2011 varroa levels

[Jon]

I started treating colonies around mid August with Apiguard and have seen hardly any mites dropping. Other years I have had a drop of 150 in the first 24 hours from some colonies. This year I am seeing just a few mites on the boards I have examined.
Anyone else seeing lower than usual varroa levels? Last season's treatment was Apiguard in September and Oxalic in December.

[gavin]

Had been going to leave the smaller colonies still down here, but I'm now persuaded to treat (Apiguard) having seen the thymol-induced knock-down on a friend's colony that hadn't been dropping mites without treatment. The stronger ones in the hills pose a bit of a problem as they cannot be treated yet - maybe in a week or so.

Does your paucity of mites also apply to the big booming colonies that raised lots of drones?

[Jimbo]

Just started treatment. Last year used Apiguard and Oxalic. This year so far the natural drop has been very low but I treated with Thymol Crystals in alcohol anyway and after a week counted only 30 mites but will treat again with Oxalic in December. Our club apairy colonies which have been treated with Bayvarol strips have had a low drop as well. Where are all the varroa?

[Jon]

Does your paucity of mites also apply to the big booming colonies that raised lots of drones?

I am not seeing significant numbers of mites in any colony, just like Jimbo's observations, only a few dozen here or there after treatment has started.


Where are all the varroa?

That's what I was wondering.
I don't like to tempt fate but my bees have been really healthy and vigorous all year.
Maybe we started with very low levels of varroa due to the effectiveness of Oxalic and that severe cold spell.
Colonies must have been 100% broodless for quite a while.

[Adam]

Low mite levels for me too. :) I treated with Apiguard at this time last year and Oxalic Acid between Christmas and New Year. Just before treatment last year I did see some deformed wings indicating that the varroa were starting to have a deleterious effect on bee health. This year I have seen just one bee with deformed wings.

I had external inspections from the bee inspector and also for my General Husbandry certificate this year and comments from both visitors that they were 'pleasantly' surprised that there were no varroa in the drones that were ripped out.

For you guys further North than me with a longer broodless period in winter, Oxalic Acid should be a more effective treatment than it is for us Southerners.

[Jon]

Oxalic Acid should be a more effective treatment than it is for us Southerners.

And it costs under 10p to treat a colony whereas other treatments such as Apiguard, Apistan and Bayvarol cost over £3.

[Neils]

mixed bag here. I've had my "best" colony really struggle with varroa this year. My best (non honey producers) have been swarms that have been treated with OA before they established brood.

As an ongoing, low cost treatment, I think I disagree with Jon about icing sugar. I think it has its place, is effective in isolation and if you understand its weaknesses. It is not a replacement for thymol or oxalic acid nor is it a treatment to be used in isolation, but I feel that it is not to be discounted either.

All that aside I have to say that our varroa levels have been a mixed bag, if you run an apiary with other people you MUST run treatments at the same time, agree an IPM and so on. There is no point putting OA on one swarm and not on another, putting Icing sugar on some and not others.

I..We've screwed up this year, we both have bees that are struggling with varroa. If there's a plus side, we've identified the colonies not to raise queens from. We've tried, as much as possible to be hands off, while still treating, and we're obviously not doing enough.

I still recall gavin's post from two years ago and I have bees from that queen so it remains a possibility, but we all take queens from survivors?

Varroa are evil little buggers, you can play, you can try not treating, or just treating enough, but it's a sad, sad sight to see a colony struggling for the sake if having given them a dose of OA. I have bees in the latter. If they live I'll requeen them in the spring but I failed, I made a colony suffer because I knew better and that does make me hurt. I know it's a box of bugs but it pains me to see them struggle when I could, should have sorted them out when I had the chance.

[gavin]

I still recall gavin's post from two years ago and I have bees from that queen so it remains a possibility, but we all take queens from survivors?


I'm touched! I remember it too. We probably all have pieces of that jigsaw in our bees. Varroa Sensitive Hygiene (excavation of infested brood), grooming and biting of mites, and other things that give resistance.

As for powdered sugar, well, it will knock down some mites but however appealing the method sounds it is of very low efficacy. Those beginners who are being encouraged to adopt it as a main treatment are heading for the loss of their bees and that is sad and unnecessary.

Varroa increase -

Approximate monthly increase in worker brood during the active season: 100%

Approximate monthly increase in drone brood during the active season: 300%?

Against which there will be a small natural mortality rate, and maybe a larger one imposed by some bees.

Varroa decrease with powdered sugar -

Mites protected in sealed cells during treatment: 70%? (Guessing)
Knock-down rate of mites on adult bees: 30% (Real data, many are clamped on)
Mites lost on each sugar treatment: 30% x 30% = 9%

So, if that is anywhere near right, even *weekly* powdered sugar treatments (and who can manage that) can't keep up with the expected multiplication rate. The Ellis et al study showed that fortnightly treatment made little difference to the mite build-up.

*Maybe* if you have bees that are resisting the mite themselves, or some other factor is suppressing their build-up, that small help that powdered sugar gives matters. But usually it will not.

This year Jon could have been trying dowsing round his apiary (it disorientates mites, don't you know, and they fall off onto or through the floor!) and would have shown that it is effective as a Varroa treatment because of his low levels. Point me to proper controlled trials that show that the effect of powdered sugar is good enough to hold mite populations down and I'll listen. Tell me of folk that tried it and say that it seemed to work for them, and I'll keep telling folk that 9% efficacy is not enough.

Feel free to come up with a better figure than 9% if you can.

Gavin

[Jon]

This year Jon could have been trying dowsing round his apiary (it disorientates mites, don't you know, and they fall off onto or through the floor!)

Nah! I'm going to make an effigy with a willow twitcher in the scary form of Roger Patterson and that should drive the mites from my colonies like the rats from Hamlyn.
Might even give it a penny whistle.

Nellie, I still believe icing sugar is placebo - makes the beekeeper feel good due to being proactive.

Gavin, I have always read that 80% of mites are under cappings at any given time so your estimate should maybe be nearer 6% than 9%.

[madasafish]

I treated this year 8 colonies with thymol mix. Very low drop before - (under 2/day) from each hive: during treatment less than 20/day. Last year my 2 colonies had hundreds drop.

Did not use oxalic acid in winter, no sugar icing (more work for little impact in my view) but did 2 x artificial swarms this year which will have knocked levels down...

(All TBHs or warre.)

Largely same with Association apiary's 13 hives.

[Neils]

Absolutely not suggesting that Icing sugar is suitable as a main treatment nor that is terribly effective in isolation and I think if you start using it you pretty much have to keep using it every inspection throughout the season AND THEN TREAT with something effective.

I'm tyring to find the link for it, but I read a report suggesting that the lower the mite count the more reproductive varroa become.

But I do still believe that Icing sugar has a place if nothing else because I watch our ex inspector use it gauge mite levels on bee samples. Stick bees in jam jar, cover in icing sugar, shake them around a bit and see what drops off.

But let's be absolutely clear here I am not suggesting that icing sugar, in isolation, is a suitable control for varroa any more than having an open mesh floor is varroa control but it has its place as part of an IPM scheme. Whether you judge it to be worthwhile is a different question.

[gavin]

Never mind, you gave us an excuse to have a wee rant there. Members of my local association will recognise that need to vent about inappropriate reliance on ineffective methods.

Using icing/powdered sugar to assess the population of mites is fine by me. It was one of the recommended methods on the Varroa mapping (http://www.sbai.org.uk/varroamapping/) page.

[The Drone Ranger]

I think generally it's a good idea to give different treatments a try.
I don't hold out much hope for sugar dusting (and it's a bit messy) it's gentle on the bees though
I also haven't much faith in spaying on lactic acid -
One year I was collecting varroa from the floors in winter and examining them under a microscope to see if they still had oxalic acid crystals on their bodies ( I was trying to work out the best timing for second oxalic evaporation treatment)

Anyway after counting the drop the floor sweepings were stored for 8 days before I got round to checking some of them for crystals and I still found varroa which were alive after getting the first oxalic treatment and lying on an insert in sub zero temps for 5 days. (cold probably helped survival)

So I took a couple of survivors and put a couple of drops of lactic acid (as sold by Thornes) on the slide -- 2 Hours later they were still wiggling their toes at me and not being a torturer by nature I gave up and squashed them.

What frustrates me, is after I have knocked myself out year after year trying to kill off varroa, someone pops up claiming the moral high ground saying they are breeding for resistance (usually followed by the question have I any bees for sale ?? -- two word reply ---unprintable)

The argument that the natural resistance will appear is illogical
If that really worked then people in areas where malaria is prevalent would sensibly be protected by a very thick skin
In fact natural selection at a cellular/immune system level, results instead in Sickle Cell Anemia--itself a killer.
Varroa have a much more adaptable breeding model as far as natural selection goes (many mothers, inbreeding, mutation etc)
You are more likely to breed a more benign varroa than a resistant bee.

[gavin]

You are more likely to breed a more benign varroa than a resistant bee.

If there was a mechanism to support the individual mild mite in a population of aggressive, multiplying ones. The idea that whole colonies of bees with non-aggressive mites is the ideal doesn't account for the mite-to-mite competition that must take place all the time.

G.

PS Mite tolerant bees exist, no question. Maybe they are not good enough, but they are there.

[The Drone Ranger]

If there was a mechanism to support the individual mild mite in a population of aggressive, multiplying ones. The idea that whole colonies of bees with non-aggressive mites is the ideal doesn't account for the mite-to-mite competition that must take place all the time.

The theory is aggressive virile mites kill the colony and less productive slower reproducing weaker mites don't

As you say Gavin
"Mite tolerant bees exist, no question. Maybe they are not good enough, but they are there."

That's the hygenic gene theory of mite control.
That's fine in principle and 75 years ago the same mechanism was supposed to be going to eradicate foulbrood (as I wrote in SBA mag last month)

If I walked out to my garden now I could photograph a rabbit in the middle of the lawn , its eyes are puffed and closed its breathing wheezy. It is suffering from the effects of myxomatosis.
Most likely a flea bite introduced the virus and what we see is death by secondary infection , pneumonia etc.
The rabbit may survive 10% certainly do because they have some resistance but they are weakened damaged often sterile and have a much reduced lifespan.

In the SBA mag Eric MacArthur and others often quote this so called resistance to myxamatosis as an example of how bees will develop resistance to varroa.
Well that rabbit has fleas it hasn't learned to get rid of them and it most likely never will. It's obvious to us the problem is the fleas but to the rabbit's defence mechanisms the problem is virus.

Bees which have some resistance to varroa may well be useless in every other way and it doesn't confer on them the ability to resist virus and other disease in fact they could be weakened and more vunerable.

[Jon]

The theory is aggressive virile mites kill the colony and less productive slower reproducing weaker mites don't

That's the theory, but it doesn't really stack up. if you have fast reproducing and slow reproducing mites in a colony the fast reproducing ones will soon dominate.
If the colony starts to collapse due to mite load it will be robbed out by neighbours and the mites will hitch a lift elsewhere.
Slow reproducing mites could coexist with bee colonies if there were no faster reproducing mites present but I cannot see how a situation could arise where faster reproducing mites disappear.

[The Drone Ranger]

That's the theory, but it doesn't really stack up. if you have fast reproducing and slow reproducing mites in a colony the fast reproducing ones will soon dominate.
If the colony starts to collapse due to mite load it will be robbed out by neighbours and the mites will hitch a lift elsewhere.
Slow reproducing mites could coexist with bee colonies if there were no faster reproducing mites present but I cannot see how a situation could arise where faster reproducing mites disappear.

Totally agree with you on that Jon in fact any of the theories of how the bees can defeat the mites without help seem weak to me.
I personally think everyone should try to remove as many mites as they possibly can.
We don't wait for the cat to develop a strategy for dealing with fleas we treat the cat's fleas by sterilising them for the benefit of the cat (and ourselves)

[Jon]

Totally agree with you on that Jon in fact any of the theories of how the bees can defeat the mites without help seem weak to me.
I personally think everyone should try to remove as many mites as they possibly can.

I agree, but it is worth keeping a close eye on colonies which seem better able to coexist with mites for whatever reason. VSH, more effective grooming or something else. I don't see any magic bullet though. The Russian (Primorski) strain has coexisted with varroa for about 150 years and has developed some resistance.
The 'right on' no treatment people are just killing bee colonies with no possible benefit as resistance is highly unlikely to arise in this way.
On the Irish list Dan Basterfield memorably likened the no treatment strategy as being akin to dropping babies off a bridge with regard to what it tells you about ability to cope.
My Apiguard treatment is just about finished and I will do an oxalic acid treatment after the first decent cold snap in December.
I cannot believe the low mite fall I am seeing this year, just a few dozen it seems although half my colonies are on solid floors so I don't have an insert tray to monitor.

[The Drone Ranger]

Lots of people seduced by the "lets breed for resistance" bandwagon have learned the hard way and abandoned that strategy which is better for everyone.

It doesn't take that many people to drop out of the measles vaccine program to get a serious outbreak.

[Jon]

I think any breeding for resistance should be a gradual thing rather than some kind of cold turkey treatment.
I don't think it is futile at all but I think it needs to be carefully thought through.
The non-treaters imagine that 50% of their colonies will survive and breeding from survivors will lead to more mite resistant bees.
Nice theory but not grounded in reality.
The thing is, survival is more likely to be 5.0%.or 0.5% than 50% and you would need to be starting with a very large number of colonies and be prepared to lose most of them in the short to mid term.
You only have to read biobees.com to get an idea of how many people are losing their bees over and over again, including most of the gurus.
Groundhog beekeeping.
I don't know how they keep the faith in the face of such catastrophic losses.
It must be the ranting against Bayer and the neonicotinoids which keeps them going as it sure ain't the beekeeping success.

[The Drone Ranger]

Alan Teal said much the same thing in an Email to me a couple of years ago when I suggested the SBA mag was leading beekeepers up a blind alley by printing so many articles suggesting non treatment was a route to resistance.
He was SBA president at the time I think ? he gave me his formula for thymol treatment so I'm pretty sure he treated his own bees but still believed the principle of letting the bees die would lead somewhere eventually.

Things went from bad to worse with a certain contributor encouraging the release of swarms which once they were feral bees would breed resistance ????
How the -### is that supposed to work ??
You can't keep them alive in a protected environment but they are going to become super bees left to their own devices ?

[Jon]

Ferals have a chance if they are well isolated from other bees as you don't get the problems associated with drifting and robbing and cross transfer of mites.
Letting hives swarm themselves into oblivion with a view to establishing feral colonies is an exercise in futility.

I must read the Arnot forest (http://www.beesfordevelopment.org/uploads/seeley_apidologie_2007(38)19-29.pdf) paper again as it looked at a lot of this stuff.

[The Drone Ranger]

Most of the crazy ideas about resistance and feral bees are all in "Breeding Better Bees" Milner and Dews which is a BIBBA book.
Somebody should revise that text before it leads anyone else up the garden path.

'http://biobees.libsyn.com/interview-with-murray-mc-gregor

here's a link from the site you mention its an interview with Murray MacGregor about the Carniolans he is importing.

Gavin gets a mention

[Jimbo]

To go back to the low mite numbers dropping after treatment. A comment was made by Willie Robson in his talk at the Conference in Perth that this year he was seeing low mite numbers in his colonies. This was the first time he had observed this but did not have an answer. This is from a commercial beekeeper who runs hundreds of colonies. Other hobby beekeepers are seeing the same low drops but others are still getting large drops after treatment. My money is on last years cold winter weather. Any other ideas?

[The Drone Ranger]

Could be Jimbo lots more people are using Oxalic as a winter treatment now and very few are relying on the apistan strips
Did he mention his treatment program ??

[Neils]

I think the combination of autumn treatments and OA might have more to do with it. I've not applied a winter OA treatment for the past two years and we're definitely starting to see the mite counts increasing. Yes Thymol knocks a good number of them down, but this year is the first that we've seen colonies showing signs that they aren't coping very well with the varroa.

That pretty much knocks a lot of the sit back and see how they get on approach, from my point of view, on the head. The short answer is that they don't cope. The difference between the colonies in residence compared to the swarms that were all dosed with OA on arrival is pretty stark. I haven't completely discounted that we have a bunch of "won't treat" keepers on the allotment now as well which might account for some of the issues, but taking a longer term view I'm more inclined to point the finger at not using OA.

From the point of view of leave them be and raise new colonies from survivors all the people I've seen have any success taking that approach have one thing in common, they all started with 100+ colonies and lost 95%+ of them to get to a stage where they had survivors to try and raise from and are in relative isolation so it's no surprise that people on the hobbyist end of the scale with 1-10 hives find they end up with none in a short space of time.

I think you could take the approach, as I'm inclined to, that the colonies that have obviously struggled this year go into the 50% of colonies that I'll look to requeen (I'm using Roger Patterson/BIBBA's 50-50 scheme for now to determine which colonies I'll raise queens from). I'm not suggesting for a second that the rest are Varroa tolerant to much greater degree, but they haven't struggled as obviously as the others despite having the same IPM regime. I wouldn't raise queens from a colony that appeared susceptible to ChalkBrood so I don't see any real harm in not raising queens from colonies that appear to struggle with varroa despite treatment.

[gavin]

Any other ideas?

1. Summer populations of bees high, stocks healthy, weather induced staying at home, boredom, might as well pick off the mites.

Or (/and)

2. Some unseen pathogen of Varroa sweeping the land, maybe a virus. (smaller fleas on fleas' backs idea)

I do like guessing.

Maybe ....

3. Such a terrible year for queen mating, so lots of colonies had an extended brood-free period during which the mites died off or were kicked/dragged/carried out.

[gavin]

You're talking a deal of sense Nellie. One thing though, I know a beekeeper with about 20 colonies who has survivor stock that is doing quite well. He is in a relatively isolated area with feral colonies to keep him company and a few colonies kept by a few beekeepers. And what about Pete Haywood's experiences with Welsh beekeepers around him, as discussed on the Irish List?

That feral colony enthusiasm you mentioned DL partly comes from the enthusiastic SB article writer seeing these apparently resistant bees for himself. It was naive of course (very) to try to encourage the spread of swarms through suburban Glasgow, but perhaps, in isolated areas where genetics can get to work, feral colonies help. It could be that they are less liable to collapse than colonies in apiaries and so are a better vehicle to increase the right genetics gradually. If there are lots of them. But you may just be selecting for swarminess and long broodless periods, not useful traits in managed bees.

[Neils]

Sure, do think that it's rather telling that queens from "tolerant" stock rarely seem to do well when taken out of their isolated apiaries and put in amongst the general population of bees. Whether that's tolerant bees or perhaps less virulent mites, who knows? There doesn't seem to be a lot of hard evidence about but I've seen enough reports from people who've had queens/nucs from "varroa tolerant bees" that aren't very tolerant when surrounded by other bee(keepers).

[The Drone Ranger]

Nellie I'm with you on this.
Les Bailey "Infectious Diseases of the Honey Bee" recognised hygienic behaviour exits but says that it is a recessionary trait.
Difficult to breed in and ever so easy to lose again
Buying queens for this trait --guaranteed lock in

[Adam]

How much do other bees/beekeepers contribute to your own varroa levels?

My guess is that 'third party' bees will cause varroa to move from apiary to apiary over time - as has happened of course - but I would not have thought that a few extra varroa mites entering the hive on the backs of drifting bees would tip the balance so that a varroa tolerant hive then becomes susceptable.
Unless there are different strains of mites - more clingy ones perhaps.

More likely is that varroa levels were building up slowly and only became noticable after a certain period of time.

You do read of people saying that they "haven't got varroa" and then find out their colonies have dwindled to next to nothing or died over winter due to varroa.

[Adam]

Alan Teal said much the same thing in an Email to me a couple of years ago when I suggested the SBA mag was leading beekeepers up a blind alley by printing so many articles suggesting non treatment was a route to resistance.

Things went from bad to worse with a certain contributor encouraging the release of swarms which once they were feral bees would breed resistance ????
How the -### is that supposed to work ??
You can't keep them alive in a protected environment but they are going to become super bees left to their own devices ?

It did happen with rabbits and myxy. In that the disease - imported from abroad deliberately to reduce the rabbit polulation - killed off 95% of the population of rabbits. They now don't nest in warrens much as they used to so they changed ther behaviour and some that were lease susceptable bred and produced rabbits that can now cope with myxomatosis. Its sad to see them in the countryside with bulging eyes but at least they are there to eat our bedding plants and carrotts. Thankfully numbers are increasing as they are genetically getting more resistant.

You could argue that if honeybees were able to cope with varroa unaided, they would have done so already as there were ferel colonies before varroa invaded our shores.

I have written this before as advice from a Master Beekeeper near me. He simply says "If you don't treat your bees for varroa they will die". Can't be plainer than that.

[The Drone Ranger]

Adam I live in the country about 2 miles from where I was born I'm 58 now.
when I was 4 years old they found me holding my new pet rabbit it was a wild one blind and dying from Myx
Every three years or so I watch the rabbit population collapse again its a cycle of population growth and disease
This year there are lots of infected rabbits again
Rabbits don't learn other than possibly to avoid the really sick ones.
After 54 years of breeding they still don't have real resistance let alone immunity.
If we killed off their fleas the disease would disappear though.

Thats why your right the varroa have to be killed

[Jon]

Les Bailey "Infectious Diseases of the Honey Bee" recognised hygienic behaviour exits but says that it is a recessionary trait.

They beg to differ with that statement in other quarters but you may get one of the geneticist geeks to adjudicate re. who is correct.


Are the genes for suppressed mite reproduction dominant or recessive?
The VSH trait is thought to be controlled by more than one gene, just how many is uncertain at this point. These genes are neither dominant nor recessive. They are what is called "additive" which simply means that the more of them that are present, the more strongly the trait will be expressed. This works in favor of beekeepers since a queen with VSH genes can mate to any drones and still have the trait expressed in her colony enough to reduce the mite population. So naturally mated queens produced from pure VSH breeders are mite resistant.

http://www.glenn-apiaries.com/vsh.html#anchor107505

[Jon]

I think the combination of autumn treatments and OA might have more to do with it. I've not applied a winter OA treatment for the past two years and we're definitely starting to see the mite counts increasing. Yes Thymol knocks a good number of them down, but this year is the first that we've seen colonies showing signs that they aren't coping very well with the varroa.

I have done apiguard followed by oxalic for two years now. My mite drop this time is far lower than 12 months ago so I think there must be another factor, maybe the cold winter and longer broodless period as Jimbo suggests.

[Neils]

I have done apiguard followed by oxalic for two years now. My mite drop this time is far lower than 12 months ago so I think there must be another factor, maybe the cold winter and longer broodless period as Jimbo suggests.
Is it too optimistic to think that it might also be partly down to increased awareness amongst the beekeeping community. Anecdotally during the IBRA conference it was suggested that the re-infestation levels from outside apiaries could be considerable, especially when treatments aren't being co-ordinated. Even in the time I've been keeping bees I've seen a marked increase in the amount of coverage and hence level of activity from beekeepers taking a more (pro)active stance in their IPM schemes.

I concede at the moment we could take any number of possibilities, chuck them in the air and pick one that we like the sound of. This year I've seen my mite numbers skyrocket. Is it that I haven't treated with OA (so why a problem now and not last year when I treated my colonies with apiguard in the spring again as I did last year)? I've just got a generation of queens particularly susceptible to varroa and related conditions? The no treat crew a few hundred yards away? More colonies on the apiary giving the varroa more colonies to reproduce in? A combination of everything?

[Jimbo]

In our association our Oxalic acid treatment is co-ordinated and has been for the last 3 years. I know that every member treats within a two week period as we make the Oxalic acid in bulk and distribute the required number of doses free as a service to our members. There are no beekeepers in our area who are not members of our association that we are aware off and there are no 'No treat people' so re-infestation would not be a problem. This year some people are seeing low drops with there preferred Autumn treatment but other's are seeing high drops. We suspected varroa resistance at first but some colonies were treated with thymol or apiguard where there is no reported resistance. The same was seen with Apistan strips some colonies gave low drops and others high drops. My money is still on a weather effect

[The Drone Ranger]

They beg to differ with that statement in other quarters but you may get one of the geneticist geeks to adjudicate re. who is correct.



http://www.glenn-apiaries.com/vsh.html#anchor107505

Hi John
The difference is Glen apiaries sell queens
Les Bailey was a scientist researching bee health
Line breeding can fix any trait.
They sell Cordovan coloured queens
That's recessionary and can't be fixed in open breeding either

[The Drone Ranger]

Jimbo
Predicting the total drop is hard to predict, I hope you are right, certainly if you all treat together you will have good data but could log the whole period to get a full picture.
Some of the drops in this table of my hives might were a surprise815

[Jon]

Hi DR.
I know they sell queens by the thousand but in general the information about bee breeding and be genetics on that site seems to be very accurate.

VSH behaviour is a relatively complicated trait so I am not in the least surprised that it might involve several genes.
If you see the behaviour in all the daughters of VSH queens it is unlikely to be a recessive trait.
What year did Bailey do his research. It could have been superseded by more recent work.

[The Drone Ranger]

Hi John

I wrote short article for Scottish Beekeeper making the point that all these claims for breeding resistance have been made before in the 1930's
Resistant queens were on sale then as well
At that time the most famous beekeepers of the time were convinced that foulbroud resistance could be bred in and eliminate the disease.
One of the cornerstones was the belief that the hygenic gene for brood removal was the key to success.
Les Bailey's book I mentioned is around 1969 or so about 40 years on and he explains why the project failed
It might be better to think of these traits as switches i.e. on or off not as continuously variable like a volume control
You might remember "Spinal Tap" where they thought they made their amps louder by painting a number 11 on the volume controls :)

[Adam]

Jimbo
Predicting the total drop is hard to predict, I hope you are right, certainly if you all treat together you will have good data but could log the whole period to get a full picture.
Some of the drops in this table of my hives might were a surprise815

I agree. Its an odd set of results in a way. Column 25 seemed to have a serious problem and with apistan (no effect) and thymol treatments it still produced loads of varroa after Oxalic Acid. Maybe the thymol treatments were too far apart. C21 seems pretty well varroa free. 8 had 4 thymol treatments and still threw out loads of varroa after Oxalic treatment later on. The delays between treatment and 'mites out' is also quite marked in some cases. It has to be said that Apiguard seemed to be generally effective.

I admit that I don't monitor varroa drop as thoroughly as perhaps I should and I make the assumption that a double treatment of Apiguard will do the trick followed up by Oxalic Acid in the winter. However there does seem to be the odd hive which persists wil varroa after treatment - I had one of these a couple of years ago - I was embarassed when the bee inspector came late in September. He gave me an different treatment which produced a large drop soon after.

[Jon]

One of the cornerstones was the belief that the hygenic gene for brood removal was the key to success.

That's the issue though, it is a false assumption to imagine that hygienic behaviour is going to be controlled by a single gene.
You need to get Geeky Jim or Geeky Gav to explain chapter and verse but I think the explanation on the Glenn apiaries site fits the observations well.

[The Drone Ranger]

Jimbo
Tramping round is the snow is no fun :)
I decided home made thymol and oxalic acid treatment was the best compromise.
Didn't really give formic a chance (cowardly me)
I think its whether bees emerge at peak treatment strength with thymol.
The timing of treatments needs some investigating
Your breeding group could get the wellies on and gather some data :)

[The Drone Ranger]

That's the issue though, it is a false assumption to imagine that hygienic behaviour is going to be controlled by a single gene.
You need to get Geeky Jim or Geeky Gav to explain chapter and verse but I think the explanation on the Glenn apiaries site fits the observations well.

Jon
I am with you there- but heres the dillema- If you can't breed resistance yourself are you going to abandon your breeding AMM project and buy Primorsky hybrids instead?
If the next generation are not hygenic do you just carry on buying queens ?
The notion that AMM were unable to deal with acarine led to its near replacement with Italian and Carnica.
Are we all off on another similar journey.
Not one switch I agree but many switches all which need to be on and fixed in the breeding population.
Each switch affecting more than one thing like a complicated chain of two way light switches.
If you have resistant bees and don't treat then my bees are doomed eventually.
Likewise your AMM are doomed if I have resistant primosky hybrids bees and dont treat.

[gavin]

I'd use the word recessionary in a different context. For example:

'The ConDem government's tactics of attacking the conditions of public workers are highly recessionary.'

The variants of a single gene (its alleles, organisms usually have two alleles but drones have only one) can be:

- dominant (masks the effect of another one)
- recessive (is masked by the effect of another one)
- co-dominant or additive (if you have two different alleles you see an intermediate effect)

The term 'additive' is also used when you have several (or a few) different genes and alleles at each one also show incremental effects on the total.

So, Varroa Sensitive Hygiene alleles (and genes, as there are more than one) have an additive effect on the expression of the trait. I'd bet that the important genes are few in numbers though.

When you have several genes controlling a trait it hardly matters whether individual genes are dominant or recessive as each contributes only a small part of the overall trait. Intermediates abound.

DL, there is genetic variation for such traits. Lines of Scottish bees resistant to AFB were documented in the middle of last century. Acarine was probably an element in the Isle of Wight disease (maybe not the main problem) and the general resistance of the UK bee stock since then probably has a genetic cause. Maybe. Yesterday I was talking to a prominent bee farmer who reports a few lines of evidence that our more native stocks are more susceptible to EFB than are some imported highly bred stocks. If that is true then past exposure to the pathogen has driven resistance in the co-evolving stocks. For our bees this is a new pathogen. I should add that this is speculation, might just be wishful thinking on the part of the person relative this to me.

What reasons do Bailey give for the failure of hygienic breeding? There has been a recent resurgence in interest in this thanks to the efforts of Sussex University. AFB resistance is a bit more complex than hygienic removal, just as Varroa tolerance is more complex than VSH. Early rapid death of an AFB-infected larvae might be important, then the whole thing can be ejected intact without spilling open the load of infective bacterial cells.

DL, I've seen good signs of Varroa tolerance in near-Amm bees myself. I like to think that they may be better at it than some other strains, not the hygienic behaviour (opening brood) but the grooming and biting and carrying out. So in my mind breeding should first focus on stabilising a good strain of bee, preferably Amm, then selecting within that pool for better Varroa tolerance (perhaps a harder one to crack than Amm itself). I wouldn't expect 100% Varroa resistance, just a better level of tolerance.

[Jon]

Jon
I am with you there- but heres the dillema- If you can't breed resistance yourself are you going to abandon your breeding AMM project and buy Primorsky hybrids instead?
If the next generation are not hygenic do you just carry on buying queens ?

I imagine the genes which govern VSH and varroa tolerance are to be found in all bee populations to a greater or lesser extent so resistance could be developed in whatever strain tickles your fancy. The Primorsky strain has a 150 year advantage coexisting with varroa compared to most of the others.

More pupa removal is not necessarily better though, as there have been some reports that colonies which are excessively hygienic are slow to build up. There is probably an optimum level of hygienic behaviour. You don't have to kill every mite for a colony to thrive. The mite population just needs to be kept below a critical number, mainly linked to the level at which viruses will be facilitated, which will vary according to the time of year, the size of the colony and the size of the brood nest.
I have the odd colony which removes hundreds of pupae as soon as the apiguard goes in. I wonder is this liked to hygienic behaviour or is it just an intolerance to thymol?

[The Drone Ranger]

The method used to deal with codling moth (apples) is pheromone traps
malaria mosquito sterile males I think
Dog / cat fleas chemical sterilisation of the laying female
The weakest link in the varroa breeding chain is the first egg she lays is the male if that one fails or is sterile then the varroa population disappears
The magic bullet would be something that kills or sterilises the male varroa.
I hope you are right about breeding solving varroa problems (Gavin, Jon and Jimbo) but I doubt if it will happen in my lifetime.
In a sense varroa tolerance will/could make the problems worse as it seems the spread of virus and the damage to the immune system will continue

[Trog]

Bright yellow plastic strips covered in sticky goo are used to control whitefly in greenhouses. I wonder if something could be inserted in a normal frame (in place of foundation) which had a pheremone attractive to varroa mites and lured them to a sticky end. The bees could be protected by a coarse mesh either side of the trap so that they didn't come into contact with the sticky stuff but still got close enough for piggybacking mites to jump off to investigate.

[The Drone Ranger]

Heat kills them well before the bee larva round about 40'-42'C

[The Drone Ranger]

There is an American patented device called Mite Zapper or something which involves wires in the foundation being heated electrically.
The momma varroa is in the brood food snorknel up waiting, when the heat rises suddenly and kills it.
As far as I can tell reading between the lines the larva mostly gets killed as well (not good)

You may have used the type of hand warmer with the liquid which you click a disk or otherwise knock it and it then goes solid giving off heat for about 1hr.
The heat output is constant temperature around 50'C Max

My suggestion for truly organic control would be a thin version of the hand warmer in between two foundation sheets to form 1 complete comb.
At the time all the brood has been sealed trigger the reaction to give off the heat. Moma wont be at that end of the cell but junior the only male will be because he hangs out at the base of the cell on the 'Faecal Accumulation' waiting for the ladies (his sisters !!) to appear.

I wrote an article for Scottish Beekeeper some time ago including the formula for making your own DIY hand warmer contents.
Just a bit of fun really but in my own experiments varroa dropped onto wax cappings containing honey heated to just 40'C died almost instantly.

I also experimented with a sprayer and water at about 80'C which by the time it had produced a fine spray was detected at 40'C
Sprayed that on live varroa and it stunned them temporarily but they soon recovered

[Jimbo]

Hey DR,

Ever thought of going on Dragons Den with your hand warming varroa killer.

[The Drone Ranger]

Hey DR,

Ever thought of going on Dragons Den with your hand warming varroa killer.

Lol

I did think of building a box with good thermal properties (all the parts are available from RS components) and thermostatic control.

This was after a chat with a chap who was using frame trapping the queen as his varroa control.
He put the sealed brood in the freezer to kill the mites (and the brood)
This link to a pdf gives the full method http://www.google.co.uk/url?sa=t&source=web&cd=2&sqi=2&ved=0CC4QFjAB&url=https%3A%2F%2Fsecure.fera.defra.gov.uk%2Fbeeba se%2FdownloadDocument.cfm%3Fid%3D204&rct=j&q=queen%20trapping%20varroa&ei=MjNyTvubOYGs8gPcntT0CQ&usg=AFQjCNEiCxgNKGx902VJ-GBs12UOSJp6PA&cad=rja
It involves destroying a full frame of brood 3 times at 9 day intervals

This was so he could produce organic honey I believe, anyway I felt if he could have warmed the sealed brood to 4o'C for 24hrs, or possibly 42'C for a couple of hours the varroa would be dead but the brood should survive OK.

[The Drone Ranger]

regards low mite drops I am seeing the same thing but

On the SBA website www.scottishbeekeepers.org.uk/.../Beekeeper%20April%2009(2).pdf

Page 9 of 28 Wally Shaws article says
"The bottom line is, that I have not found
monitoring mite fall in July to be a useful
guide to the mite population in the hive as
subsequently revealed under treatment.
As an extreme example, a hive that yielded
0 (zero) mites during 7 days of monitoring
in mid-July, 4 weeks later produced a
fall of 6,000 mites under treatment"

I think as mentioned elsewhere that lots of varroa which drop end up as a tasty snack for something else.
Either way its better to be over cautious I think

[The Drone Ranger]

[/QUOTE=gavin;7081
What reasons do Bailey give for the failure of hygienic breeding? There has been a recent resurgence in interest in this thanks to the efforts of Sussex University. AFB resistance is a bit more complex than hygienic removal, just as Varroa tolerance is more complex than VSH. Early rapid death of an AFB-infected larvae might be important, then the whole thing can be ejected intact without spilling open the load of infective bacterial cells.
[/QUOTE]

Hi Gavin

Les Bailey stated that bees would develop resistance to diseases that they were exposed to over long periods.
He postulated that disease spores/agents/virus can be present at low levels in most colonies but an outbreak only occurs when an additional challenge say for example food shortage triggers it. Stress of some other kind might also result in the same problem.
I read an article by you Gavin in the SBA mag and I concluded that you were saying that EFB was only found in apiaries contiguous with ones where an outbreak had occurred sorry if I misunderstood that.


Now the AFB breeding for resistance program involved taking survivor colonies from an outbreak area to a breeding station in Iowa .
They bred from the queens and then sprayed their colonies with AFB they also sprayed some control colonies.
The controls all developed disease as did most of the 'resistant' group but not all.

More queens were bred from the survivors and the experiment repeated
This time slightly fewer of the resistant group developed disease but it still was only a very small proportion that didn't develop disease.

The project continued but no further improvement was made to resistance levels.

Bailey analysed the results and found that the results were statistically not significantly different from those obtained by carrying out the same experiment on non selected stock.
The conclusion was that although resistance obviously existed that the breeding for resistance programme had not succeeded in improving on the results achieved without any selection process.

The methods they chose seem to me to parallel the varroa breeding for resistance program being attempted by some beekeepers
I suspect the outcome will be similar unless they use complex line breeding where we all are locked into buying queens.
You are as likely to see resistance developing in bees who have been exposed to varroa and helped to overcome it (by treating) as in bees who have had no help.
Therefore non treatment would be dead end strategy with no gains

[The Drone Ranger]

Hey DR,

Ever thought of going on Dragons Den with your hand warming varroa killer.

If you ever have even a crazy idea it's best to get it out in print otherwise somebody can patent something similar and block everyone else from manufacturing it .
I was amazed how many bee equipment /devices are being patented (mostly useless) all the time.
Once it's in the public domain it can't be patented

[The Drone Ranger]

http://www.beedata.com/apis-uk/newsletters05/apis-uk0205.htm

ORGANIC METHODS OF VARROA CONTROL

There is a good coverage of all the methods here in this edition of apis-uk
including lactic acid which is an October treatment (if you have missed the boat with thymol) and also heat treatment is briefly mentioned using heated boxes in Germany

[Jon]

I just re read this thread where were most of the posters noted a low varroa drop in autumn - far less than usual.
In spring everyone was reporting little or no colony losses.
I wonder are those two facts related.
The winter survival figures for UK regions must be due out soon.
Will be interesting reading.

[Jimbo]

Hi Jon,

I had a low varroa drop, little colony loss and since then no Nosema detected using the PCR method, no traces of any pesticides in either wax or brood according to Keele University.

[Neils]

I still think varroa currently represent the biggest problem for Honeybees and beekeepers.

It's been dismissed before, but I still think that a shift in treatments and beekeeper education is playing its part. There are no silver bullet treatments in most places, you can't just slap in pyrethoid strips at the end of the season and ignore varroa otherwise. Certainly around our parts new and prospective beekeepers have that taught to them over and over and the module syllabus teaches the same; you can't ignore varroa, you need to use a system of IPM, keep monitoring and take action when appropriate, using numerous different techniques, not just slap some chemicals in at the end of the season and assume they're doing the job.

I don't think beekeeping is noted for it's dynanicism or reception to change, but it's also the hobby du jour and I think that is also playing it's part. Yes there are those who've bought the line that beekeeping is easy and their garden will flow with honey with minimal effort or that treating for varroa is "un-natural" but they, along with those who refuse to adapt are being culled from the beekeeping pool too. You have a whole generation of new beekeepers who don't remember the good old days, we've always had to monitor and treat for varroa. I think when SHB gets here we'll see something similar.

I think there is still much we don't understand about varroa, I've seen it opined recently that the widely held belief that Varroa prefer drone brood might not be true, for example (and if we over-cull drone brood, do we simply select for mites that happily breed in worker cells instead?). I do also wonder whether the shift from chemical treatments to ongoing IPM puts a different pressure on the mites? We've perhaps previously encouraged a lifecycle that encourages a rapid population expansion and collapse of the host colony to ensure that the mites can spread, IPM is a more tolerant approach: "you can live in the hives and as long as you don't cause a problem we'll leave you alone, start causing problems and we'll hit you from various different directions until you don't.".

before anyone starts shouting "prove it/quote some research";) I don't have any, it's just one of the many things I ponder when I'm reading through things.

[Jon]

Beekeepers certainly have to be smarter than they used to be.
My father's generation just lifted the supers on and off and caught as many swarms as they could, although acarine used to be much more of a problem in the good old days.
Not many beekeepers cull drone brood. I rarely do unless I have a dodgy colony which i don't want making drones.
Roger Patterson always asks his audience who culls drone brood and he says you don't get many hands in the air.
The extra couple of days the drone brood is sealed makes a big difference to the average number of viable mites raised per foundress mite.

And my mantra for ages has been that good management of varroa and nosema means that you should have healthy bees.


Hi Jon,
no traces of any pesticides in either wax or brood according to Keele University.

Bad talk Jimbo. You must be on the payroll of the evil empire same as Gavin and the man from Bristol!

[Neils]

I generally cull the first drone cells of the season and then rely on uncapping to monitor after that, not much help if you keep removing it all :) I also think that continually chopping out drones isn't helpful except in rare circumstances, they want to raise drones so continually preventing them from doing that adds a stress factor to the colony.

I do tend to make a point that foundation comes in packs of 10 which is perfect for leaving a foundationless frame for them to raise drones in.

[Jimbo]

Ok Jon I confess. I have been on the payroll of the evil empire. I have done some work in the past for various chemical companies. Not for apiculture or agriculture but for human medical research. Does that still make me evil?