Tag Archives: Apivar

Autumn cleaning

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Over the last fortnight, despite some occasional warm and sunny days, the autumn has made its presence known. 

Flaming autumn aspen

The aspen down the road are a stunning colour at this time of the year. Although I’ve planted a couple of dozen, they’re still not more than thigh-high and it will be quite a few years until they can match the display shown above.

Almost overnight hundreds of redwing have arrived from Scandinavia and many of the rowan have already been stripped bare 1.

In Fife, the leaden skies are filled with skeins of geese forming raggedy V’s as they fly in from the North Sea. It’s an evocative sight … it reminds me of my first weeks as an undergraduate student at Dundee University half a lifetime ago

And it also emphasises that the beekeeping season is over.

Of course, there will be jobs to do in the winter, but the bees are pretty much on their own for at least the next five months.

Apivar

The final essential task of the season for me is to remove the Apivar strips that went into the hives in August. Initially the strips were placed on either side of the – still large – brood nest. A few weeks ago I removed the strips, scraped them free of propolis and wax and re-inserted them around the, now shrunken, brood nest.

Mid-autumn and time for the Apivar strips to be removed

You can just about see them in the photo above, flanking the four central frames.

It is important to remove the strips. Although Apivar has a relatively short half-life, some residual activity will remain. If you leave them in the hive any surviving Varroa – and there will be survivors 2 – will continue to reproduce in the presence of trace levels of amitraz, the active ingredient in Apivar. 

With reduced – and possibly borderline for killing – levels of amitraz present, these are ideal conditions in which resistance may develop. Although this has been reported it does not appear to be widespread. 

Therefore, to ensure that Apivar remains an effective miticide it is important to remove any remaining strips before the winter.

Your next adventure in Glenrothes awaits!

Tragic isn’t it?

That’s the subject line on the emails I receive from Travelodge where I stay when I’m doing my beekeeping in Fife. 

Have you ever been to Glenrothes?

‘Adventure’ isn’t the word most people associate with Glenrothes. 

Good morning Glenrothes

GetMeOuttaHere is. 

This is a town where every third car being driven late at night has a raucous exhaust, lowered shocks, tinted windows and a spoiler. The drive-in queue for McDonald’s sounds like the pit lane at the Indianapolis 500 and there are more donuts in the car park than in the fast food outlets 3.

But none of that usually bothers me as, by the time I get to the hotel, I’ll have been driving for 5 hours and will have spent about the same amount of time inspecting colonies or lifting cleared supers. I may also have squeezed in a couple of hours of meetings at work.

The environment might be noisy, but the beds are comfortable. 

But visits in late autumn are a bit different.

No colonies to inspect, no grafting to do, no nucs to check for mated queens and no supers to remove.

All I need to do is gently lift a few crownboards and pull out the Apivar strips now that treatment is complete.

So, what do I do for the rest of the day?

Long range weather forecasting

Is that an oxymoron?

I book my trips to Fife to fit in with what the bees need. To make the hotel affordable I book many weeks in advance.

I therefore put up with whatever the weather throws at me. Usually it works out OK.

Furthermore, as regular reader know, several hives are in a bee shed, so the weather is largely irrelevant.

But ~60% of them are outside.

And Monday was really wet. 

Having driven for four hours through increasingly heavy rain – stopping en route to make a honey delivery – I fortified myself with a cappuccino and excellent almond croissant from Taste, the best independent coffee shop in St Andrews 4.

Essential fortifications

I then sat in the shed enjoying my late breakfast listening to the rain hammering on the roof.

I needed something to occupy me until either:

  • the rain stopped
  • it got so late in the day that I’d just have to open the hives and remove the strips anyway

And the obvious thing to do was a bit of spring autumn cleaning. 

During the season the bee shed is used on a daily or weekly basis depending upon the experiments underway. In addition, we have a storage shed on the same site and a number of additional hives in the same apiary. I also do most of my queen rearing in this apiary (the bee shed provides a near-perfect environment for grafting), distributing the nucs to other apiaries for mating.

And all that beekeeping tends to leave a bit of a mess. At least, it does where I’m involved.

Super job

For the last couple of years I’ve not bothered returning the extracted supers to the hives for the bees to recover the last of the honey.

Instead I’ve just stacked them ‘wet’ in the shed, protected from wasps, mice and robbing bees, by covering the top of the stack with a well-fitting roof.

Or a snug-fitting crownboard and a badly fitting roof.

Stacked ‘wet’ supers

Experience has taught me that the floor of the shed isn’t level and/or has gaps between the planking. Rather than seal all these gaps I simply stand the stack of boxes on the sort of closed cell foam sheeting used for packing furniture, or – when I run out – on double thicknesses of cardboard 5. This stops the wasps, ants and bees from getting access. 

So I started by tidying the stacks of supers. Inevitably this necessitated moving them first, sweeping the floor clean, laying out the foam/cardboard and then restacking them. There’s not enough space in the shed to move ~60 supers so they went out in the rain.

So I got wet 🙁

Floors, roofs, boards, unidentifiable objects and wax moth

Once they were back I could turn my attention to the other side of the storage shed which houses spare roofs, nuc feeders, floors, boards (split, crown, surf, Morris, Snelgrove etc. 6 ), a breeding colony of queen excluders 7 and a motley collection of other items that:

  • might come in useful
  • don’t logically belong anywhere else
  • appear valuable and/or difficult to make … but I don’t know what they are
  • are essential and were needed several times in the season … but I’d lost them 🙁

Sorting this lot out took another hour or two, and involved a further soaking as I needed to clear the space before I could refill the space.

Early on in the process … 

Is beekeeping the largest volume hobby?

… and when at least partial order had been restored …

Floors from Abelo, Pete Little and some homemade abominations

I also found several brood boxes full of drawn comb or sealed stores.

Excellent 🙂

And I found a nuc box lurking in the far corner containing comb riddled with wax moth 🙁

Wax moth larvae and damage

Aargh!

DiPel DF

Wax moth are something I’ve largely avoided or ignored for most of the last decade. The cold winters in Scotland seem to keep their numbers down.

Not this time … 

All of the infested frames were bagged up for burning at the earliest opportunity. The remaining brood frames were treated with DiPel DF, a suspension of Bacillus thuringiensis kustaki spores and toxins. If ingested by the larvae of wax moths, the δ-endotoxin component dissolves in the alkaline environment of the gut, is activated following cleavage by gut proteases and then ‘punches’ a hole through the gut wall.

Ouch.

And the spores germinate, allowing the bacteria to grow inside the larva.

As I wrote in a post several years ago about this treatment:

This isn’t good for the moth larva. Not good at all. Actually, it’s probably a rather grisly end for the moth but, having seen the damage they can do to stored comb, my sympathy is rather limited.

DiPel DF is non-toxic for bees.

DiPel DF

I’ve not had problems with wax moth infesting supers stored ‘wet’ … they’re after the old cocoons and other rubbish that accumulates in brood frames.

Vita used to sell a product called B401 – also a suspension of Bacillus thuringiensis spores and proteins – which was withdrawn from sale in 2019. Despite assurances that a replacement – imaginatively labelled B402 – would be available ‘soon’ it appears to only currently be sold in the US.

Out with the old … and the not fit for purpose

I was on a roll … 

All this organisation meant I discovered things that I’d lost … like a small stack of contact feeders hiding in the corner that had not been used this season as I hadn’t done any shook swarms.

There they are! Contact feeders lurking shyly in the furthest corner (unlike those brazen frame feeders at the front)

I also found some mini-nucs I’d built for queen mating almost 10 years ago. They were made of ply and housed a tri-fold full-size brood frame (you can now buy these, but couldn’t when I built them). 

Tri-fold brood frame

However, the ply was starting to delaminate and it was pretty clear that they wouldn’t survive a Scottish summer season so they were unceremoniously binned.

And I finally bit the bullet and got rid of all my XP Plus queen excluders. These were bought from Thorne’s a few years ago and had been used only when I ran out of everything else.

In principle they are a good idea. A white plastic queen excluder with bee space on the underside provided by a raised rim and a series of small X-shaped spacers that stand on the top bars.

XP Plus queen excluder (the plus must mean ‘plus warp’)

However, in practice, they’re rubbish. They were the ‘ugly’ in my 2017 description of queen excluders that included the phrase ‘the good, the bad and the ugly’.  

They warp really badly. The photo above – if anything – obscures the warp because the QE is not being held flat. When you place them under a super the centre bows up and contacts the underside of the super frames.

Rubbish. 

Out they went.

The little things

There’s something rather poignant about the death throes of the beekeeping season. It can end with a bang as autumn storms roll in, or it can end in a protracted stutter as intermittent good days allow the bees to forage late into October. 

Of course, it’s au revoir 8 and not a final goodbye. 

It forms such a large part of my life for six months of the year that little things found during the clear-out bring back a flood of memories …

Nicot cup and (partly squidged) queen cell amongst the debris on the shed floor

A Nicot cup and vacated queen cell reminded me what a good queen rearing season we’d had on the east coast. Although the first round of grafting was a near-total failure, successive rounds were excellent, and queen mating was very successful. One of the best seasons in memory 9.

Coffee stirrer … or AFB test kit

Not all the memories were good ones though. I received one of the dreaded ‘AFB alert’ warnings for the apiary and spent a very long couple of days checking every cell on every brood frame in every colony, and testing any that looked suspicious.

I don’t take sugar, and the coffee stirrer shown above is provided in the AFB LFD kit to lift the dodgy-looking larva into a tube for analysis. Everything looked clear, but it gave me a few very stressful days.

And … after all that tidying, and repeated trips to the industrial-scale bins, it finally stopped raining.

Finally … some practical beekeeping

I fired up the smoker and quickly, but gently, removed all the Apivar strips. The crownboards on all the hives were very firmly stuck down with propolis and the bees, although calm, weren’t exactly overjoyed to see me.

Autumn still life – smoker, hive tool, Varroa trays and Apivar strips

I still had another apiary to visit. With rain threatening there wasn’t time to monitor the level of brood present so I slipped cleaned Varroa trays under the hives. This will allow me to inspect both residual mite drop and look for the presence of the characteristic biscuit-coloured cappings when brood is uncapped.

And then, after about half an hour of practical beekeeping, I set off back to the west coast as the rain started again.

The Moidart hills – An Stac, Rois-Bheinn and Sgùrr na Ba Glaise

Two days later the Moidart hills had their first dusting of snow.

It’s official, autumn is here and the beekeeping season is over.

 

Apivar & Apitraz = Amitraz

The range of miticides available ‘off the shelf‘ to UK beekeepers has recently been increased by the introduction of Apitraz and Apivar.

‘Off the shelf’ because, until recently, these were only available with a veterinary prescription.

Considering the extensive coverage on this site of oxalic acid-containing miticides and more recent posts about the – regularly ineffective – Apistan, it seemed fair and appropriate to write something on the active ingredient and mode of action of these new products.

Mites on drone pupae ...

Mites on drone pupae …

Conveniently, because the active ingredient is identical, these can be dealt with together in a single post. The similarities don’t end there. The amount of the active ingredient is the same and the way it is administered is very similar. They are different commercial products; Apitraz is distributed by Laboratorios Calier, SA and sold by BS Honeybees, Amitraz is distributed by Veto Pharma and sold by Thorne’s. The strips have a different appearance and a slightly different mechanism by which they are hung in the hive.

They even cost about the same – a single packet of 10 strips (sufficient to treat 5 hives) costs £30.50 and £31 respectively for Apitraz and Apivar.

Amitraz

The active ingredient in both Apitraz and Apivar is Amitraz.

Yes … I find these three names confusing similar as well 😉

Amitraz is a synthetic acaricide – a pesticide that kills mites and ticks. It was discovered and developed almost 50 years ago by the Boots Co. (the drug development predecessor of the Boots the Chemist 1 found in most high streets). Amitraz is the active ingredient in a range of medicines approved by the Veterinary Medicine Directorate, including Aludex and Certifect, both of which are used to treat mange in dogs.

Amitraz

Amitraz …

For completeness I should add that Amitraz used to be used by US beekeepers and was sold as a generic pesticide under the name Taktic, though this was withdrawn in about 2014. I believe that Apivar is now available as a slow-release Amitraz-containing Varroa treatment in the US.

Mechanism of action

Amitraz has to be metabolised (essentially ‘modified’) before it is active. This modification occurs much less well in bees than in mites. In fact, the toxicity of Amitraz for bees has been determined to be about 7000 times less than in mites.

Once converted into an ‘active’ form the most important mechanism of action for Amitraz is through interaction with the alpha-adrenoreceptor and octopamine receptors of Varroa 2.

OK, since you asked … octopamine receptors normally bind a neurotransmitter called – rather unimaginatively – octopamine. Quelle surprise as an apiculteur would say. It’s likely that occupancy of these receptors by Amitraz triggers a series of so-called downstream events that change the behaviour of Varroa. Similarly, amitraz also acts as an agonist 3 when binding to the alpha-adrenoreceptor which normally interacts with catecholamines. This results in neurotoxicity and preconvulsant effects.

That all sounds a bit vague. Essentially, amitraz binds and activates receptors that are critically important in a range of important aspects of the Varroa activity and behaviour. Remember here that the mite is entirely dependent upon proper interaction with the bee to complete the life cycle. For example, if the mite fails to enter a cell at the correct time or doesn’t hitch a ride on a passing nurse bee for a few days, it will likely perish.

Amitraz changes behaviour and so exhibits miticidal activity. It has additional activities as well … these multiple routes of action may explain why resistance to amitraz is slow to develop. More on this later.

Usage of Apitraz and Apivar

Both Apitraz and Apivar are formulated as plastic strips impregnated with amitraz. The bees must come into contact with the strips to transmit the amitraz around the hive. Two strips are therefore placed between frames approximately one-third of the way in from each side of the brood box – typically between frames 4 & 5 and 7 & 8 of an 11 frame box. This assumes the bees occupy the entire box. If they don’t, arrange the strips in the appropriate part of the box with 2 frames separating them. Both types of amitraz-containing strips have a means of securing them hanging between the frames.

The recommended treatment period is 6 (Apitraz, or Apivar with little/brood present) to 10 weeks (Apivar with brood present). As with Apistan, treatment should not be applied during a honey flow or when honey supers are present. Further details are included on the comprehensive instructions provided with both products. There’s also a reasonable amount of information on this New Zealand website for Apivar.

Efficacy

This is the good bit … very, very effective. When used properly, amitraz-containing miticides can kill up to 99% of the Varroa in a colony.

Toxicity and wax residues

The good news first. Amitraz does not accumulate in wax to any significant extent. It is not wax-soluble. This is in contrast to Apistan which is found as a contaminant in most commercially-available beeswax foundation.

And now the bad news. Beekeepers also have alpha-adrenoreceptors and octopamine receptors. So do dogs and fish and bees. Although amitraz has increased specificity for the receptors in mites and ticks, it can also interact with the receptors in other organisms. Consequently, amitraz can be toxic. In fact, if you ingest enough it can be very toxic. Symptoms of amitraz intoxication include CNS depression, respiratory failure, miosis, hypothermia, hyperglycemia, loss of consciousness, vomiting and bradycardia.

And it can kill you.

Admittedly, the doses required to achieve this are large, but it’s worth being aware of what you’re dealing with. Amitraz-containing strips should be used only as described in the instructions for use, handled with gloves and discarded responsibly after use.

Resistance

Multiple modes of action makes it much more difficult for resistance to evolve. But it can and does. Resistance to amitraz is well-documented and is understood at the molecular level. However, this is in cattle ticks, not Varroa.

At least, not yet, though there are numerous anecdotal reports of Varroa resistance.

I’ll deal with resistance in a separate post. It’s an important subject and avoiding it is a priority if amitraz-containing compounds are going to remain effective for Varroa control.

Cost

At about £6 per colony, amitraz-containing treatments are not significantly more expensive than the majority of other approved miticides, perhaps with the exception of Api-Bioxal which is appreciably less expensive (though more restricted in the ways it can effectively be administered 4).

Apivar ...

Apivar …

When you purchase a couple of packets of Apivar – enough for 10 colonies – it might feel expensive 5. However, it’s worth remembering that this is still less than the likely ‘profit’ on a couple of jars of your fabulous local honey per colony per year, which seems pretty reasonable in the overall scheme of things.

And, if you look after your colonies well, you are maximising the potential yield of honey in the future … so you’ll be able to afford it 😉

 

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.