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Coevolution of Honey Bees and Varroa Mites: A New Paper

74K views 225 replies 24 participants last post by  souficoufi 
#1 ·
Here's a beautiful new paper. Look at this statement:

"Coevolution by natural selection in this system has been hindered for European honey bee hosts since apicultural practices remove the mite and consequently the selective pressures required for such a process."

More sound backing for the understanding: treatments ('apicultural practices') prevent the rise of resistance which otherwise occurs rapidly.

Mike

Host adaptations reduce the reproductive success of Varroa
destructor in two distinct European honey bee populations
Barbara Locke, Yves Le Conte, Didier Crauser & Ingemar Fries

Ecology and Evolution 2012; 2(6):
1144–1150
http://onlinelibrary.wiley.com/doi/10.1002/ece3.248/pdf

Abstract
Honey bee societies (Apis mellifera), the ectoparasitic mite Varroa destructor, and honey bee viruses that are vectored by the mite, form a complex system of host–parasite interactions. Coevolution by natural selection in this system has been hindered for European honey bee hosts since apicultural practices remove the mite and consequently the selective pressures required for such a process. An increasing mite population means increasing transmission opportunities for viruses that can quickly develop into severe infections, killing a bee colony. Remarkably, a few subpopulations in Europe have survived mite infestation for extended periods of
over 10 years without management by beekeepers and offer the possibility to study their natural host–parasite coevolution. Our study shows that two of these "natural" honey bee populations, in Avignon, France and Gotland, Sweden, have in fact evolved resistant traits that reduce the fitness of the mite (measured as the reproductive success), thereby reducing the parasitic load within the colony to evade the development of overt viral infections. Mite reproductive success was reduced by about 30% in both populations. Detailed examinations of mite reproductive parameters suggest these geographically and genetically distinct populations favor different mechanisms of resistance, even though they have experienced similar selection pressures of mite infestation. Compared to unrelated control colonies in the same location, mites in the Avignon population had high levels of infertility while in Gotland there was a higher proportions of mites that delayed initiation of egg-laying. Possible explanations for the observed rapid coevolution are discussed.
 
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#6 ·
Hurrah! The bees are starting to coexist with mites successfully. There is unfortunately a disconnect between the people lauding this study and the people who are commercial beekeepers - that is - the potential for 100% loss of bees by the commercial beekeeper. That could very well put the beekeeper out of business. I applaud those who are big enough to play the percentage game and live in climates where rebuilding stocks are possible. It isn't for everyone. I continue to search for genetics that will make it treatment free in my climate. I am heavily feeding my yard of treatment free bees from Texas. They stored no where near enough honey to get them through a typical Maine winter. Should I just let them die because they weren't good enough to make it? I think not, as I want them to have another chance at getting accustomed to Maine and what they need to do to survive up here. If i let them die, I'm out a bunch of money and am still looking for "good" genetics. Studies like the one mentioned are encouraging and serve to remind us that in beekeeping there is no one size fits all answer.
 
#7 ·
Andrew - Have you ever tried Kirk Webster's stock? I have two nucs on order for next year. He's not a small cell guy. His are on 5.2 and his bees coexist with mites. VT is pretty close in terms of climate. If you are near the cost you have much more humidity to deal with than I do. I'm anxious to find other folks with his bees and find out what their experience has been.
 
#8 ·
I took some time to sit down and read the whole paper last night.

I don't meant to toot my own horn, but this paper says many of the things that I have been saying for years.

1. There are multiple methods of mite coexistence not necessarily including the VSH trait.
2. Bees don't necessarily have to have the VSH trait to survive mites.
3. Treating bees doesn't allow them the opportunity to become resistant to the mites.
4. It works both ways, the mites have to evolve to become less virulent AND the bees evolve (or express) methods to handle them.

Especially number four, the mites beekeepers are breeding by treating are stronger. Non-treatment produces weaker mites ultimately because the more virulent mites kill the hive and themselves die. Killing mites with various methods decreases the population of mites and therefore may allow the hive to survive, but the mites that remain are those that are the strongest and most capable of surviving the treatment. Therefore treating bees makes the problem worse and pushes it down the calender a bit, but it most assuredly doesn't fix anything.

The paper talks about populations of bees that have been feral and unkept for 10 years. I have kept mine treatment-free for nine and a half years. There is no eminent crash as I have been told over and over and over. The population has stabilized. Capable and worthwhile honey production has returned to my population. Some of the credit goes to breeding, but much of it goes to allowing weak hives to die. This year, I also have taken the step of not only allowing weak hives to die, but requeening hives that fail to thrive given a reasonable opportunity.

This is the work of beekeeping that needs to be done. The solution is simple: quit treating and the bees will sort it out themselves. If backyard beekeepers with limited number of hives want to keep them year after year, then they must quit buying packages like cheap plastic China-made toys and buy quality locally raised treatment free stock. You get what you pay for. A $20 queen is a queen you're going to pay for over and over and over, so don't buy it.
 
#9 ·
I totally agree with Solomon, and also would like to add that people need to broaden their horizons and quit killing feral colonies. I think the small scale guys are going to save the big guys once again, when this is all sorted out. And Andrew Dewey - you should try some Zia stock from New Mexico - our mountain bees live in cold conditions very similar to Vermont. I would think they would do better than TX bees.
 
#12 ·
I appreciate the suggestions of Kirk Webster and Zia stock. Folks may remember last Spring when I was lamenting the seeming lack of commercially available survivor stock (which is how I ended up with Bee Weaver packages.) I anticipate looking for queens to over winter in nucs prior to placing the nucs in production colonies. Any other stock suggestions? Most places won't start taking 2013 orders until January, but I do want to be at the front of the line!
 
#14 · (Edited by Moderator)
Hi Guys

Mike, thanks for the link.

Years ago, I setup a small cell test yard optimized for the scientific method. But when those small cell hives become mite tolerant, I dropped my scientific approach and switched all my hives over to small cell, including the control hives.


At the time I was more interesting in running healthy, productive hives. And less interesting in proving something.


Since then, I’ve always wished I’d left a few of those control hives untouched. I've still got a few questions about that experience that nag me. And the impacts of natural selection and co-evolution are at the top of the list.


And that's why, besides still having some small cell equipment, I'm going to try and replicate those past small cell successes. This time I'll be more interested in the whys and less interested in the hows.

As a natural beekeeper, I've found that the more I can cooperate with the natural processes, the better my bees do. But as with any natural process, there's an interaction of a whole scheme of things:

- bee genetics.
- mite genetics.
- colony health/stress.
- environment.
- colony decisions.
- colony management.

Alter just one and the results can dramatically change.

Beekeepers tend to focus on bee genetics and will go to great lengths to get the right stuff. As a small time queen producer I focused on bee genetics and found out the hard way that:

- when you select for something, you are also selecting against something.

And that something that was selected against often becomes the bee's next weakness in the co-evolutionary dance for survival between the bee and its pests.

My narrowly selected bees were absolutely varroa tolerant. But they were all wiped out by CCD.

Regards - Dennis
 
#16 · (Edited)
Didn't mean to cause drama by my "small scale" comment, just meant to say that local non-migratory beekeepers have provided most of the impetuous for change in the last 30 years or so.

I am all for feral stock. I think a lot of what is being bred for is the wrong stuff. For whatever reasons, my "commercial" stock bees never seem to do as well as my bees of feral origin. By "do as well" I mean survive without treatments or undue manipulations to keep them strong. In fact, they usually don't make it. I have wild derived colonies going strong after several years with no treatments at all, the only manipulations being swarm prevention or the occasional split. Just have to watch their temperament and nervousness.

It is a bit hard to find bees that thrive where I live. they either seem adapted to desert life or high altitudes, but not so much both. I am always looking for wild bees that can do both.
 
#17 ·
Drama? On Beesource? Nah, just wondering what event you might be basing your statement on. Nothing wrong with seeking out and working with feral genetics. I do have my doubts, though, that it will have as much of an impact on the industry as will a large scale breeding program done by those with a very broad genetic pool at their disposal. Let's not forget if humans bred only from the strongest survivors we would have been deprived of a genius such as Steven Hawking. I would maintain that even the most obscure of hives has some desirable traits.
Out of curiosity are your best survivor hives showing any AHB tendencies?
 
#18 · (Edited)
Well, officially it is too cold here for full Brazilian AHB to survive the Winter according to scientists, but we do see them, and bees with their traits. We have had African genetics in New Mexico for many, many years - centuries actually from what I have learned. The Spaniards brought them over with their Iberian/Intermissa bees. They say the Brazilian bees are just passers-by and do not stay. If they do, their genetics are pretty watered down.

I re-queen any bees that are nervous and runny or too defensive. Most of the feral bees where I live are fairly tame, but a lot of them are nervous and runny, and a bit flighty. I have had hives that would fit the description of Brazilian AHB, but those are way out in the desert by themselves and get re-queened pretty quick - or they just fly off when you mess with them too much. They are actually fairly rare. I did 15 removals this year and only ran across two like that. Hard working bees though. They will fill up a box of honey, just have to feed them drawn comb - and not bang them around too much. I only keep the bees that are calm on the comb, store a nice rainbow of honey in the brood comb, and don't mob me when I check them. The others get new queens. On the good side of African/AHB genetics - the bees are all VSH and will pick the mites from each other. I have sat and watched them do it. They will not tolerate hive invaders either - like yellowjackets. I have seen more domestic varieties just let them come right in.

The key traits to watch out for are nervous and runny (as in dripping en-masse from frame when picked up), overly defensive, coming out of the hive and bearding while the hive is opened (heavy bearding in general), very little nectar in the brood nest (it is stored in the next box), and bees that enter and exit the hive like they are being blown out by a leaf blower. I have found the other traits as depicted in the scientific literature to be inaccurate - especially the overwintering part. In general - they behave like untamed, undomesticated wild bees. I do DNA test my bees when they show these traits. Like I said - it earns them a new queen. My mountain bees are mostly Russian/feral crosses - mated at around 8000' feet. Not your usual AHB area. I do not let my bees in the desert keep a queen past the second generation - especially if she is open mated down there - just to be safe. They get one of my Russian/Feral/Survivor queens or similar local survivor based stock from another local beek.

So yeah, AHB is a scary thing, but I have found it to be mostly hype, at least around here. A little closer to the border, yeah, I can see it, but not where I live.
 
#20 ·
Coming late to the game, but, you are assuming that Stephen Hawking came about from the combination of weak genes?

You are also assuming that we humans are outside of Nature and natural selection. Or that what we do w/ the husbandry of species is not in fact natural, part of Nature. Is that correct?

I'm sure I am one of those people who don't understand, so I don't mind whatever answer comes my way.
 
#22 ·
Coming late to the game, but, you are assuming that Stephen Hawking came about from the combination of weak genes?.
Hi Mark: no. I've made no assumptions about the cause of his illness at all.

You are also assuming that we humans are outside of Nature and natural selection. Or that what we do w/ the husbandry of species is not in fact natural, part of Nature. Is that correct?
If you think of Nature as what is, and happens, without humans in the picture, and 'artificial' as what happens as a result of our acts, you get a nice clear dividing line that enables to think clearly about the two separate spheres of causes. Humans practice 'arts', operate with 'artifice'. A round rock tumbling down a hill follows an entirely natural path.

The human construct 'Nature' was devised to make this distinction (by the ancient Greeks), and I think that's the best way to use it. (Acts of Gods are also ruled out of Nature BTW. That leaves 'physica' as a mechanical sphere in which matter simply rubs against, and moves matter - and that makes it possible to look for 'laws' of nature. With all else ruled out you can make the assumption that identical causes will have identical effects - and the rest is the history of science.)

Of course, we come from nature, and are part of nature - but if you think that way its very hard to have conversations about what is 'natural'.

Mike
 
#24 ·
I'm not sure I'd put it quite that way. Adopting that position enables clear and simple conversations, that's my point. This is human activity, that is natural activity. Natural stuff happens alone - the rock rolling down a hill example - human activity is artful, purposeful. Its results are artifacts, and artificial, in the sense of non-natural (according to our definition).

Its not perfect, but its a useful way of working. We can say: 'bees naturally mate competitively', without having to then think about how we remove humans from the picture. We can talk about natural 'selection' as opposed to human selection (of parents).

Mike
 
#26 ·
Yes they do. Quite naturally I guess. I think we're going a bit off topic here Mark. Why don't you try reading the Wiki article (an extract below), and thinking about the issues for a little while?

Best wishes,

Mike

Within the various uses of the word today, "nature" often refers to geology and wildlife. Nature may refer to the general realm of various types of living plants and animals, and in some cases to the processes associated with inanimate objects – the way that particular types of things exist and change of their own accord, such as the weather and geology of the Earth, and the matter and energy of which all these things are composed. It is often taken to mean the "natural environment" or wilderness–wild animals, rocks, forest, beaches, and in general those things that have not been substantially altered by human intervention, or which persist despite human intervention. For example, manufactured objects and human interaction generally are not considered part of nature, unless qualified as, for example, "human nature" or "the whole of nature". This more traditional concept of natural things which can still be found today implies a distinction between the natural and the artificial, with the artificial being understood as that which has been brought into being by a human consciousness or a human mind. http://en.wikipedia.org/wiki/Nature
 
#32 ·
mike bishop said:
Do you think they should have to? I'll be happy to offer a defence of my treatment-free beekeeping. I don't suppose the forum rules allow us to ask treaters to defend their point of view? But then, perhaps its rather obvious; they want to keep their bees alive, and (sometimes) to preserve and enhance their livelihoods, and they don't see an easy path to doing that without treating. Often they don't believe it is possible. Both positions are understandable. But I think non-treaters are entitled to complain, on grounds that treaters downgrade and endanger both wild bees (and the genetic diversity that belongs to future generations) and their own (i.e. my) bees. It effectively amounts to mass slaughter by genetic poisoning.

Best wishes,

Mike
Mike,
In my own case I have experienced that not treating is not a viable option. For me. Not yet. How to keep bees in largeish numbers w/out antivarroa mite treatments is not something I can afford or have not figured out how to establish in my business.

This is sort of what you eluded to above. And I don't write it in defence as much as to agree w/ your point.

I'm finding this discussion interesting. I look forward to reading more.
 
#33 ·
Mike,
In my own case I have experienced that not treating is not a viable option. For me. Not yet. How to keep bees in largeish numbers w/out antivarroa mite treatments is not something I can afford or have not figured out how to establish in my business.
What sorts of things have you tried Mark?
 
#34 ·
Well, my main experience w/ not treating for varroa waas either the same year as CCD was identified or the year before. I had 732 hives in May 2006(?) or was it 2005(?) and had not treated them that Spring. By Fall, when it was time to transport them South for the Winter I was down to 432 and did not treat them then either. By March of the next year I was down to 100 colonies. I have not yet recovered back to the original number or up to the 800 I have pallets for, for a number of reasons.

I did not consider continuing not treating or even raising queens from the survivors. I am not that organized or that good at grafting. So I borrowed colonies to cover my pollination contracts. I bought honey to cover my obligations to my customers, stores. I bought queens to use in splits, every Spring. I used mite treatments which successful beekeeping friends used.

Since then I have not had really big loss. I have had some years of 33% loss, but this last year losses were more like 10 or 15%. The best in years. Attributable to what exactly I can't really say. Don't really know. Coulds have been the mild Winter. But my hives Winter in SC where harshly cold weather is usually not much of a factor. Bees can be worked almost during any week of the Winter in SC.

What else can I tell you? Thanks for asking.
 
#35 ·
Hi Mark, When you wrote earlier: "In my own case I have experienced that not treating is not a viable option. For me. Not yet. How to keep bees in largeish numbers w/out antivarroa mite treatments is not something I can afford or have not figured out how to establish in my business."

...I had imagined that you'd looked into given treatment-free beekeeping, come to understand the principles, tried it, and failed. (Had you rebuilt from your survivors I think you'd likely have made it!)

A lot has been learned about raising mite resistant bees in recent years. If you undertook to study the principles and form a structured breeding program to that end, I'm pretty sure you'd be able to do it. There might be some cost to productivity for a while.

I can't offer any more than that - I've never kept bees on that scale, and am in the early stages of a much more modest breeding program. But everything I learn shows that the increasing number of people who think that treatments are addictive and a major part of the problem, are right. The paper I linked to is just one of a number of sources that can help us understand the underlying nature of the problem - a useful first stage I think in forming a plan to overcome it. There are more from my link page at the website below my signature.

Best wishes,

Mike
 
#37 · (Edited)
Hi Mark, When you wrote earlier: "In my own case I have experienced that not treating is not a viable option. For me. Not yet. How to keep bees in largeish numbers w/out antivarroa mite treatments is not something I can afford or have not figured out how to establish in my business."

...I had imagined that you'd looked into given treatment-free beekeeping, come to understand the principles, tried it, and failed. (Had you rebuilt from your survivors I think you'd likely have made it!)

Best wishes,

Mike
I should have made it clear that I meant for me when I wrote that treatment free is not viable. Viable for me. If I did not make thaty clear.

You could very well be correct Mike. But life circumstances will quite often direct actions. I am sure you understand that. Had I another source of income, a job other than what I supplied myself, perhaps developing a business based on nontreatment could possibly been doable. On the other hand I have only heard of a small handful of commercial operations smaller than mine here in the US. So, it seems that indicates that goinbg treatmenty free on a commercial basis is not practical, yet.

Commercials do seem to be going towards softer, more natural, miticides like formic acid and thymol based materials. Perhaps in time this will lead to less or even no treatment. Time will tell. Then we will look back and wonder why we didn't do things differently from the start.

ps: thanks for your patience and willingness to naddress this issue with me.
 
#38 ·
I have observed there seems to be a size cut-off for being able to go totally treatment free. I cannot tell if it is because of the ability to provide more oversight of the hives or if it is the "too many rats in tha cage" effect. The larger you get, the harder it becomes to stay totally treatment free. It seems to be that way with many animals.
 
#41 ·
As I understand it John Kefus and his partners have managed this - I think they run several thousand hives. I think operations on that sort of scale are requeening yearly, and I would think it would be necessary to be taking breeding queens (and sourcing drones) from the farmed stock, in order to be managing a process of co-evolution with the mites. But it could be there is just too much horizontal transmission of mites genes to allow the milder, less fecund strains of mites to evolve - something that is I believe key.

It may be too that there are limits to the degree to which you can pack hives and expect them to thrive without throwing chemicals at them. Like battery hens; at a certain size and density its impossible to continue without systematically feeding antibiotics.

In theory at least a large operation could be composed of a number of smaller genetically independent apiaries - in which case any such critical-mass problem shouldn't exist...?

These are just my own thoughts mind...
 
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