from a post on bee-l about vsh
from a post on bee-l about vsh
mike syracuse ny
I went to bed mean, and woke up meaner. Marshal Dillon
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?
It seems to me that you advocate mimicking the natural selection model, in which productivity under natural (unaided) conditions is the measure of success/ideal assay. (You add in temperament as a secondary and optional feature)
This is great (by me). However it presents difficulties to established apiaries wishing to move away from treatment based regimes while maintaining the productivity and or population numbers that pay their costs. They can't make 'survivability' assays - its too costly.
It is this problem that the breeders are primarily trying to solve.
Or perhaps, there are a range of problems seeking solutions.
I think you are right to say that selecting for a single (if compound) trait (vhs) risks lowering the frequency of competing traits (while selection for survivability and productivity [SSP] doesn't); and that supplies a reason to be cautious. (At least for some - if constant importation of 'vhs' queens solves a commercial problem that's fine)
Are you saying that SSP provides the best breeding approach for any and all breeders, and that the resultant stock will be suitable for all (non-treatment) purposes?
And at the same time, agreeing that the best breeding approach (SSP) is not a suitable in-house way to tackle the problem of shifting an established treating apiary to non-treatment?
Meanwhile, you're also offering a critique of the accuracy of vhs claims.
I'm trying to create a sort of flow-chart of your reasoning here. It seems to me there are top-level and secondary arguments in play, and it isn't quite clear to me which are which in your mind.
The race isn't always to the swift, nor the fight to the strong, but that's the way to bet
Someone who makes a living off breeding can afford productivity losses due to stock replacement, and he can charge more for his genetics to compensate. Not to mention that "the best of 10" is not statistically likely to be as good as "the best of 100".
I know that's how I run, at least. Survivability is very important to me, because we have harsh winter conditions. So is my target a 5% winter mortality rate? No. That implies giving ideal wintering conditions. If I want my stock to have decent survival rates in the hand of beginners, who represent a fair share of my clients, then I must not give my bees better wintering conditions than many beginners do. Survival of the fittest only kicks in when a selection pressure is applied. I do skip the first month of bee sales to recover from my losses, though.
I was wondering when you'd post about this!
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...e#.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.
Last edited by adamf; 11-28-2014 at 09:23 AM. Reason: omition
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.
"People will generally accept facts as truth only if the facts agree with what they already believe."- Andy Rooney
I'd be interested in 2 things:We now perform two tests in our breeding program that select for VSH in addition to other economic traits.
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?
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'.VSH expression will exist in a population where both sides of the cross carry the heredity for the behavior.
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....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.
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.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'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.
"Imagine a world in which we are all enlightened by objective truths rather than offended by them."Neil Tyson
We perform Alcohol Wash test and the Non-Reproductive VSH test on some candidates. Seasonal performance results are considered as well. We make our breeding decisions based on some of this data.
If we test strains of bees here, under our non mite-treatment management, the candidates that are not from VSH expressing colonies barely make it through their first season. These results in addition to our test data
demonstrate that there is a threshold level of VSH expression that needs to be maintained for colonies to survive. We don't usually quantify "%VSH" as that metric; although helpful in thinking about VSH vs Non-VSH
it is not accurate when thinking about the degree of expression. More useful are the survival and performance results, we select those that are great candidates overall.
Hum. Maybe. The literature describes potential VSH expressions (phenotypes) based on proposed genotypes. Once the molecular marker work is done and tested, it will be much simpler to select for high-expression breeding candidates.
This will need to be used wisely, as with any tool that aides, but does not substitute for a comprehensive evaluation of breeding candidates.
VSH expression is found in ALL populations of Apis mellifera. How one selects for it and then combines it with other desirable expressions is what a breeder, breeding for mite resistance, does.
If a queen producer is marketing "VSH Expression" as a benefit, determining how their breeding program and results have been, is a good selection tool for evaluating them. We both know that barely anybody tests for VSH behavior, as of
Hopefully, this will change soon!
Bee breeding has always been a challenge because of how honey bees mate, in the air, with drones from more then one colony. Isolated matings and artificial insemination overcome this challenge. Managing this, has been a goal for any bee
breeder throughout bee breeding history.
Using VSH expression as one component in our breeding program, has helped us to remain treatment-free. We're very grateful to all the people at the USDA who were involved in the discovery and development of VSH for bee breeding!
Last edited by adamf; 11-28-2014 at 08:05 AM. Reason: spellink
I am confused by this statement... If you are advertising based on a genetic characteristic, why would you not select for it? It seems the only way to select for it at this time, would be to measure "%VSH" expression or some similar definition. Since the marker work is not ready yet and there are environmental interactions with the expression of behavioral traits, I would think you would have to rely on measuring the phenotypic expression, at least to some degree.
I do not wish to speak for deknow, but I think that is basis of his question.
Breeder Queens & Honey Bee Nutritional Supplements
We *do* select for VSH behavior. We use two specific tests, and we use gross selection: we choose our breeders from breeding candidates that perform well without any mite treatments.
The statement: "% of VSH expression" is a misnomer and was used originally to describe how close to high VSH expression colonies were estimated to be after crossing. As the genetic mechanics of VSH expression is elucidated
I'm sure there will be several phenotypes that express VSH that are genotypically different. A breeder's selection however, would still be on the overall colony health and performance of the candidate.
Screening for the presence of VSH behavior is what you're describing I think. Certainly that can be selected for and given a value. I'd give it a binary value though: ex: expresses VSH or doesn't express VSH, where there is a cut-off for minimum
score, rather then as a "%VSH Expression".
Is this any less confusing?
Last edited by adamf; 11-28-2014 at 11:18 AM. Reason: formattink