Tag Archives: winter

Small, but perfectly formed

We’re in the hiatus between the end of the beekeeping season and the start of the beginning of the planning for the preparation for the next. Or, I am.

Of course, if you’re reading this from Australia (G’day … the 5th largest readership globally) or Chile (Hola … 62nd in the list) then things are probably just getting really busy.

Inevitably things here are going to be a bit quiet for a few months. Have patience.

Getting ready for winter

Here in the Northern hemisphere, at a latitude of about 56°N, the nights are rapidly getting longer and the temperature is tumbling. We’ve had several sharp frosts already. I checked my bees yesterday through the perspex crownboards – where present – and most were pretty tightly huddled together. In the very warmest part of the day there were a few flying in the weak sunshine, but the majority of colonies were quiet.

Since many of the most recent posts have been rather long (and I’m pressed for time with work commitments) I’m going to restrict myself to a few brief comments about this tidy – and tiny – little hive tool from Thorne’s.

Pocket hive tool

Pocket hive tool

One of the final tasks of the year is to slice off the brace comb built in places along the tops of the frames while feeding colonies. I only use fondant, usually adding 12.5 kg to start with and then a further few kilograms if I think the hive is a bit light. All this fits nicely under one of my inverted, insulated perspex crownboards. However, as the fondant it taken down and stored, the bees tend to build little pinnacles of comb under or around the plastic bag.

Before closing the colony up for the season all these bits of brace comb need to be tidied away. I simply run a sharp hive tool along the top bars of the frames, remove the wax and – eventually – melt it down in my steam wax extractor. If you leave the wax in place you can’t put the crownboard back the right way up … or, when you do, you risk crushing bees.

Bargains in the sales

In the Thorne’s summer sales this year I bought the usual range of stuff I have almost no use for, together with half a dozen of the cheapo copies of their claw hive tool to replace those I’ve lost or lent during the year.

In addition I bought a couple of their ‘pocket hive tools’ (shown above) for a quid each.

These are small and neat, have a simple frame lifter at one end and a very good, sharp, chisel tip at the other. They are made of stainless steel. They fit neatly into the palm of the hand, don’t project too far and yet are enough to provide the leverage to separate all but the most stubbornly propolised frames.

For tidying up the top bars of my hives before closing them up for year this little hive tool was just the job.

‘Pocket hive tool’ is a bit of a misnomer though. It’s certainly small enough to fit into your beesuit pocket, but just about sharp enough it won’t be staying there long. Any serious pressure, for example as you get back into the car/van/truck risks either a nasty injury ( 😯 ) or it will eventually escape through a neatly sliced-through seam.

It might be better to keep it in your bee bag, or – as I do with other hive tools – store it in a bucket of soda in the apiary.


The phrase small, but perfectly formed is at least 200 years old. Google Books first lists it in the Gentleman’s Magazine and Historical Chronicle of 1779 (though in those days they used a medial or long ‘s’ so the title was the Gentleman’s Magazine and Hiſtorical Chronicle) where it appears in an article by Mr Rack describing (or deſcribing) a new found aquatic animal. Whether ‘small, but perfectly formed‘ is now an idiom or a cliche is unclear. The usually excellent Brewers Dictionary of Phrase and Fable (2014) defines the idiom as meaning “something noticeably small but compensating for this by a perfection of quality”. Their first reference to the phrase occurs in a letter written in October 1914 by Duff Cooper to Lady Diana Manners, later his wife, and quoted in Artemis Cooper’s Durable Fire (1983): ‘Your two stout lovers frowning at one another across the hearth rug, while your small, but perfectly formed one kept the party in a roar’. The expression was probably not original to Cooper but drawn from the fashionable talk of the period. The usage is often tongue-in-cheek or journalistically formulaic for anything small … which is exactly how I’ve used the term in the title of this post.



Trick(le) and treat

Tools of the trade

Tools of the trade

This is the third and final post on why, with what, when and how to minimise mite levels in colonies in midwinter.

In the first post I explained why midwinter mite treatment makes sense. In the second I described how oxalic acid-containing solutions should be prepared and stored.

Oxalic acid-containing” solutions includes both Api-Bioxal, the VMD approved treatment, and the unadulterated chemical. All three posts focus on trickling or dribbling – I’ve covered sublimation previously and both are essentially equally effective. Sublimation or vaporisation is currently very fashionable … but trickling is simplicity-itself and requires almost no special equipment.

In this post I’ll discuss how to administer the oxalic acid-containing solution.

For readability I’ll use the term OA solution to mean any oxalic acid-containing solution. About 50% of the readers of this site are from outside the UK; local rules may determine what you are or are not allowed to administer to your bees.

Trickling or dribbling

You’ll hear both terms used interchangeably1. The general principle is that you directly administer 5ml of a 3.2% w/v solution of oxalic acid in thin (1:1) syrup per seam of bees in the colony.

Directly‘ because you administer the OA solution to the seam of bees. You don’t count the seams and then simply pour it into the hive. You don’t spread it across the top bars. The idea is that the bees at the top of the seam get coated in the solution and that it dribbles down through the colony, being passed from bee to bee as they feed and groom and move about.

Two seams of bees

Two seams of bees …

During this process any phoretic mites will also get exposed to the oxalic acid. Since mites are readily damaged by the OA solution they fall off and gradually drop out of the bottom of the cluster. Gradually, as it takes a few days for gravity to deliver all the corpses.

You can therefore determine whether mites were present and killed by placing a Varroa tray underneath the open mesh floor of the hive. Note that this doesn’t tell you how effective the treatment has been … for that you’d need to know the mite infestation level before treatment as well.

When to treat

In many ways this is the critical decision. As described previously, maximal benefit occurs when the colony is broodless. Ideally you want an extended cold period late in the calendar year. The colony will cluster tightly and brood rearing will slow down or stop completely.

If the cold period has lasted 2-3 weeks, even better. This will mean that some or all of the brood present will have emerged. The more sealed brood present, the less effective trickling OA solution is as a means of controlling mites.

Choose a calm, cool or cold day. I usually wait for a day with temperatures between 0 and 5°C. Much warmer than that and the cluster starts to break up or the bees are more likely to fly about as the crownboard is lifted. Windy or wet days disturb the bees (at least when you prise the crownboard off), so it’s best to avoid those.

I prefer to treat before the year end, rather than after, if I can. From a few irregular midwinter peeks into the cluster I think queens start laying earlier than most beekeepers think.

It pays to be prepared …

Trickle 2 - £1

Trickle 2 – £1

… Aesop (~620-560BC) was right, though he wasn’t talking about beekeeping. Before treating your colonies there is some preparation needed. Do this properly and it’s a doddle.

Purchase a Trickle 2 container from Thorne’s. These are a measly quid each. You’ll only need one.

Practice with the Trickle 2 container (see below).

Gently warm your pre-prepared OA solution to about 25°C. If you made it up in advance and stored it at 4°C in the fridge this will take an hour or two. The easiest way is to stand the container (preferably thin-walled … I use a well-rinsed milk carton) in a basin of warm water.

Pour the pre-warmed OA solution into a well-labelled vacuum flask. You can buy these from Tesco for £2.50 with a capacity of 1 litre. The aim here is to take everything you need ready-prepared to the apiary so the treatments take the minimum time possible.

Remember that OA is toxic. Label everything carefully, make sure children can’t get near it and don’t use it again for food/drink purposes.

That’s it … you’re ready. You’ll need a hive tool, a bee suit, thin gloves (to protect you from the OA, not the bees), your vacuum flask of OA solution and the Trickle 2 bottle. By all means take your smoker, but you shouldn’t need it.

I’ve got a 5 ml (or 25 ml) syringe … won’t that do?

Yes … but no.

A Trickle 2 bottle holds 100ml of prepared OA solution. It takes two hands to fill the bottle, but only one hand to use it. That 100ml is sufficient for 20 seams of bees i.e. two completely full colonies (assuming an 11 frame National box). In midwinter the colony is unlikely to occupy 10 seams. A Trickle 2 bottle is also pretty accurate, reproducibly dispensing about 4.6-4.8ml of liquid. That’s close enough to 5ml.

In contrast, a syringe also takes two hands to fill (and refill). However, unless it’s a 5ml syringe, it’s difficult to accurately and reproducibly dispense liquid without using two hands. A 5ml syringe gives you the necessary accuracy, but needs refilling for every seam of bees. This takes time … during which the crownboard is off and the colony is getting chilled.

I’ve done both and can assure you that the Trickle 2 bottle is much better. Just buy one. It’s only £1 and it’ll last ages if one of your association members doesn’t borrow it … or doesn’t return it.

How to use a Trickle 2 bottle

  • Remove the cap and fill to the top of the lower chamber with liquid (practice with water).
  • Replace the cap.
  • Hold the bottle with your thumb and fingers on opposite sides of the lower chamber, with the external ‘pipe’ to the upper chamber next to your palm.
  • Undo the spout about a turn.
  • Gently squeeze the lower chamber. Liquid is forced up the pipe into the upper chamber. Hold it against the light to observe this.
  • Once the upper chamber is full, stop squeezing. Excess liquid drains back into the lower chamber.
  • If you are right handed turn the Trickle 2 bottle anti-clockwise2 using your wrist and gently squeeze the bottle to dispense the liquid in the upper chamber from the spout. If you’re left handed you need to turn the bottle clockwise.

And in practice

The single-handed operation for the Trickle 2 container really pays dividends when treating a colony. You can gently prize up one side of the crownboard, hold it in one hand, administer the OA solution to each seam with the other hand and gently lower the crownboard back down … all in less time than it took me to write that.

Like this:

This is a reasonably sized colony being treated in the second week of January 3 years ago. The video is 1’45” long, but the crownboard is only open for about 50 seconds. And I was chatting with Mick Smith off camera, so could have perhaps gone a bit faster if I’d concentrated … 😉

Here’s a more detailed view of treating a small colony:

33 seconds of warmed, acidic goodness to slaughter the mites and give the colony the best possible start to the upcoming season.

Cautions and considerations

Discard any OA solution that’s not been used. Warming it will have raised the HMF levels and this may be toxic for your bees. However, read footnote 3 for another way to avoid HMF buildup3.

Wash everything carefully – the Trickle 2 bottle, the vacuum flask, gloves etc. Since the OA solution was in syrup everything gets sticky and gummed up. Clean stuff up, make sure it’s labelled and not going to be used in the kitchen and put it away until next year.

Oxalic acid kills mites, but it’s also toxic for unsealed brood. This is perhaps unsurprising considering it has a pH of 1 (i.e. very acidic) and ‘naked’ larvae aren’t protected by the tough exoskeleton that adult bees have. This is another reason to treat during a broodless period in midwinter.

In summer, swarms can also be treated with trickled oxalic acid-containing solutions before they have sealed brood. If a swarm arrives in bait hive, let it settle and start drawing comb on the foundationless frames. A day or so later treat it with oxalic acid by trickling. When I’ve done this I usually wait until late afternoon or early evening, so most of the bees are in the box. The colony obviously won’t be clustered, but the principle is the same – 5ml of syrup down each seam. Easy peasy. Effective.

Swarms have a significant mite load, so it’s well worth treating them before they rear brood and give the phoretic mites somewhere to breed.

Finally, it’s often recommended that a colony is only treated once per year with oxalic acid by trickling or dribbling. I’m not sure where this advice originates, but it’s probably wise.

‘Vaping’ vs. trickling

The discussion forums are awash with recommendations to ‘vape’ the colony, rather than trickle. Vaporisation, or more correctly sublimation, is a widely used method and has been in use for two decades. It’s currently very fashionable. I’ll write a more substantial comparison sometime in the future, but the following brief notes might be of interest.

Sublimation can be done repeatedly with brood present (though there’s no peer-reviewed evidence of efficacy) and is both well-tolerated by the colony and is not toxic to unsealed brood. It requires specialised and potentially expensive equipment, both for delivery and personal protection. You can build your own vaporiser, but shouldn’t skimp on protection for the operator. With a well designed vaporiser and hive there’s no need to open the colony to administer treatment.

In contrast, trickling requires only the Trickle 2 bottle and vacuum flask described here. Personal protection is a pair of latex gloves. It should only be conducted when the colony is broodless, should probably only be conducted once and does require the hive to be opened (albeit briefly).

You’ll be told that vaporisation is faster. It isn’t. Watch the videos above. Even my Sublimox – probably the fastest ‘active’ vaporiser on the market – takes well over a minute per colony if you take into account sealing the box, moving the generator about, unsealing the hive etc.

There are reports that sublimation is more effective, but the difference is marginal, and possibly not statistically significant. There is also a report that colonies are stronger in the Spring after sublimation, though this may be due to toxicity to open brood by trickled OA solution. If the colony is broodless this shouldn’t be an issue.

I’ve used both many, many times without a problem. Across the UK I suspect more beekeepers trickle OA, rather than ‘vape’ (a word I dislike), though the vocal ones on the discussion forums currently favour vaporisation.

What’s more important than how you deliver the oxalic acid, is that you do treat. Trickling OA solution is so easy and inexpensive that there’s no reason not to … and your colonies will be much healthier for it.

Get dribbling 😉

If the beekeeper is of a certain age you’ll hear these terms used in a different context. We’re restricting discussions here to delivering OA 😉

If you are left handed you need to turn the Trickle 2 bottle clockwise. Actually, to be pedantic, if you are left handed and holding the bottle in your left hand, turn it clockwise. It’ll make sense once you try.

3 In the previous article on preparing oxalic acid solutions Calum posted a comment on preparing the OA in water and only adding and dissolving the required amount of sugar just before use. This has the advantage that there will be no HMF buildup. OA solution in water should be perfectly stable. I’ve not done it this way, but it makes sense and might be worth trying.


The title of this article is a twist on the term Trick or treat. This is not entirely inappropriate as Trick or treating is a Halloween (31st October … just a few days away) custom dating back – in various forms – centuries.

The modern usage, essentially North American, dates back to the 1920’s and refers to children in costumes going house to house threatening to play a trick unless the homeowner provides a treat, usually sweets or toys. In Britain these traditions date back to the 16th Century, both of children going house-to-house asking for food and of dressing up in costumes at Halloween.

Closer to home, ‘guising‘ – children in Scotland going from door to door in disguise asking for food, coins or chocolate  – dates back at least a century.

The term Trick or treat only entered common usage in the UK in the 1980’s.



Oxalic acid preparation

This is the second of three articles on midwinter treatment of colonies with oxalic acid to minimise Varroa levels. In a recent post I explained why a midwinter treatment was necessary, even if you’d treated three months earlier. Essentially this is because:

  • there will still be some residual Varroa, particularly if you treated in late summer rather than early autumn (and this post explains why early treatment is preferable)
  • midwinter is the time when brood levels are at a minimum, so most mites will be phoretic and readily accessible to the miticide treatment

Midwinter is the time to use oxalic acid-containing treatments. It can be delivered in a variety of ways; by sublimation (vaporisation), spraying or trickling (dribbling).

Trickling or dribbling

This post is about the preparation and storage of oxalic acid-containing solutions for trickling. Sublimation is covered elsewhere and spraying is not approved or widely used in the UK.

The process for trickling is very straightforward. You simply trickle a specific strength oxalic acid solution in thin syrup over the bees in the hive. The oxalic acid kills the mites. How isn’t entirely clear – it’s thought to corrode the mouthparts and soft tissue. It’s more than 90% effective in killing phoretic mites when used like this.

Beekeepers have used oxalic acid for years as a ‘hive cleaner’, as recommended by the BBKA and a range of other official and semi-official organisations. All that changed when Api-Bioxal was licensed for use by the Veterinary Medicines Directorate (VMD).

Oxalic acid and Api-Bioxal, the same but different

Spot the difference ...

Spot the difference …

Api-Bioxal is the VMD-approved oxalic acid-containing miticide. It is widely available, relatively inexpensive (when compared to other VMD-approved miticides) and very easy to use.

It’s very expensive when compared to oxalic acid purchased in bulk.

Both work equally well as both contain exactly the same active ingredient. Oxalic acid.

Api-Bioxal has other stuff in it (meaning the oxalic acid content is a fraction below 90% by weight) which actually makes it much less suitable for sublimation.

How much and how strong?

To trickle or dribble oxalic acid-containing solutions you’ll need to prepare it at home, store it appropriately and administer it correctly.

I’ll deal with how it is administered next time. This is all about preparation.

The how much is easy. You’ll need 5ml of oxalic acid-containing solution per seam of bees. In midwinter the colony will be reasonably well clustered and its likely there will be a maximum of only 8 or 9 seams of bees, even in a very strong colony.

Hold on … what’s a seam of bees?

Two seams of bees

Two seams of bees …

Looking down on the colony from above, a seam of bees is the row visible between the top bars of the frames.

Remember to prepare ~10% more than you think you need. You’ll inevitably spill some when using the Trickle 2 bottle to administer it to the colony. It’s not that expensive, so don’t risk running out.

And the how strong? The recommended concentration to use oxalic acid at in the UK has – for many years – been 3.2% w/v (weight per volume) in 1:1 syrup. This is less concentrated than is recommended in continental Europe (see comments below on Api-Bioxal).

My advice – as it’s the only concentration I’ve used – is to stick to 3.2%.

Listen very carefully, I shall say zis only once

A bit of basic chemistry coming up. Skip to the warning in red below and then the recipes if you want, but this explains some important things about working out how much to use.

The molecular formula of oxalic acid is C2H2O4. The molecular weight of oxalic acid is 90.03 g/mol. However, the oxalic acid you purchase – including Api-Bioxal – is the dihydrated form of oxalic acid.

Di as in two, hydrated as in water.

The molecular formula of oxalic acid dihydrate is C2H2O4.2H2O and oxalic acid dihydrate has a molecular weight of 126.07 g/mol.

Therefore the weight of oxalic acid in 1 g of oxalic acid dihydrate is 90.03/126.07 = 0.714 g.


Oxalic acid is toxic

  • The lethal dose for humans is reported to be between 15 and 30 g. It causes kidney failure due to precipitation of solid calcium oxalate.
  • Clean up spills of powder or solution immediately.
  • Take care not to inhale the powder.
  • Store in a clearly labelled container out of reach of children.
  • Wear gloves.
  • Do not use containers or utensils you use for food preparation. A carefully rinsed plastic milk bottle, very clearly labelled, is a good way to store the solution prior to use.

Recipes : oxalic acid

The standard recipe is 100 g water plus 100 g white granulated sugar. Mix well and then add 7.5 g of oxalic acid. The final volume will be 167ml i.e. sufficient to treat over 30 seams of bees, or between 3 and 4 strong colonies (including the 10% ‘just in case’).

This final concentration is 3.2% w/v oxalic acid … (7.5 * 0.714)/167 * 100 = 3.2. Check my maths.

0.01 g to 500 g

0.01 g to 500 g

If you have more colonies to treat, or have trouble weighing 7.5g, scale everything up ten-fold. Or buy a small, accurate set of digital scales – like these for £9 which work very well. 1 kg of sugar plus 1 kg (1 litre) of water requires 75 g of oxalic acid and makes 1.67 litres … enough to treat all the colonies in the association apiary.

Which is not such a bad idea. Make it up carefully once and share it with your fellow beekeepers. Storage details are provided below.

Recipes : Api-Bioxal

Warning – the recipe on the side of a packet of Api-Bioxal makes up a much stronger solution (4.4% w/v) of oxalic acid than has historically been used in the UK. Stronger isn’t necessarily better. The recipe provided is 35 g Api-Bioxal to 500 ml of 1:1 syrup. By my calculations this recipe makes sufficient solution at a concentration of 4.4% w/v to treat 11 hives. 

To make a 3.2% Api-Bioxal-based oxalic acid-containing solution using the 35 g pack of Api-Bioxal you need to mix the entire contents of the pack with 691 ml of 1:1 syrup.

Here’s the maths:

  • 35 g of Api-Bioxal contains only 22.14 g of oxalic acid. 88.6% of the 35 g is oxalic acid dihydrate (the remainder is cutting agents like glucose and powdered silica) and so the oxalic acid content is ((35 * 0.886) * 0.714) = 22.14 g.
  • To calculate the volume of syrup you need to divide it by the final percentage required i.e. (22.14 / (3.2/100)) = 691 ml. I don’t know the exact amount of sugar and water needed to make this amount … it’ll be about 430 g of each (I think).

A 35 g packet of Api-Bioxal is therefore sufficient to treat about 15 colonies (assuming 5 ml per seam, 8 seams per hive and 10% ‘just in case’) at the recommended concentration of 3.2% w/v.

Api-Bioxal is sold in three pack sizes (35 g, 175 g and 350 g). If you are wealthy enough to be able to purchase the larger pack sizes you’ve probably got your own beekeeper (or mathematician). Relax on your yacht while they do the calculations for you 😉

On the other hand … if you have a smaller number of colonies either make a full 35 g packet up and share it, or use accurate scales and the following table:

Api-Bioxal recipes for 3.2% OA trickling

Api-Bioxal recipes for 3.2% OA trickling


Storage of oxalic acid syrup at ambient temperatures rapidly results in the acid-mediated breakdown of sugars (particularly fructose) to generate hydroxymethylfurfural (HMF). As this happens the colour of the oxalic acid-containing solution darkens significantly.

This breakdown happens whether you use oxalic acid or Api-Bioxal.

Stored OA solution and colour change

Stored OA solution and colour change …

HMF is toxic to honey bees at high concentrations. Studies from ~40 years ago showed that HMF concentrations below 30 mg/l were safe, but above 150 mg/l were toxic1. HMF buildup is one way overheated honey is detected.

At 15°C HMF levels in OA solution can reach 150 mg/l in a little over a week. At room temperature this happens much faster, with HMF levels exceeding 150 mg/l in only 2-3 days. In the dark HMF levels build up slightly less quickly … but only slightly 2,3.

Only make up OA solutions when you need them.

If you must store your oxalic acid-containing syrup for any length of time it should be in the fridge (4°C). Under these conditions HMF levels remain well below toxic levels for at least one year. However, don’t store it for this long … use it and discard the excess. Don’t use discoloured oxalic acid solutions as they’ve been stored incorrectly and may well harm your bees.

Please re-read the comments above about the toxicity of oxalic acid. If you are going to store it in the fridge it must be very clearly labelled and there must be no chance that children can reach or open the container.


Api-Bioxal is the least expensive VMD-approved miticide and powdered oxalic acid is much, much cheaper. Both contain the same active ingredient, oxalic acid, which is highly effective against phoretic mites.

In midwinter, with very low levels (or no) of brood, a single oxalic acid-containing treatment minimises mite levels for the coming season.

Oxalic acid-containing solutions are easy to prepare. I recommend you make sufficient for your own colonies and those of your beekeeping friends and association members. My previous BKA used to distribute litres of the stuff for use in midwinter. Use this solution in midwinter and then discard any that is unused.

Oxalic acid-containing solutions are inexpensive and easy to administer by trickling. As I shall demonstrate next time.

Please re-read the safety instructions highlighted in red above.

Michelle Dubois

Michelle Dubois

† Listen very carefully, I shall say zis only once was a catchphrase used by “Michelle of the Resistance” in the 1980’s comedy ‘Allo ‘Allo! Michelle (Dubois) was rarely seen without a trench coat and beret, had a corny French accent and was played by Kirsten Cooke.

‘Allo ‘Allo! ran for 85 episodes in the decade from 1982 on BBC one. It was about a café in Nazi-occupied France and the French Resistance, just about. It mixed bawdy humour with gross stereotypes (posh British twits, sex-obsessed French) and was a parody of ITV’s series Secret Army (’77-’79).

Early episodes had obvious and rather dull titles. In the later series the individual episodes had some quite good puns like Awful Wedded Wife.

Michelle – Listen very carefully, I shall say zis only once

René – Well, in that case, could you please speak slowly?

You had to be there … 😉

‡ Oh alright then, since you insist. The 175 g pack of Api-Bioxal (~£39) needs to be made up in 3.459 litres of 1:1 syrup and the 350 g pack (~£65) 6.919 litres of 1:1 syrup. Determining how much water and sugar to mix to make these amount is, as they say, an exercise for the reader. Assuming a 3.2% solution and 8 seams of bees per colony Api-Bioxal costs between 63p and 41p per hive (see note below), depending upon the pack size you purchase. I know that beekeepers moan on and on about the outrageous cost of Api-Bioxal (as do I), but is 63p per colony really an unreasonable amount to spend on VMD-approved medicines to keep your colony as clear of Varroa as possible? I don’t think so.

Note – the costs in the paragraph were calculated using the lowest prices I could currently find for Api-Bioxal. C Wynne Jones has the 35g packets for £9.50 and Maisemores have the 350g packets for £64.79. Prices correct on 9/10/17.

1 Jachimowich T., El Sherbiny G., Zur Problematik der verwendung von Invertzucker für die Bienenfüttering, Apidologie 6 (1975) 121-143.

2 Bogdanov S., Kilchenman V., Chamere J.D.. Imdorf A. (2001) available online.

3 Prandin, L., Dainese, N. , Girardi, B., Damolin, O., Piro, R., Mutinelli, F. A scientific note on long- term stability of a home-made oxalic acid water sugar solution for controlling varroosis Apidologie, 32:) 451-452


Kick ’em when they’re down

Out, damn'd mite ...

Out, damn’d mite …

Why bother treating colonies in midwinter to reduce Varroa infestation? After all, you probably treated them with Apiguard or Apivar (or possibly even Apistan) in late summer or early autumn.

Is there any need to treat again in midwinter?

Yes. To cut a long story short, there are basically two reasons why a midwinter mite treatment almost always makes sense:

  1. Mites will be present. In addition, they’ll be present at a level higher than the minimum level achievable, particularly if you last treated your colonies in late summer, rather than early autumn.
  2. The majority of mites will be phoretic, rather than hiding away in sealed brood. They’re therefore easy to target.

I’ll deal with these in reverse order …

Know your enemy

DWV symptoms

DWV symptoms

The ectoparasite Varroa feeds on honey bee pupae and, while doing so, transmits viruses (in particular DWV) that can completely mess up the development of the adult bee. Varroa cannot replicate anywhere other than on developing pupae. It’s replication cycle, and the resulting mite levels in the colony, are therefore tightly linked to the numbers and availability of hosts … honey bee pupae.

If developing brood is available the mite can replicate. Under these conditions, newly emerged adult, mated, female Varroa spend a few days as phoretic mites, riding around the colony on young bees. They then select a cell with a late-stage larvae in, enter the cell and wait until pupation occurs. If developing worker brood is available each infested cell produces 1 – 2 new mites (drone cells produce 3+) and mite numbers increase very rapidly in the colony.

In contrast, if there’s no developing brood available, the mites have to hang around waiting for brood to become available. They do this as phoretic mites and can remain like this for weeks or months if necessary.

Therefore, when brood is in abundance and the queen in laying freely mites can replicate to very high levels. In contrast, when brood is limiting and the queen has reduced her egg laying to a   v  e  r  y     s  l  o  w     r  a  t  e     the mite cannot replicate and must be predominantly phoretic.

When does this happen?

Lay Lady Lay … or don’t

Ambient temperature, day length and the availability of nectar and pollen likely influence whether the queen lays eggs. When it’s cold, dark and there’s little or no pollen or nectar coming into the hive the queen slows down, or even stops, laying eggs.

About 8 days after she stops laying there will be no more unsealed brood in the colony. About 13 days after that all the sealed brood will have emerged (along with any Varroa). Therefore, after an extended cold period in midwinter, the colony will have the lowest level of sealed brood … and the highest proportion of the mite population will be phoretic.

Under normal (midsummer) circumstances about 10% of the mite population is phoretic. It’s probably unnecessary to state that, if there’s no brood available, 100% of the mites must be phoretic.

All licensed miticides work extremely well against phoretic mites.

Caveats, guesstimates, global warming and the Gulf Stream

Global warming

Global warming …

Whatever the cause, the globe is warming (irrespective of what Donald Trump tweets). Long, hard winters are getting less common (or perhaps even rarer, as they were never particularly common in the UK). In Central, Southern or Eastern Britain it’s possible that the colony will have some brood present all year. In parts of the West, warmed by the Gulf Stream, I’d be surprised if a colony was ever broodless. Only in the North is it likely that there will be a brood break in midwinter.

Most of the paragraph above is semi-informed guesswork. I don’t think anyone has systematically analysed colonies in the winter for the presence of sealed brood. Sure, many (including me) have opened colonies for a quick peek. Others will have peered intently at the Varroa board to search for shredded wax cappings that indicate emerging brood. The presence of brood will vary according to environmental conditions and the genetics of the bees, so it’s not possible to be dogmatic about these things.

However, it’s safe to say that in midwinter, sealed brood – within which the mites can escape decimation by miticides – is at a minimal level.

Reducing mite levels and minimal mite levels

Within reason, the earlier you apply late summer miticides, the better you protect the all-important overwintering bees from the ravages of viruses, particularly deformed wing virus. This is explained in excruciating detail in a previous post, so I won’t repeat the text here.

However, I will re-present the graph that illustrates the modelled (using BEEHAVE) mite levels.

Time of treatment and mite numbers

Time of treatment and mite numbers

The gold arrow (days 240-300 i.e. September and October) indicates when the winter bees are being reared. These are the bees that need to be protected from mites (and their viruses). Mite numbers (starting with just 20 in the hive on day zero) are indicated by the solid coloured lines. The blue, black, red, cyan and green lines indicate modelled mite numbers when the colony is treated with a miticide (95% effective) in mid-July, August, September, October or November respectively.

The earlier you treat, the lower the mite levels are when the winter bees are being reared. Study the blue and black lines.

This is a good thing.

In contrast, by treating very late (the cyan and green lines) the highest mite numbers of the season occur at the same time as the winter bees are being reared. A bad thing.

But … look also at mite numbers after treatment

Look carefully at the mite numbers predicted to remain at the end of the year. Early treatment leaves higher mite levels at the start of the following year.

This is simply because mites escaping the treatment at the end of summer have had an opportunity to reproduce during the late autumn.

This is why the additional midwinter treatment is beneficial … it kills residual mites and gives the colony the best start to the new calendar year§.

Kick ’em when they’re down

Early treatment protects winter bees but risks exposing bees the following season to unnecessarily high mite numbers. However, in midwinter, these residual mites are much more likely to be phoretic due to a lack of brood in the colony. As I stated earlier, phoretic mites are relatively easy to target with miticides.

So, give the mites a hammering in late summer with an appropriate and effective miticide and then give those that remain another dose of the medicine in midwinter.

But not another dose of the same medicine

Since the majority of mites in a colony with little or no brood will be phoretic, you can easily reduce their numbers using a single treatment containing oxalic acid. This can be administered by sublimation (vaporisation) or by trickling (dribbling).

There’s no need to use any treatment that needs to applied for a month. Indeed, many (Apiguard etc.) are not recommended for use in winter because they work far less well on a largely inactive colony.

Trickle 2 - £1

Trickle 2 – £1

I’ve discussed sublimation previously. However, since this requires relatively expensive (£30 – £300) specialised delivery and personal protection equipment it may be inappropriate for the two hive owner. In contrast, trickling requires almost no expensive or special equipment and – reassuringly – has been successfully practised by UK beekeepers for many years. I did it for years before I bought my Sublimox vaporiser.

Therefore, in two further articles this autumn (well before you’ll need to treat your own colonies) I’ll describe the preparation and storage of oxalic acid solutions and its use.

Be prepared

If you want to be prepared you’ll need to beg, borrow or steal the following – sufficient oxalic acid (or Api-Bioxal), a Trickle 2 bottle sold by Thorne’s, a cheap vacuum flask (Tesco £2.50), granulated sugar and a pair of thin disposable gloves.

Do this soon. Don’t leave it until midwinter. You need to be ready to treat as soon as there’s a protracted cold spell (when brood will be at a minimum). Over the last few years my records show that this has been anywhere between the third week in November and the third week in January.

More soon …

† Only MAQS is effective against mites sealed in cells. This is why most miticides are used for extended periods in the late summer or early autumn … the miticide must be present as Varroa emerge from sealed cells.

‡ I’ll repeat the caveat that this is an in silico simulation of what happens in a beehive. Undoubtedly it’s not perfect, but it serves to illustrate the point well. It’s freely available, runs on PC and Mac computers, and is reasonably well-documented. In the simulations shown here the virtual colony was ‘primed’ with 20 mites at the beginning of the year. BEEHAVE was run using all the default settings – climate, forage etc. – with the additional application of a miticide (95% effective) in the middle of the months indicated. Full details of the modelling have already been posted.

§ The National Bee Unit recommend Varroa levels are maintained below 1000 throughout the season. Without treatment, 20 mites at the start of the season can easily replicate to ~750 in the autumn. If you start the season with 200 mites then levels are predicted to reach ~5000 in the following summer. The colony will almost certainly die that season or the next. There’s a more detailed account of the consequence of winter brood rearing and the level of mite infestation written by Eric McArthur and reproduced on the Montgomeryshire BKA website that’s worth reading.

¶ The cumulative (year upon year) effect of late summer treatment with no midwinter treatment has been discussed previously. I’ll simply re-post the relevant figure here – 5 years of bee (in blue, left axis) and mite (in red, right axis) numbers with only one treatment per season applied in late September. Within two years the higher mite numbers that are present at the start of the year reproduce to dangerously high levels.

Mid September

Mid September

Avoiding disaster

Top view of Kewl floor

Top view of Kewl floor

Kewl floors (sometimes called Dartington-inspired floors) have an ‘L’ shaped entrance that I think offers advantages to the colony when defending against wasps (or robbing by nearby colonies) and negates the need for mouse guards. However, the very feature that provides these advantages – the ‘L’ shaped gap about 9mm high – also makes them liable to get blocked with bee corpses during late winter.

During the depths of the winter, with a relatively quiescent colony and winter bees that are only a couple of months old, this isn’t usually a problem. However, as the winter turns to spring and the colony starts to become active again the attrition rate increases. As the weather improves and the winter bees expire the corpses can block the entrance, trapping the remaining colony inside.

Blocked Kewl floor

Blocked Kewl floor …

This is the sort of thing that should only happen once. Early in the season you go and visit the apiary on an unseasonably warm and calm day. With one exception the colonies look reasonably active. Foragers are returning with pollen and there are bees setting off on orientation flights.

If you listen carefully at the hive with no activity you might be able to hear the bees panicking inside. Splitting the brood box from the floor reveals the scale of the devastation. It’s a distressing sight. If you’re lucky there will be good numbers of flying bees. If you’re unlucky the colony will have already perished or there will be obvious signs of Nosema.

Kewl floor unblocker ...

Kewl floor unblocker …

With reasonably regular visits to the apiary this is a situation that can easily be avoided. Insert a piece of bent wire – I use an old bicycle spoke – in the entrance slot, turn through 90° and drag it across the full width of the entrance. The ‘vertical’ piece of the wire needs to be longer than the depth of the entrance slot on the floor, but not so long that it fouls the bottom of the frames.

 But, do we always learn from our mistakes? I’ve had this happen a couple of times. In both cases the colony was strong going into the winter and on a double brood box. The first time the colony perished, though it’s not actually clear whether they died from being trapped or from a midwinter virus overload. The second time, April 2015 (shown in the hive photo above), the colony survived. When I discovered the blocked entrance there were still lots of flying bees. I swept the floor clean and cleared the entrance, reassembled the hive and left them to it. On checking a couple of days later they were taking in pollen and I found the laying queen, none the worse for wear, at the first full inspection the following week.



Those pesky mites

DWV symptoms

DWV symptoms

If you haven’t yet treated your colonies to reduce Varroa levels before the winter arrives it may well be too late. High Varroa levels are known to result in the transmission of virulent strains of deformed wing virus (DWV). These replicate to very high levels and reduce the lifespan of bees. If this happens to the ‘winter bees’ raised in late summer/early autumn there’s a significant chance that the colony will die during the winter.

Mite levels in most of my colonies have been very low this year. Partly due to thorough Varroa management in the 2015/16 winter (the only thing I can take credit for), partly due to the relative sparsity of beekeepers in Fife, partly due to the late Spring and consequent slow build-up of colonies and partly due to an extended mid-season brood break when requeening. Most colonies yielded only a small number of mites (<50) during and after a 3 x 5 day treatment regime (to be discussed in detail in a later post) by sublimation.

Infested arrivals

The low mite drop definitely wasn’t due to operator error or vaporiser malfunction. At the same time I treated a swarm that had moved into a bait hive in early June …

Out, damn'd mite ...

Out, damn’d mite …

This is ~20% of the Varroa tray. Have a guess at the number of mites in this view only. Click on the image to read the full legend which includes the mite count.

The image above was taken on the 18th of September, a day or two after starting the second round of 3 x 5 day treatments. The colony really was riddled. When a colony swarms 35% of the mites in the colony leave with the swarm (or, in this case, arrives with it). For this reason the swarm was treated for mites shortly after it arrived in June. It did have a reasonably high mite load but subsequently built up very quickly and didn’t experience the mid-season brood break my other colonies benefitted from.

The colony now has an acceptable mite drop (<1 per day). Similar colonies are still rearing brood – I’ve not checked this one, but they are bringing in some pollen from somewhere – so there’s a possibility the majority of the remaining mites are tucked away in sealed cells. I’ll keep a close eye on this colony through the next few weeks and will be treating again midwinter to further reduce the parasite burden.

Treat ’em right

If you are treating this late in the season make sure you use a miticide that is appropriate for the conditions. Apiguard (a thymol-containing treatment) is almost certainly unsuitable unless you’re living in southern France as it needs a temperature of 15°C to be effective. MAQS has a recommended temperature minimum of 10°C which may be achievable.

Hard chemicals such as Apivar and Apistan can be used at lower temperatures but there’s little point in treating with Apistan unless you’re certain all your mites are sensitive. They almost certainly are not as Apistan/Bayvarol resistance is very widespread in the UK mite population. Just because you get an increased mite drop in the presence of Apistan does not mean treatment has been effective. Perhaps all you’ve done is killed the sensitive mites in the population, leaving the remainder untroubled. This is what’s known as a bad idea … both for your bees next season and for your neighbours.

 I’m posting this now due to the large number of searches for, and visits to, pages on use of Apiguard or other Varroa treatments. These are currently running second to ‘fondant‘ in one form or another.

Everynuc feeder

I bought a few of these Ashforth-style feeders when I standardised on using Everynucs from Thorne’s a year or two ago. They’ve sat more or less unused since then, largely because the design of this poly nuc – a Langstroth-sized box adapted to take National frames – includes an integral feeder. This year I’ve used these nucs for queen mating and holding ‘spare’ queens when undertaking swarm control. Most of these have either migrated up to a full colony or been returned to the original hive, but I have a few left to take through the winter. These are now being fed up for the coming months. All are, or will be, housed in the bee shed overwinter for additional protection, though I’ve previously overwintered colonies in them outside reasonably successfully.

Everynuc feeder ...

Everynuc feeder …

Syrup and paint

The feeder is well designed, with an opening at one end leading to a good-sized reservoir for syrup or fondant. The volume of the reservoir is a little more that 3.5 litres when filled to dangerously near the brim. When using syrup – which I don’t – there’s a folded wire mesh screen that should prevent the bees drowning. They can climb up and over the dam to reach the syrup, but don’t have free access to the reservoir. This should reduce that distressingly high ‘body count’ sometimes seen with badly designed feeders. Additionally, the mesh screen prevents bees from leaving the hive when the clear plastic crownboard is removed to top up the reservoir. Convenient  🙂

Rodent damage ...

Rodent damage …

Like all poly hives, and particularly poly feeders, these should be painted before use (remember, Do as I say, don’t do as I do … some of mine aren’t painted due to poor planning). Syrup soaks into the poly if the surface isn’t sealed first. This can lead to problems with fungus growth and attack by rodents when the feeders are stored. As an aside, I try and remember to seal the entrances of my poly hives when not in use to prevent mice from destroying them … they seem very enthusiastic about having polystyrene chip parties at my expense. A couple of my poly bait hives have already been attacked this autumn – these just smell of bees and propolis (and now strongly of mouse 🙁 ) without the added attraction of syrup residues which would just make things worse.

The wire mesh screen on the Everynuc feeders is a bit ‘springy’ and probably needs holding in place with a couple of drawing pins (see image above). Additionally, both sides of the dam wall should also be painted and, when still wet, sprinkled with sand to improve the grip for bees accessing the syrup (as I show on the landing boards on my kewl floors).


Feeder with fondant

Feeder with fondant …

At one end of the feeder, opposite the syrup reservoir, is a well that can be filled with fondant if the wire mesh screen is fitted. My crude measurements suggest it should hold about 1.5 kg of fondant if packed in tight. It might be possible to directly carve off suitably sized lumps from an intact block but it’s easier to pack it with a variety of offcuts and squeeze them down. Bees are be able to access the fondant from underneath and adjacent to the dam wall. As with syrup, feeding them like this means the fondant can be topped up without bees escaping.

Alternatively (and see the next section) you can simply stuff a big lump of fondant into the well of the feeder and omit the wire mesh – as shown above.

Easy top-ups

Easy top-ups …

I had a few concerns about how well the bees would access the fondant through the mesh – might the fondant dry out too quickly, would access be restricted as the fondant block shrank in size etc? Therefore, before it got too cold I set a couple up of feeders with or without the mesh fitted to see how readily the bees could access and take down the fondant (this post was started in mid-September). Both methods seemed to work fine though I suspect feeding through the mesh directly above the frames is likely to work better as the weather cools further, simply because it’s less far for the bees to travel and likely to be a little bit warmer.


Peter Edwards has recently written a short article in BIBBA’s Bee Improvement on modifying the Miller-style feeder supplied by Maisemores for their poly nuc. He simply drilled a series of ~25mm holes through the bottom of the one side of the feeder, leaving the other side unbutchered for delivering syrup if needed. A simple but effective solution ideally suited to Maisie’s double-sided feeder. Since I’m so wedded to the use of fondant for my autumn/winter feeding I may do this on a few of these Everynuc feeders as well … accepting that they’ll be trashed for use with syrup.

That’s all folks

The last week has seen temperatures peaking in the low teens, with the first overnight frosts of the year. Active beekeeping is effectively over for the season. Colonies checked at the end of last week are taking fondant down well and two that I briefly inspected had reasonable levels of brood in all stages, wth the queen laying at a consistent rate albeit much less than earlier in the season. These new bees will help the colony get through the winter and – because mite treatments were completed several weeks ago – will have been reared in a hive with very low Varroa levels, ensuring they are protected from virulent strains of deformed wing virus. I have a couple more colonies to check in the next few days and one more nuc to move to the bee shed.

However, before the autumn tidying and winter tasks are started there’s still some reasonable weather to get out and enjoy the beautiful Fife countryside.

Ballo Reservoir and West Lomond

Ballo Reservoir and West Lomond


 The Ashforth-style feeder has the entrance at one end or side, the feeder with the double entrance in the middle is the Miller feeder.


Fife’s fondant mountain

A little later in the year than usual due to work commitments …

In late August 2014 I described how I feed my bees fondant in the autumn. It’s a simple, quick, clean and efficient way to feed colonies. Additionally, I’m reasonably convinced that there are advantages for the bees as well as the beekeeper. The advantages (over syrup, either homemade or Ambrosia for example) are numerous:

  1. Readily available, pre-packed and very easy to store.
  2. Ready to use … just unbox it, slice it open and add to the hive.
  3. Addition takes only a minute or two per hive.
  4. Compatible with many Varroa treatments (Apiguard and sublimation are two I’ve used at the same time as feeding fondant).
  5. No spillages (during preparation or delivery) so far less risk of attracting wasps or getting into trouble in the kitchen.
  6. No need for specialised equipment such as Miller or Ashworth feeders that need to be stored for the remaining 11 months of the year.
  7. It’s taken down and stored better in cold weather (than syrup) as evaporation of excess water isn’t needed.
  8. You can get later brood rearing as the brood nest isn’t packed out with syrup (possibly, see below).

Point 8 is perhaps debatable. This is my impression having used it for several years, though I’ll admit to never conducting a proper side-by-side comparison. Fondant is certainly taken down more slowly than syrup. A full block (12.5 kg) might take 4-5 weeks, though it can disappear much faster. Since the water content of fondant is not wildly different from honey it takes about the same amount of storage space. In contrast, even thick syrup (2:1 sugar to water by weight) needs to be concentrated by the bees, requiring more temporary storage (where the queen might be laying or you might want her to lay to raise those all-important winter bees), reasonable temperatures and more energy.

Don’t take my word for it …

Peter Edwards of Stratford BKA used to have a posting on feeding fondant but I’m reliably informed it’s disappeared in a website revamp. He was a strong a advocate of the ease and benefits of using fondant … so don’t think that this is just my crackpot idea. Actually, it’s not his crackpot idea either … it’s not crackpot at all. And there are very few new ideas in beekeeping.

I’ve used nothing but fondant for winter feeding for at least 5 years. I’m not aware of any problems doing this. My overwintering colony losses are satisfactorily low and almost always attributable to issues other than feeding. Like a Mac, “It just works.

How to feed fondant

Open the box and slice the block of fondant in half. There are two easy ways to do this:

  1. Use a strong breadknife in the kitchen. Cover the opposing faces with clingfilm. The idea here is to stop the fondant ‘fusing’ back together as you transport it to the apiary.
  2. Use a nice sharp spade in the apiary … forget the finesse, just stomp down hard and cut the block in two. Don’t worry about the few bits of mud and grass that get included.
Neater but harder ...

Neater but harder …

In both cases leave the plastic wrapping on and don’t cut right through it … the idea is to open the block out like a book and place it face down onto the top of the frames. I used to leave the queen excluder in place but generally only do this if there’s a reason I might need to inspect the colony again (with care you can lift the QE and fondant off together). The plastic wrapping on 5 sides of each half block stops the fondant drying out.

Finesse ... nul points ...

Finesse … nul points …

A block of fondant is about 20 x 20 x 32 cm. You’ll therefore need to work out a way of providing sufficient ‘headroom’ under the crownboard. The easiest way is to use an empty super. Alternatively, where I’ve got insulated perspex crownboards, I invert them over a simple eke allowing me to see how fast the fondant is used and top it up as necessary. If, like me, you consider hive insulation important leave this in place under the roof. If I’m using a super to enclose the fondant I try and use a polystyrene one for the same reason.

Poly super and fondant ...

Poly super and fondant …

I usually remove the empty  bag when I do the midwinter Varroa treatment, or before if they’ve finished it (in which case I might add another half block or so if ”hefting the hive’ indicates it’s still a bit light). The bees usually build some brace comb on the top of the frames extending into the bag. Just gently smoke them down and scrape it off, or leave it there until the Spring.

The end is nigh

Feeding the colony up for winter marks the end of the practical beekeeping season for me. I usually experience a mixture of sadness that it’s over again for the year, together with anticipation of what’s to come the following season. With the exception of a few nucs and some colonies in the bee shed, inspections and any sort of regular checks on the colonies are over. The summer honey harvest has been taken – hopeless this season unfortunately – and Varroa levels have been monitored and minimised.

Nevertheless, winter preparations such as feeding the colony up, uniting weak colonies which are unlikely to overwinter well, protecting the colony from mice or woodpeckers and hammering down the Varroa levels are some of the most important activities of the year. If done successfully there’s every reason to look forward to having strong, healthy colonies to start the following season.

You can purchase fondant from bakers and wholesale bakery suppliers such as Fleming Howden. The price I paid – thanks to a friend in the East of Scotland Beekeepers Association – was  £10.55 for 12.5 kg. Ordering in bulk – for example via a co-operative purchasing scheme through your local association – makes a lot of sense and will reduce (or remove altogether) the delivery costs. Single blocks purchased from your local baker might cost 50% more than the price I’ve quoted. Sugar prices vary on the commodities markets … in 2013 I paid about the same as this year, but in 2014 paid only about £9 a box.

BFP wholesale used to sell fondant and had regional outlets (Tamworth in the Midlands and Livingstone in Scotland) from which collection was possible. However, although they have gone into administration, I saw one of their lorries on the way to the office this morning and it appears that the Leeds and Livingstone branches may have been bought and remain operational.

 If you have the storage space it makes sense to buy in bulk. Keep it dry and away from wasps, rodents (and other beekeepers) and it has a shelf life of at least three years. You’ll also find it useful for a mid-winter boost, for feeding mini-nucs when queen rearing, for blocking queen cages and for Chelsea buns 😉

Bee shed inspections

A brief update on how things have been progressing in the bee shed. This is my first full season keeping colonies full-time within a shed or building though I’ve successfully overwintered mini-nucs in an unheated greenhouse in the past.

Under construction ...

Under construction …

When installed at the end of last season there was almost no need to open the hives, so it’s only this Spring that the pros and cons of the bee shed have begun to be properly understood.

The colonies are completely enclosed with simple tunnels leading to exits on the East/South East face of the shed. All the colonies are housed in standard National cedar boxes or poly nucs. Other than clear perspex insulated crownboards, there is no additional insulation and the shed is not heated. The shed is situated in open parkland with woodland and arable land nearby containing good forage and there is a permanent water supply nearby.

Colony development and Varroa loads

Colonies went through the winter in single National brood boxes, fed with fondant and treated with oxalic acid by vaporisation in September (before moving them to the shed) and in midwinter. The first inspection was conducted in late March. Colonies were building up well and were significantly stronger than colonies headed by sister queens in the same apiary or in my other apiary. Between late February and early May colonies dropped only 3-4 mites in total, with Varroa boards located within pull-out trays in the hive floor. I’m sure I missed a few mites, but doubt it was very many. We’ve recently uncapped a full frame of drone brood – each cell uncapped individually – and found no Varroa present. Mite levels are therefore reassuringly low – for reasons to be discussed in a future post – with no signs of DWV-related disease.

Varroa tray ...

Varroa tray …

Since mid-April colony development has been very good and they are now on double National brood boxes with 2-3 supers. A fourth super went onto one colony on the 25th of May and the stack now nearly reaches the shed roof. A four frame nuc has been split off one colony already to cool it down a little. Quite a bit of developing brood has also been harvested at weekly intervals for our research, usually by simply cutting a big slab out of the middle of a frame. This has probably also held the colonies back a bit and it’s only now I’m starting to plan for swarm prevention/control.


Inspections have been easier than expected. These colonies are headed by queens with reasonable genetics (Heinz queens – local mongrels of 57 varieties, reared by me in 2015). The bees are steady on the comb and tend not to fly up at you when the crownboard is lifted. They’re nothing particularly special, but would be considered reasonably placid and non-aggressive.

The colony is gently smoked from outside the shed (through the entrance tunnel) and a small amount is wafted under the crownboard or between the QE and the bottom super. After allowing them to settle the supers and crownboard are removed and placed outside on an overturned roof. The queen excluder and adherent bees are also left standing outside (unless it’s cold when the bees are shaken off into the open hive).

Inspecting the colony is straightforward. Any frames removed to make space are rested on the hive stand. Double brooded colonies are split into two, with one box stood aside on an eke on the roof of an adjacent hive roof. Inevitably, the queenless half of the split tends to get tetchy within a few minutes, so it’s best to deal with them first. When frames need to be shaken free of bees this can be done either over the open hive or, better still, directly into a gap between the frames. If done outside many of the nurse bees on the frame fail to get back to the hive (they’ve probably not been on orientation flights yet).

The smoker is usually stood just outside the shed door … if you keep it in the shed during inspections you can end up being kippered 😎

Flying bees

Perhaps surprisingly, even going through all 22 frames in a double colony, the shed does not fill with a maelstrom of flying bees. Undoubtedly this is partly because they’re reasonably calm colonies. Those that do fly rapidly find the window or open door and make their exit. When I first started doing inspections in the bee shed I’d manually help the stragglers outside after reassembling the hive. It turns out that there’s really no need … almost all the bees quickly vacate the shed by making a beeline ( 😉 ) for the bright lights of the windows or doors.

The great escape ...

The great escape …

Just how quickly the bees leave the shed was emphasised last Sunday when selecting larvae for grafting. I opened and inspected a double brooded colony, found a suitable frame with 24 hour larvae on it and placed it in a two frame nuc for protection. Within 5 minutes I could work without a veil (I react very badly to stings to the face so take particular care over this) without interruption from flying bees.

Weather and temperature

I’m sure that the temperature influences the behaviour of the colonies in the shed. They certainly forage – or perhaps collect water to use fondant or crystallised stores – at lower temperatures than those situated outside. When inspections are conducted on a cold day (say 10-11°C) they are even more steady than usual. However, those that do fly take longer to leave the shed and they can end up clustering in small, rather pathetic, little groups which then need to be scooped up on a hive tool and dropped into the colony. On cool days I don’t leave the supers or QE outside the shed as the bees would rapidly get chilled. Work commitments mean that inspections must be conducted on certain days, so I don’t have the luxury of simply waiting until it’s a bit warmer. Although the shed is unheated the temperature differential between the inside and outside is significant – perhaps 4-8°C – or more if the sun is shining on the window side of the shed. On a warm, sunny day the temperature inside the shed can easily reach the mid-20’s which makes inspections a hot and sweaty activity.

Needless to say, inspections on damp or wet days are much better than on colonies located outside. I avoid days when it’s raining hard, partly for my own comfort to avoid getting wet accessing the apiary, but also because I’d prefer not to force the bees to fly on a really wet day. However, on damp or drizzly days, inspections proceed as normal.

And the bad news is …

Almost everything I’ve written above is positive and my overall initial impression is that the bee shed offers very significant advantages for the sort of beekeeping I need to do. However, there are some drawbacks and design issues that either currently cause problems, or might in the future.

The first is that it’s too small. The shed is 12 x 8 feet and I should have got one at least half as long again. This is largely because it’s also used for equipment storage and has a small table for working on. With four hives I need storage for 8-12 supers, additional brood boxes and spare frames. If I was starting again, knowing what I know now, I’d get an 18 x 10 shed with the intention of housing at least 6 colonies and some additional nucs (by contrast mine will accommodate 4 full colonies and 2 nucs down the sunny side of the shed, with the possibility of 2-3 additional nucs at a squeeze). It’s not only equipment storage that takes up the room … you need considerable room to work as well, with space for turning, stacking and temporary placement of hive parts. Working in the bee shed encourages an efficiency of movement – or causes a lot of collisions – I’d not expected.

Essential storage ...

Essential storage …

Secondly the lighting is – at best – variable. On a sunny morning there’s ample light to see eggs and tiny larvae. However, as the colonies have grown, the added supers restrict the amount of light getting through the windows. On an overcast day, or late in the afternoon, the lighting is pretty hopeless – good enough to see queen cups/cells, good enough to locate the queen, but (particularly on dark frames) too dim to see eggs, small larvae or to check frames for signs of disease. It’s not unusual to have to carry frames outside to inspect them fully. I’m currently investigating 12V LED systems run from a solar panel-charged caravan battery. My only concern is that this might disorientate the bees and slow their exit from the shed during inspections.

Multiple supers ...

Multiple supers …

Thirdly, I should have spent more time designing the hive stands. I made them an inch or so too low which caused some problems with locating the hive entrances centrally in the T&G planks, but was not insurmountable. More problematically, as a consequence of the leg locations it’s difficult to keep the floor clear of hive debris that falls through the OMF. With the Varroa boards in place this isn’t an issue, but when they’re out – which I prefer if there’s a chance of the shed getting very warm – the debris needs to be regularly swept up to keep the shed clean. Some sort of removable debris trays would have been a good addition, but are not easy to fit retrospectively. However, the overall hive stand design – with the legs going through the suspended floor to avoid vibrations – works very well.

Finally, swarm control has yet to be tackled. My preferred simple method is doing a vertical split (or using a Snelgrove board that I’m experimenting with this year) but this requires an upper entrance which, obviously, cannot easily be arranged. One possibility is using the Demaree method of swarm control. Alternatively, it would be straightforward to remove the queen into a nuc and let the colony requeen. Currently I’m trying to postpone the inevitable by removal of some brood, ensuring they have enough space within the brood boxes which I swap (top to bottom, bottom to top) periodically, ensuring they have sufficient space in the supers and keeping a close eye on them. The queens are clipped. If they do swarm they’re likely to end up in a lump outside the hive entrance – the ground is flagged and so they should hopefully be relatively easy to scoop up.


Beekeepers’ holidays

It can be tricky balancing the annual cycle of beekeeping activities with maintaining family responsibilities and domestic bliss. At least, I’m told I find it tricky 😉  Holidays, in particular, are problematic. I’m talking here about beekeepers’ holidays not beekeeping holidays, which are an entirely different thing. Many of the standard “family holiday” periods overlap with key events in the beekeeping calendar … and because the latter is influenced by the weather, it’s difficult to predict a few days ahead, let alone the 6-9 months that appear to be required to arrange a fortnight’s yacht charter in the Bahamas§.

Mallorcan market honey and (sort of) observation hive

Mallorcan market honey and (sort of) observation hive

With good weather, colony build-up is going to be full-on in April, and in a really good year you can be starting queen rearing at Easter if it is late in the month. May is when the swarming season starts … and ends in June, just in time for the “June gap” to start which (in a bad year) might require colonies to be fed. The summer months of July and August are busy with the main flow, preparing colonies for the heather or harvesting (and possibly more queen rearing). September means Varroa treatments should be applied and colonies should be fed syrup or fondant for the winter. And then midwinter is interrupted by oxalic acid treatment (or Api-Bioxal if you’re the type of beekeeper who can afford Bahamian cruises), checking stores etc. And almost all of the timings above can be plus or minus at least a fortnight to take account of the vagaries of the weather.

February and November might be provisionally free … which creates another weather-related problem. Firstly – if honey sales have gone well during the year (and they’ll need to have been good as the 90m Athena is an eye-watering $350,000/week) – you’ll not want to be going island-hopping in the Bahamas in November as it’s still the hurricane season. Secondly, if your knees are as bad as many beekeepers’ backs, skiing in February might be a non-starter even if snow is available.

Less is more …

… likely to avoid you losing a swarm. The duration of the family holiday is also an issue. Inspections really need to be conducted at 7 day intervals during the main part of the season – say late-April to late-July. A fortnight away can mean missing the development of queen cells which are capped on the ninth day, at which point the prime swarm with your queen and foraging workforce disappear over the apiary fence. Not only do you return to a rather emptier hive, but your chance of a good honey crop has just been significantly reduced. You can increase the inspection interval to 10 days if you clip your queens, but that’s still four days short of the fortnight.

Queen rearing, from colony preparation, through grafting, cell raising and getting the virgin queens mated, takes about a month and – although not hugely time-consuming – is very-much time-critical. Getting to your cell raiser a day late might mean you have a box with one virgin running about and a pile of virgin queen corpses.

Apiary in Andalucia

Apiary in Andalucia

Nevertheless, with a little preparation, an appreciation of colony development and your fingers firmly crossed it is possible to get away during the beekeeping season without too many problems.

Holiday solutions

It seems to me that there are three obvious solutions …

  1. Go between late autumn and early spring, to the southern hemisphere if you’re after some warm sunshine. Or to Aspen or Whistler for the skiing if your knees are up to it.
  2. Get a friend to look after your colonies and go whenever you want. Depending how well behaved your colonies are, or the state you find them in on your return, this might only work once per friend 😉
  3. Accept that some beekeeping activities will be interrupted, prepare well and go for a week.

My knees are a bit dodgy and I get more than enough long-haul with work commitments so option 1 doesn’t work for me. I’ve avoided option 2 as I either have too many colonies to think it’s reasonable to foist upon a beekeeping friend, or they’re so badly behaved I’m too embarrassed to ask. So option 3 is the only choice … which is why I didn’t post anything last week as I was enjoying the walking in the Serra de Tramuntana in Mallorca.

Benjamin Franklin was right

Bait hives ...

Bait hives …

By failing to prepare you are preparing to fail. Sneaking off for a week just as swarming period was kicking off, with the best weather of the season predicted to arrive and the OSR in full flower, might have been asking for trouble. However, a little time spent on preparation helped avert disaster. Bait hives were put out near the apiaries. Remaining overwintered nucs were unceremoniously dumped into a full hive. Any colonies looking even vaguely crowded were given lots of additional space and almost all were on double broods by the time I left. Every full colony was given one additional empty super. Where necessary, one or two frames stuffed with stores were removed and replaced with foundation or drawn comb. Finally, all colonies were checked for queen cells and other obvious signs of swarm preparation the day before I left.

Nine days later I returned … none of the bait hives had been occupied, none of the colonies had swarmed, almost all of the colonies were doing precisely what they should have been doing which was building up strongly and filling the supers. Two in the bee shed were doing particularly well, having almost filled several supers. Pretty much everything was under control with the exception of one queenless colony that, the day before my departure, had been given a frame of eggs and young larvae but had failed to make any decent queen cells.

During my absence the weather in Fife was excellent … in contrast, I walked into this lot in the Tramuntana …

Thunderstorm overlooking the Bay of Pollenca

Thunderstorm overlooking the Bay of Pollenca, Mallorca …

Despite not going on a beekeeping holiday, it’s still possible to see – and sample – some of the local beekeeping activities, as shown in the photos at the top of the page from Mallorca and Andalucia taken in previous trips.

§ I wish

 Just in case you’re thinking of buying bees from me please note that this is a rather poor joke 😉

As an aside … I’ve never seen an area with more hornets that this region of Southern Spain