps logical to consider what resolutions would lead to improvements in our beekeeping.

Beekeeping resolutions

The short winter days and long, dark nights are an ideal time to develop all sorts of fanciful plans for the season ahead.

How often are these promptly forgotten in the stifling heat of a long June afternoon as your second colony swarms in front of you?

The beekeeping season starts slowly, but very quickly gathers pace. It doesn’t take long before there’s not enough time for what must be done, let alone what you’d like (or had planned) to do.

And then there are all those pesky ‘real life’ things like family holidays, mowing the lawn or visiting relatives etc. that get in the way of essential beekeeping.

So, if you are going to make beekeeping resolutions, it might be best to choose some that allow you to be more proactive rather than reactive. To anticipate what’s about to happen so you’re either ready for it, or can prevent it 1.

Keep better records

I’ve seen all sorts of very complex record keeping – spreadsheets, databases, “inspection to a page” notepads, audio and even video recordings.

Complex isn’t necessarily the same as ‘better’, though I’ve no doubt that proponents of each use them because they suit their particular type of beekeeping.

Objective and subjective notes

My notes are very straightforward. I want them to:

  • Be available. They are in the bee bag and so with me (back of the car, at home or in the apiary) all the time. If I need to refer to them I can 2. They are just printed sheets of A4 paper, stuffed into a plastic envelope. I usually write them up there and then unless I forget a pen, it’s raining and/or very windy or I’m doing detailed inspections of every colony in the apiary. In these cases I use a small dictation machine and transcribe them later that evening.
  • Keep track of colonies and queens. I record the key qualitative features that are important to me – health, temper, steadiness on the comb etc. – using a simple numerical scoring system. Added supers are recorded (+1, +1, -2 etc) and there’s a freeform section for an additional line or two of notes. Colonies and queens are uniquely numbered, so I know what I’m referring to even if I move them between apiaries, unite them or switch from a nuc box to a full hive.
  • Allow season-long comparisons ‘at a glance’. With just a line or two per inspection I can view a complete season on one page. Colonies consistently underperforming towards the bottom of the page usually end up being united in late August/early September.
  • Include seasonal or environmental jottingsMay 4th – first swift of the year”, “June 7th – OSR finished”, “no rain for a fortnight”. These are the notes that, over time, will help relate the status of the colony to the local environment and climate. If the house martins, swallows and swifts are late and it’s rained for a month then swarming will likely be delayed. Gradually I’m learning what to expect and when, so I’m better prepared.

Monitor mites

Varroa remains the near-certain threat that beekeepers have to deal with every season. But you can only deal with them properly if you have an idea of the level of infestation.

Varroa levels in the colony depend upon a number of factors including the rate of brood rearing, the proportion of drone to worker brood and the acquisition of exogenous mites (those acquired through the processes of drifting and robbing).

Pupa (blue) and mite (red) numbers

In turn, these factors vary from colony to colony and from season to season. As I discussed recently, adjacent colonies in the same apiary can have very different levels of mite infestation.

Additional variation can be introduced depending upon the genetically-determined grooming or hygienic activity of the colony, both of which rid the hive of mites.

Since the combined influence of these factors cannot be (easily or accurately) predicted it makes sense to monitor mite levels. If they are too high you can then intervene in a timely and appropriate manner.

Quick and effective ways to monitor mite levels

Any monitoring is better than none.

Easy counting ...

Easy counting …

There are a variety of ways of doing this, some more accurate than others:

  1. Place a Correx tray under the open mesh floor (OMF) and count the natural mite drop over a week or so. Stick the counts into the National Bee Unit’s (appropriately named) Varroa calculator and see what they advise. There are quite a few variables – drone brood amounts, length of season etc – that need to be taken into account and their recommendation comes with some caveats 3. But it’s a lot better than doing nothing.
  2. Uncap drone brood and count the percentage of pupae parasitised by mites. The NBU’s Varroa calculator can use these figures to determine the overall infestation level. The same caveats apply.
  3. Determine phoretic mite levels by performing a sugar roll or alcohol wash. A known number of workers (often ~300) are placed in a jar and the phoretic mites displaced using icing sugar or alcohol (car screenwash is often used). After filtering the sugar or alcohol the mites can be counted. Sugar-treated bees can be returned to the colony 4. Infestation levels of 2-3% (depending upon the time of season) indicate that intervention is required 5.

Does what it says on the tin.

Overwinter nucs

If you keep livestock you can expect dead stock.

Unfortunately colony losses are an inevitability of beekeeping.

They occur through disease, queen failure and simple accidents.

Most losses are avoidable:

  • Monitor mites and intervene before virus levels threaten survival of the colony.
  • Check regularly for poorly mated or failing queens (drone layers) and unite the colony before it dwindles or is targeted by wasps or other robbers.
  • Make sure you close the apiary gate to prevent stock getting in and tipping over hives … or any number of other (D’oh! Slaps forehead 🙄 ) beekeeper-mediated accidents).

But they will occur.

Corpses

Corpses …

And most will occur overwinter. This means that as the new season starts you might be missing one or two hives.

Which could be all of your colonies if you only have a two 6.

Replacing these in April/May is both expensive and too late to ensure a spring honey crop.

Winter colony losses are the gift that keeps on giving taking.

However, if you overwinter an additional 10-25% of your colonies as 5 frame nucs (with a minimum of one), you can easily avoid disaster.

Here's one I prepared earlier

Here’s one I prepared earlier

If you lose a colony you can quickly expand the nuc to a full hive (usually well before a commercially-purchased colony would be ready … or perhaps even available).

And if you don’t lose a colony you can sell the nuc or expand your colony numbers.

Sustainable beekeeping

If you’ve not watched Michael Palmer’s The Sustainable Apiary at the National Honey Show I can recommend it as an entertaining and informative hour for a winter evening.

Michael keeps bees in Vermont … a different country and climate to those of us in the UK. However, his principles of sustainable beekeeping without reliance on bought-in colonies is equally valid.

Overwintering nucs requires a small investment of time and money. The former in providing a little more care and attention in preparation for winter, and the latter in good quality nucleus hives.

I reviewed a range of nuc boxes six years ago. Several of these models have been discontinued or revised, but the general design features to look for remain unchanged.

Here's three I prepared earlier ...

Everynuc poly nucs

Buy dense poly nucs for insulation, make sure the roof isn’t too thin and flimsy and choose one with an entrance that can be readily reduced to a “bee width” 7. Choice (and quality) has improved over the last 5-6 years but I still almost exclusively use Thorne’s Everynuc. I bought 20 a few seasons ago and remain pleased with them, despite a few design weaknesses.

Beekeeping benefits

I do all of the above.

Having learned (often the hard way) that my beekeeping benefits, these habits are now ingrained.

I had about 20 colonies going into the 2019/20 winter, including ~20% nucs. All continue to look good, but it won’t be until late April that I’ll know what my winter losses are.

In the meantime I can review the hive notes from last season and plan for 2020. Some colonies are overwintering with very substandard queens (generally poor temper) because they’re research colonies being monitored for changes in the virus population 8. They will all be requeened or united by mid/late May.

My notes mean I can plan my queen rearing and identify the colonies for requeening. I know which colonies can be used to source larvae from and which will likely be the cell raisers. The timing of all this will be influenced by the state of the colonies and the environmental ‘clues’ I’ve noted in previous years.

Capped queen cells

Capped queen cells

Of course, things might go awry before then, but at least I have a plan to revise rather than making it up on the spur of the moment.

I learned the importance of mite monitoring the hard way. Colonies unexpectedly crashing in early autumn, captured swarms riddled with mites that were then generously distributed to others in the same apiary. Monitoring involves little effort, 2-3 times a season.

So these three things don’t need to be on my New Year’s resolution list.

Be resolute

More people make New Year’s resolutions now than 90 years ago.

However, increasing participation unfortunately does not mean that they are a successful way to achieve your goals.

Richard Wiseman showed that only 12% of those surveyed achieved their goal(s) despite over 50% being confident of doing so at the beginning of the year.

Interestingly, success in males and females was influenced by different things. For men, incremental goal-setting increased the success rate 9 (I will write hive notes on every apiary visit, rather than Keep better notes). For women, the peer pressure resulting from telling friends and family increased success by 10%.

More generally, increased success in achieving the goals resulted from:

  • Making only one New Year’s resolution – so perhaps the three things above is overly ambitious?
  • Setting specific goals and avoiding resolutions you’re previously failed at.

My New Year’s (beekeeping) resolutions?

Since I’m a man, the chance of achieving my goals is not influenced by peer pressure so I’m not publishing them. We’ll have to see in 12 months whether I’m in the 12% that succeed … or the 88% that fail 😉


 

Questions & Answers

One of the challenging things about beekeeping is that the season can be both confusing and entertaining in equal measure.

It’s entertaining because it’s always a little bit different from the seasons that have preceded it. The environment changes. There’s an early spring, or late frosts, a drought, a monsoon or the local farmer changes from one strain of OSR to another.

Sometimes you get all of those in a single season … or month.

Mainly dry ...

Mainly dry …

But not only does the environment change, so do your bees. Inevitably your queens will be replaced over the years. In turn, they influence the performance of the colony. Your virgins fly off to the drone congregation areas where they mate with the ‘bad boys’ from colonies run by a nearby beekeeper with much thicker gloves and a fleece under his beesuit 🙁

Mayhem ensues. Inspections get a whole lot less fun. Quickly.

Or you collect a swarm headed by a fecund queen who busies herself producing calm, prolific, frugal and productive workers.

The colony gets bigger. And bigger. It shows no signs of swarming.

As you add the fourth super you feel like you’ve really cracked this beekeeping lark.

Sorted 🙂

But these things also make beekeeping incredibly confusing to the newcomer.

If you take a calendar-centric view there is no right answer to ‘When will the colony swarm?’ or ‘Is this the right time to treat for mites?’ or ‘Should I remove the supers now?’.

And many beginners do have a calendar-based viewpoint. It’s so much easier to prepare if you’re told that swarming starts in the third week of May and the supers should be removed at the end of August.

Not only is that easier to understand, but the telltale signs that the bees produce aren’t – for a beginner – very good at telling tales.

The first half-hidden charged queen cell, a reduced laying rate, the reduction in loaded returning foragers etc.

Play cup or queen cell?

Play cup or are they planning their escape …?

But, for me, at least half of the enjoyment is deciphering these signs and working out what the colony is doing, or going to do.

And therefore, what I should be doing.

Questions and answers

Most of this is observation, interspersed with a bit of record keeping and sprinkled with some ‘best guesses’.

If you keep asking the (right) questions you will slowly but surely start finding the answers.

Are they running out of space, making more play cups, and slimming the queen down for the great escape?

But many of these things are too subtle for beginners overwhelmed by the difficulty in just finding the queen amongst 38,789 of her daughters.

Inevitably this means that beginners – quite rightly – ask other beekeepers lots of questions.

I did.

I still do.

And in this increasingly connected world, some of those questions take the form of internet searches.

And some of these questions pop up as search terms on this site.

Mites

Willie Wonka meme

Many of these queries are about mite management:

  • best time to treat for varroa in honey bees?
  • should bees be treated for mites in spring?
  • use apiguard in june?
  • oxalic acid to treat varroa can i do it this week?
  • when to treat bees with oxalic acid in arkansas?

Very specific questions, very calendar-centric. There are hundreds more queries like these 1.

A correct answer requires an understanding of the biology of the mite and an appreciation of the state of the hive.

Neither necessarily involves the calendar. Both can be acquired with a little homework and good observation. However, the very fact that ~25% of queries are about mite management emphasises that many struggle with this aspect of beekeeping.

I remain convinced that the biggest challenge new beekeepers face is how to effectively manage mites. Without proper mite management your colonies will perish.

If you lose your colonies every winter you soon get disheartened.

The easiest way to properly control mite numbers is with chemicals.

It’s what I do.

Returning a marked and clipped queen

However, it’s not the only way.

Excellent beekeeping, selective rearing of mite-tolerant colonies (or of attenuated viruses!) and yet more excellent beekeeping – coupled with a favourable environment – may mean you can keep colonies without chemical intervention, and without excessive losses 2.

All beginners lack the necessary experience to achieve this. Most lack the ability to learn the skills quickly enough to save their colonies and the majority probably live in areas that are unsuitable.

Most importantly, many beginners aren’t resilient enough to ‘learn the hard way’. They believe the (largely incorrect) statements about the evils of treatment, they want their bees to be ‘healthy and happy’ 3, they like the sound of the term biodynamic 4 … but they cannot cope with losing their stocks every single winter through disease and starvation.

So they give up.

Learn to keep bees … then learn (again, using the years of knowledge already accumulated) to keep them without chemical intervention if you want. Not the other way round.

Read all you can – here and elsewhere – but remember that nothing is as valuable as time spent observing your bees.

Technical queries

These are the sorts of questions that probably can be easily answered 5.

Remembering of course that there are usually at least two correct answers for every question, and any number of incorrect ones.

  1. honey warming cabinet plans
  2. how long does it take bees to chew through newspaper?
  3. what is the chance of a queen being left in my hive when i have just lost a huge swarm?
  4. alighting board angle
  5. where and how to set up bait hives?

My honey warming cabinet is one of the most useful things I’ve built for my beekeeping and the pages that first describe it, the plans and its use, remain some of the most popular on this site.

The answer to Q2 obviously depends upon how many sheets of newspaper are involved.

I think we all know the answer to Q3 and it’s not going to make the questioner happy 😉

It’s very rare that you can provide an absolute definitive answer in beekeeping. However, after many years of exhaustive, well-controlled and independently verified trials I have unequivocally shown that the answer to Q4 is 47.7°.

47.7° precisely

Not more, not less.

Remembering of course that a landing (alighting) board isn’t actually needed at all 😉

Tom Seeley has done the definitive studies on bait hives (Q5). He clearly describes the ‘where’. My recommendations are rather more pragmatic. It’s easier to monitor and move bait hives if they’re not 5 metres above the ground.

Miscellaneous or just weird

And then there are lots of queries that are simply amusing typos, nonsensical or just odd. My favourites this year are:

  1. maxant crank mechanism
  2. langtorthe eke
  3. how to wear rigger boots?

I’ve no idea how the first of these landed up on the apiarist.org as it’s a term I’ve never used. The middle query (Q2) is a typical typo. It’s an obvious one, but it constantly amazes me how good fuzzy matching algorithms are these days.

Q3 is about beekeeping footwear. My last pair of rigger boots were abandoned years ago when the lining fell apart and they eventually turned my feet to a bloody pulp.

How to wear them?

I wore mine while hobbling. It’s not something I’d recommend.

I now wear Muck boots – specifically the now discontinued Edgewater II short boots – which are lightweight, very comfortable and fully waterproof. No steel toe cap, but I never drop full supers.

Oops ...

Oops …

Well, almost never.

Questions and comments

Not all questions originate in internet searches. Many come via the comments sections at the end of most posts. Most of these are both welcomed and useful; they allow me to clarify things that I’d presented confusingly, or they provide an opportunity to expand on parts of the post.

The numbers of comments have increased significantly this year.

More words and more comments

This increase probably reflects the increased readership (and page accesses) of the site.

Alternatively it might mean the writing is getting worse as the comment numbers correlate with the increased length of posts 🙁

I try and answer as many comments/questions as I can. Many make very salient points and I’m very grateful for those who take the time to comment, either to correct me, to seek clarification or to provide their own insight on the topic.

I ignore those that are dogmatically stupid or just plain wrong. My prerogative. There’s enough bad advice on the internet without propagating more.

I apologise to those who comment via Facebook or Twitter. I almost exclusively use both for promoting posts made here 6. Both generate a lot of traffic to this site but I simply don’t have time (or interest) to use them interactively.

If you want to contact me do so via the comments section or the, aptly named, contact form.

More Readers’ Questions

Which, in a rather circuitous way, brings me to the Readers’ Questions Answered column in the BBKA News. I was asked to tackle these a few months ago and January and February are already written 7.

BBKA News Readers’ Questions Answered proofs

The BBKA News is the monthly newsletter of the British Beekeepers Association. It has a circulation of ~25,000. Each year a different victim expert mug contributor prepares the answers. I’m taking over from Bob Smith, NDB from Medway BKA who did an excellent job and will be a hard act to follow. Some of the previous contributors have been anonymous which might have been a sensible option, but it’s too late for me now.

My family joke that I’m now an agony aunt for beekeepers.

I discussed this with Calum, a regular contributor to the comments section of these pages, who provided (as usual) some very sage advice, including “Bees put up with a lot of sh1t from beekeepers”. I don’t think the BBKA will want to use that as my strapline but it certainly sums things up pretty accurately.

Happy New Year … may your queens be well mated, your mite numbers low, your supers heavy and may your prime swarms be in my bait hives  🙂


 

2019 in retrospect

The winter solstice, the shortest day of the year, is tomorrow. It will be a long time until there’s any active beekeeping, but at least the days are getting longer again 🙂 

The queens in your colonies will soon – or may already – be laying again.

What better time to look back over the past season? How did the bees do? How did you do as a beekeeper? What could be done better next time?

Were there any catastrophic errors that really must not be repeated?

Overview of the season

Overall, in my part of Scotland, it was about average.

But that, of course, obscures all sorts of detail.

Spring was warm and swarming started early. I hived my first swarm before the end of April and my last in early July. This is about twice the length of the usual swarming season I’ve come to expect in Scotland. However, it wasn’t all frantic swarm management as there was a prolonged ‘June gap’ during which colonies were much more subdued.

The summer nectar, particularly the lime, was helped by some rain, but the season was effectively over by mid-August. I don’t take my colonies to the heather. Overall, the honey crop was 50-60% that of the (exceptional) 2018 season.

Looking at the yields from different apiaries for spring and summer it’s clear that – despite the warm spring – colonies did less well on the early season nectar (~40% that of 2018). I suspect this is due to their being less oil seed rape (OSR) grown within range of my apiaries. The colonies were strong, but the OSR just wasn’t close enough to be fully exploited..

Over recent years the area of OSR grown has reduced, a trend that is likely to continue.

Winter oil seed rape – the potential is not obvious

The winter rape is already sitting soggily in the fields; I’ve chatted to a couple of the local farmers and will move some hives onto these fields if colonies are strong enough and the weather looks promising.

Bait hives

Every year I’ve been back in Scotland I’ve put a bait hive in the garden.

Every year it has attracted a swarm.

This year – with the extended swarming season – it led to the capture of three swarms in about 10 days. As the June gap ended the weather got quite hot and sultry 1 and the first swarm arrived near the end of that month.

One week after the first swarm arrived there was lots more scout bee activity. There were also quite a few dead or dying bees littering the ground underneath the bait hive. It turned out that these were the walking wounded (or worse) scout bees from two different hives fighting.

Gone but not forgotten

Within 48 hours another swarm arrived and I was fortunate enough to watch it descend.

Incoming!

I moved the hive that evening, placing another bait hive on the same spot. By the following morning there were yet more scout bees checking the entrance and a third swarm – by far the biggest of the three – arrived later that day.

Each was a prime swarm and none were from my own hives which are in the only apiary 2 within a mile of the bait hive.

Watching the scout bees check out a bait hive is always interesting. There’s a fuller account of the observations and lessons learnt – of which there were several – written in the post titled BOGOF (buy one get one free 😉 ).

Swarm prevention

My swarm prevention this year either used the nucleus method or vertical splits (with an occasional Demaree for good measure) for most hives. All prevented the loss of swarms and queen mating went about as well – or badly – as it usually does i.e. never as fast as I’d like, but (eventually) all were successful.

Split board

Split board …

I did miss a couple of swarms. One relocated underneath the OMF of the hive it originated from because the queen was clipped and, having fallen ignominiously to the ground, she just clambered up the hive stand again.

The second swarm was also not lost as I inadvertently trapped the queen on the wrong side of the queen excluder. D’oh! In my defence, I’ve had a rather busy year at work 3 and it’s little short of a miracle that I got any beekeeping – let alone swarm control – done at all.

Mites

Considering the extended June gap, which resulted in a brood break for some colonies, mite levels were appreciably higher this year than last. I think this can largely be attributed to the warm Spring which allowed colonies to build up fast. Several colonies were strong enough to swarm in late April.

I do a limited amount of mite counting during the season but also monitor virus loads in emerging bees in our research colonies. In most colonies these stayed resolutely low and no production colonies needed any mid-season interventions for mite control.

Poly Varroa tray from Thorne's Everynuc with visible mites.

Gotcha! …

Newly-arrived swarms were treated as were some broodless splits. The former because many swarms carry a larger than expected mite population 4 and the latter because it’s an ideal opportunity to target mites as – in the absence of brood – all will be phoretic.

All colonies were treated with Apivar immediately after the summer honey came off. At the same time they were fed copious amount of fondant in preparation for the winter ahead.

In late November most colonies were broodless and were treated with a vaporised OA-containing miticide.

What worked well

In what was a pretty tough year for non-beekeeping reasons even small beekeeping successes have assumed a significance out of all proportion to the effort expended on them.

In my first year or two of beekeeping honey extraction was an unbridled pleasure. As hive numbers increased it because more of a chore. An electric extractor marginally improved things.

However, there was still the never-ending juggling of frames trying to balance the extractor and jiggling of the unbalanced machine as it sashayed across the floor.

Rubber-wheeled castor with brake

Two years ago I purchased some rubber braked wheels to add to the extractor legs.

This year I finally got round to fitting them.

The jiggle-free revolutions were a revelation 🙂

I know some beekeepers who stand their extractors on foam pads. Others who have them bolted to a triangular wooden platform. I can’t imagine either solution works better than these castors, which also make moving the extractor to and from storage much easier.

I changed my hive numbering system this season. I’d previously referred to hives by position or with a number written on the box. This caused some issues with the (sometimes shambolic) way I do my beekeeping.

If the hive moves and it’s numbered by position then its number should change. Manageable, but a bit of a pain.

If the position does not change but they’re expanded from a nuc to a full brood box do they get a new number or retain the old one? A problem if it’s written on the box.

And what happens when you move queens about in the apiary (which we sometimes need to do for work)?

Numbers for hives and queens

Numbers for hives and queens

All hives and queens were assigned a number – small red discs for the queen and big, bold numbers for the box. They stay with the colony or the queen … and the records 😉

This has worked very well. As colonies expand the numbers move, if queens are moved I know from and to where (and keep a separate record of queen performance). When colonies are united the queenless component loses both the queen number and the colony number.

The numbering has been a great success. The numbers themselves less so. Most of the red discs have faded very badly and a few of the hive numbers have cracked and/or blown away.

Numbered nuc and production colonies.

Never mind … the system works as intended and it has significantly improved my record keeping. I now know which hive and queen I’m referring to 😉

The Apiarist in 2019

I might squeeze in a more thorough overview of funny search terms and page accesses before the New Year. Briefly … there are significantly more subscribers and an increase of ~20% in overall page reads.

This year marks the sixth full season of The Apiarist which still surprises me. There still seem to be things to write about. Post length continues to increase, though the overall number of posts remain almost exactly one a week. Amazingly I’ve written nearly 95,000 words this year.

Words, words, words …

We had some server issues but most of these appear to have been resolved. Spam remains a problem and the machine auto-filters several hundred messages a day to keep my inbox only unmanageably overflowing. It has meant I’ve had to add some “I am not a robot” CAPTCHA trickery to the contact and/or comment forms. I’m aware that this has caused some problems making contact but can’t find an alternative solution that doesn’t swamp me in adverts for fake sunglasses, Bitcoins or Russian brides.

I live in Scotland and have no use for any of these things 😉 5

The year ahead

There are three main items on the ‘to do’ list for 2020 6.

The first is to start queen rearing again. Pressure of work has prevented this from happening over the last couple of seasons and I’m missing both the huge satisfaction it brings and the improved control over stock improvement. I’ve done lots of queen rearing in the past, but work has muscled its way in to too many weekends and evenings recently 7.

3 day old QCs ...

3 day old QCs …

I now have some perfectly adequate bees.

Actually, although they’re far from ‘perfect’ they are also far better than ‘adequate’.

I’ve got a couple of lines that have too much chalkbrood and almost all of them are less stable on the comb than I’d like. They don’t fall in wriggling gloops off the corner of the frame as some do, but they’re more active than I’d prefer. It’s a trait that has crept into some stocks over the last couple of years and I need to try and get rid of it.

The second is to provide better information on the provenance of my honey to potential and actual purchasers. There’s increasing interest in sourcing high quality local food and, as I’ve discussed recently on honey pricing, we should be aiming to provide a premium product (at a premium price 😉 ). The public are also increasingly aware that some of the major supermarkets have been reported to be selling adulterated honey. Providing details of the batch, the apiary and the area in which it was produced should help define it as a quality local product.

And generate repeat business.

Local honey

Finally, I’m planting up a new apiary on the west coast with dozens of pollen-bearing trees before I start beekeeping there. This has been a long and protracted process as it has involved clearing large areas of invasive rhododendron. The first 125+ native trees go in this winter – a mix of alder, loads of willow, hazel, blackthorn and wild cherry. More will follow if I manage to stop the deer eating them all.

Only another few acres of rhododendron to clear 🙁

The new apiary is in a Varroa-free region so I will not be moving my current bees there, but instead sourcing them from other areas fortunate enough to be mite-free. This is a long-term project.

Bee shed #3 … bigger and better.

The trees will need a few years to mature but the bee shed (bigger than all that have gone before 🙂 ) foundations are finished and the shed will be assembled sometime in March.

Holibobs

The holiday period is almost here. Many beekeepers will be thinking about fondant top-ups and oxalic acid mite treatment. I’ve done the latter already and – if your colonies are also broodless – hope you’ve done the same. All my hives remain reassuringly heavy but as the weather warms and brood rearing gears up I’ll have some fondant ready ‘just in case’.

I’ve covered last-minute beekeeping gifts in previous years. I think the (digital edition) American Bee Journal remains good value and provides a different perspective for UK beekeepers of what happens in the US.

And with that I’ll pour another glass of mead red wine 8 and wish you all Happy Christmas/Holidays (delete as appropriate).

David


 

Rinse and repeat

Midwinter mite treatment is no substitute for a properly applied late summer treatment that protects your all important winter bees. However, you also need to control mites in the winter or there is a good chance their numbers will reach damaging levels the following season 1.

Mid September

Late summer treatment and no winter treatment – mite levels in red.

OA (oxalic acid-containing) treatments are the ones to use in midwinter (e.g. Api-Bioxal). These can be trickled in syrup onto each seam of bees or they can be vaporised (sublimated), effectively coating everything in the hive with a very fine dusting of crystals.

Trickling damages open brood whereas sublimation is exceedingly well-tolerated by the colony.

If you are certain the colony is broodless then trickling is faster 2 and – because you don’t need power or any more PPE 3 than a pair of gloves – much easier.

If the ambient temperature is consistently below ~6°C and I know the colony is broodless I usually trickle. If the temperature is higher and/or I’m uncertain about whether there is brood present I usually vaporise.

I watch the weather and treat after the first prolonged cold spell of the winter.

Experience over the last few years suggests this is when colonies are most likely to be broodless.

Most likely is not the same as certain 🙁

Count the corpses

After treating I closely monitor the mite drop over several days. I use white Correx Varroa trays that slide underneath the open mesh of my kewl floors.

Easy counting ...

Easy counting …

I don’t count the mites every day, but I do try and count the day after treatment and 2-4 days later. I record the mite drop per hive and, over time, look for two things:

  1. The cumulative mite drop. This indicates the original infestation level of the hive. Usually it’s in the range 10-75 mites (total) for my colonies in midwinter, but – as you’ll see – it can be much higher.
  2. The speed with which the daily mite drop falls to a low single-digit average. OA treatment is very effective at killing phoretic mites. If there’s a continuing high level of mite drop it suggests that more are getting exposed over time.

In my experience, vaporised OA often results in a greater mite drop 24-48 hours post-treatment rather than in the first 24 hours 4. After that I expect (hope) the daily mite drop tails off very quickly.

Vaporised OA remains effective in the hive for several days. Randy Oliver reports studies by Radetzki who claims it remains effective for up to three weeks. I think this is an overestimate but I’m sure it continues working well for four to five days.

OA, whether vaporised or trickled, on broodless colonies is 90-95% effective i.e. if there were 100 mites in the colony you should expect as few as 5 remain after treatment.

Four to five days after the initial treatment I eyeball the numbers across all the hives in an apiary and look at the profile of the mite drop.

Mite drop profiles

I couldn’t think of a better term for this. Essentially, it’s the shape of a graph of mites dropped per day after treatment.

I don’t usually draw the graph – I have a life – but I do look carefully at the numbers.

Here are a couple of sketched graphs showing what I mean. Days are on the horizontal (X) axis, dead mites per day are on the vertical (Y) axis. Treatment applied on day 0. No count (yet) on day 6.

Mite drop profile – this is what you want

In the graph above there are high(er) levels of dropped mites on the first day or two after treatment, but levels thereafter drop to a basal level of perhaps 1-4 mites per day.

Each time I count the mites I clean the Varroa tray (the rinse in the title of the post).

Assuming the day 5 mite drop is very low, the profile above is what I’m looking for. It shows that treatment has worked and no repeat is necessary.

The profile below is much less promising 5.

Mite drop profile – this suggests additional treatment is needed

In this graph (above) the mite drop remains high every day after treatment. Sometimes they even increase over time.

If you assume treatment is equally effective – say 90%+ – on the five days after treatment 6 this must mean that there are mites being killed on days 4 and 5 that were not exposed to treatment on the earlier days.

How can this be?

The most likely explanation is that the colony had some sealed brood that has emerged in the days following treatment, exposing previously ‘hidden’ mites to the miticide.

It’s good that they’ve perished, but are there more hiding? How do you tell?

Enough of my hand drawn idealised graphs with no real numbers … what about some actual data?

Real world data

The graph below shows data for seven colonies in a single apiary. All were treated with Apivar in late summer. All were treated with a vaporised oxalic acid-containing treatment on the 28th of November. 

Mite drop profiles – real world data

I counted the mite drops on the 29th (T+1), the 2nd (T+4) and 3rd (T+5). The figures for 30th to the 2nd were averaged, which is why the bars are all the same height.

  • Colonies 3 and 6 had very low mite levels. Though not the lowest in the apiary 🙂
  • Colonies 2 and 7 had pretty good mite drop profiles, with low single-digit numbers on day T+5. None of these four colonies (2, 3, 6, 7) need treating again.
  • Colonies 1 and 5 have high mite levels 7 and – despite the pretty good levels on T+5 in colony 1 – were both re-treated.
  • Colony 4 was also treated again as the profile was flat and I suspected they had low levels of mites but were rearing brood..

And repeat

Note: The instructions for Api-Bioxal specifically state that the maximal dose of 2.3g/hive should be made in a single administrations with only one treatment per yearPrior to the VMD licensing and approval of Api-Bioxal there was effectively tacit approval for beekeepers to use unadulterated oxalic acid by trickling or vaporisation, without any particular limitations on frequency of usage.

It’s worth stressing that you should not repeat oxalic acid trickling 8.

Here is some real data for repeat treatments of another colony in the same apiary.

Repeat treatment for brood-rearing colony

The average mite drop per day over the first 5 days was ~60. This justified an additional treatment. Over the next 6 days 9 the average drop was ~20. I considered a third application was needed after which the mite drop per day was in the low single digits.

And again

Repeated treatment is needed if there is sealed brood in the colony.

The likelihood is that two additional treatments will be required.

Why two?

Here’s a reminder of the development cycle of the Varroa mite in developing worker or drone brood.

Repeated oxalic acid vaporisation treatment regime.

Worker brood occupies capped cells for 12 days (days 10 – 21 of development, shown above). Vaporised oxalic acid-containing treatments show a drop in efficacy after 4-5 days 10.

Therefore, to cover a complete cycle of capped brood, you need 3 x 5 day treatments to be sure no mites emerge without them being greeted with a lethal dose of something really, really unpleasant 😉

There should be no drone brood in your winter hives 11 but, if there was, 3 x 5 day treatments should just be enough to cover the complete cycle of capped drone brood as well. However, a fourth treatment might be needed.

Note (again): The instructions for Api-Bioxal specifically state that the maximal dose of 2.3g/hive should be made in a single administrations with only one treatment per year

Not all hives are equal

There are 15 hives in the apiary containing the bee shed. Colony 1 had just about the highest mite levels. However, as shown in one of the graphs above, adjacent colonies can have markedly different mite levels.

There is no clear correlation between mite drop after treatment and colony size. Colony 1 is a double brood monster, but the others in the bee shed are all single brood 10 and 11 frame Nationals 12.

Some colonies need repeated treatment, others did not.

To maximise efficient treatment and minimise unnecessary miticide usage it is necessary to monitor all the colonies.

It’s also worth noting that monitoring only a single hive in an apiary may be misleading; compare colonies 1 and 6 above in the graph of real data from the bee shed.

This monitoring takes just a few minutes. I usually do it after work. In the bee shed this is easy as I now have LED lighting and it’s nice and dry.

Easy conditions to count mites

In my out apiaries I have to do it by headtorch … under an umbrella if it’s raining 🙁

Checking mite drop by torchlight

That’s the last job of the winter completed … time now to review the season just gone and plan for next year.


Colophon

Rinse and repeat

Rinse and repeat is a truncation of instructions often found on the side of shampoo bottles – Lather, rinse and repeat. Other than potentially resulting in an endless loop of hair washing, it also means that a process is (or needs to be) repeated.

In The Plagiarist by Benjamin Cheever, a marketing executive becomes an industry legend by adding one word – REPEAT – to shampoo bottles. He doubles sales overnight.

For Varroa treatment the instructions should be amended to Repeat if necessary … and note again the instructions on Api-Bioxal which, at the time of writing, is the only oxalic-acid containing VMD approved miticide that can be administered by vaporisation.

 

More local bee goodness?

Before the wind-down to the end of the year and the inevitable review of the season I thought I’d write a final post apparently supporting the benefits of local bees. This is based on a recently published paper from the USA 1 that tests whether local bees perform better than non-local stocks.

However, in my view the study is incomplete and – whilst broadly supportive – needs further work before it can really be seen as an example of better performing local bees. I suspect there’s actually a different explanation for their results … that also demonstrates the benefits of local bees.

This is a follow-up to a post three weeks ago that provided evidence that:

  1. Colonies derived from different geographic regions show physiological adaptations (presumably reflecting underlying genetic differences) that seem pretty logical e.g. bees from Saskatchewan express more proteins involved in heat production, whereas Hawaiian bees show higher levels of protein turnover (which would make sense if they had evolved locally to have high metabolic rates).
  2. In a study by Büchler, European colonies survived better overwinter in their local environment; a fact subsequently attributed to the colonies being stronger going into the winter. In turn, this agrees with a recent study that clearly demonstrates the correlation between overwintering success and colony strength.

I suggest re-reading 2 that post as I’m going to try and avoid too much repetition here.

Strong colonies

Strong colonies overwinter better and – if you’re interested in that sort of thing – are much more likely to generate a profit for your honey sales.

So how can you ensure strong colonies at the end of the season?

What influences colony strength?

One thing is colony health. A healthy colony is much more likely to be a strong colony.

In the ambitious 600-colony Büchler study in Europe they didn’t do any disease management. The colonies were monitored over ~2.5 years during which time 84% of colonies perished, at least half due to the ravages of Varroa.

Clearly this is not sustainable beekeeping and doesn’t properly reflect standard beekeeping practices.

Study details

The recent Burnham study makes a nice comparison to the Büchler study.

It was conducted in New York State using 40 balanced 3 colonies requeened in late May.

Queens were sourced from California (~4000 km west) or Vermont (~200km east in the neighbouring state, and therefore considered ‘local’) and colonies were assigned queens randomly.

Unlike some previous studies the authors did not evidence the genetic differences between queens.

A local queen

A local queen

However, the queens looked dissimilar and the stocks were sourced from colonies established in California or Vermont for at least 10-15 generations. I think we can be reasonably confident that the queens were sufficiently distinct to be relevant for the tests being conducted.

Colonies were maintained using standard beekeeping practices, Varroa levels were managed using formic acid (MAQS for European readers) and the colony weight and productivity (frames of bees) was quantified, as was the pathogen load.

In contrast to the Büchler study, Burnham and colleagues only followed colonies over one beekeeping summer season. This was not a test of overwintering survival, but mid-season development.

Results

The take-home message is that colonies headed by the ‘local’ Vermont queens did better. The colonies got heavier faster and brood levels built up better.

Bigger, faster, stronger …

It’s notable that colony weight built up before any brood would have emerged from the new queen (upper panel) and that brood level in colonies headed by the local queen recovered much better after formic acid treatment (arrow in lower panel).

Nosema levels

However, Nosema levels were significantly different (above) as were the levels of Israeli Acute Paralysis Virus (IAPV; below).

Virus loads (DWV, BQCV and IAPV)

There were no significant differences in the Varroa loads before or after treatment (not shown), or in the levels of DWV or Black Queen Cell Virus (BQCV).

Taken together – bigger, heavier, stronger colonies and lower pathogen loads (at least of some pathogens) – seems good evidence to support the contention that local bees are beneficial.

The benefits are precisely what you want for good overwintering – strong, healthy colonies.

That’s a slam-dunk then?

Case proven?

No.

IAPV is a virus rarely detected in the UK. It causes persistent and systemic infections in honey bees and can be found in every caste (drones, workers, queens) and at every stage of the life cycle.

As IAPV is detectable in eggs and larvae – neither of which are Varroa-exposed – it is assumed to be vertically transmitted from the queen. IAPV is also found in the ovaries of the queen, which is additional evidence for vertical transmission.

At the first timepoint (12 days post requeening) the levels of IAPV are different between the two colony types, but not significantly so. However, by 40 days (T2) the levels are very different. At this later timepoint all the bees in the colony will be have come from the introduced queen.

The authors explain the differences in IAPV levels in terms of local bees being more resistant to ‘local’ pathogens … in much the same way that Pizarro’s 168 conquistadors, being more resistant to smallpox, defeated the might of the Inca Empire with the help of the virus diseases they inadvertently introduced to Peru.

I suspect there’s another explanation.

Perhaps the Californian queens were IAPV infected from the outset?

If this was the case they could introduce a new and virulent strain of IAPV to the research colonies and – over time – the levels would increase as more and more workers in the colony were derived from the new queen. IAPV is present in ~20% of US colonies so it seems perfectly reasonable to suggest it might have been largely absent from the Vermont queens and the test colonies, but present in the queens introduced from California.

How should they have tested that?

The obvious thing to do would be to characterise the IAPV present in the colony. IAPV shows geographic variation across the USA. If the predominant virus was of Californian origin it would suggest it was brought in with the queen. This is a relatively easy test to conduct … a sort of 23andme to determine bee virus provenance.

Alternatively, though less conclusively, you could do the experiment the other way round … ship Vermont queens to California and compare their performance with colonies headed by Californian queens on their own territory. If the Californian queens again performed less well it undermines the ‘local bees do better’ argument and suggests another explanation should be sought.

Nosema is sexually transmitted but it is not vertically transmitted, so the same arguments cannot be made there. Why the Nosema levels drop so convincingly in colonies headed by the local queens is unclear. Nosema was present at the start of the study and was lost over time in the stronger colonies headed by the local queens.

One possibility of course is that the stronger colonies were better fed – more workers, more foragers, more pollen, more nectar. Improved diet leads to a more active and effective immune system and an increased ability to combat pathogens. Simplistic certainly, but it is known that diet influences pathogen resistance and colony performance.

So what does this paper show?

I suspect it doesn’t directly show what the authors claim (in the title) … that local queens head colonies with lower pathogen levels.

This largely reflects the lack of proper or complete controls. However, it does not mean that local bees are not better.

More than anything I think this paper demonstrates the impact queen quality has on colony performance.

Perhaps the Vermont-sourced queens were just better queens. Local certainly (on a USA scale definition of the word local), but not better because they were local, just better because they were better.

However, if my interpretation of the source of the IAPV is correct i.e. introduced from the Californian queens, I think the paper indirectly demonstrates one of the most compelling reasons why local bees are preferable.

If they’re local – your apiary, your neighbours, someone in your association – there is little chance they will be bringing with them some unwanted baggage in the form of an undetected exotic pathogen.

Or a more virulent strain of one already circulating relatively benignly.

Extensive bee movements, whether of queens, packages or full colonies, risks spreading parasites and pathogens.

There is compelling evidence that hosts and pathogens co-evolve to reduce the pathogenicity of the interaction. Naive hosts are always more susceptible to introduced pathogens, or novel strains of pre-existing pathogens. After all, look what happened to the Peruvian Inca when they met the measles- and smallpox-ridden conquistadors.

So, when thinking about the claims being made by bee importers (or, for that matter, strong advocates of local bee breeding), it’s worth considering all of the factors at play – queen quality per se, genetic adaptation of the queen to the local environment and the potential for the introduction of novel pathogens with introduced non-local stock.

And that’s before you also consider the benefits to your beekeeping of being self-sufficient and not reliant on others to produce your stocks.

I never said it was simple 😉


 

Midwinter, no; mites, yes

There’s a certain irony that the more conscientious you are in protecting your winter bees from the ravages of Varroa in late summer, the more necessary it is to apply a miticide in the winter.

Winter bees are the ones that are in your hives now 1.

They have a very different physiology to the midsummer foragers that fill your supers with nectar. Winter bees have low levels of juvenile hormone and high levels of vitellogenin. They are long-lived – up to 8 months – and they form an efficient thermoregulating cluster when the external temperature plummets.

Winter bees production

In the temperate northern hemisphere, winter bees are reared from late summer/early autumn onwards. The combination of reductions in the photoperiod (day length), temperature and forage availability triggers changes in brood and forager pheromones.

Factors that influence winter bee production

Together these induce the production of winter bees.

For more details see Overwintering honey bees: biology and management by Döke et al., (2010).

Day length reduces predictably as summer changes to autumn. In contrast, temperature and forage availability (which itself is influenced by temperature and rainfall … and day length) are much more variable (so less predictable).

All of which means that you cannot be sure when the winter bees are produced.

If there’s an “Indian summer“, with warm temperatures stretching into late October, the bees will be out working the ivy and rearing good amounts of brood late into the year. The busy foragers and high(er) levels of brood pheromone will then delay the production of winter bees.

Conversely, low temperatures and early frosts reduce foraging and brood production, so bringing forward winter bee production.

It’s an inexact science.

You cannot be sure when the winter bees will be produced, but you can be sure that they will be reared.

Protect your winter bees

And if they are being reared, you must protect them from Varroa and the viral payload it delivers to developing pupae. Most important of these viruses is deformed wing virus (DWV).

Worker bee with DWV symptoms

Worker bee with DWV symptoms

Aside from “doing what it says on the tin” i.e. causing wing deformities and other developmental defects in some brood, DWV also reduces the longevity of winter bees.

And that’s a problem.

If they die sooner than they should they cannot help in thermoregulating the winter cluster.

And that results in the cluster having to work harder to keep warm as it gets smaller … and smaller … and smaller …

Until it’s so small it cannot reach its food reserves (isolation starvation) or freezes to death 2.

So, to protect your winter bees, you need to treat with an appropriate miticide in late summer. This reduces the mite load in the hive by up to 95% and so gives the winter bees a very good chance of leading a long and happy life 😉

Time of treatment and mite numbers

Time of treatment and mite numbers

I discussed this in excruciating detail in 2016 in a post titled When to treat?.

The figure above was taken from that post and is described more fully there. The arrow indicates when winter bees are produced and the variously coloured solid lines indicate mite numbers when treated in mid-July to mid-November.

The earlier you treat (indicated by the sudden drop in the mite count) the lower the peak mite numbers when the winter bees are being reared.

Note that the mite numbers indicated on the right hand vertical axis are not ‘real’ figures. They depend on the number present at the start of the year. In the figure above I “primed” the in silico modelled colony with just 20 mites. This will become very important in a few paragraphs.

Late season brood rearing

Compare the blue line (mid-August treatment) with the cyan line 3 (mid-October treatment) in the figure above.

The mid-October treatment really hammers the mite number down and they remain low until the end of the year 4.

The reason the mite numbers remain low after a mid-October treatment is that there is little or no brood being reared in the colony during this period.

Mites need brood, and specifically sealed brood, to reproduce on.

In the absence of brood the mites ‘colony surf‘, riding around as phoretic mites on nurse bees (or any bees if there aren’t the nurse bees they prefer).

And that late season brood rearing is the reason the end-of-year mite number for the colony treated in mid-August (the blue line) remains significantly higher.

Mites that survive the miticide in August simply carry on with their sordid little destructive lives, infesting the ample brood available (which could even include some highly mite-attractive and productive drone brood) and reproducing busily.

So, the earlier you treat, the more mites remain in the hive at the end of the year.

Weird, but true.

Early season brood rearing

The winter bees don’t ‘just’ get the colony through the winter.

As the day length increases and the temperature rises the colony starts rearing brood again. Depending upon your latitude it might never stop, but the rate at which it rears brood certainly increases in early spring.

Or, more correctly, in mid- to late-winter.

And it’s the winter bees that do this brood rearing. As Grozinger and colleagues state Once brood rearing re-initiates in late winter/early spring, the division of labor resumes among overwintered worker bees.”

Some winter bees revert to nurse bee activity, to rear the next generation of bees.

And this is another reason why strong colonies overwinter better … not because they (also) survive the cold better 5, but because there are more bees available to take on these brood rearing activities.

Strong, healthy colonies build up better in early spring.

Colonies that are weak in spring and stagger through the first few months of the year, never getting close to swarming, are of little use for honey production, more likely to get robbed out and may not build up enough for the following winter.

Midwinter mite treatments

Which brings us back to the need for miticide treatment in midwinter.

The BEEHAVE modelled colony shown in the graph above was ‘primed’ at the beginning of the season with 20 mites. These reproduced and generated almost 800 mites over the next 10-11 months.

What do you think would happen if you start the year with 200 mites, rather than 20?

Like the 200 remaining at the year end when you treat in mid-August?

Lots of mites … probably approaching 8000 … that’s almost as many mites as bees by the end of the season.

So, one reason to treat in the middle of winter is to reduce mite levels later in the season. The smaller the number you start with, the less you have later.

Vapour leaks out ...

Vaporisation … oxalic acid vapour leaks out …

But at the beginning of the season these elevated levels of mites could cause problems. High levels of mites and low levels of brood is not a good mix.

There’s the potential for those tiny patches of brood to become mite-infested very early in the season … this helps the mites but hinders the bees.

Logically, the more mites present at the start of brood rearing, the more likely it is that colony build up will be retarded.

So that’s two reasons to treat with miticides – usually an oxalic-acid containing treatment – in midwinter.

Midwinter? Or earlier?

When does the colony start brood rearing again in earnest?

This is important as the ‘midwinter’ treatment should be timed for a period before this when the colony is broodless. This is to ensure that all the mites are phoretic and ‘easy to reach’ with a well-timed dribble of Api-Bioxal.

In studies over 30 years ago Seeley and Visscher demonstrated that colonies have to start brood rearing in midwinter to build up enough to have the opportunity to swarm in late spring. These were colonies in cold climates, but the conditions – and season length – aren’t dramatically different to much of the UK.

Low temperatures regularly extend into January or February. The temperature is also variable year on year. It therefore seems (to me) that the most likely trigger for new brood rearing is increasing day length 6.

The apiary in winter ...

The apiary in winter …

I therefore assume that colonies may well be rearing brood very soon after the winter solstice.

I’m also aware that my colonies are almost always broodless earlier in the winter … or even what is still technically late autumn.

This is from experience of both direct (opening hives) or indirect (fresh brood mappings on the Varroa tray) observation.

Hence the “Midwinter, no” title of this post.

Don’t delay

I therefore treat with a dribbled or vaporised oxalic acid-containing miticide in late November or early December. In 2016 and 2017 it was the first week in December. Last year it was a week  later because we had heavy snow.

This year it was today … the 28th of November. With another apiary destined for treatment this weekend.

If colonies are broodless there is nothing to be gained by delaying treatment until later in the winter.

Most beekeepers treat between Christmas and New Year. It’s convenient. They’re probably on holiday and it is a good excuse to escape the family/mince pies/rubbish on the TV (delete as appropriate).

But it might be too late … don’t delay.

If colonies are broodless treat them now.

If you don’t and they start rearing brood the mites will hide away and be unreachable … but their daughters and granddaughters will cause you and your bees problems later in the season.

Finally, it’s worth noting that there’s no need to coordinate winter treatments. The bees aren’t flying and the possibility of mites being transferred – through robbing or drifting – from treated to untreated colonies is minimal.


 

Bee bombs

The last couple of posts on overwintering survival and local bees have been heavy going 1. So, rather than more of the same, here’s something that is both informative and entertaining 2.

Though it maybe wasn’t at the time.

Six-legged soldiers

I’m currently enjoying reading Six-legged soldiers by Jeffrey A. Lockwood. This is an account of the many and devious applications man has found for employing insects in warfare. Whilst the topic certainly isn’t ‘laugh out loud’ entertaining, the book is written in an engaging style with plenty of graphic descriptions, ample Biblical and historical references, and enough wriggly, stinging, aggressive insects to make “I’m a celebrity, get me out of here!” 3 appear like a walk in the park.

As a beekeeper I’m pleased to see that bees feature significantly in the book.

And as a beekeeper who appreciates the importance of the integrity of the colony to bee survival I also found it a little distressing.

But as a source of all sorts of stories for friends and families over the forthcoming holiday season it probably cannot be beaten.

It’s pretty good on mosquitos as well …

Bombus away

The genus Bombus includes lots of the well known bumble bees e.g. Bombus terrestris (Buff tailed), B. pascuorum (Common carder) and B. hypnorum (Tree) . The generic name Bombus is derived etymologically from the Latin word bombus which means buzzing i.e. the noise a bee makes when it flies.

Bombus lucorum

Etymologically, the word bomb, has a similar origin – via bombe in French, bomba in Spanish, bombo and then the Latin bombus.

Boom also has a similar origin.

But that’s not the only link between bees and bombs.

Mushroom shaped clouds

Have you ever seen anyone drop a full brood box?

It is an amazing sight and one best appreciated from a distance and when wearing a full beesuit.

Bees do not appreciate being knocked, shocked or jarred. When I transport hives between apiaries I always give them several minutes to settle before removing the entrance block. If you don’t they tend to boil out the front spoiling for a fight.

So you can imagine that dropping a brood box from waist height achieves – simultaneously – the sudden jarring of the colony and the release of the bees.

Not so much ‘shock and awe‘ as shock and aargh!

The mushroom-shaped cloud of bees that are released are distinctly agitated.

In the absence of a beesuit you’re likely to get hammered.

Even with a beesuit there can be some uncomfortable moments.

And, since soldiers don’t routinely go into battle wearing camouflage BBwear battledress with an inbuilt fencing-style veil, this neatly brings us to using bees as weapons.

Package bees

These days a ‘package’ is one way to buy bees to start a colony.

But as a weapon, a colony of bees isn’t much use until it’s actually in something.

How do you carry them? How do you use them as a projectile?

Well, man is nothing if not ingenious when it comes to weapons development.

The Tiv people of Nigeria used a specially shaped horn, loaded with angry bees (presumably not so much Africanized as African 😯 ). In the heat of battle these would be fired at the opposition, with the horn-shape ensuring the bees both reached the enemy and were kept at a distance from friendly forces 4.

But then, 9000 years ago, pottery containers started to be used for beekeeping … and it got a whole lot easier to move the bee bombs to the front line and drop them on the opposition.

A big, beautiful wall

A wall seems like an obvious way to defend yourself.

The enemy have to knock the wall down, or go over or under the wall.

And if they choose to tunnel under the wall then they’re going to be less than enthusiastic if the tunnel is filled with bees.

Which is what happened in 908 when the Scandinavians laid siege to Chester. The city’s fortifications were impenetrable, so they tunnelled underneath them. The siege was ended when all the city’s beehives were dumped into the tunnel.

Chester City walls. Originally built in ~100 AD by the Romans.

The Scandinavians appear not to have learnt their lesson as they were again repelled by bees while storming the walled city of Kissingen (Germany) during the Thirty Years War (1618-48). In this instance the bees were dropped from a height onto the Swedish forces.

The troops were heavily armed and armoured, and were unfazed.

Their horses were not.

The siege collapsed as the cavalry mounts were driven into a frenzy by the bees. Even now, most beekeepers are aware that bees and horses don’t mix well.

Again in the 1600’s, the besieged nuns of Wuppertal (Germany) knocked over all the hives in their apiaries before – wisely – hiding indoors. The maelstrom of bees drove the marauding soldiers away and the town was subsequently renamed Beyenberg (‘bee town’).

Bee boles

A bee bole is a recess in a wall 5 designed to house a hive of bees, which – in the days when they were constructed – was likely a skep. Many castles and fortified town walls have bee boles built into them.

How convenient.

What could be easier than to drop these on the marauding troops trying to scale the ramparts or storm the drawbridge?

Bee boles in Kellie Castle, Fife, Scotland

As an aside, IBRA (The International Bee Research Association) maintain the comprehensive Bee Boles Register which is well worth searching if you are interested in historical beekeeping (or early bomb design).

Avoiding friendly fire

You’ll notice that a lot of these bees were being used in relatively close combat situations.

Having witnessed a brood box being dropped, I can assure you that bees are rather indiscriminate after a “dropped from a great height onto a hard surface” experience.

Far better to use the container housing the bees as a projectile, launching them at the opposition from a safe distance.

Safe in terms of contact with the enemy … and the bees 😉

The Greeks and subsequently the Romans developed and perfected the siege engine, capable of launching all sorts of things up and over defensive walls.

Including beehives.

Illustration of a ballista being loaded and drawn – note BBwear ‘Corinthian helmet’ style beesuit and veil.

The Greek ballista and the Roman onager were torsion powered siege engines developed between 400 BC and 350 AD. Both were capable of firing stones, often wrapped in combustible material set alight, with smaller later models also used as battlefield weapons firing projectiles 500 – 1000 yards.

They’d have barely broken a sweat firing one or more skeps at the enemy.

The Romans were so keen on bee bombs that there was a documented decline in hive numbers during the late Roman Empire.

And this enthusiasm continued … as did the demand for hives to hurl.

By the 14th Century those dastardly weapons designers had developed a windmill-like device capable of launching hive after hive from the end of its rapidly rotating arms.

Bees will not fly over water

But they will in a skep catapulted from a ship.

As the army developed entomological weaponry the navy exploited it.

As early as 330 BC pottery hives were being thrown at enemy ships during naval battles. Cannons and cannonballs eventually superseded 20,000 A. mellifera ligustica in a skep, but there is well-documented use of bees in naval warfare until at least the 1600’s.

Bees would therefore have been carried by warships for hundreds of years. It’s not documented how the colonies were managed or maintained. Perhaps they only fought local battles? However, since that rather defeats the purpose of a highly mobile navy it can be assumed that bees were probably transported long distances by sea … bringing a whole new meaning to the term migratory beekeeping.

Gunpowder and bees

Eventually the development of modern weaponry overtook the use of bees and beehives. Fortunately we don’t have to discuss the aerodynamic benefits of cedar vs. poly hives 6.

Gunpowder and explosives made the Gatling gun-like skep-launching windmill catapult a relic of the good old days of warfare, when the infantry hankered after really cold days when the bees would be torpid and much less aggressive.

But, as a couple of masochists have already demonstratedApis mellifera is pretty tame where stinging is concerned.

Apis dorsata, the giant honey bee of South East Asia, is much bigger than our honey bee, and is reputed to pack more of a punch when stinging 7.

These bees build large exposed nests and the colony may have up to 100,000 bees in it.

Apis dorsata nest, a single exposed comb which may be a metre wide.

Which doesn’t mix too well with gunpowder or, more specifically, a firecracker containing gunpowder.

During the Vietnam War the Viet Cong would attach firecrackers to dorsata nests relocated to the jungle trails used by the enemy. As a patrol passed by they would ‘light the blue touch paper’ and set off the firecracker.

And then stand well back.

And, at about the same time (1960’s), the Americans were developing chemical warfare approaches using isopentyl acetate, the alarm pheromone, with the intention of spraying it onto enemy troops and redirecting the bees to attack them instead.

Six-legged soldiers

There’s lots more in Six-Legged Soldiers … get a copy and enjoy reading it over the Christmas vacation. Jeffrey Lockwood is an entomologist and University of Wyoming Professor. The Sunday Times 2009 review of the book criticised it as ‘scarcely scholarly’, being a mix of myth, legend and historical facts.

I cannot imagine a better review and it probably explains why it is so entertaining to read 🙂

Mite bombs

These are something altogether different to bee bombs … and for regular beekeepers, much more relevant.

A mite bomb is a heavily mite infested and collapsing colony that liberally spreads Varroa mites around the neighbourhood. Recent evidence suggests that this occurs primarily during late-season robbing of weak (mite infested) colonies by strong colonies.

This is the primary reason late summer miticide treatment should be coordinated over a wide geographic area. What’s the point of treating your strong colonies if they’re going to load up on mites when robbing weak colonies in the adjacent fields?

Which reminds me, and should remind you, that winter mite treatments will be needed in the next few weeks to ensure your bees get the best possible start to the new season.

We’ve had a protracted cold period here in Fife and my colonies will probably be treated in the next 5-7 days before there’s a chance they start brood rearing again.


 

Locally adapted bees

This is a follow up to the last post on Strong hives = live hives which was written in response to the oft-repeated mantra that ‘local bees are better adapted to the local environment’.

In that previous post a study of the overwintering survival of colonies headed by queens from very different locations was discussed. There was no difference whether the queen (and consequently all the workers she subsequently mothered) had come from Vermont or Florida.

Instead, the primary correlate of overwintering success was the strength of the colony 1 going into the winter.

Migratory beekeeping

Despite the size differences between the US and UK (or Europe), the honey bee population structure is actually more distinct on this side of the Atlantic.

In the USA the huge impact of migratory beekeeping causes considerable mixing of the bees on the continent. Those on the east and west coasts are distinct, but those in the north and south, or across smaller geographic scales, are really rather similar.

It’s not only commercial migratory beekeeping that enforces this, it’s also some of the very large-scale queen rearing operations. These ship queens all across the USA ensuring that there is less genetic diversity than you’d expect from the vast geographic (and climatic) differences.

Bee caravan

Bee caravan …

So, perhaps the study I discussed last week was not particularly surprising after all … ? 2

In contrast to the US, beekeeping activities in the UK and Europe are rather more localised.

In the UK we still import thousands of queens, but we don’t move our hives across the continent – often more than once a season.

We might take a dozen hives to the heather moors 150 miles away, but we never take them 2500 miles to pollinate almonds.

‘Local’ bees in Europe

Probably as a consequence of less large-scale migratory beekeeping, and less ‘centralisation’ of commercial queen rearing, there is genetic evidence for ‘local’ strains of bees in Europe.

In addition, there is evidence that these genetic differences result in changes to the individual proteins that the bee expresses … and that these may result in local ecological adaptations.

However, this still doesn’t get us to ‘local bees are better adapted to the local environment (and this explains why local bees survive better)‘ …

Andalucian apiary

Local Andalucian apiary

But there is even some evidence to support this last statement as well.

So let’s look at each of these points in turn 3.

Genetically diverse bees

Biologists use the terms genotype and phenotype to describe the genetic makeup of an organism and its appearance. Most beekeepers are familiar with the different phenotypes of honey bee – the dark ‘native’ bees, carniolans, Buckfast etc.

The phenotype is defined and determined by the genotype, but we don’t necessarily know which genes determine which physical characteristic. Population geneticists therefore often use different genetic features to discriminate between different groups or populations.

Microsatellites are DNA markers that contain variable numbers of short tandem repeat sequences. In honey bees, microsatellites are abundant and highly variable. They are therefore very useful for differentiating between populations or groups of populations, though how this is done is outside the scope of this post.

In 1995 Arnaud Estoup and colleagues reported the microsatellite analysis of 9 populations of honeybees from Africa (intermissa, scutellatacapensis) and Europe (mellifera, ligustica, carnica, cecropia), previously distinguished phenotypically. In their enticingly titled paper Microsatellite Variation in Honey Bee (Apis Mellifera L.) Populations: Hierarchical Genetic Structure and Test of the Infinite Allele and Stepwise Mutation Models 4 they support the earlier morphometric (phenotypic) definition by Ruttner of three distinct evolutionary branches of honey bee.

In a series of particularly impenetrable tables and phylogenetic trees they also demonstrate the the European lineages are genetically distinct and, importantly, that sub-populations could be readily identified 5.

Ecological adaptation of bees

Microsatellites are essentially non-functional genetic markers that we can use for analysis. They are carried alongside the thousands and thousands of genes that encode the proteins that make the wings, eyes, guts, feet etc. of honey bees. Other proteins also influence the behaviour of bees – how and when they swarm, their cold tolerance, there longevity.

We can now measure genetic variation of individual genes easily through so-called ‘next generation sequencing’ of the whole genome of the honey bee. However, the variation we see is one step removed from the variation at the protein level that directly influences how the bee copes in (or is adapted to) different environments.

But, it turns out, we can measure the variation at the protein level as well using a technique termed proteome profiling.

If distinct genetic populations of bees have adapted to particular environments (through selection, either natural or by beekeepers) we would expect the proteins they express – that both make the bee and determine its behaviour – should be different.

For example, simplistically, if a bee had evolved to live in a very windy environment we might expect the proteins forming the flight muscles would be stronger, enabling the bee to fly on windier days 6.

Collect the data, decipher what it all means …

Alternatively, you could turn the analysis around:

  • Identify the differences in the proteins that are expressed
  • Work out (or look up) what those particular proteins do and …
  • Conclude that those adaptive changes are required by that sub-population of bees in a particular ecological environment.

And, using proteome profiling, this is exactly what Robert Parker and colleagues reported in 2010 7. They compared proteins from adult bees sourced from geographically dispersed locations (Canada, New Zealand, Chile, USA).

They then grouped proteins into particular pathways e.g. energy metabolism, and observed significant differences.

Pathway analysis of honey bee midgut proteins across the populations studied.

As far as we’re concerned here – which is evidencing that locally adapted bees are actually different from each other in a meaningful way – the precise differences Robert Parker and colleagues aren’t too important.

But … if you insist.

Cold-adapted bees e.g. those from Saskatchewan (SK1, SK2), exhibited much higher levels of proteins involved in heat production in the mitochondria. In contrast, bees from warmer climates e.g. Hawaii (HI), showed higher levels of proteins involved in biosynthesis/folding and degradation of proteins.

Importantly, distinct populations of bees from geographically-distant regions exhibit differences that, logically, could be expected to make them better adapted to that environment.

But, there’s a bit still missing …

The key phrase in that last sentence is ‘could be expected’.

What was not shown in these two studies is that the differences observed are responsible for the better performance or survival of those bees in those environments.

Which finally brings me to a study by Ralph Büchler entitled The influence of genetic origin and its interaction with environmental effects on the survival of Apis mellifera L. colonies in Europe 8.

Local bees do survive better

This was an ambitious and large scale study of the survival of ~600 colonies in 21 apiaries in Europe. The colonies included 5 sub-species (carnicaligusticamacedonia and mellifera) and 16 different genotypes of bees.

In each of the 21 apiaries a local genotype was tested in parallel with at least two non-local genotypes. The large team of scientists/beekeepers involved used standardised management protocols which excluded any form of disease management e.g. no control of Varroa or other diseases. Consequently (many) colonies were lost to Varroa and were removed from the study once infestation levels had reached 10% (i.e. 1 in 10 workers carried phoretic mites) or bee numbers dropped below 5000.

The study started in autumn 2009 and ended in March 2012. During this ~2.5 years 84% of the colonies perished. Almost half of these losses were attributable to Varroa … not a particular surprise.

There are a lot of variables in this study – sub-species (5), genotypes (16), apiaries (21) – so the statistics and analysis are a bit of a minefield.

Count the corpses

Essentially the researchers ‘counted the corpses’ (i.e. colonies that died). They then looked at the survivors and tried to determine the characteristics they shared.

Unsurprisingly, survival of colonies in different apiaries was not the same. Graphed below is the percentage of colonies that survived (vertical axis) in each of the 21 apiaries against time (horizontal axis).

Trajectories of colony survival for the different locations.

These differences are presumably due to local forage availability, colony management, climate etc. We know that bees do better in some places than others 9.

When survival of different genotypes was compared they were much of a muchness, with two outliers.

Trajectories of colony survival for the 16 different genotypes

But, very significantly, colonies headed by local queens did significantly better than colonies headed by non-local queens.

Trajectories of colony survival for the origin of the queens

Why do local bees survive better?

The differences between the two lines – local and non-local queens – in the Kaplan-Meier survival curve above may not look particular good … they both drop disconcertingly quickly, indicating lots of dead colonies.

But it is.

The authors unequivocally demonstrate this statistically, but for beekeeping purposes it’s perhaps even more convincing to simply state that:

“colonies with local queens survived on average 83 ± 23 days longer than those with non-local queens”

That’s a key quote from the paper. It also probably explains why colonies headed by local queen survive better.

In a follow-up paper to Büchler et al., 2014, the same authors did a more in-depth analysis of a range of colony parameters that correlated with survival 10 which contains an additional piece of the jigsaw explaining why colonies headed by local queens survived better.

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

And, by significantly higher, I mean ~20% higher.

Which finally completes the story and brings us back to the Strong hives = live hives from last week.

Local queens head up colonies that survive better in the local environment to which they (and their workers) are adapted.

The colonies survive significantly longer because the colonies are significantly stronger.

Caveats and conclusions

There are a number of caveats to the ‘count the corpses’ study conducted by Büchler and colleagues.

For example, the local bees might have actually been adapted to the local beekeeping management practices. In future experiments there might be ways to control for this 11.

The absence of Varroa control meant colonies were always weaker in the second year of the study. For the majority of beekeepers this is not a sustainable way to manage colonies. A fourth year would have been impossible as they would have run out of colonies.

Nevertheless, under the conditions tested, this is confirmation that ‘local bees are better adapted to the local environment (and survive better)‘.

But as a scientist there’s always another ‘Why?’ question.

Why are the colonies stronger? Is it increased longevity of worker bees? Perhaps it is better foraging skills, meaning more brood can be reared? Is it an adaptation of the queen to the chemicals in the local pollen that increases her fecundity?

Question, questions, questions …

I can think of at least two additional compelling reasons why local bees and queens are preferable. I’ll cover these at some point in the future.