Breeding for mite tolerance

[bjosephd]

Any ideas?
Well, you could start by trawling through the forum to locate those who are treatment free and beg a queen or two?

 

[bjosephd]

BUT ....Breeding for mite tolerance may not be necessary ... I started out with a swarm and decided (for a variety of reasons) that I was not going to treat for varroa .. I have five good colonies that have all descended from that original swarm and one that came, last year, from a compost bin cut out from miles away from home. They are all surviving and look healthy ... it's too early to inspect properly but through the clear crownboards and on the landing boards they seem fine.

So ... I'm NOT trying to breed selectively, I haven't lost a colony yet for any reason and it's working for me ...

The worst case scenario is that you do lose your bees ....but before that happens, as a vigilant beekeeper, you will see the signs of a weakening colony .. heavy mite fall, DWV, lethargy, reducing numbers, dysentry etc. ... all associated with a varroa infestation that has become out of control (and YES - I've seen that in other colonies - I look after one that seems to attract every bloody varroa mite in the county no matter how much it gets treated) and it's not too late to give them a hand with an OA Sublimation.

Some colonies seem to be targets for varroa mites and yet colonies next to them have very few ... I don't begin to understand why ... it's such a complicated set of factors that there is, at present, an element of luck involved in becoming treatment free - certainly as a hobbyist with just a few hives there is going to be a risk ... but until you take that risk with a colony or two - you won't know.

The thinking that 'Your bees will die if they are not treated' does not always hold true ... it might have done once upon a time ... but it's not always the case now.

also!

 

[Fusion_power]

The best path to treatment free is to get your bees from a treatment free source. I got really lucky back in 2004 when a swarm moved into one of my hives and tested very highly for varroa tolerance. I got doubly lucky that I was able to get some queens from someone who had put in several years of hard selection to produce bees that were varroa tolerant. Then I got triply lucky that the combination of my queen's genes with the drones from Purvis' queens was a really good combination for this area. Most beekeepers won't get that many chances. I'd like to emphasize that I am doing everything I know to spread the genetics in this area. There are three beekeepers here who don't know what it means to treat bees for varroa. If you asked them if they are treatment free, they would scratch their head and look at you funny and ask what on earth is a treatment. This is what I would like to see beekeeping become again, a place where people don't have to worry about varroa.

If I were in your area, I would certainly be checking the stock John Kefuss has in France and I would check out Juhani Lunden's stock in Finland.

 

[charlievictorbravo]

.
One story from Holland Dec 2015

https://www.wageningenur.nl/en/news...arroa-mites-may-use-different-mechanisms-.htm

..............the naturally selected colonies rapidly acquired resistance to Varroa mites and are now able to survive without any treatment against the mite.

What this university in Holland has "discovered" is what Ron Hoskins at Swindon (http://www.swindonhoneybeeconservation.org.uk/) found 10 years earlier. His bees were grooming and removing infected larvae and have been chemical-treatment free since 1995. His website does not appear to give figure for probability of mite removal but I'd hope they were better than the Dutch figures.

The interesting aspect of all this is the work done on Ron's bees by a group of virologists coordinated by Prof Declan Schroeder at the MBA in Plymouth. The scientists found that there was a different Deformed Wing Virus variant in the Swindon bees that by a process known as superinfection exclusion protected the bees from the more virulent variants of DWV. This discovery has posed almost as many questions as it has answered.

Ron Hoskin is trying to get a virologist on board (anybody who's tried to read the Schroeder paper will understand why) in order to carry out more research but for me the interesting question is does the Swindon variant of DWV make bees hygienic or does hygienic behaviour somehow remove the virulent form of DWV and just leave the the non-lethal variant in the colony. Other tests are needed to understand transmission of immunity. I.e Queen via her eggs, Drone via his semen, Worker via their feeding, etc.

Ron is a member of this forum but does not post very much (and who can blame him if he were to get the sort of treatment here that other non-treaters get) but here is a link to his latest post about hygienic bees and virus research - http://www.beekeepingforum.co.uk/showthread.php?p=508868#post508868 Any beekeeper or beekeeping group wishing to contribute financially to Ron's research should contact him via his website or at the Holsworthy Spring Convention in north Devon next Saturday- http://holsworthybeekeepers.org.uk/spring_convention_2016.shtml

CVB

 

[TryingToLetThemBee]

What this university in Holland has "discovered" is what Ron Hoskins at Swindon (http://www.swindonhoneybeeconservation.org.uk/) found 10 years earlier. snip . This discovery has posed almost as many questions as it has answered.

snip

Yes, as I said above.

But I'm going to deploy my MBO degree here and say that a lot of the "questions" are pretty laughable. Immunity acquired (non genetically) through bee semen. Come on! At the MBO course they give you an Occam's Razor and that simply says that "B" is a dominant gene. Treatment keeps the populations off equilibrium and allows the recessive "A" to emerge / dominate even after it has done its original tour, as in Hawaii. At least, it gives that as a hypothesis worthy of investigating. So dollars gets you donuts that Dutch population has the "B" virus.

ADD The key is in the paper in the word "RAPIDLY". Bees do not evolve rapidly, but mites and virus populations can switch from recessive to dominant genes RAPIDLY.

 

[Fusion_power]

Bees do not evolve rapidly

Bees adapt just as fast as the selection pressure applied. Very high selection pressure produces very fast rates of adaptation. Varroa represents an extremely high level of selection pressure when there are no beekeepers treating.

The significant takeaway from the Dutch paper is that there are multiple resistance mechanisms to varroa. This strongly suggests that competitive displacement is not necessarily present in diverse mite tolerant populations of bees. It also suggests that combining multiple mite tolerance mechanisms will produce better results over the long term. So Ron's bees could likely benefit from crossing with another mite tolerant line with a different resistance mechanism. A combination of VSH + Allogrooming has been exceptionally productive for me. Carpenters queens mated to my line drones are better honey producers than either parent line and have very low varroa counts at any time of year. http://www.carpentersapiaries.com/

With genetics, it is best to avoid simple explanations. Single gene traits are easy to analyze, but are rarely the entire story. As example, roughly 10% of Cream Legbar hens carry a trait that reduces size of eggs and lowers egg production numbers. I have not seen a single example of a Cream Legbar breeder who has figured out why a significant number of their hens are low producers. The bad part is that the trait involved is probably a chromsome deletion instead of a defective gene. I spotted the pattern after detailed analysis to find out if I could use Cream Legbars for some breeding work.

 

[mbc]

If I were in your area, I would certainly be checking the stock John Kefuss has in France and I would check out Juhani Lunden's stock in Finland.

Kefuss's bees have a reputation for overly defensive behavior, Juhani's bees arent overly sought after even in his native Finland and both are the other side of the channel from where we in Britain should be looking to source our bees imho.

 

[jenkinsbrynmair]

both are the other side of the channel from where we in Britain should be looking to source our bees imho.

But where would we be if we didn't import our bees

 

[bjosephd]

Sounds like the best bet is Ron Hoskins' bees from Swindon Honeybee conservation group. But I can't seem to find any queens for sale. Maybe I need to make a call or two.

Fusion_power - that makes a lot of sense what you say about extreme selection pressure. I think I read something in book saying something to the effect of if nobody had treated ever for varroa that we'd probably be out the other side by now. I know it's not that simple. But there's some value in the point. (Albeit a period of devestation for commercial beeks and very sad for hobby beeks)

 

[charlievictorbravo]

But where would we be if we didn't import our bees

We'd have a thriving bee/queen breeding industry and we would not have Varroa.

CVB

 

[charlievictorbravo]

It also suggests that combining multiple mite tolerance mechanisms will produce better results over the long term. So Ron's bees could likely benefit from crossing with another mite tolerant line with a different resistance mechanism. A combination of VSH + Allogrooming has been exceptionally productive for me.

From my reading of the Swindon Bees website, Ron's bees had both behaviours - grooming/biting and larvae removal. The interesting question is are bees hygienic because they have Type B DWV or does the Type B DWV come to dominate in a hive.colony because the bees are using hygienic behaviours.

The Type B virus is calculated to have been around for 180 years - http://www.pubfacts.com/fulltext/26...riant-of-the-Deformed-Wing-Virus-quasispecies so it is not developing now from Type A in mites or bees. The mites tested from Swindon had both Type A DWV and Type B whereas the bees only had Type B, which is where the theory of superinfection exclusion came from.

Clearly research is needed to establish the mechanisms whereby these viruses affect bees and the method of transmission. This is not work for amateurs!

CVB

 

[jenkinsbrynmair]

We'd have a thriving bee/queen breeding industry and we would not have Varroa.

CVB

didn't take long for that trap to spring

 

[mbc]

didn't take long for that trap to spring

Kept my foot out just long enough....

 

[mbc]

My thoughts on resistance, evolution and co-evolution, are that it's always going to be a hard road with regards to varroa and bees, at least in our lifetimes.
The nature of insect populations is naturally boom and bust, and however hardy, vsh, grooming, isolation, or whatever that allows bees to survive for a while despite varroa, when that bust comes it's always going to be more dramatic and devastating with varroa there as a vector.
Several times I've thought there was light at the end of the tunnel, only to feel the pain as another wave of losses occur.
Oav all round for me at the moment, and breed from the bees which respond best to this management.

 

[TryingToLetThemBee]

But where would we be if we didn't import our bees

Isle of Man?

 

[TryingToLetThemBee]

snip The interesting question is are bees hygienic because they have Type B DWV or does the Type B DWV come to dominate in a hive.colony because the bees are using hygienic behaviours.

snip

Clearly research is needed to establish the mechanisms whereby these viruses affect bees and the method of transmission. This is not work for amateurs!

CVB

No but amateurs can have a view and this amateur says that the idea of a virus CAUSING hygienic behaviour is pretty far-fetched; think about the effect on its survival.

 

[charlievictorbravo]

No but amateurs can have a view and this amateur says that the idea of a virus CAUSING hygienic behaviour is pretty far-fetched; think about the effect on its survival.

Without more research, we are just speculating.

We know that mites can hide in plain sight by mimicking the scent of the colony. Suppose that one effect of the Type B virus is that the bees or the mites change such that the bees can detect the mites and deal with them. That's just one possible explanation but I'm sure there are others - that's why further research is needed.

CVB

 

[TryingToLetThemBee]

Without more research, we are just speculating.

We know that mites can hide in plain sight by mimicking the scent of the colony. Suppose that one effect of the Type B virus is that the bees or the mites change such that the bees can detect the mites and deal with them. That's just one possible explanation but I'm sure there are others - that's why further research is needed.

CVB

Occam here: bees with "B" can fly. But let's see what happens. I am going to continue to try to treat varroosis not mites.

 

[charlievictorbravo]

Isle of Man?

Australia?

 

[Juhani Lundén]

Kefuss's bees have a reputation for overly defensive behavior, Juhani's bees arent overly sought after even in his native Finland

With 500€ price tag I don´t wonder...

Italy has been my main market area so far, Poland comes second.