Coevolution of Honey Bees and Varroa Mites: A New Paper

[WLC]

Adam:

We're obviously looking at how egg cells (and possibly sperm cells) are made.

My understanding is that these RNP particles move into the oocyte along with other other components that are being transferred from the nurse cells.

You might have to look up gametogenesis to get a better feel for the process.

The RNP then makes it to the nucleus (possibly via the cytoskeleton) where it then reverse transcribes and integrates into the host genome.

So, the transposable element makes it to the nucleus during gamete formation and integrates.

After that, it's resistance via RNAi, as in the Maori paper.

This is the only example of Honeybee disease resistance by evolution, that I am aware of, that is so well documented.

I don't think that we can say the same for any of the other possible mechanisms being discussed. That's what makes it special.

--------------------------------------

Out of 8 splits from an obviously DWV infected hive (there was a funnel of dead bees, with shriveled wings, leading back to the hive), 1 was good enough to rehive.

Even though we're going to take a look for evidence for DWV integration, it might take a while before we actually know if the new hive is truly resistant.

Hunting for jumping genes is never an easy task.

[sqkcrk]

Adam:

My understanding is that these RNP particles move into the oocyte along with other other components that are being transferred from the nurse cells. [within the reproductive organs of the queen] Right, WLC?

--------------------------------------

Out of 8 splits from an obviously DWV infected hive (there was a funnel of dead bees, with shriveled wings, leading back to the hive), 1 was good enough to rehive.

Even though we're going to take a look for evidence for DWV integration, it might take a while before we actually know if the new hive is truly resistant.

Hunting for jumping genes is never an easy task.

What did you do w/ the other 7 splits? What was their composition?

"we"?

[WLC]

This was DWV without mites, by the way, in VSH stock.

2 frames from the original hive, and an additional drawn frame for each split

No feeding or treatments.

4 came through, and I took the best looking one and rehived it. I allowed the other three to dwindle away.

The new hive was close to filling one deep when we took samples.

"we", Someone else gets to do the tests.

[Adam Foster Collins]

When are you likely to have test results from what you've tested?

[sqkcrk]

DWV without mites. You sampled the colony to establish that?

Two frames of brood? What was in the additional drawn frame? Just comb? a frame full of honey? Or Honey and pollen?

When you write that you took samples from the new hive, I assume you mean you took samples of bees? And what will you be doing to test them for resistance to DWV? I guess you will be looking for some sort of genetic marker or something?

[WLC]

We've already extracted, PCRed and run gels. We've got good extractions, amplifications, and gels.

It'll be some time before I can report any findings. It's someone else's project.

If they do a great job of it, then it can take them places.

As a side note, I have another Honeybee virus related project going on as well.

This one is more theoretical though.

[sqkcrk]

Extracted what exactly? Please. You are talking to people not in your line of work.

[WLC]

sqkcrk:

There was some pollen and honey in each of the splits with an extra partially/fully drawn frame.

I took the original hive apart w/ a large carving knife, scraper, etc., I found the queen and left her with about 4 frames in the original location. Checked everything in 'good light'.

The original hive is still leaking DWV.

I've got bees from before the split, and then after the successful split from the parent and daughter colonies.

Boy, am I glad I converted a Dustbuster to a bee vac sampler.

We can do virus (RNA), target integration site (rDNA), virus vs integrated virus expression (RNA).

Personally, I only care about the target rDNA site. The other stuff has already been done by others.

My thing is catching 'instant evolution' in the act:

DWV jumping into Honeybees, because of a split, and perhaps even testing positive for DWV resistance.

Hunter et al. already found DWV in Honeybees, but I doubt that they used this kind of experimental design.

sqkcrk:

Regardless, somebody is going to learn something.

WLC.

[sqkcrk]

Regardless someone always learns something. Quite often what someone learns is not what someone else was trying to teach. Haven't you noticed that to be true? Porejemplo, we have learned something about each other, haven't we? But, some of us have not learned what we wanted to. What can we do?

[WLC]

Now, for a gratuitous link for the thread:

http://www.slu.se/en/faculties/nl/ab...locke-barbara/

I learned that we've got alot to learn about the coevolution of the Honeybee, the Varro mite, and other pathogens.

I hope to learn how to make transgenic, DWV resistant, treatment-free bees (OK, so I fed them peppermint candy) by splitting a DWV infected hive.

I think that would be alot to learn on a thread like this.

[sqkcrk]

Here is something you can learn, if you will, peppermint candy has no appreciable effect on Varroa or Tracheal mites. Nor does it do any good on DWV. Lesson taught. Now it is up to the student to learn.

Check w/ Geulph University, Guelph, Ontario. I don't know if Gard Otis is still there or not, but he did a study way back in the late 1980s, putting bars of menthol into beehives to treat T. mites. No positive effects.

[WLC]

The peppermint seems to improve their disposition. They're less defensive.

It certainly doesn't help w/ DWV though.

[sqkcrk]

Okay, I haven't noticed that. But you have, so, what can I say, but, okay.

[TooFarGone]

WLC
I have read the entirety of this thread with great interest. I have recently had some coursework in both immunology and infectious agents/virology and will attempt to reconstruct your argument for splitting infected hives to try to induce spontaneous resistance to a viral pathogen.

Your premise is bases on the assumption that it is the viruses carried and spread by the Varroa mite that are causing the damage to the bee population and not so much the mite itself. By breeding "sick" colonies, you are trying to encourage the emergence of bees that have successfully "reverse engineered" the viral RNA and inserted it into their own DNA in a way that allows them to immediately have resistance to the virus. This is a genetic mechanism that is separate and distinct from the "usual" Mendelian genetics that we are all used to- which works by breeding "the best to the best". From a Mendelian perspective, breeding impaired/sick bees is the a "very bad thing" and is the basis of much of the resistance noted in this thread to the idea of breeding sick bees. I am going to try to explain how the alternate system might work for generating resistant bees.

Bees have some (limited) ability to spontaneously develop resistance by incorporation of the virus genetic material into their own DNA is a fashion that allows them to develop innate immunity to the virus. that is to say that when the virus infects the bee, the bee already has immunity in place to immediately remove or neutralize the virus. They have to have an active infection with the virus in order for this genetic incorporation to occur (hince the splitting of sick hives). My understanding of how this happens is as follows:
1) Viral genetic material in the case of the Deformed Wing Virus is made of strands of a material called Ribonucleaic Acid, or RNA.
2) Before this genetic code can be inserted into the bee genome, it must be converted to Deoxyribonucleaic Acid or DNA. This conversion is accomplished by an enzyme called a reverse transcriptase- it takes the viral RNA strand and molecule by molecule converts it to an equivalent DNA strand.
3) In order to get the freshly minted DNA material from the virus inserted into the bee DNA genetic code, a special enzyme called a retrotransposon is utilized. This enzyme takes newly formed piece of DNA (formed from the viral RNA), and (I believe) randomly inserts it into the bee's genetic code. Once inserted, it stays.
4) The tough part is that the new DNA may or may not insert into a part of the bee DNA that is used to control the bees immune system. The bee reportedly has 10,000 genes, and if this genetic material is (randomly) inserted into most of them, it would not function in the immune system and might even be bad (or lethal) to the offspring. Eventually, after enough tries, the correct insertion would occur and the offspring would have innate resistance to the virus!
5) I think that the queen bee would have to be infected with the virus in question. In a manner that I am not completely clear on, the retrotransposon is active in the reproductive tract of the queen and is randomly inserting the genetic material into cells that divide an become eggs. It is not clear to me if each individual egg have a randomly placed piece of genetic material or if all of them have the material inserted into the same spot. This suggests that drones would be carrying the genetic material as well.
6) In order for the new innate resistance to be manifested in a colony formed by splitting, the split would have to raise a queen from brood from the prior queen. This new queen would have to bear the virus genetic material at just the right spot in her genome so that she had viral resistance. Then her offspring would have resistance-Voila- new immediate resistance to the viral pathogen!

And that is how I think it works!

Hope it helps.
TooFarGone

[mike bispham]

I think that I'm addressing the conclusion of the paper rather directly.

You must be explicit and explain in terms we can understand. Take a sentence or paragraph from the paper (you mention the conclusion) and show how it bears on your thinking - or vice versa. At things stand you're building castles on thin air. That's a waste of our time and space, and a distraction from our topic. Start your own topic if you want to talk about a new mechanism beekeepers can experiment with to supplement the known routes to resistance.

We need to address how resistance evolves.

Resistance evolves due to natural selection for the fittest strains. What you seem to wish to talk about is the way resistance arises in the first place. It seems to me you wish to replicate what you believe to be a mechanism whereby some of the genetic material from the organism causing problems is somehow bought into service in the host's genetic structure, in a way that then supplies resistence to the host.

Is that what you are talking about?

Mike

PS from what Toofargone has written it seems that's about right. Its interesting. But it should be on a thread of its own, since our subject paper is directed at evolution working in the more common manner - by natural selection for the fittest strains. Your topic is related, but is getting in the way of this conversation. And this one is important - it deals directly with the mechanisms that will make the most difference to the great majority of beekeepers seeking to go treatment free. As the orginator of the thread I'm asking you to start your own. I'll subscribe to it and listen in and ask questions.

[WLC]

Mike:

"Therefore, more detailed investigations
are necessary to identify and tease apart the possible
mechanistic differences."

I was discussing one possible mechanism by which bees can evolve resistance to varroa mites: molecular immunity to the viruses that they carry via transgenesis.

My main contention is that molecular immunity to viruses by Honeybees is also better understood as a mechanism of co-evolution and resistance than any of the other mechanisms being considered.

They can't seem to be able to identify the specific genes (sequences) involved for the other mechanisms.

I've noticed that in the literature.

I gave specific evidence for co-evolution.

I've provided a mechanism for virus resistance.

It doesn't require human intervention to occur naturally in treatment-free bees.

However, I'd like to see if we can detect an actual act of 'instant evolution'.

I do understand the issues involved.

Are we clear now?

WLC.

[mike bispham]

Mike,

JB is fine.

You have elaborated needlessly for the most part. I have a well-founded understanding of fundamental evolutionary principal and animal husbandry.

Hi JB,

I will continue to contend: no you don’t. I often had people say to me that they understand natural selection. But ‘understand’ is a broad word. It often means they’ve heard of it, and have a rough idea of what its about – but little more. I think your comprehension is quite good. But you’ve a little further to go.

Specifically, you are not factoring in the ‘arm’s race’ aspect, nor appreciating to extent of the effect of allowing non-resistant genes to go through wholesale to the next generation.

Let’s try a thought experiment to bring the main issues into focus. We can imagine two apiaries of identical bees, both middle resistant, and both with middle-fecund varroa. For the sake of this thought experiment we’ll ignore any changes in the mite population. We’ll also assume any external input is identical, and similarly both sets of bees are middling in terms of resistance.

Apiary A) will be managed by close selection of the most resistant bees. Their genes will replace the weakest by queen rearing and re-queening.

Apiary B) will be managed by a systematic treatment regime. There will be no attempt to breed through selection.

This represents my way and yours respectively.

In my apiary any non-resistant strains will be swiftly terminated, leaving each new generation to be made from resistant parents. Genetics/the law of inherited traits will ensure the new generations are similarly resistant, and so within a few generations all non-resistant strains will be extinguished except those that have come in from outside. This will throw up non-resistant offspring, but less often that will be happening in your as my own drones will tend to reinforce resistance. My apiary will be made resistant, and kept resistant by systematic selection.

In your apiary both resistant and non-result equally contribute to each new generation. Each new generation, made of the same mix, will result in similar levels of resistance to the previous. This is exactly what the passage we’re interested in means: acaricide use inhibits the rise of resistance. Non-resistance doesn’t result in death – you stop that by treating. It doesn’t – even though it doesn’t work 100% - result in any progress, since many that would have failed go through.

The cost of hygienic behaviours
I can see your point: if the treatments don’t work 100% then you might think there will remain a small pressure toward growing resistance. But actually it doesn’t work like that: for this reason. The hygienic behaviours carry a small penalty – they carry a cost. Bees fussing about over-cleaning the place are not bees fetching pollen and nectar. For that reason the evolved mechanisms are, in nature, dropped as soon as possible. As mites become less of a problem those hives with a lower proportion of resistant patrilines gain an advantage over those with what is now too many. And this dropping of resistance is rapid. What this means is that the slightest easing in pressure to become resistant results in fast abandonment of resistance. And that is exactly the scenario in lightly, or incompletely treated apiaries.

So while my bees, and any feral bees far enough away from treaters to enjoy the benefits of natural selection will rapidly gain resistance due to the ruthless extinction of vulnerable strains, yours will make no progress whatsoever.

Now, separately, we can look at three possible further objections. I’ve mentioned drone input, and we can do that first. Then we’ll look at the possibility of inbreeding and loss of genetic diversity.

Both our apiaries, as you’ve pointed out, will be affected by external drones. In my case any benefits will be enjoyed, and disbenefits rapidly negated by my system. If the inputs contribute to health they’ll be incorporated; if they don’t, they won’t. Neat huh?

In your case the opposite will occur – any benefits will be lost as you press unfit strains forward in your mix, while any unfit drone input will just decrease any nascent resistance still further.

As to the fact of open breeding: yes, we cannot control mating, and so we cannot work with the sort of (probabilistic) precision that closed husbandry enjoys. But we can get ¾ of the way there, by adopting different strategies.

First, we can have total control over the queen side genetics. That’s 50% of the input, and is sufficient alone to start swinging things our way.

Second, we can increase our share of the male side input by two means: 1) by keeping large drone producing hives in and around our apiaries (standard bee farmers practice) and b) by the fact that our modus operandi encourages feral bees to establish and thrive around them – so we get the benefit of their (naturally selected) drones. Note; your management severely represses the local feral population, and so you get none of that resistant input.

Inbreeding.
The fact of open mating, the contact local ferals will have with bees from the wider area, and the possibility of deliberate input of selected resistant strains now and then add up to no danger of inbreeding.

(Possible loss of genetic diversity is covered below)

Your points are well taken and spot on. They work well in the lab, or petri dish or in completely controlled populations. Our bees are none of the above. Your bees and my bees will mate with feral and transient populations that we have no husbandry control over whatsoever.

First, I’m grateful for your appreciation, and I’d like to return it.

To real-world application. First, many people have been keeping bees treatment free for many years by using these techniques. The empirical evidence is there. The explanations for why it works are also there.

I’ve already addressed external input above, will add: the systematic nature of the selective propagation program is easily capable of dealing with input from neighbouring (treating) apiaries and transients – as long as they are not overwhelming. So its sensible to be at some distance from larger operations, and to make your own operation as large as possible so as to dominate the drone space. As to ferals – well as indicated above – their input is highly desirable.

In the real world, the evidence fits my way of thinking perfectly.

We agree on much but disagree on a few important points. Really only disagree on only one important and basic point. That revolves around your words of “prevent “, “never” and “stop”. Once again you read “hinder” as prevent and I read it as impede. Once again you ignore the time part. I’ll also quote from the article (I usually don’t for copyright issues) From the article:

“The coevolutionary process required for establishing a coexisting relationship between this parasite and its new host is lacking, both in time and in selective pressures because the selective disadvantage of being virulent is removed by apicultural practices aiming to control this damaging new mite pest.”

I agree, the paper does speak of a time factor. I will maintain that under strong treatment regimes, with no compensating feral or non-treater or deliberate resistant breeding to ameliorate, development of resistance cannot occur. I’ve covered that under ‘the cost of hygienic behaviours’.

It appears that you disagree with the time element as much as I disagree with the “selective pressure is removed” aspect. Selective pressure is impeded, not removed and there is a difference, removal dictates 100% success of treatments which is not the case.

Well, lets imagine you are right about this. Can you state the factors, the parameters under which resistance will rise, and give us a time frame? I’m not asking for guesses – I can give you a time frame for doing things my way – and prove that it works. Can you make a substantial claim that your slow development of resistance will outpace any compensating evolution in the mites? What is your evidence?

At least can we agree: my way clearly works; your way might do, but we know, and we can’t know when either?

Also history has shown husbandry is capable of making the wrong selections and breeding out a characteristic that was later determined to be important and desirable.

(Possible loss of genetic material or valuable traits)
I’m sure this is true (though I’d appreciate some examples with references). However, as far as I’m aware there is no comparable danger in what I’m advocating. In fact its exactly the point made by Marla Spivak: to have lots of beekeepers all maintaining their local populations by breeding on a local basis is the best possible protection for genetic diversity.

I’m no expert here, but my understanding is that there is little to no cost in diversity in allowing nature to play out in this sort of situation – which the bees have faced countless times before – nor in the kind of husbandry that mimics natural selection. The ‘winners’ carry through pretty much all the diversity in the prior population. Very very small populations may be at risk of ‘bottlenecks’ But we’re talking here about a handful of individuals – not the millions at large in the US or the UK.

A single isolated apiary that is overbred might suffer such a problem. But a bit of new (preferably resistant) blood will sort it out.

Evolution will march right on with or without human muddling. And it will likely march to a tune of it’s choosing not ours.

If you consider domesticated animal have marched very much to our tunes – and then think how much influence we have over bees wherever the great majority are in apiary hands – you’ll see that we can and are influencing them strongly. And … that is what the paper tells us is happening. Its not the first scientific study to make the point:
Survival of mite infested (Varroa destructor) honey bee
(Apis mellifera) colonies in a Nordic climate (2006)
Ingemar Fries, Anton Imdorf, Peter Rosenkranz
"Our results allow us to conclude that the problems facing the apicultural industry with mite infestations is probably linked to the apicultural system, where beekeepers remove the selective pressure induced from the parasitism by removing mites through control efforts."
http://www.apidologie.org/index.php?...6/05/m6039.pdf
This is the part most beekeepers – and, it seems regulators and the advisors don’t understand: giving medical aid to an openly mating species has a horrific effect. The species simply adapts to the new situation, and doesn’t bother raising any defences against what it perceives to be non-problem. The pathogens, meanwhile, continue adapting – resulting in their growing resistance to the treatments.

Genetic care is an art. Go wrong and the results can quickly be catastrophic. As you yourself point out, bees are not closed mating populations, and the usual rules do not apply. Treating openly mating animals as you can closed populations is very much taking a wrong turn. The predictable – and now deeply demonstrated - result is a kind of ‘addiction’. The more you treat, the more the bees will adapt to your lifting their burden – and so it goes on.

Your stance, if accurate will doom any of your results to fail as soon as exposed to the “treated” populations. By your stance, the superior genetics you are breeding to, will fail. So where does that superiority go and what does it achieve? How does that flow into fundamental evolution?

Not where the sorts of precautions I’ve outlined, if needed, are taken. The point is to raise the number of resistant patrilines to a sufficient level (and variety of required behaviours) not to seek complete dominance. And then to keep them at a suitable level through ongoing selective propagation. That’s what nature does, and we can improve and lose most of the weakest. The trick is: build the selective _process_ into your management. Genetic management is part of the art of beekeeping – just as in closed populations.

Sorry, but you are wrong. Superior genetics will win out, treatments or not.

This is not substantiated, either by reference to theory or by any evidence. Its an article of faith. The well-established theory says: treatments supply an environment in which the pressure for change is removed. No change.

When an inferior genetic line is allowed to reproduce it produces inferior genetics. AGREED?

Two weak lines will most often produce a weak offspring. Agreed.

When an inferior line is allowed to cross breed with superior genetics, the superior genetics have a better chance at survival with or without treatments/intervention.

More or less, yes.

But everything above aside, I am going to ask a series of questions, I will provide my answers and you (or anyone else) can provide your/their answers, and then maybe a more focused conversation can follow. I am sure you will get a feel of where I am headed from the questions.

What is the currently accepted average time from introduction of mites to colony collapse if untreated and nonresistant?
JB: 3 years

MB Depend on level of resistance in bees and voracity of mites. I’m not sure, given that, that an average really indicates mush that is of use to us. What we want to know is: you much resistance do _these_ bees have.

Are treatments 100% effective at removal of varroa?
JB: No

MB I don’t know. Some might be some of the time.

Do 100% of the treated non-resistant hives survive?
JB: No

MB I doubt it. 100% of any hives anywhere anytime is unlikely given a reasonably large sample.

Which has the better chance of survival, a treated resistant colony or a treated nonresistant colony?
JB: Resistant colony.

MB Close to equal (dependent on effectiveness of treatment), but I’ll grant you the point.

Which has the better chance of survival, a non-treated resistant colony or a non-treated nonresistant colony?
JB: Resistant colony.

MB Resistant colony

Which has the better chance of reproduction whether treatments are present or not, Superior or inferior genetics?
JB: Superior genetics.

MB I’m not sure that speaking in terms of ‘superior’ and ‘inferior’ is useful. Resistance is supplied by specific genes that confer specific behaviours. In the natural context possession of those behaviours confers superiority. Only when all colonies have those protective behaviours can other considerations come into play. Same in the non-treated apiary.

However, in the context of a treating apiary, all sorts of other factors come into play that make resistance irrelevant. So the ‘superior’ bee (i.e. good producer) may have no resistance, but be a outstanding layer.

Are there less tracheal mite treatments applied in US apiaries today than 5 years ago?
JB: yes, tracheal mite treatments are almost never applied.

MB No idea – I’ll take your word for it. But how widely were tracheal mite treatments applied? I’m not sure a simple parallel can be made.

Are there less Varroa treatments applied in US apiaries today than 5 years ago?
JB:yes; less people treat and treat less often than 5 years ago.

MB Again, I’ll have to take your word for that. Can you supply proper support for the claim? How much have treatments been fine-tuned – just as effective though applied less often? How much have alternative systems of mite management been substituted? Don’t forget, they have exactly the same effect in breeding terms.

Are feral populations rebounding at all?
JB: Yes, the feral populations are slowly returning.

MB: Yes. And, its noteworthy that, as Joe Waggle predicted, this is happening first in those remote places where apiaries are few and far between. Treatments suppress feral populations by supplying incoming genetic material that undermines self sufficiency.

[mike bispham]

"Therefore, more detailed investigations
are necessary to identify and tease apart the possible
mechanistic differences."

I was discussing one possible mechanism by which bees can evolve resistance to varroa mites: molecular immunity to the viruses that they carry via transgenesis.

Ok, thanks for the heads up. I'd advise: spend some time learning how to relate your thinking to the general public. We've had to pick apart for ourselves what it is your talking about. (BTW: I think this would be better expressed: 'gain resistance intially, which then enters the evolutionary mechanisms that operate through natural selection' or something of that kind.)

My main contention is that molecular immunity to viruses by Honeybees is also better understood as a mechanism of co-evolution and resistance than any of the other mechanisms being considered.

Fine. But the subject of the paper, and our interest in it, is centred alomost entirely on the mechanisms and relations that pertain to bee-mite coevolution, through the mechanism of natural selection. That subject supplies us with insights that we can take to our own treatment-free beekeeping. There is, in other words, a clear point to this thread, and a clear subject - and intention of starting the thread was to provide a forum for exploring that. As I've said, I'm interested in your input.

I'm now asking another direct question: wouldn't you agree that starting a new thread is simple and appropriate, given that several of the main posters to this thread have indicated impatience, the moderator has recommended ignoring you, and the originator has asked for you to stop interrupting the discussion?

We'd like, please, to work through the paper at our own pace, looking at the parts we can relate to our own knowledge and practices. You are constantly hijacking the space we use to do that. Again, please, start your own thread. Its easy and effective - it will give you the space you would like to talk about the things you want to talk about.

Mike

[WLC]

Mike:

People are asking questions because they're interested, thus the drawing out of the explanations.

Try not to be so patronizing.

My challenge to you is this:

prove to me that co-evolution is responsible for the survival of the Gotland and Avignon hives.

WLC.

[mike bispham]

Mike:

People are asking questions because they're interested, thus the drawing out of the explanations.

Try not to be so patronizing.

My challenge to you is this:

prove to me that co-evolution is responsible for the survival of the Gotland and Avignon hives.

WLC.

No. You clearly want to disrupt the discussion. I'm going to abandon the thread and start another. Please don't hijack that one too.