# Is Hygienic behavior sufficient to suppress Varroa?



## jim lyon (Feb 19, 2006)

JW, How do the "all" and "nothing" groups compare in terms of seasonal populations and productivity?


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## squarepeg (Jul 9, 2010)

one of the other traits our researchers have been looking into at the usda lab in baton rougue is the ability of the bees to decrease the mites' reproduction rate, (mechansim not understood at present).

randy oliver's model predicts that just a 10% reduction in mite reproduction results in an 80% decrease in mite population at the end of the season. (see his comments on the 26 minute presentation @ 9:20 and 24:00).

perhaps progress on this will show more promise than vsh has so far.


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## crofter (May 5, 2011)

Thanks for posting this: it certainly is in the face of commonly accepted thinking about the relative effectiveness of VSH behaviour. It calls question to possibilities that other mechanisms may be at work for people whose bees seem to be managing better than average success against the mites. There is something just a bit disappointing about having the right answer, but for the wrong reason!

The fading of resistance seems often a problem that makes treatment free hard to transport away from the often isolated conditions where it originates.


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## jwcarlson (Feb 14, 2014)

SP, I thought that was an interesting figure as well. The reduction in population with only 10% reproduction rate. I wonder how difficult that 10% is to obtain...?


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## AR Beekeeper (Sep 25, 2008)

When they say 'hygienic" aren't they talking about the removal of sick brood and not the Varroa Sensitive Hygiene, which is a different type of action?


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## JWChesnut (Jul 31, 2013)

AR Beekeeper said:


> When they say 'hygienic" aren't they talking about the removal of sick brood and not the Varroa Sensitive Hygiene, which is a different type of action?


Correct. The paper is very specific that they use a Freeze Killed Brood removal assay to assess hygienic behavior. The paper discusses the odor of DWV infected pupa as a trigger for hygienic removal.

Danka's paper highlights a distinction between the Freeze assay and VSH as determined by artificial innoculation with mites. http://www.ars.usda.gov/SP2UserFile...519-Danka--Varying congruence of hygienic.pdf


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## deknow (Jul 17, 2006)

This is pretty much agrees with the data on HYG and AFB...that it is really a brink effect and in the case of AFB, I think the magic number was 94%.


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## squarepeg (Jul 9, 2010)

brink effect? what's that dean?

more on 'suppression of mite reproduction' - smr:

http://www.ars.usda.gov/Services/docs.htm?docid=2744&page=13


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## deknow (Jul 17, 2006)

1. Don't get confused by the acronyms. SMR was rebranded VSH years ago...anything referencing SMR is likely rather old....but they are the same thing.

2. By brink effect I mean that at a very high percentage of HYG, you get some impressive disease and pest resistance. When you go below that threshold where the effect is seen you don't find an effect almost like that above the brink.


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## squarepeg (Jul 9, 2010)

thanks for the correction dean, i should have waited until i read the last report: 

http://www.ars.usda.gov/Services/docs.htm?docid=2744&page=16

"Analyses were restricted to cells infested by a single varroa foundress because few multiply infested cells were found (17 in a total of 329 infested cells). Fewer mites were found in combs that had been transferred to SMR colonies (Table). This suggests the hygienic removal of infested pupae by the adult bees with the SMR trait. SMR bees removed 91 % of pupae having reproductive mites and 58 % of pupae having infertile mites that had produced progeny. Pupae having infertile mites that had no offspring were apparently not removed (Table). Thus, the cue for varroa-sensitive hygiene by bees with the SMR trait is probably related to the presence of mite offspring (Figure)."

apparantly the hygienic behavior is selective for fertile mites, leaving the infertile ones behind and giving the impression that fertility is affected, when in reality it's just selective hygiene.

still learning here. 

wrt the brink effect, figure 6 of the page 13 (smr trait) report suggests intermediate results can be seen when bees bred for resistance are outcrossed.


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## johno (Dec 4, 2011)

VHS and the removing of brood is one thing, but there was another mechanism that interfered with the fertility of mites so those mites were not able to breed. Some of the breeders actually open capped brood and count the number of breeding mites and look for the number of mites without daughters. It really becomes a bit much for the average beekeeper to keep track of mite fertility so all we can go on is colony mite loads, and when they are low we just guess that it is from some sort of mite resistance.
Johno


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## deknow (Jul 17, 2006)

I'm trying to be clear...

1. Note that they talk about 'having the SMR trait' and 'not having the SMR trait...but this is like saying that people have height or they don't have height...the trait is defined by an overexpression of a characteristic by inbreeding...a hypertrait. If i said I was going to breed people who have height with people who don't have height, you would point out that it makes no sense...everyone (outside of flatland) has height...some have more than others, and at some point, in some contexts, much height becomes 'tall'.

2. When I talk about the SMR trait being the same as VSH I'm not making an analogy...the same trait (set of traits) that used to be called SMR is now called VSH. ...regardless of how you interpret the behavior or the labels. Even wikipedia documents this: https://en.wikipedia.org/wiki/Varroa_sensitive_hygiene 

3. I don't know what the percentage of SMR expression is in the crossed colonies...but the crossed colonies were open mated, and both the control and SMR were II.


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## squarepeg (Jul 9, 2010)

johno, it does make one wonder why it is that some of those foundress mites are infertile. randy oliver mentions some new areas of research at the end of his 26 minute presentation involving botanicals that may suppress mite reproduction. it made me wonder if areas with resistant bees have something in the environment that could be helping in that way. 

i've also wondered about the percentage of beekeepers that breed their own queens vs. purchasing commercially produced ones. selecting breeders based on low mite counts is something that a lot of us could probably do and maybe it would make a difference in the long run.


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## John Davis (Apr 29, 2014)

Johno is correct in that the folks working on the development of VSH bees use a count of opened cells recording number of cells that contain mites and also percent of reproductive females. Breeders are chosen for both low mite loads and low levels of reproductive female mites. This is a workable method of expressing the level of VSH shown. The other method of measuring the expression is to put combs of highly mite loaded brood into a hive and then recounting the level after several days and reporting the percent reduction. This method requires maintaining highly loaded hives for the production of the measurment combs.


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## beemandan (Dec 5, 2005)

John Davis said:


> The other method of measuring the expression is to put combs of highly mite loaded brood into a hive and then recounting the level after several days and reporting the percent reduction.


This would appear to me to be a much more accurate method of quantifying VSH than the freeze killed brood (fkb) method. FKB, to my thinking, is a broader measure of the bees ability to detect and remove dying or dead brood...regardless of the cause...and may or may not show their ability to detect and remove varroa infested brood. Just my opinion.


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## beemandan (Dec 5, 2005)

squarepeg said:


> selecting breeders based on low mite counts


Countless professional researchers and queen breeders have done this for decades. They've used all sorts of closed mating and II methods in an effort to limit the influence of unselected populations. And...to this day....I'm not aware of any substantial breakthroughs i.e. bee strains that limit mites without beekeeper intervention.


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## squarepeg (Jul 9, 2010)

i hear what you're saying dan, and i'm not really disagreeing with you, but i must admit that my exposure to the universe of beekeeping is pretty much what i read hear on the forum and what i can glean from skimming over what articles are published online.

what the ars published recently regarding their pol-line collaboration with breeders since 2008 leads me to believe that progress is being made toward increasing mite tolerance in the commercial stock.

reading between the lines it sounds like jim lyon has been working within that program, i.e. incorporating proven genetics and then selecting his breeders from his most tolerant, and that he is has been making some gains over the years. of course he is aggressively nucing and requeening (similar to how randy oliver runs his operation) and that may play into how he is able to avoid multiple and year round treatments, but this is in stark contrast to operations who report 'the mites are winning' and having to increase their treatment regimens to stay ahead of them.

what i don't have is any way of knowing and what my comment was getting at was whether or not the 'typical' beekeeper is taking advantage of the opportunity to select breeders from the best of their best vs. relying on commercial breeders who may be mass producing queens from a limited stock.

again i hope that you can forgive my naivete on the subject, and breeding one's own queens may be more trouble than it is worth to many, and i'm not talking about treatment free so much as just trying to advance resistance in the general bee population in hope of gaining some ground with mite tolerance, but it seems like if most everyone were using selection in this way the story line would have a better chance of reading 'the bees are winning'.


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## beemandan (Dec 5, 2005)

I think producing one's own selected queens is a fine idea. I just wouldn't want any newcomer to think that the idea of selecting for low mite counts was anything new. All too many seem to conclude that mite resistance is a simple matter of a few generations of selection....and voila!....mites are no longer an issue. If their research is limited to Beesource...it might come across that way.


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## beepro (Dec 31, 2012)

They can somewhat suppressed the mites.
But after uncapping them the mites are free running often
clinging to one individual helpless newly hatched young bee.
On a few occasion I saw this mite family sister reunion going on.
Once the new broods are ready the mites will enter the cells again.
I have to use the oav gadget to knock out some of them. Yep, the mites
are still in there alright.


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## squarepeg (Jul 9, 2010)

beemandan said:


> I think producing one's own selected queens is a fine idea. I just wouldn't want any newcomer to think that the idea of selecting for low mite counts was anything new. All too many seem to conclude that mite resistance is a simple matter of a few generations of selection....and voila!....mites are no longer an issue. If their research is limited to Beesource...it might come across that way.


good post dan, and i believe were are in agreement.

what i am curious about is how large or small percentage of meduim to large scale operations have been doing the work of selection over the 20 years varroa has been with us vs. opting for the easier and less expensive approach of treating and outsourcing their queens from suppliers who may not be so aggressively selecting for mite resistance.

i do understand that there can be a trade off between resistance and productivity that potentially factors into the bottom line, but on the other hand there are those reporting here that find those traits are not necessarily mutually exclusive, again assuming the work of selecting for both traits is in play. 

what i think is just as misleading for those getting all of their information from this forum only is that strains of bees being kept off treatments and still productive is nothing more than a fairy tale. a common argument given is that we see no one shipping their resistant queens all over the country and others getting the same results with those queens.

while the issue of queens not performing miracles when transplanted to areas far away from their origin may be true enough, i think those with enough background and an open mind understand the many factors at play here, so i take those types of remarks for what they are worth which is not much.

in my view anyone sitting around waiting for someone else to come up with the answer to all of their problems and not even trying to work within their own stock to advance desirable traits forfeits the opportunity to be cynical and certainly shouldn't be criticizing those who are trying. 

i am appreciating more so now than when i first read it randy oliver's admonishment is his 'queens for pennies' article for all us to look at selecting the best from our best as part and parcel of beekeeping, especially in these days with varroa. i'm not talking cold turkey treatment free here, but at least we need to be moving the bees in the right direction. sorry for the rant.


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## beemandan (Dec 5, 2005)

squarepeg said:


> what i think is just as misleading for those getting all of their information from this forum only is that strains of bees being kept off treatments and still productive is nothing more than a fairy tale.


The pendulum seems to swing to both extremes, no doubt. There are those who seem to believe it is a fairy tale as well as those who suggest that it is a relatively simple process. 
I will say that those countless professional researchers and breeders the world over who have, apparently, failed to produce a genuinely treatment free bee after many decades of diligent effort, suggests to me that backyard breeders who achieve success are a rarity. I believe that they exist as is indicated by a number of posters here, but I think they've had exceptional good fortune. Just my opinion.
By the way Kevin, didn't you send some queens to Baton Rouge for evaluation? If so, did they ever report any results?
I hope you have had a grand Christmas and New Year.


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## squarepeg (Jul 9, 2010)

beemandan said:


> The pendulum seems to swing to both extremes, no doubt.


agreed. 



beemandan said:


> didn't you send some queens to Baton Rouge for evaluation?


not yet. i've only raised a limited number of queens myself and i was hoping to buy a couple from the original supplier this year to send. unfortunately the supplier met with health issues and wasn't able to propagate last year. i've actually got more hives than he does at this point. we had a good talk the other day and are going to try and work together on queen production in the upcoming year. chances are good we'll get some to the bee lab. bob danka has expressed interest and willingness to give them a look.



beemandan said:


> hope you have had a grand Christmas and New Year.


many thanks dan! all the best to you and yours, and to the forum as well.


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## Richard Cryberg (May 24, 2013)

beemandan said:


> .
> I will say that those countless professional researchers and breeders the world over who have, apparently, failed to produce a genuinely treatment free bee after many decades of diligent effort, suggests to me that backyard breeders who achieve success are a rarity.


You can never say impossible as sooner or later the right combination of mutants will come along. We might, or might not have all the needed mutants today. No way to tell.

But, I think there are more important things for the backyard guys to worry about than varroa. Take swarming for instance. I think there is decent evidence that swarming is highly genetic. Yet most likely the favored way for the average backyard bee keeper to propagate is either splitting a hive with swarm cells or cutting out swarm cells and putting them in mating nucs. In either case you are selectively breeding for increased swarming. To make matters worse one major way bees cope with varroa is by swarm induced brood breaks. Start selecting low varroa hives then propagate from those hives via swarm cells and you may just be selecting for more swarming twice.


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## beemandan (Dec 5, 2005)

Richard Cryberg said:


> You can never say impossible as sooner or later the right combination of mutants will come along.


I'd never say impossible....but....I don't know that there's any guarantee that the right combination of mutants will come along. I am hopeful though.


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## crofter (May 5, 2011)

A host / parasite arrangement is an ongoing fluid process is it not? If mutations among bees occur will their success related to mites be worth the possible tradeoffs? Will it also incur a genetic bottleneck where genetic diversity is lost? I have seen laments about how limited the bees already have become, yet I see comments that we will not solve the mite problem till all the commercials start running bees with the same package of developed coping habits. That is not a recipe for resilience.

Can we expect the mite to stand still in its own genetic mutation program or will it mutate and cancel our present moves?

Diddling with the bees genetics seems a noble pursuit compared to genetically modifying varroa but the latter might have less potential "bite us in the arth" consequences in the long run; we dont exactly have a trouble free record of making only wise decisions with our manipulations and transporting of species! Are we making some huge unfounded assumptions that because it is what _we_ really, really want it is destined to happen and with no downsides.


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## Fusion_power (Jan 14, 2005)

Yes, mutations are occurring, however, 99% of all mutations are detrimental and the remaining 1% are mostly harmless. In other words, a truly beneficial mutation is a very rare bird. It is not necessary to generate new mutations in bee breeding for varroa tolerance. There are mutations already present in the genome that can be combined to improve tolerance. The issue is that we need huge numbers of colonies to get a chance of a few having really good combinations. So long as the majority of commercial colonies are treated for mites, that chance is highly unlikely to occur.

I am posting this highly aware that the bees I keep already have significant varroa tolerance, but have a lot of room left to improve.


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## crofter (May 5, 2011)

Once these mutations even if they are existant in small numbers, are selected for and promulgated in large numbers to drown out the existing susceptible bees, will they not bring into dominance all their other characteristics. I just cant underdstand the assumption that only what we desire will come with this overwhelming package. Apis ceranae's has some very unmarketable habits. What will the next parasite be? Will what we will have done in our solution to the present varroa nuisance, have implications for the next challenge that the bees face? Is it a simplistic solution?


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## Eduardo Gomes (Nov 10, 2014)

"A suggested mechanism involved in reducing the mite's reproductive success could be for example, the adult bee behavior known as Varroa-sensitive hygiene (VSH), which involves the uncapping or removal of mite-infested brood (Harbo and Harris 2005; Ibrahim and Spivak 2006). It has been shown that bee colonies expressing this behavioral trait may selectively remove pupae with reproducing mites resulting in the remaining infested cells having a misrepresented higher proportion of infertile mites (Harbo and Harris 2005; Ibrahim and Spivak 2006). This could potentially be a mechanism of the Avignon population, in light of the observed high mite infertility rates. *Since the Gotland population does not demonstrate hygienic behavior (Locke and Fries 2011) nor had significantly high proportions of infertile mites, there is no reason to suspect that they are expressing VSH. Instead, the suppression of mite reproductive success in Gotland may be due to another mechanism, such as pupal volatile compounds that can inhibit the initiation of egg-laying of mites (Garrido and Rosenkranz 2003; Milani et al. 2004).*" 

in Host adaptations reduce the reproductive success of Varroa destructor in two distinct European honey bee populations; Barbara Locke, Yves Le Conte, Didier Crauser and Ingemar Fries; Ecology and Evolution Volume 2, Issue 6, pages 1144–1150, June 2012


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## crofter (May 5, 2011)

If your bees have varroa sensing behaviour it would be quite an advantage even if it were not sufficient to make them totally mite tolerant. I dont think it has to be an all or nothing proposition. If their own capabilities can be augmented a bit by the beekeeper even if forever, why not. People who keep horses may have to deworm them twice a year (as I do) but that seems an acceptable proposition. Rotation of treatments are necessary to prevent the very real development of resistance but that should be taken for granted with any treatment. That seems like a reasonable analogy to me.

We brought a bug to this continent that was native to Europe, then accidently introduced another species from Asia for which it has no inherent coping mechanism. The Asian bee that seemingly co habits with the varroa mite took, what, hundreds of thousands of years to adapt (swarming half a dozen times a summer and producing a mere fraction of the honey) yet we assume that adaptation here of the European bee can be accomplished in a handful of years. Some claim all that needs to be done is merely stop helping them cope.

Whatever can be done with the bees _without_ burning any bridges (or setting the scene for them to burn their own bridges) seems like a good proposition, but since the mite problem is presently manageble, I think we should be very cautious when contemplating actions when we cannot foresee all their consequences. It supposedly is very hard to put a Genii back in the bottle!
.


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