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Dr. Keith S. Delaplane and the Importance of Polyandry - your thoughts?

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In this video dated February, 2013...

Dr. Keith S. Delaplane of the University of Georgia gives a talk entitled "Honeybee Breeding: Fact or Fiction", in which he challenges the effectiveness of selective breeding, and suggests that polyandry (or the queen's mating with many males of different genetic make-up) is the key to the success of the bee.

He talks about some early results he got in recent work where they compared the performance of different colonies in a variety of categories, in which the queens had been mated with increasing numbers of drones. Their findings suggested a clear correlation between positive performance and a higher number of matings.

He concludes that he feels that a better direction for bee breeding may be one in which people are selecting for traits in their bees, but then sharing drones with others, so that a given breeder has access to a wide variety of drones - each representing strengths in specific areas, such as varroa resistance, productivity, gentleness, etc etc.

I'm wondering if any of you are familiar with this philosophy, and even if you are not, what your thoughts are on what Dr. Delaplane is suggesting.

Thanks,

Adam

Here's the link again http://www.youtube.com/watch?v=txZtQrMTeag
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David Tarpy, North Carolina State University, has been talking about this for years. His work is online. Look for his 50:50 theory...concerning resistance to chalkbrood.

His theory, which I believe, is why I no longer use an isolated mating yard. I feel it's better to stock my mating area with a good mix of my stocks than to attempt to use only a very narrow number of colonies in isolation.
 

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MP. What range do you consider to be your mating area? I have had a few anecdotal experiences that suggest to me that you need to have lots of drones within a half mile to get optimal mating.
 

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I think the importance of genetic diversity in bees has been greatly ignored for 150 years. Almost all breeding programs narrow the gene pool significantly. It's important to maintain multiple lines of bees and not raise all your queens from only a few "mothers".
 

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Discussion Starter · #5 ·
David Tarpy, North Carolina State University, has been talking about this for years...
Delaplane specifically references Tarpy's work, and talks about the paper, "The curious promiscuity of queen honey bees (Apis mellifera): evolutionary and behavioral mechanisms", by David R. Tarpy & Robert E. Page Jr.

Mike Palmer, you say that you no longer use an isolated mating yard. Have you noticed specific changes for the better in your bees since doing that? Or did you just lose faith in the method and find results just as good while simplifying your process?

I'm just wondering specifically how some of these theories might translate into practices for a smaller breeder - and by that I mean 100-300 colonies.

Adam
 

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A few thoughts: Can anyone remember that last year there was a beesource member who wanted to start a drone exchange program in which he was sent drones and then sent back queens? I wonder how that went?

I had another thought, could it be that treatment-free beekeepers(by whatever definition they choose to use) are seeing success in their apiaries (again by their definition) not as a result of the lack of treatment but by the drift in their stocks to heterozygosity compared to the queens that are generally supplied?
 

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> could it be that treatment-free beekeepers(by whatever definition they choose to use) are seeing success in their apiaries (again by their definition) not as a result of the lack of treatment but by....

This is like saying "could it be that Joe is healthier, not because he quit smoking but because he exercises every day?"

Of course it's both...
 

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MP. What range do you consider to be your mating area? I have had a few anecdotal experiences that suggest to me that you need to have lots of drones within a half mile to get optimal mating.
If you look at what's written, the recommendations are all over the place. Some say drone mothers in the same apiary, some say a quarter mile. Some say farther. I've read that if you want pure mating, you must be 8 miles from the nearest colonies.

I have a valley that is bordered by lake Champlain to the west, and a ridge line to the east. Total length of valley about three miles. I have three apiaries in the valley, one at 3/4 mile, 1.5 mile, and 2.5 mile. Another's apiary is about 1.5 mile to the north.

I used to truck everything over to the Adirondacks. Too much driving to do the work. Also not sure I really want isolated mating, so I changed. Rather I build up those three yards with goo stocks and let them be. The patterns are good.
 

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I would lean heavily on Brother Adam's work to say that both selection and diversity are important in honeybees. If they are unselected, then you get any traits that are present, bad or good. This usually means heavy swarming, dark honey, and poor production. With a moderate level of selection pressure, that can be changed to moderate swarming, light honey, and good production.

As for varroa mites, I have not had a problem with them since 2005. My bees are all highly tolerant. I deliberately triggered heavy swarming a few years ago with the result that there are wild colonies all over this area now. I am now catching swarms that originate from bee trees. It has been 20 years since this happened on a routine level

So why are honeybees so susceptible to inbreeding?
 

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Discussion Starter · #12 ·
If they are unselected, then you get any traits that are present, bad or good. This usually means heavy swarming, dark honey, and poor production... So why are honeybees so susceptible to inbreeding?
A question:

Aren't most of our honeybees pretty heavily "selected" already? I mean, with most of our bees by far coming from a relatively few breeders, and everyone talking about how the feral population is so low - aren't our bees pretty well selected for things like production and swarming? I suppose areas with AHB might have some issues, but generally speaking - how much truly terrible stock is out there?

Brother Adam was working from a relatively clean slate, with local bees having been decimated by disease. He then brought in distinctly different races of bees from all corners of the world to build up from, selecting along the way.

But most of North America has a pretty solid population of "bred bees" - or bees originating from breeders, or beekeepers who are keeping bees for the same reasons. So the broad strokes (gentleness, production, disease resistance, low swarming) are all areas almost everyone is selecting for to some degree.

Aren't they?

Adam
 

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Fusion, according to Delaplanes lecture, and also I recall seeing the same thing in ABJ, honeybees are vulnerable to inbreeding - particularly in the US. The reason given was that we started off with a far narrower range of bee "races" as parents and not a particularly diverse sample of bees from those races as compared to the range that were available in Europe.
There are important bans on live bees to prevent disease, but there has been recent work to bring in new stock. I think it was Sue Coby who was going back into Europe and bringing back honey bee semen to add to the diversity of stock. She had to get permits if my memory is correct.
 

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>So why are honeybees so susceptible to inbreeding?

Reproducing naturally they are not. Reproducing by grafting, you end up with hundreds up to thousands of full sisters. Reproducing by grafting AND Instrumental Insemination, you could end up with thousands of full sisters mated to the same genetic line on the male side, in other words full sisters who are all mated to the same drone mother's drones. viz mated to drones who are all full brothers.
 

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Discussion Starter · #15 · (Edited)
I feel that all of this has a potentially huge part to play in one's approach to bee breeding.

How do you take the importance of polyandry, and an understanding of a bee's susceptibility to inbreeding and apply it to your program? What are the practical applications? Is it as simple as selecting only for the broadest areas such as pest resistance, production and gentleness, and then making an effort to make sure they mate broadly? Openly?

I don't see yet how you can do both - select and breed widely. Selection is counter to polyandry. And that's the crux of it. Delaplane's suggestion is that the success of the bee is rooted in her mating broadly, from a wide genetic range. And it makes sense.

To me the importance of polyandry is reflected in the fact that the urge to mate with many males as stood the test of evolution. Mating flights are highly perilous. There is a high probability that queens will die during mating flights. So it would seem that queens who mated less would survive more often. I'm sure that's true - odds are in the favor of queens who take that flight fewer times. However, the colonies who are built from queens with a wider range of mates survive more often, so the selection pressure of surviving multiple mating is outweighed by the health of colonies who are built from it.

I just don't see how you can both select, and maintain polyandry in practice.

Any ideas?

Adam
 

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I am not sure that I agree with the assumption that there is little polyandry in breeding programs. Assuming first that a well mated breeder will be laying fertile eggs from a number of different drones and given that you are free to choose from any number of different breeders not just from within but from what you choose to bring in from other sources, and this dosent even factor in the many hives which raised their own via self raised swarm or supercedure cells. So then the biggest concern would seem to be whether you have a lot of genetic diversity in not just your operation but your area as a whole supplying the needed drones. I would think it depends to a large degree on how your program is structured. We use quite a few breeders and as a visual example the last time we bought any Cordovans was almost 30 years ago. Since we have raise our own we have never used any breeders with the distinctive Cordovan coloration yet we quite often still see these bees (both workers and drones) mixed in with the general hive population.
 

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>I just don't see how you can both select, and maintain polyandry in practice.

Polyandry is built into the instincts of the bees. We short circuit the results with a narrow gene pool. If a queen mates with a bunch of drones who are all from the same mother, then while physically there is polyandry, genetically there is not.
 

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This whole question is extremely complex. Generally in most any domestic stock bred for some type of performance there must be some minor inbreeding at minimum to fix traits. Without fixing traits you simply do not get anyplace close to optimum performance. There is no other critter that presents the genetic difficulties that bees present as far as I know. Bees have two problems. They tolerate inbreeding poorly. Queens mate with multiple drones. The whole trick with inbreeding is to get enough inbreeding to fix desirable traits without so much inbreeding that you get inbreeding suppression.

Different animals tolerate inbreeding to different extents. The largest, healthiest, most showy guppies for instance are the result of crossing two lines that have each been brother sister mated for 20 or more generations. All mice used in lab testing are the result of many generations of brother sister matings. In both cases inbreeding suppression is simply horrid around generation five to eight and many lines are lost, but then becomes less and less of a problem. But, bees simply will not stand that kind of inbreeding. Still, that does not mean zero inbreeding. Anyone in the business of developing a line of breeder queens is going to have to do some inbreeding. He may well not realize it but he will be doing it. He will also do some outcrossing from time to time.

A big problem with inbreeding is it is not simply the last generation or two that counts. You really need to look back eight or ten generations. With bees this is simply impossible due to mating with multiple drones. So you can not calculate inbreeding coefficients like you can normal critters. As a bee keeper your only real choices are to breed queens from your best performing queens and at any hint of inbreeding problems bring in new blood preferably from a source that has some distant relation to your bees. And you can still expect to raise dud queens fairly often. With today's technology that is about the best you can expect. In another 20 years or so DNA sequencing is going to be cheap enough it will likely become practical to sequence individuals and with various DNA analysis techniques learn exactly which genes give superior performance in the production hive. Holstein cattle are there today. At that point we can hope to see some great progress. At that point things like Varroa will likely become a distant memory.
 
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