Tag Archives: nadiring

Is the honey ready?

Synopsis : How and when do you remove the supers to maximise the honey ready for extraction (and minimise the drudgery of extracting 😉 ). What is the ‘shake test’, and what do you do with frames that fail?

Introduction

Unless your bees are now up on the heather moors, or one or two other specific cases (e.g.ivy), the productive part of the beekeeping season is now more or less over.

Productive in terms of honey, queen and nuc production (or propolis, Royal Jelly etc.).

The days are shortening, it’s cooler in the mornings and – at least here in north-west Scotland – there’s the first hint of leaves changing colour on the trees.

Your hives should be full of bees. The drones – as discussed last week – are counting the days 1 or perhaps hoping 2 for one last chance at mating with a late virgin queen.

It’s not completely finished – and it depends upon where you live – but ’the end is nigh’. Of course, not an actual apocalyptical and eschatological event … just that most of the fun is over until next May 🙁 .

It didn’t last long did it?

Hopefully the hives are heavily laden with bulging supers 🙂 .

Colonies may start to get defensive if they’re being pestered by wasps or subjected to robbing by other colonies.

It’s about now that the beekeeper robs the hives of some or all of the summer honey and starts to make the all-important preparations for winter.

Summertime, and the livin’ is easy

About six weeks ago I wrote a post about the change in intensity of beekeeping once the swarm season is over. From then (late June or early July) until now I’ve pretty much stopped routine colony inspections. Visits to the apiaries are a lot more relaxed.

Most of the colonies have new queens (or I’m pretty certain that the 2020 or 2021 queens – all of which are clipped anyway – won’t swarm 3 ) and there is little to be gained from rummaging through the brood boxes.

What’s more, those supers are heavy 🙂 .

I’ve no interest in lifting off this lot …

For Scotland that’s a lot of supers (and see text)

… solely to (disruptively) confirm what I’m 98% certain of already i.e. that the queen is laying and has space to lay, that – nevertheless – the brood nest is contracting and they’re starting to backfill cells with nectar, that there’s enough pollen for the brood they are rearing and that there’s increasing (but still well within safe limits.4) numbers of mites in the colony.

Admittedly, I know some of these things because I’m familiar with the ’rhythm of the seasons’ here, having kept bees in eastern Scotland for several years.

That doesn’t mean I’ve abandoned beekeeping. Far from it.

Any boxes I’m unsure about have been regularly inspected. These include some with new queens and my hives on the west coast 5.

Just this afternoon I found my last new laying queen of the season 6. It’s been a shocking summer in the north-west, but she got out to mate in two days of half-decent weather last week.

The honey harvest

Most of my beekeeping has been in the Midlands and lowland Scotland. Neither area has heather and the only reliable late nectar sources are ivy and Himalayan balsam (Impatiens glandulifera).

I reckon that balsam is just about in range

Reliable in that there should be nectar available, not that the bees would reliably collect it.

In my experience ivy is usually too late for my bees in Scotland. Balsam is earlier, but is localised around rivers or damp ground.

In both cases, if the bees can get it, I let them keep any nectar they collect.

I therefore usually remove the honey supers soon after the main summer flow has finished. Last year that was the first week of August. All the supers were removed by about the 12th. This year – with fewer hives but a lot more supers 🙂 – I started removing full supers on the 1st of August and expect to have them all off by early next week 7.

I know some beekeepers remove supers one at a time or as they’re filled and capped. With sufficient time and easy access to your hives that can work well.

However, most of mine are 140 miles away, I’m reasonably time-poor and – importantly – I consider extracting the third worst task in beekeeping 8.

I therefore prefer to collect as many supers as possible in as short a period as practical. I stack them somewhere warm and then spend a day or two (or in a bad, so therefore antithetically, good year, three days) hunched over the extractor.

The sniff test

The water content of nectar can range between about 50 and 90%. Different nectars have different water content. Much of this water needs to be evaporated off by the bees or the resulting stored honey will ferment.

If you visit the apiary late on a calm summer evening you can hear the entire hive ‘humming’ as the bees fan their wings to create an airflow to evaporate the excess water off.

Late evening in the apiary

Sniff testing hives late in the evening

It often smells fantastic 🙂 .

Once the water content is low enough (less than 20%) the honey will not ferment and the bees usually seal the full cells with a wax cap.

Nicely capped and ready to extract

However, it’s unusual that every frame in every super is capped. Many or most will be, but there are often frames – particularly the outside frames of a super – which are partially (or even completely) filled and not capped.

(Very) partially capped honey super frame ...

(Very) partially capped honey super frame …

The super above is almost completely full, but the vast majority of the cells have not been capped.

Can it be extracted?

Will the honey ferment?

How can you avoid this situation in the first place?

So many questions … let’s go back to the apiary.

Checking the supers

Although I don’t lift off all those supers to inspect the brood boxes, I do periodically look at what’s going on in the supers.

With one or two supers and a clear crownboard you can usually see how the bees are getting on filling the frames without lifting anything but the roof.

If you add new supers to the top of the stack you can be reasonably sure that the lower supers will be more completely filled and better capped than the top one.

And, in case you’re wondering, it apparently doesn’t make any difference whether you add supers to the top or bottom of the stack.

So, if you top-super – and are over eight feet tall – you can check the stack as it grows without any lifting 😉 .

If the central frames are capped and the outer ones only part-filled/uncapped I swap them around (as shown in panel A and B, below, where black bars indicate capped frames and mid-grey bars indicate part-filled or uncapped frames).

Rearranging super frames and checking cleared supers – see text for details

Similarly, if the outside of the outer supers is being ignored I turn them round.

Evenly filled frames are easier to extract because they all weigh about the same so the extractor remains balanced.

My extractor takes 9 frames … and so do my supers 🙂 .

At least, they do once the comb is fully drawn.

I start the supers with 11 frames and foundation, but remove two once they’re drawn. The wider spacing encourages the bees to build deeper cells – more honey, less wax and (more importantly) less frames to extract.

However, don’t just start with 9 undrawn frames or the bees will probably build lots of brace comb in the big gaps between them.

Clearing supers

I’ve discussed clearing supers several times previously 9. In my opinion the three important points are:

  • use a clearer board with no moving parts (and avoid those abominable Porter escapes)
  • make sure there is a gap below the clearer and above the box below the super being cleared
  • that the supers of a queenright colony should be almost completely cleared within 12-16 hours

My clearer boards have a deep lower rim and two wide-spaced escapes. They work very well.

Clearer boards

Clearer boards – note two well-spaced exits and a deep lower rim

In the cartoon diagram above, panel C shows a hive with supers ready for clearing and removal.

The day after adding the clearer I remove the supers, leaving the clearer in place and undisturbed for the moment.

The supers are temporarily stacked in an upturned hive roof and covered with another roof – to keep them wasp and bee free.

If, as I remove the supers, I see bees that haven’t been cleared I drop the entire super 10 on an unoccupied hive stand to shake the stragglers off.

I then check individual supers. Those that are completely capped can be stacked – again with protection from robbing wasps and bees 11 – ready for transport.

Part capped super frames are subjected to …

The shake test

Honey with a water content lower than about 20% cannot be easily i.e. manually, shaken out of the cells. This is convenient because 20% is the upper limit 12 allowed for the sale of ‘honey’. Any higher than that and it’s likely that the honey will ferment (and therefore spoil).

Or it’s not ‘honey’ 13.

Therefore, after removing the cleared supers you should test any frames that are partially or completely uncapped to confirm that the honey is ‘ripe’ and ready for extraction.

The ‘shake test’ takes just seconds to perform.

Hold the super frame horizontally by the side bars and give it a single sharp shake. If nectar flies out of the cells the water content of at least some of the uncapped cells on the frame is over 20%.

If, when you hold the frame horizontal – before shaking the frame – nectar drips or pours out of the cells then don’t even bother doing the shake test … the frame is not ready. Any frames like these, or any that fail the shake test, should be transferred into an empty super which can go back on the hive.

In the cartoon diagram above, the supers removed from the hive (C) included uncapped frames that passed the shake test (mid-grey and stacked with capped frames in D) and those that were insufficiently ripened which ended up in stack E.

Since there are almost no bees on these frames, you can mix’n’match the frames containing unripe honey from several hives.

Tidying up

I usually do the shake test over an inverted Correx roof. The dark colour makes it easy to see the drops of nectar that are shaken out. Doing it this way also means I don’t leave spilt nectar around the apiary that might induce robbing 14.

Unripe nectar is easy to shake out of super frames.

Alternatively, you can shake the frames over the top of an opened hive. Since I try and clear all the supers in an apiary at once I prefer not have a hive open for the time it might take to check all the uncapped frames.

Once the supers are off, sorted, graded and stacked away ready for transport I shake the bees from the underside of the clearer and close the hives up, having placed the super(s) containing the frames of unripe honey on top of the strongest colony 15. This is the most likely to ripen and cap the honey, or to use it for winter stores.

Preparation for winter

On the same day I remove the supers I often start the preparations for winter. I don’t want to write about this here (I’ve written about is previously and I don’t have the space) but it essentially involves:

  • conducting a final inspection of the brood box
  • adding Apivar, the miticide I usually use in late summer
  • adding a 12.5 kg block of fondant

If the colony is healthy but weaker than I’d like, or not queenright, I would unite it with a strong colony. Far better to take your ‘losses’ in the autumn than in the winter.

But, back to those supers …

Having consolidated all of the extractable frames into the smallest possible number of boxes I then try and squeeze all 48 supers into the back of my little car and – yet again – wish I could sell enough honey to purchase a truck and trailer.

Room for another up top … the passenger seat is already full

I must try harder 😉 .

Back at the ranch

Serious beekeepers have ‘warm rooms’ in which they stack the supers prior to extraction. This keeps the honey nicely warmed. It is therefore much easier to spin the honey out of the frames and it retards crystallisation.

I’m not a serious beekeeper 😉 .

But I do have a honey warming cabinet that I can stack a lot of supers on 😉 .

Supers being warmed ready for extraction

If you build your own honey warming cabinet it’s worth making it strong – joints glued and screwed etc.. There’s at least 200 kg of honey in the supers pictured above 16. I would not try this with any of the commercial 17 honey warming cabinets I’ve seen (all of which are too small anyway).

The honey warming cabinet is set to 40°C and the supers are rotated, top to bottom and vice versa every day or two until I’m ready to extract.

It’s a lot of lifting, but the ease with which the honey is spun out makes it worthwhile 18.

Spring honey from oil seed rape

The high glucose content of nectar from oil seed rape (OSR) means that the honey crystallises fast. Keeping it warm helps, but you still need to extract within a few days of getting the supers off the hive. In contrast, summer blossom honey often takes ages to crystallise, so you can deal with things in a more leisurely fashion.

Yikes! … wet frames at home

Sometimes a frame or two – or a super or two – of incompletely ripened honey sneaks through all those careful checks you conducted in the apiary.

You notice nectar dripping from a frame when you lift it out of the super … you give it a quick ‘shake test’ and a lot more nectar is shaken out.

What can you do with these frames or supers?

It rather depends how many of them there are and how much you want the honey.

But first … what you should not do is extract them and mix them with the high quality, low water content honey that forms the bulk of the stuff you are extracting. Doing this risks ruining an entire bucket 19.

I think the choice is probably one of:

  • returning the frames/supers to the apiary for the bees
  • stacking the supers in a small warm room with a dehumidifier. If you do this, place spacers between the supers to encourage good airflow
  • spinning out the ‘wet’ honey at low speed before uncapping the frames and extracting as normal. If you do this, make sure you empty the extractor and use the ‘wet’ honey as winter feed for the bees (or for mead)

I’ve only ever really done the first two of these. A dehumidifier works, but that was long ago when energy was cheap.

These days I’m much more rigorous in screening frames/supers in the apiary and any that slip through are returned to the bees 20.

Points I failed to mention earlier

Inevitably I missed a few things I intended to cover, or remembered them too late to weave into the main part of the post … 21.

Caveats

Remember … the ‘Can’t shake honey with less than 20% water out of a frame’ rule somewhat dependent upon how strong you are.

The accurate way to test the water content of honey

You should still test your extracted honey with a refractometer.

Brace comb

If you find the bees are building brace comb under the clearer you can be certain that the nectar flow is not finished yet (or another has started).

Brace comb in clearer

Brace comb in clearer

The clearer above was inadvertently left on for a few days, but they can build a surprising amount of new comb within 24 hours in a strong nectar flow. If this is the case you should expect many of the frames will not be ready for extraction.

Failed clearers

If your clearer doesn’t almost completely clear the supers overnight, either:

  • it’s a lousy design and/or blocked with dead drones, or
  • the colony is not queenright (it might be worth checking 😉 )

Returning supers for capping and/or stores

When returning supers with unripe stores for the bees I place them over the brood box (and queen excluder) if I want the bees to ripen and cap the honey. Obviously – at least it should be to anyone who reads the instructions – in this instance I don’t add Apivar, or start feeding for winter.

However, if I’m returning the super for the bees to store the nectar I nadir the super i.e. place it underneath the brood box. Any capped stores in the super are bruised by gently pushing down on the cappings. The damaged cells consequently weep small amounts of honey. Since the colony stores honey above and to the sides of the brood nest they usually empty the nadired super and move the honey up.

If the laying rate of the queen has slowed sufficiently she is unlikely to fill the nadired super with brood. Depending upon the time of the season you need to judge when to remove this nadired ‘super’ 22, or whether to leave it on overwinter.

By the time you get to it in the spring it’s likely to have brood in 🙂 .


 

Queens and amitraz residues in wax

A question following a recent evening talk to a beekeeping association prompted me to look back at the literature on amitraz and wax residues.

The question was about reuse of honey supers that were present on a colony during miticide treatment.

With the exception of MAQS, there are no approved miticides that should be used if there are honey supers on the hives. The primary reason for this is that there is a risk that the miticide will taint the honey. Since the latter is for human consumption this is very undesirable.

However, it’s not unusual at the end of the season to have a half empty super, or a super containing just uncapped stores. Typically this would be ‘nadired’ i.e. placed below the brood box, with the expectation that the bees will move the stores up into the brood chamber 1.

Two colonies overwintering with nadired supers

And sometimes this super remains in place during the annual early autumn Varroa slaughter. 

The question was something like “Can I reuse the honey super next season?”

My answer

As anyone who has heard me speak will know, my answer was probably rambling, repetitive and slightly incoherent 🙁

However, the gist of it was “Yes, but I don’t”.

With Zoom talks and written questions from the audience you often don’t get all the details. The answer must be sufficiently generic to cover most eventualities 2 including, for example, the range of possible miticides that were used for treatment.

Assuming the nadired super is emptied by the bees during the winter, what are the chances that the wax comb will be contaminated with miticides?

This depends upon the miticide used.

I explained that the organic acids (formic or oxalic) are not wax soluble and so the super can be reused without a problem. 

In contrast, Apistan (a pyrethroid) is known to be wax soluble, so it should probably not be used again to avoid any risk of tainting honey subsequently extracted from it 3.

But (I probably digressed) you really shouldn’t be using Apistan as resistance in the mite population is already widespread.

But what about Apivar (the active ingredient of which is amitraz)?

Since Apivar isn’t wax soluble it would probably be OK to reuse the super … but I qualified this by saying that I don’t reuse them “just to be on the safe side”.

What they don’t tell you about Apivar

This wasn’t really an application of the precautionary principle.

Instead, it reflected a dim memory of some posts I’d read earlier in the year on the Bee-L discussion forum. This is a low volume/high quality forum frequented by scientifically-inclined beekeepers.

It turns out that, although amitraz (the active ingredient in Apivar) is not wax soluble, it’s broken down (hydrolysed) to a formamide and a formamidine

Read that again … I didn’t write the same word twice 😉

The formamide has no residual activity against mites. In contrast, the formamidine retains miticidal activity and is wax soluble

Is this a problem?

Well, possibly. One of the things discussed by Richard Cryberg on Bee-L was that there appears to be no toxicology data on these two products. It’s probably been done, just not published.

Perhaps we can assume that they’re not hideously toxic to humans (or bees)? If it was, amitraz (which is the active ingredient in all sorts of mite and tick treatments, not solely for bees) would carry sterner warnings.

Or should 🙁

The residual miticide activity is potentially more of a problem. A well understood route to developing miticide resistance involves long-term exposure to sub-lethal doses. There are several reports of amitraz resistance in the scientific literature, and bee farmers are increasingly providing anecdotal accounts of resistance becoming a problem.

This, and the possibility of tainting honey, are reason enough in my opinion to not reuse drawn supers that have been on the hive (e.g. nadired) during Apivar treatment.

But it turns out that there are additional potential issues with amitraz residues in comb.

Miticide residues in wax

Commercial wax foundation – like the stuff you buy from Thorne’s or Maisemores or Kemble Bee Supplies – is often contaminated with miticide residues. A large US survey of drawn comb from hives and foundation demonstrated that:

Almost all comb and foundation wax samples (98%) were contaminated with … fluvalinate 4 and coumaphos 5, and lower amounts of amitraz degradates and chlorothalonil 6, with an average of 6 pesticide detections per sample and a high of 39.

I’m not aware of an equivalent published analysis of UK foundation. I’m know one has been done and I’d be astounded if it produced dramatically different results. There’s a global trade in beeswax, some of which will be turned into foundation. The only exception might be certified organic foundations.

Freshly drawn comb

A freshly drawn foundationless frame

I always purchase premium quality foundation but am under no misapprehension that it doesn’t also contain a cocktail of contaminants, including miticides and their ‘degredates’. 

I’d be delighted to be proved wrong but, since I think that’s unlikely, it’s one reason I use an increasing number of foundationless frames … which also saves quite a bit of cash 🙂

Drones and queens and miticides in wax

Numerous studies have looked at the influence of miticide residues on worker, drone and queen development. These include:

  • Sublethal doses of miticides can delay larval development and adult emergence, and reduce longevity 7
  • Tau-fluvalinate- or coumaphos-exposed queens are smaller and have shorter lifespans 8
  • Queens reared in wax-coated cups contaminated with tau-fluvalinate, coumaphos or amitraz attracted smaller worker retinues and had lower egg-laying rates 9.
  • Drones exposed to tau-fluvalinate, coumaphos or amitraz during development had reduced sperm viability 10.

All of which is a bit depressing 🙁

These studies used what are termed ‘field-realistic’ concentrations of the contaminating miticide. They didn’t use wax saturated in miticide, but instead contaminated it with parts per million (ppm), or parts per billion (ppb).

These are the highest concentrations reported in surveys of comb tested in commercial beekeeping operations in the US, so hopefully represent a ‘worst case scenario’.

It’s also worth noting that some commercial beekeepers in the US use significantly more – both in amount and frequency – miticides than are used by amateurs. If you read American Bee Journal or the Beesource forums it’s not unusual to find accounts of spring, mid-season, late-summer and mid-winter treatments, often of the same colonies.

Queen mating

To add to the literature above, a new paper was published in November 2020 which suggested that amitraz residues in wax increased the mating frequency of queens.

The paper is by Walsh et al., (2020) Elevated Mating Frequency in Honey Bee (Hymenoptera: Apidae) Queens Exposed to the Miticide Amitraz During Development. Annals of the Entomological Society of America doi: 10.1093/aesa/saaa041

This piqued my interest. Queen mating frequency is an important determinant of colony fitness.

If a queen mates with more drones there’s inevitably increased genetic diversity in the colony and, in landmark studies by Thomas Seeley, an increase in colony fitness 11

Colony fitness includes all sorts of important characteristics – disease resistance, foraging ability, overwintering success etc.

So, perhaps this is a benefit of amitraz residues in your wax foundation … the reduced egg-laying rate being compensated by increased patrilines 12 and a fitter colony?

The study

Walsh and colleagues grafted queens into JzBz queen cups containing wax laced with one or more miticides. They reared the queens in ‘cell builders’ that had not been miticide treated, shifted mature queen cells to mating nucs and then – after successful mating – quantified two things:

  • the viability of spermatozoa in the queen’s spermatheca
  • the mating frequency of the queen

Irrespective of the miticides incorporated into the wax lining the queen cup, sperm viability was very high (98.8 – 99.5% viable), and no different from queens not exposed to miticides during development. 

Queen cells after emergence in mating nucs

This suggests that miticide contamination of queen cells is unlikely to have a deleterious effect on sperm viability in mated queens.

However, rather oddly, this contradicts a not dissimilar study 5 years ago from some of the same authors where the presence of tau-fluvalinate and coumaphos did reduce sperm viability 13, as did an earlier study looking at the effect of amitraz 14.

This contradiction is pretty-much ignored in the paper … clearly something that “needs further investigation”.

It might be due to experimental differences (for example, they used different methods to determine sperm viability). Alternatively, since the queens were open-mated, it might reflect differences in the miticide-exposure of the donor drones.

Mating frequency

The authors used microsatellite analysis to determine the mating frequency of the queens reared during the study. They compared queens reared in the presence of amitraz or tasty cocktails of tau-fluvalinate & coumaphos, or clorothalonil & chlorpyrifos 15, with those reared in the absence of chemicals contaminating the waxed queen cup.

They measured the observed mating frequency and then calculated the effective mating frequency (me). Conveniently they describe the difference between these parameters:

The observed mating frequency refers to the total number of drone fathers represented in a queen’s worker progeny. The effective mating frequency uses the proportion of each subfamily within a colony and compensates for calculating potentially skewed estimates of paternity (i.e., unequal subfamily proportions in sampled pupae) and intracolony genetic relatedness.

‘Convenient’ because it saves me having to explain it 😉

The observed mating frequencies of the control queens (untreated wax), or those reared in the presence of amitraz or tau-fluvalinate & coumaphos cocktails were not statistically different. However, queens reared in clorothalonil & chlorpyrifos-laced wax had a lower observed mating frequency.

Strikingly though, when calculated, the effective mating frequency of amitraz- or tau-fluvalinate & coumaphos-exposed developing queens was significantly higher (~12.9-13.4) than either the untreated controls or clorothalonil & chlorpyrifos (~8.2-8.8) 16.

And … ?

The amitraz result is new.

The influence of tau-fluvalinate & coumaphos on effective mating frequencies has been reported previously (by some of the same authors 17) which, since this was a new study in a different region, is at least encouraging because it supports the earlier work.

Taken together, these results suggest that miticide residues (of at least two chemically different types) increase the number of drones that a queen mates with.

The discussion of the paper speculates about why this difference is observed. 

The number of drones a queen mates with is influenced by several things. These include the number and duration of the mating flights. Perhaps the amitraz-exposed queen can’t count properly, or loses her ability to judge time … or just flies more slowly?

All of these would result in exposure to more drones.

Before returning to the hive, a queen must be able to determine whether she has mated with sufficient drones. It is suggested that stretch receptors in the oviducts are involved with this, forming a negative feedback stimulus once the oviducts are full. Perhaps amitraz impairs stretch receptor function or signalling?

Clearly there’s a lot left to learn.

Hyperpolyandry

The effective mating frequencies determined in the presence of amitraz (and tau-fluvalinate & coumaphos) were higher than the controls. However, they still appear rather low when compared with previous reports of hyperpolyandrous 18 colonies with up to 77 distinct patrilines (I’ve written about this previously, including descriptions of how it was determined).

Don’t mix the two observations up. In the studies of hyperpolyandry they analysed queens to determine their patriline.

A queen from a very rare patriline is still a queen, so can be screened.

In contrast, if you only screen a handful of workers (from the thousands present in the colony), you are very unlikely to find extremely rare patrilines. Those you do find will be the ones that are most common. 

A logical extension of the studies reported by Walsh et al., would be to determine whether hyperpolyandry also increased in amitraz-exposed colonies. If the effective mating number is increased you should observe a larger number of patrilines.

Alternatively, perhaps Withrow and Tarpy (who published the hyperpolyandry paper 19) should look again at whether the colonies they screened had a long history of amitraz exposure.

And what about that nadired super?

It’s probably fortunate I’d not fully read the literature before answering the question after my talk. 

If I had, I’d have tried to paraphrase the ~2000 words I’ve just written … so making my answer interminably long.

Of course, it’s unlikely that an amitraz (Apivar) contaminated super will ever be visited by a queen (but these things do happen 🙁 ).

Or be a location for developing queen cells. 

So, in this regard, I think it’s irrelevant whether the super is reused.

In contrast, the wax solubility and residual miticide activity of one of the hydrolysis products of amitraz is more of a concern. I don’t want this near honey I’m going to extract, and I’d rather not have it in the hive at all.

All of which explains the “Yes, but I don’t” answer to the original question about whether the super can be reused.

Fondant feeding on a colony with a nadired super

The super in the picture above will be removed early next season, before the queen starts laying in it. The super will be empty and I’ll melt the wax out in my steam wax extractor. 

In a good nectar flow the bees will draw a full super of comb very quickly. Yes, they’ll use some nectar that would otherwise be used make honey, but that’s a small penalty.

And what will I do with the extracted wax? 

I’ll probably trade it in for new foundation 20.

And since this is what many beekeepers do it explains why I’m certain that most commercial foundation is contaminated with miticides 🙁

But don’t forget …

Mite management is important. Miticides are chemicals and, like other medicines, have both beneficial and detrimental effects. The beneficial effects far outweigh the detrimental ones. If you do not treat, the likelihood is that mites and viruses will kill the colony … if not immediately, then eventually.