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VSH Breeding?

68K views 169 replies 34 participants last post by  adamf 
#1 ·
I've noticed the number of threads with VSH in the title, so I thought I would ask this question, as I've been wondering about this for a while.

I've read the postings over on the VSH Breeders website/forum, and I can't tell if (outside the formal USDA program) anyone is actually testing for VSH.

We know that HYG and VSH will not persist in the population unless they are constantly selected for generation after generation.

...so how are breeders (that are not just propagating USDA stock) qualifying their bees as VSH? How are they able to provide VSH behavior without testing? How many generations have these stocks gone since they have been properly evaluated for VSH?

There is certainly less of a consensus about what constitutes a valid VSH test than there is for HYG...but if someone is going to claim that their bees are HYG or VSH, it seems there should be something observable that is being evaluated?

Any thoughts?

deknow
 
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#159 ·
We have the same problem with the VSH bees we have produced in my country, variability. Which is interesting, considering the base stock we began using to produce the VSH bees is likely different to that used in the US. An 80% VSH queen can be mated to an 80% VSH drone, but the daughter queens can be anything from 80% down to 20%. Our researchers have concluded that there cannot just be one gene involved in VSH, but a combination that all has to come together.

None the less, this does not mean we should just give up. My belief is we should continue to select from the best, concentrating the useful genes in the general bee population.

From the same study mentioned by DeKnow
http://www.beesource.com/forums/showthread.php?277652-VSH-Breeding/page8

"Genetic effects of queen type affected the change
in infestation of brood by V. destructor (Table 1).
Colonies of ARS VSH and Glenn Apiaries VSH reduced
infestation by 76 and 64%, respectively. Infestation
was reduced an average of 44% by VSH production
colonies (six sources combined) and 7% by
control colonies".

So there is considerable variability in mite reduction in these colonies, and in that respect, it could be claimed that the purchaser "does not know what they are getting". However the amount of reduction is quite clearly useful, especially if someone was wishing to attempt treatment free beekeeping, or keep treating but use less.

In my country, the researchers also monitored (but did not select for) honey production, and have discovered no significant difference in honey production between our high VSH bees, and non VSH bees. So, one could say about using these bees, "what's to lose?"
Although I have been told that with the US VSH bees it is thought there is a difference, but have not seen any figures.
 
#162 ·
Mike,

Very interesting study.

The F1 VSH removed 51% of varroa infested larvae as compared to 66% for VSH.

In a practical sense I wonder how this relates. For instance, someonewho sells VSH queens grafted from VSH breeders. The area has a lot of VSH drones. I wonder how much VSH behavior you would get by raising queens from those F1's?

Tom
 
#165 · (Edited)
I was wondering when you'd post about this! :D


We now perform two tests in our breeding program that select for VSH in addition to other economic traits. We use a large population and have an initial two-year selection cycle.

No colony is treated for mites in our operation. We're going on our 16th year without mite treatment. Our bees our gentle, productive and have done well for us. Our customers

like them too! Good VSH expression is one of many qualities good stock should have.


There seems to be an interest to make a VSH selection program more organized and cooperative at some point. Measuring VSH expression along with other good qualities

constitutes a breeding program. When one selects in a program, the chances of finding suitable breeding candidates is greater when one has a larger population. The "numbers game" again.

A group working together would achieve this more readily by having a greater collective population to select from. Still, finding a group of potential bee breeders who can readily make queens over the season and keep good records

has not been simple. Performing the non-reproductive VSH test: http://www.extension.org/pages/30984/selecting-for-varroa-sensitive-hygiene#.VHhy7kSweJs as well, has been a challenge.



You are correct that there are many claims for VSH expressing stock now.

We've found that this rubric works well when advising people on queen producers and queen strains:


"Follow the consistently good producer who consistently has good queens/bees."


Year in, year out, the outfits that have good stock will always do well for their customers.


VSH expression will exist in a population where both sides of the cross carry the heredity for the behavior. If the breeding population

does not have significantly high levels of VSH expression, the queens mated in that area will have less and less VSH, and less chance for mite resistance.

When curious about a strain's VSH expression, ask a queen producer for the history of their breeding program and ask if they will provide references.


Cheers,

Adam
http://vpqueenebees.com
 
#167 ·
I was wondering when you'd post about this! :D
Hi Adam....I didn't post about this again...the post you are quoting is the one I posted almost 2 years ago.


We now perform two tests in our breeding program that select for VSH in addition to other economic traits.
I'd be interested in 2 things:
1. What are the tests?
2. When you tested your existing breeding population, did the tests mirror your assumptions as to the amount of expression in various populations?

VSH expression will exist in a population where both sides of the cross carry the heredity for the behavior.
I don't think statments like this help with general understanding (which is my goal). VSH behavior is not 'present' or 'not present'....it is the extent of the expression that counts. It would be like trying to classify humans as either having height or not having height...in fact the question is 'how tall'.


...does not have significantly high levels of VSH expression, the queens mated in that area will have less and less VSH, and less chance for mite resistance.
Certainly they have 'less chance for bite resistance THROUGH THE VSH MECHANISM, and (in the scenereos i laid out on the first page of this discussion) by the time you have selected for VSH to produce a strong expression you have probably selected against other mite resistant traits...the ones the bees actually use when no one is selecting for VSH.

When curious about a strain's VSH expression, ask a queen producer for the history of their breeding program and ask if they will provide references.
I'd give that advice to anyone curious about the substance and quality of a breeding program (ask history and ask for references). I don't think these will help very much in determining the VSH expression of a stock. The history (unless it is all first generation II USDA VSH breeder stock) doesn't tell you much about the VSH expression, and unless the references are doing a VSH assay on the colonies, they can't really offer any insight as to the extent of VSH expression.

I'm all for good queens from good operations with good reputations for producing good queens. In the end, I don't think VSH has much to do with it, and certainly the way it is so often used (to produce a mite resistant localized line by crossing VSH breeders with local stock) doesn't accomplish lasting results....unless VSH stock is constantly brought in....in which case the only real breeding that is happening is from the VSH supplier, and there is no lasting local progress to be made.

deknow
 
#166 ·
Nice post Adam. I got a few queens from Adam and Kelly a couple years ago and am really pleased with them. One in particular I am watching like a hawk. Made a huge crop of honey and came into the winter just as strong. I'm planning on it being the star of my breeding operation this coming spring.
 
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