The four quarter days are:

• Lady day or the Feast of the Annunciation 25th March;
• Midsummer’s day around 25th June;
• Michaelmas 29th September;
• Christmas 25th December – lest we forget. Fat chance.

They all approximately coincide with either an equinox or a solstice.

Equinoxes

An equinox is when day and night are of equal duration. There are two of them – spring and autumn:

• Spring equinox 21st March;
• Autumn equinox 23rd September.

Solstices

As for the solstices there are two of these too – summer and winter.

• Summer solstice (longest day and shortest night) 21st June;
• Winter solstice (shortest day and longest night) 22nd December.

Christmas

Nobody knows the day or the month when Jesus Christ was actually born. However, the Feast of the Annunciation falls on the 25th March which is when Christians celebrate the day Gabriel called on Mary to tell her she was to be the mother of the son of God.

Imagine that!

Christmas is exactly 9 months after the Feast of the Annunciation. That’s biology for you.

Christmas also coincides approximately with the Winter Solstice on 22nd December. Also known as The Shortest Day. Now there’s cause to celebrate.

Christmas Traditions

You don’t need me to tell you about the ‘traditions’ of Christmas. Suffice to say, it is cruel that we have to bear it in the middle of the darkest, wettest and most depressing time of the year. It’s enough to push you over the edge!

We can never really know what Jesus might think about Christmas traditions, However, we do know what happened when he discovered the merchants had set up shop in the temple, so we can guess:

‘But what about the bees?’ says you…

Us beekeepers are fortunate because there is a lot of stuff out there to be getting on with at christmas.

Treat them

The bees should have been fed and treated for Varroa after the honey was extracted at the end of summer. However, midwinter is the time when the queen bees should be off lay and there should be a short broodless period which is ideal for a backup treatment with Oxalic acid. I say should be because it is not always the case especially in a mild year or where they ivy bloomed late. So long as there has been a bit of cold weather – below 15 degrees – and a decent interval since you last saw yellow ivy pollen going in to the hives – Christmas should be perfect.

Click here for how to do that.

Click here for more about Oxalic acid for Beekeepers.

I should add that midwinter treatment may not be necessary if you are confident that the conditions in autumn were good enough to allow your thymol/MAQS to work properly.

Feed them

While you are out there – check the feed status of your bees. Heft the hives to assess the weight and if they seem light put some fondant on. It won’t do any harm and if they need it later – it’s there.

If the bees seem weak and are clustering close to the top of the frames you could choose to remove the crownboard and place the fondant directly onto the bees where they will find it easily. If you do this – add an eke and pack the space around the fondant with old jumpers, sacking or some other cosy stuff.

Don’t put pollen substitute on yet – too early – wait for February.

Apiary Watch

Make sure the hive roofs are weighted down with stones or tied with ropes – winter has hardly started and there could be gales. And there could be animals.

Maintenance

Mend broken equipment. Treat spare boxes if they need it. Make up new stuff but don’t put wax into new frames till spring or it will just lose its fragrance and go all crispy then the bees won’t work it properly – they’ll draw all that abstract stuff with holes and buttresses.

All your equipment, supers, spare brood boxes etc could all do with a good scrape down – propolis flakes off well in the cold weather.  Save all the little bits of beeswax you will be amazed how it mounts up.

Click here for how to tackle your beeswax mountain.

Strip down old frames with black, knackered or holy wax. Holy wax is comb with holes in it. Burn the really black horrible wax – use if for lighting fires that’s the only thing it’s good for.

Save the paler, cleaner wax and render it:

Click here for how to render beeswax.

Then do something interesting with it but take care not to set fire to yourself:

Click here for beeswax polish recipe

Click here for beeswax lipbalm recipe

Click here for beeswax handcream recipe

Click here for candle making

Click here for soap making

Wax Moth

If you are storing used brood frames and you know you have a  wax moth problem you might like to take this opportunity to treat them with acetic acid. Acetic acid is not the stuff you put on your chips – treat it with respect.

Click here for how to do that thing

There is also a biological control agent from Vita which uses a micro-organism to attack wax moth.  The product is called Certan and the micro-organism is called Bacillus thuringiensis.

Click here for Certan information

Christmas Forage

There is very little floral forage out there for the bees at Christmas. This year there is quite a lot of gorse in bloom. In some years there may be the dregs of the ivy. Also some winter garden plants such as Mahonia or even snowdrops.

• Ivy pollen is yellow
• Gorse is orange/brown
• Snowdrops pollen is orange/brown too
• Click here for more about ivy
• Click here for how to take a crop of ivy honey.

Happy New Year!

Copyright © Beespoke.info, 2017.  All Rights Reserved.

Benefits

The main benefit to a mesh floor is that Varroa falling from the frames above drop through the metal mesh and meet a chilly end in the grass below. It is thought that up to 20% of hatching Varroa may drop out of the hive this way. All well and good.

Varroa floors can also be fitted with a removable slide below the mesh floor. This can be used to count the mite drop on a daily or weekly basis to assess the mite level in the hive and to decide when to treat.

Mesh floors also allow the much of the hive debris to drop through so there isn’t that accumulation you see on a solid floor and this helps to inhibit wax moth hell and other hive floor creepy crawlies.

Snags

Most of the snags with mesh floors relate to the fact that the bees can smell their colony through the mesh. If you move a hive up onto a taller stand, the bees will return to the vacant space where the entrance used to be and then go and hang up under the mesh floor. They will eventually re-orient on the new entrance but when carrying out such manoeuvres – it is best to temporarily put the insert back in or set the hive on a sheet of plywood or similar.

A more challenging variation on this theme is when a clipped queen tries unsuccessfully to swarm but then manages to crawl back up the legs of the stand. Gradually most of the bees in the hive follow her and a new colony sets up shop right there under the floor.

This can also happen when a virgin queen flies out to be mated and on her return she can’t locate the hive entrance; instead she goes under the floor and mooches about under the mesh. These cases are only resolved by finding the queen and transferring her into the hive.

It can be some time before the beekeeper realises something is wrong though – mostly the conclusion he or she comes to in the meantime is that the hive has gone queenless because there are no eggs and the bees in the hive are cranky and dwindling. Of course the colony under the floor expands, they draw wax, rear brood and eventually the ball of bees becomes visible to even the most short-sighted of beekeepers. Me for instance:

Within the wild comb is quite a quantity of capped brood so these bees must have been there for some time:

Thoughts of fixing these combs into frames was dismissed when we saw the shocking amount of Varroa present in the brood. Click this photo below for a close up – the white specks you can see on the inside of the cells are Varroa crap:

Sadly there was nothing for it but to dismantle the lot, gently shake the bees into the hive and destroy the brood which is more or less a shook swarm and an effective but drastic way of removing a load of Varroa.

Flaw in the Floor

This case illustrates the unexpected flip side to mesh floors – the heavy level of infestation is due directly to the mesh floor! As the remaining brood in the parent hive above hatched out – with their Varroa (because this is late June and like it or not Varroa levels are high), the Varroa either dropped from the frames through the floor into the lovely, fresh new colony or more likely were drawn down like BIsto Kids by the enticing smell of the brood.

Had these bees hung up under a solid floor they would have been mostly Varroa-free. The Varroa would have been marooned above in the empty hive. Mind you – if you had a solid floor they would have been less likely to hang there in the first place.

However – it has to be said cases like this are relatively rare and the benefits of mesh floors far outweigh the disadvantages.

Sometimes though – it feels like you can’t win.

Click this for more about the life cycle of Varroa

Click here for how to breed Varroa resistant bees

Click here for Winter Oxalic acid treatment

Click here for Summer Oxalic acid treatment

Click here for Oxalic acid for Beekeepers

Click here for Shook Swarming

Copyright © Beespoke.info, 2016.  All Rights Reserved.

Basic Shook Swarm

When to do it?

If you are doing this to change a full box of comb you can do it up until late June early July. To help set back swarming and turbo charge the bees the best time to do it is around the last week in April and the first week in May.

Why?

• Eggs laid during this period would become foragers in the June gap when there is often a dearth of forage for the bees. You don’t need them;
• Eggs laid after this time are the foragers for the flow. You do need these.

When not to do it

• Don’t do it at all after mid-July as the queen is on the wane, the bees are no longer in build-up mode and are more likely to be demoralised. Also you are in danger of removing brood that would become much needed winter bees.
• Don’t do this to a weak hive of bees – it might finish them. Anything over 5 frames of brood should benefit from this but you must feed them.

Method:

• Move your target hive of bees to one side;
• Set a floor in its place;
• Put a queen excluder on top of the floor;
• Place a brood box with a full complement of frames kitted out with fresh foundation on the queen excluder – never use horrible old foundation for this – it needs to be lovely and fresh and fragrant;
• Remove three frames from the centre of the new box;
• Find the queen and place her out of harm’s way;
• Carefully shake all the bees, frame by frame, from the old box into the space in the centre of the new one;
• Brush any remaining bees from the old box and floor into the new box;
• There should now  be flying bees returning home and the shaken bees should be creeping up the frames;
• Gently persuade the queen into the new box;
• Replace the crown board;
• Feed strong syrup;
• After about a week check that there is brood present and remove the queen excluder;
• Place it above the brood box and add a couple of supers.

If you are sure the bees are disease free you can distribute the brood to weak colonies but be careful not to overload them. Give emerging brood to the weakest – only give larvae and eggs to colonies that are strong enough to feed them. You’ll have to gauge that yourself!

If the bees have Varroa, EFB or bad Chalk Brood just burn the brood.

Shook Swarm for Disease

Certain brood diseases of bees such as AFB, EFB and chalk brood can be successfully treated using a shook swarm. However, always respect the laws of your country regarding bee diseases and if they say burn the bees – well, you’d better burn them.

EFB and chalk brood and to a certain extent – Varroa – can be treated using the method above but if you want to be sure to be sure – use the method below. It’s more or less the same as above but incorporates a brief starvation period during which time any disease propagules are either consumed or incorporated into wax. Either way they are removed from the bees.

This will only work on a strong colony. If the bees are already tottering with a huge amount of disease or if the queen is mediocre or if it is late in the year – don’t bother because you are wasting your time.

• Move your target hive of bees to one side;
• Set a floor in its place;
• Put a queen excluder on top of the floor
• Place a brood box with a full complement of frames kitted out with 2 inch starter strips of foundation on the queen excluder;
• Find the queen and place her out of harm’s way;
• Carefully shake all the bees, frame by frame, from the old box into the space in the centre of the new one;
• Brush any remaining bees from the old box and floor into the new box;
• There should now  be flying bees returning home and the shaken bees should be creeping up the frames;
• Gently persuade the queen into the new box;
• Replace the crown board;
• When all the bees have returned home in the evening – close the entrance with foam and move the entire hive into a cool dark place;
• Leave it there for two days;
• During this time the bees will empty the collective honey stomach and use it to build comb and to survive. Any spores and other disease propagules will be incorporated into the wax or voided by the bees;
• Drip-feed them a little syrup during this period if you fear they are starving of if you just can’t bear it;
• Burn the frames and blow-torch the brood box, crown board and floor;
• After two days place a new floor, a queen excluder then and a new brood box kitted out with a full complement of frames with fresh full sheets of foundation on the old site. Again you don’t want them to abscond;
• Remove the middle 4 frames;
• Bring back the poor bees from that cool dark place;
• Gently shake all the bees off the frames and brush the remainder into the fresh box;
• Replace the 4 frames into the centre;
• Replace the crown board;
• Release the bees;
• Feed them like mad;
• These bees should now be disease free;
• However, burn any comb and brood they have produced and blow torch all the old equipment;
• If there were supers – these should be disease-free unless the queen was allowed to get up there and lay in which case you should probably burn these frames also;

When dealing with infectious diseases always burn your gloves, torch your hive tool and don’t forget to scrub your smoker with a strong solution of washing soda and water.

Click here for more about Brood Diseases of honey bees

Click here for more about AFB

Click here for more about EFB

Click here for more about Chalk Brood

Copyright © Beespoke.info, 2016.  All Rights Reserved.

Monitoring Mite Fall

This involves counting the daily mite-fall by examining a greased slide placed below the mesh floor. It can be done once a week or every few days and the total divided by the number of days since the last count.

The National Bee Unit has an online Varroa Calculator – feed your data into it and it will tell you when you next need to treat.

Click here for the Varroa Calculator

Bear in mind that the daily mite-fall varies wildly thoughout the season depending on: how strong the colony, how much brood, how much drone brood, have you split the colony, has it swarmed, is it queenless not to mention the whether the weather…

Apart from counting the mites here are some other things to look for…

Signs of Grooming

The dead mites can be closely examined with a magnifying glass. If mature mites – dark reddish brown in colour – are found with bite damage such as missing legs or damaged carapace you can conclude that some grooming is happening. Don’t leave too many days between your counts or you may find yourself looking at Varroa corpses damaged by the generalist invertebrate detritivores that inhabit the dark cornersof the hive floor.

If you divide the number of bitten mites by the total number of mites and multiply by 100 you’ll have an idea of the percentage of grooming activity in your colonies.

Signs of Hygienic Behaviour

Signs of hygienic behaviour to look for would be bits of dismantled pupae and immature Varroa (small pale coloured). Click here for Illustrations

An indicator of possible generalist hygienic behaviour is Chalkbrood, or rather a lack of it in the brood nest when it is present in other colonies in the apiary.  Look for umpteen grey mummies on the floorboard and lack of it in the brood nest.

Measuring Hygienic Behaviour

It is possible to assess the level of hygienic behaviour in your bees by adding a frame of capped larvae which contains an area where all of the the pupae have been killed.

• You can either kill they by piercing them with a slender needle – sharp or crewel;
• Or if you prefer to live dangerously, get hold of some liquid nitrogen and use it to freeze-kill an area of pupae;
• Either way – mark the area and count the killed cells;
• Come back in 24 hours and count the number of cells the bees have broken into and removed the dead contents;
• Divide the total removed by the total killed and multiply by 100 to get your percentage hygienic behaviour.

A word of caution here – it is possible that the bees respond to different cues with these tests. Just because they are acutely aware when a pupa has been lanced or frozen doesn’t necessarily mean they would notice when a Varroa laid an egg in a sealed cell.  It would give you an idea of general hygienic behaviour but not necessarily Varroa Sensitive Hygiene (VSH) which is different.

Again this is time consuming.

Icing Sugar Test

For most stand-alone beekeepers – the bottom line is how many Varroa are in the hives at the end of the active season after the honey has been removed and before the bees are treated.

If this can be determined, it is possible to make a decision about whether to treat or not to treat. A relatively simple test is the icing sugar test.

By the way, if you are going to do this – only test hives that have not been treated since the spring. Also – did you split them during the year because this could have a bearing on the count.

Here’s how it’s done anyway…

Materials

• A big plastic bucket suitable for shaking bees into;
• Plastic beaker with 300ml level marked;
• Perforated cap to fit or a bit of net curtain with holes smaller than bees but bigger than varroa and a rubber band;

• If you sign up to help NIHBS and NUI Galway find the Varroa Resistant Native Irish Bee you’ll get a free, custom made beaker like this one above. Details here: http://nihbs.org/wp-content/uploads/2013/09/Breeding-for-Varroa-Resistance-in-Ireland-Final.pdf
• Icing sugar;
• A tablespoon;
• A white plastic bucket with water innit.

Method

• Find your queen and isolate her;
• If you can’t find her, take a frame from the centre of the brood nest and make sure she’s not on it;
• Shake the bees off the frame into the bucket;
• Scoop 300mls of bees into the plastic beaker and put the lid on;
• Shake in a tablespoon of icing sugar through lid;
• Tumble the bees around till so they are well coated;
• Leave them alone for 5 minutes;
• Tumble them around gently for a count of ten then;
• Get your white bucket with water innit;
• Invert your beaker over it and shake till no more Varroa fall out;
• Count the Varroa – they show up very well against the white bucket;
• Divide the number of Varroa by 3 then, if there is capped brood, multiply by 2 and that’s your percentage infestation. If there is no capped brood don’t multiply by 2, just divide by 3.

The people from Galway tell me this test, although indirect, is a very accurate measure of how many Varroa are in the actual hive.

Their advice regarding treatment is that if there are 2 or less mites per 300ml of bees you probably don’t need to treat but if there are 3 or more you should treat.

Bond Method

The Bond Method seems to have evolved in Germany. The name derives from the James Bond film Live and Let Die. Dr. John Kefuss is a scientist and commercial beekeeper who lives in France and who has decided for one reason or another that treating for Varroa is a fools game. He took a calculated plunge and stopped treating his bees. He had thought long and hard about it and was prepared for a 90% loss so was pleasantly surprised to lose only 60%.

That might seem catastrophic but since then he has bred from the survivors using ‘caveman genetics’ and is now back to full strength. However, he now no longer treats – AT ALL.  He loses on average 15% per year but this is not out of line with his neighbours who do treat.

As somebody who lost 50% of her bees in the endless winter of 2012-13 I know a bit about losing lots of bees. 50% is catastrophic but I was back up to full strength again by the end of that year. You know yourself – bees really go for it when they can.

While it may seem very drastic to allow your bees to be decimated in this way it should be borne in mind that not only are the bees decimated but the most virulent strains of Varroa are decimated also. Virulent strains are failed parasites if left to their own devices because they take so much from the host, the host dies and the parasite dies with them.  As long as we blanket-treat all our bees we are helping these strains to survive.

When you stop treating your bees, eventually you are left with the most capable bees and the least capable Varroa

But this could take years. Here’s a way of speeding it up.

Bond Accelerated Test (BAT)

This method was devised by John Kefuss. It is where the Bond selection method is speeded up by adding frames of infested brood to survivor colonies. The effect is to accelerate the selection process – killing out non-resistant strains of bees more quickly – 6 months rather than 3-4 years. You need a heart of stone for this stuff – but that’s science for you.

Soft Bond Method

This method is a variant of the above method for those who lack the nerve or the confidence or the sheer numbers of bees to try the hard versions. It involves selecting a portion of your stocks to experiment with and say to yourself ‘I could afford to lose this lot’ – accept it and carry on.

Here are John Kefuss’s Soft Bond Method Instructions for Big Beekeepers:

Procedure for the selection of up to 20 breeder queens from an apiary of 500 (!)

• From the initial group of 500 hives, select the 100 best producing colonies;
• On those, perform 24-hour hygienic tests;
• Select the most hygienic 40 for Varroa count;
• Spread this breeding material by rearing daughters and requeening in all bee yards to produce selected drones;
• Leave the best 20 of the selected hives without treatment – the Bond Test to produce breeder queens.

There now – gird up your loins.

Soft Bond Method for Small Beekeepers

For those of us with too many colonies to count mites and not enough to do a full Bond or BAT test here’s something we can do.

• Use the Icing sugar method above for as many of your colonies as is practical;
• Resolve to count and examine mite-fall in the best of these next year;
• Add all of this data into your Colony Assessments and Colony Appraisals and use all the data to select queens to breed daughter queens and colonies to raise drones;

Click here for more on Colony Assessment

Click here for more on Colony Appraisals

• If you have the nerve – stop treating the best of them and see what happens;
• If you don’t have the nerve or the numbers of bees to play with, then at least get in touch with NIHBS and join the Ireland Varroa Monitoring Programme.

Click here for more about Grooming and Varroa Sensitive Hygienic (VSH) Behaviour

Copyright © Beespoke.info, 2015.  All Rights Reserved.

Grooming

Grooming is where adult bees learn to detect and remove Varroa from themselves and from each other. They then destroy the mites by biting them.

Hygienic Behaviour and Varroa Sensitive Hygiene (VSH)

Hygienic behaviour is complicated. Generally, it is the ability to detect and remove diseased or dead brood. The diseases include American Foulbrood and Chalkbrood as well as Varroa although the precise trigger mechanisms must vary with the different diseases. When the disease is Varroa – the trait is known as Varroa Sensitive Hygiene or VSH; the activities are Varroa-specific and something of a conundrum.

Varroa Sensitive Activities

Egg Detection

One hypothesis was that VSH bees are somehow able to detect Varroa in the cells only where foundress female has begun to lay eggs!

The reason for this is that studies of VSH bees where cells were uncapped and the contents examined revealed sterile female Varroa are left in-situ and the cell contents are not removed.

How bees can detect the egg-laying act is open to speculation – although it is thought there is a smell. There might be a noise though! Perhaps the sort of noise that accompanies a stubbornly drawn cork. Whatever it is – when VSH bees detect it, they open the cell and evict the contents including the Varroa, her eggs and the poor wrecked pupa.

However, further research has found that there is more to it than that.

Neurotic Behaviour

It turns out that worker bees, both VSH and non-VSH, habitually uncap and recap sealed brood – why they do this is not known but the frequency varies from colony to colony. Perhaps they’re just checking on the health of the pupae – like anxious mothers peeping in at the cradle.

But where VSH bees are different is the both frequency of uncapping and the size of the hole they make. They make a big hole and they do it often. These aren’t just anxious mothers – these are completely neurotic mothers! Not content with cradle peeping these girls whip the blanket off on a regular basis and give baby a good poke while they’re at it. Obsessive it may be but it is an activity that appears to disrupt the egg laying of the occupant Varroa foundress to such an extent it may cause her to become sterile.

Toilet Training

Here’s a quirky one – Varroa foundresses establish safe defecation sites within the cells. The reason for this being that if they defecate directly onto the pupae they are rendered sterile! There now – that’s what evolution does if you don’t learn to use the lavatory.

Click here for more on that and Varroa reproductive biology

Evolved Resistance

Because Varroa is such a recent pest on Apis mellifera, the bees have to learn how to cope with them and to learn, they need to be exposed to them; they need to be rubbing shoulders with them on a regular basis.  Like Apis cerana they have to learn to live with them because they ain’t going away.

Perhaps we beekeepers are doing the bees a disservice by trying to remove all the Varroa. Instead perhaps it would be better in the long run not to treat and allow the bees to adapt.

It’s harsh though – could you do that? A Varroa infested colony is not a pretty sight…

Click here for How to Breed Varroa Resistant Bees

Copyright © Beespoke.info, 2015.  All Rights Reserved.

The first spring inspections of 2015 have been a bit of a shock. Not that I’ve had many losses – only about 5% – and the cause seems to have been queen failure (Click here for guidance on how to conduct a post mortem). The rest are mainly good and strong heading into the summer.

However there are problems out there…

I treated all of my bees with MAQStrips after taking the honey off at the end of summer last year (2014) and following the instructions to the letter because that’s what this Pedant does. Now it must be said that most of my bees are in fine fettle but in some apiaries I am finding a lot of deformed wing virus (DFW) and more alarmingly – Varroa scuttling about on the comb and clusters of them in the drone brood. Shock horror.  So now I am on the horns of a dilemma – do I use MAQS again bearing in mind that it doesn’t seem to have worked in the first place or do I apply Something Else and foul up an early flow?

I should add that this was the second time I’ve used MAQS. I first used them at the end of 2013 on bees I brought home from the heather and it was a great big 100% success.  So I had great expectations that we had finally found a Varroa treatment that was both easy to apply and efficacious in its actions.

So, what is happening out there?

If anybody has any ideas I would be very interested to hear them. Answers on a postcard or on this here comment form below.

Copyright © Beespoke.info, 2015.  All Rights Reserved.

Oxalic acid is a very effective treatment for Varroa but only during broodless periods when the kill rate can be above 90%. When brood is present the kill rate is closer to 30% as most of the Varroa are in the brood where this acid cannot reach them. Click here for more on oxalic acid.

For this reason oxalic acid tends to be used during the mid-winter broodless period – if there is one!

However,  winter is not the only time bees are broodless and oxalic acid can also be used during summer broodless periods when the Varroa are phoretic (out and about on the bees).

Summer Treatment

Imagine a swarm…

Technically, that swarm is Varroa-free. Note I say ‘technically’ – because there are of course a few Varroa present attached to the flying bees but most are left behind sealed in the brood or creeping about on the comb and on the young bees.

This point accepted then you can deal with the other half when all the brood has hatched three weeks later. If you treat with oxalic acid at this time, before the new queen starts to lay, you can expect a spectacular knock-down of mites.

These conditions occur each time you allow a swarm to get away or when you perform an artificial swarm. An oxalic treatment can thus be incorporated into your artificial swarm routine at, or shortly after day 21. Click here for detailed artificial swarm instructions.

However, regard must be given to the possibility of honey contamination.

Taking Precautions

Oxalic acid is a natural constituent of honey. The concentration varies depending on the botanical origin of the honey but it is at levels that cause no harm to humans and experimental work has shown there is no significant increase in honey due to spring or summer oxalic acid Varroa treatment (Rademacher &Harz). And they must have had their supers on.

Now imagine your way through an artificial swarm…

After you have moved the original box to the opposite side and it loses that second cohort of flying bees it simply doesn’t have the ‘man-power’ to be putting anything into supers. It doesn’t need supers so move them to the parent stand at least for a couple of weeks until the new queen starts to lay. If it is short of stores in the meantime – feed it.

Because oxalic acid has hydrophylic or water-loving properties, it is thought unlikely to accumulate in wax either (Rademacher &Harz).

Trickle or Vaporise/ Sublimate?

I prefer the trickling method, especially for summer, as this allows you to tailor the dose according to the strength of the colony ie only trickle active seams of bees and if they are particularly weak give only 2mls of a 3.2% solution per seam instead of 5mls if they are strong. Click here for oxalic acid recipe.

It is less easy to tailor the dose if you are vaporising.

Snelgrove Boards

If, like me, you use Snelgrove boards then oxalic acid can be incorporated into methods 1 or 2 at day 21 as above but it might be an idea to temporarily cover the metal grille throughout the treatment.

Click here for Oxalic Acid for Beekeepers

Click here for Winter Oxalic Acid Treatment

Click here for more on Snelgrove

Click here for pictures and how to make your own Snelgrove board

Click here for Varroa Floor Flaw

Click here for recipes for both concentrations and instructions.

Click here for pictures and how to make your own Snelgrove board

Sources

Aliano, N. An Investigation of Techniques for using Oxalic Acid to reduce Varroa mite populations in Honey Bee Colonies and Package Bees. (2008) University of Nebraska

Nanetti, A., R. Büchler, J.D. Charrière, I. Fries, S. Helland, A. Imdorf, S. Korpela, and P. Kristiansen.  Oxalic acid treatments forVarroa control (Review). (2003) Apiacta 38: 81-87

Rademacher, E.R & Harz, M. Oxalic acid for the control of Varroosis in honey bee colonies – a review. (2006) Apidologie 37: 98–12

Rashid, M, Wagchoure, E.S., Mohsin, A.U., Raja, S., Sarwar, G. Control of Ectoparasitic Mite Varroa destructor in Honey Bee (Apis mellifera. L.) colonies by using different concentrations of Oxalic acid. (2012) Journal of Animal and Plant Sciences, 22(1): 72-76

Copyright © Beespoke.info, 2014. All Rights Reserved.

It affects Varroa directly and indirectly. Directly – the acid damages their  mouthparts. Indirectly – it increases grooming activity between bees and more Varroa are dislodged in the process.

Also…

• The mites seem unable to acquire resistance to it;
• It doesn’t accumulate in beeswax;
• Doesn’t harm the bees;
• It is an organic remedy;
• And a harmless natural component of honey.

But there’s more…

A little bit of chemistry

Oxalic acid is an organic acid also sometimes known as ethanedioic acid. The chemical formula is H₂C₂O₄  which means there are 2 hydrogen, 2 carbon and 4 oxygen arranged as per this diagram:

The carbons form the spine of the molecule. They are each attached to the other and to an oxygen (O) and a hydroxide (OH or HO) group. It is usually sold as oxalic acid dihydrate in which case two additional water molecules are also involved.

Oxalic acid in nature

Oxalic acid is present naturally in many plants but most famously in the leaves of rhubarb (Rheum rhabarbarum),  and wood sorrel (Oxalis acetosella) and common sorrel (Rumex acetosa).  Rhubarb stalks are edible but we all know from our Mothers that the leaves are toxic. However, it seems we would need to eat around 5kg of leaves to get a lethal dose but it does interfere with calcium uptake so be careful all the same.

Here’s Rhubarb:

And as for wood sorrel, you will recognise it from spring woodlands. Next time you see it – pluck a leaf and eat it – lovely in salads but don’t eat too much. Here it is:

Common sorrel is edible too. It is a member of the dock family but the leaves are smaller and shaped like arrowheads.  The flavour is acidic, green and intense – nice in salads and I bet it would make an interesting pesto. It looks like this:

It is also in honey!

Oxalic acid is commonly present in many other plants too so it should come as no surprise that it is a constituent of most honeys.  Concentrations in honey vary depending on the botanical origin of the nectar of course – in the region of 3.3–761.4 mg/kg.

Values for honeys we are familiar with in this part of the world are as follows:

• Wildflower honey 8–51 mg/kg;
• Heather 48–151 mg/kg and 85.5–168 mg/kg;
• Oilseed rape honey 13–53 mg/kg;
• Generally honey contains < 200 mg oxalic acid/kg honey.

Toxicity to humans

• It is not a carcinogen;
• It is extremely corrosive and will cause burns to eyes, skin and respiratory tract;
• It may cause kidney damage;
• May interfere with calcium uptake;
• It has been reported that the lethal oral dose is 15 to 30 grams.

Click here for Oxalic Acid Safety Data sheet

Miticide nitty-gritty

Oxalic acid is only useful against Varroa when there is a broodless period in the honeybee colony and the mites are phoretic. ‘Phoresis’ is a distribution phase in the life of a parasite when it is out in the open and moving about on the host. Otherwise the Varroa mites are safely inside the sealed honeybee brood where the oxalic acid cannot reach them.

Broodless periods occur naturally thoughout the year:

• During mid-winter quiescence;
• In summer after a swarm there is a broodless period before the new queen starts to lay;
• After day 21 of an Artificial Swarm;
• If you use Snelgrove boards it can be incorporated into either of Methods 1 or 2. Click here for L.E.Snelgrove book review;
• Queenlessness.

Oxalic acid can be used effectively during any or all of these periods.

Although oxalic acid concentrations in honey do not increase significantly when bees are treated it is best to remove supers during treatment if treating during summer.

Oxalic acid can be applied in different ways:

• Vapourising or ‘sublimation’ method
• Trickle method

Vaporising / Sublimation method

For this, a Varrox vaporiser is required. Basically it is a little pan on a stick attached to a power source.  Oxalic acid is placed in the pan and inserted through the hive entrance. The hive is then sealed, the power is turned on and the little pan heats up and the acid is vaporised in the hive. The bees seem unconcerned but the mites drop like flies. This is more suited to winter application.

Click here for more details on winter vaporising.

Trickle method

For the Trickle method, much research has been carried out to determine the concentration of oxalic acid that will kill most mites while causing least damage to the bees. The consensus, for this part of the world anyway, is 3.2%. Personally I have been using 3.3% for about 10 years with no observable ill-effects.

Click here for recipes for both concentrations and instructions.

Click here for Winter Oxalic Acid Treatment

Click here for Summer Oxalic Acid Treatment

Click here for more on Snelgrove

Click here for pictures and how to make your own Snelgrove board

Click here for Varroa Floor Flaw

Sources

Aliano, N. An Investigation of Techniques for using Oxalic Acid to reduce Varroa mite populations in Honey Bee Colonies and Package Bees. (2008) University of Nebraska

Nanetti, A., R. Büchler, J.D. Charrière, I. Fries, S. Helland, A. Imdorf, S. Korpela, and P. Kristiansen.  Oxalic acid treatments forVarroa control (Review). (2003) Apiacta 38: 81-87

Rademacher, E.R & Harz, M. Oxalic acid for the control of Varroosis in honey bee colonies – a review. (2006) Apidologie 37: 98–12

Rashid, M, Wagchoure, E.S., Mohsin, A.U., Raja, S., Sarwar, G. Control of Ectoparasitic Mite Varroa destructor in Honey Bee (Apis mellifera. L.) colonies by using different concentrations of Oxalic acid. (2012) Journal of Animal and Plant Sciences, 22(1): 72-76

Copyright © Beespoke.info, 2014. All Rights Reserved.

The two most serious brood diseases are American Foul Brood and European Foul Brood and these strike fear in heart of all beekeepers but we’ll deal with them later.

Here is a table of the less serious brood diseases. Click it for a bigger picture.

To avoid all of these, keep the bees strong with good queens. If you allow a weak queen or a drone layer to continue, the colony will become enfeebled and diseases like these can set in.

Chalk brood is the most commonly seen here and unless there is more than about 10% of brood affected then it’s not really a problem – a bit like having dandruff or athletes foot. It tends to be bad in a wet summer, being a fungus it likes the damp so keep stocks strong. Stand hives well above ground level and keep vegetation down to allow free movement of air.  Otherwise – requeen with a resistant strain.

Chilled brood can always be prevented. Don’t rob a hive of too many bees when making up nucs and don’t go adding great slabs of brood from a very strong hive to try and build up a weak one unless they have enough bees to keep it warm.

Black Queen Cell Virus has been more common lately. Again keep stocks strong and avoid stress which can bring on Nosema. Keep Varroa levels low.

Click here for Shook Swarm Treatment

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Trickle treated 35 hives of bees with oxalic acid for Varroa today at 4 apiary sites. The temperature was 6 degrees, windy and beginning to rain. It took from 1.15pm to 4.15pm including travelling time so it has to be said it is the quicker of the two methods. If we had only the one Varrox Vaporiser it would have taken 10 minute per hive – which is nearly 6 hours and without the travelling time.

It has to be said the bees were not pleased to see us. It also has to be said that they are still very well stocked with stores. Most of them were on double boxes or one-and-a-halfs and because they had so much stores they were well down in the boxes so that was a bit of a dilemma: either you disturbed them more by separating the two boxes or you took a gamble and trickled from on high. We did some of each. I’d say the hive is open for no more than 1 minute each if you’re organised and have everything ready.

The only other thing to say is that there was very little problem with brace comb but then we have most of the bees on double boxes or 1.5’s – perhaps with that extra space they don’t feel the need to pack the space between the top bars and the crown board.

We must have found at least 8 hibernating queen wasps and often – stangely enough or perhaps not – 2 per roof – common wasps I’d say, going from the marks on their faces.