# VSH trait: bees biting legs of varroa mites?



## Phoebee (Jan 29, 2014)

I just heard about this in a discussion with a few beekeeping friends a few days ago.

http://www.indianahoney.org/2013/02/Greg-Hunt-of-Purdue-University-and-his-varroa-biting-bees.cfm

I'm going over the photos I took of dropped varroa last year, wondering if this is what I've been seeing. We introduced a VSH queen to one hive last year, and that hive's mite drop rate rose as her offspring took over the hive, reaching what I thought were alarming rates (close to 200 per week). However, the sugar roll tests we did suggested a very low infestation (0-2 mites seen/300 bees), so I wondered if I was seeing a VSH behavior in operation. We finally did a formic acid treatment to see how many of the little beggars were in there, and the count was indeed low ... around 700 mites dropped over the course of a week.

Now, having been told about a VSH behavior that evidently involves biting the legs off of mites, I'm going over photos I made and I'm not seeing many legs. Many also have a light color which I thought might mean they were immature and were the result of removing infested larvae. These were collected on an IPM board sprayed with veggie spray.

The queen in question is not directly from a VSH breeder. Her mom was at least one generation removed and bred with an apiary with local mutts plus some Russian genetics. Whatever the case, I like this queen so far ... her girls survived the winter (so far) still strong, and still have honey to spare.









I've got too little experience with this to know what I'm looking at. Any comments?


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## JRG13 (May 11, 2012)

Look intact to me, but I think you'd need a scope to really tell, their legs are pretty small and not much wider than their carapace.


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## enjambres (Jun 30, 2013)

The light colored mites are younger mites (late being laid in the capped cell, and so not quite as mature when the adult bee emerges) and male mites. I have never gotten a clear story about whether they should, or should not, be counted when sticky boarding. So, I do count them. For sure you won't see them on a typical sugar roll, though, so that's one more way the number of mites counted from a sticky board and from any of the rolls will differ.

I must say, I wouldn't call 700 mites dropped over a week after a formic acid treatment a "low" or small number. To my mind, that's hive that was _definitely_ in need of treating. When I get 200-400 from a formic or OAV treatment, then I feel that the hive was ready for treatment, so I wasn't wasting my time, money or accepting any downside risk inappropriately.

My hives are average to huge in size ( 2D/2m to 4D or 2D/5m, all 10-frame).

I wish I had a microsope so I could look fro chewed off legs. Have you seen ESM pictures of the poor creatures after OAV treament with just deformed, eroded, stumps? Kinda makes me feel sorry for them, until I remember what one of my girls with DWV looks like. Then, not so much.

Do you do OAV? I think you will find it right up your alley - be sure to get the protective equipment - and use it!

Enj.


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## Phoebee (Jan 29, 2014)

For a strong colony, let's guess 60,000 bees, after a treatment that is supposed to kill 80% of the mites, to drop 700 should put the level of infestation at a bit less than 2%. That's roughly consistent with 2 mites on a sugar roll, if the sugar roll catches about half the mites present in the sample. I used the WVU treatment method ... supposed to be VERY effective in one dose, even killing mites on capped brood (that's why you keep counting after the immediate drop).

Guidelines are all over the place. One of our club experts would treat at 2%, but most guidelines say 2%, especially in late summer, is pretty low.

What the heck, I treated and they are going strong ... they were even bearding a little on Sunday.

You can pick up some sweet microscopes on e-bay, both inspection (dissection) scopes and high power biological models. I bought a 4-objective AO Spencer last fall for about $125.


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## AstroBee (Jan 3, 2003)

Phoebee said:


> Now, having been told about a VSH behavior that evidently involves biting the legs off of mites


At the risk of splitting hairs, it is my understanding that biting mites is not strictly a VSH trait. Generally, VSH involves manipulating brood in various ways to manage varroa.


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## deknow (Jul 17, 2006)

Astro...aren't you thinking of IPM?


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## shinbone (Jul 5, 2011)

Phoebee said:


> I used the WVU treatment method ... supposed to be VERY effective in one dose, even killing mites on capped brood (that's why you keep counting after the immediate drop)


What is this WVU treatment method?

I use OAV, and am very happy with how it hammers the mites without hurting the bees.


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## Phoebee (Jan 29, 2014)

http://www.wvu.edu/~agexten/varroa/FormicAcid.pdf

My mentor uses this. OAV needs a heated vaporizer and power to run it, and I don't know anybody who has used it. And technically, OAV is not yet approved (tho' I expect it will be). I expect this 50% formic acid method would raise some eyebrows too, but at least a weaker treatment is available commercially.

The WVU system is potent but it works in 1 treatment, even getting mites in capped brood. If you don't use the HBH in the mix as described, there's a 25% chance the bees will ball the queen. I've simplified the fumigator ... I just use an empty quilt box without the extra passages. 

I've tried it exactly once, so don't have enough experience to recommend it one way or the other, just that it was recommended to me, and it worked the one time.


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## AstroBee (Jan 3, 2003)

deknow said:


> Astro...aren't you thinking of IPM?


No. By "brood manipulation", I meant the combined actions that VSH bees utilize to inhibit varroa, e.g., removing varroa infected pupae, uncapping and possibly recapping brood. Again, I don't believe that biting mites is technically a VSH trait. Perhaps I'm wrong on this...


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## johno (Dec 4, 2011)

Hi Phoebee I have used the Amrine and Noel system for some time and I have found that the results vary from hive to hive depending a lot on the size of the cluster and the ambient temperature. Also I have made only 2 fume boards and have tried to treat 6 hives at a time, 2 with fume boards and 4 with FA soaked meat pads and find that the fume boards out perform the meat pads so the design of the fume board does help a lot. By the way there is no EPA label for the use of FA unless you use Quick strips, so I also use OAV after harvesting Honey and late in the season when the bees are broodless. But in the end the only way to find out whats happening are mite counts before and after treatments.
Johno


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## adamf (Jan 28, 2006)

AstroBee said:


> No. By "brood manipulation", I meant the combined actions that VSH bees utilize to inhibit varroa, e.g., removing varroa infected pupae, uncapping and possibly recapping brood. Again, I don't believe that biting mites is technically a VSH trait. Perhaps I'm wrong on this...


Hi there--

AstroBee is correct. "Mite Biting" falls under "grooming behavior". Adult bees will groom other bees and themselves, potentially removing and inhibiting parasites (Varroa) from infesting the colony.

VSH behavior is where Varroa mites are detected and disrupted from reproducing as well as being removed from bee brood (in capped cells). This is _occurring in brood_, not on adult mites.

Follow these links:

Mite "Biting" / Mite Grooming Behavior:
http://www.extension.org/pages/3084...o-measure-mite-grooming-behavior#.VNohSkS9r5A


Definition of VSH Behavior:
http://en.wikipedia.org/wiki/Varroa_sensitive_hygiene

Selecting for VSH Behavior:
http://www.extension.org/pages/30984/selecting-for-varroa-sensitive-hygiene#.VNoh40S9r5A


From the video with Dr. Hunt (previous poster) where he talks about selecting for VSH behavior,

he describes the _Infertility _test (in 3rd link). This test (Non-reproductive) is the most efficient VSH selection test and although tedious, can be performed by a breeder. 

Several breeding programs around the world now use this test to select for VSH in addition to the USDA bee lab in Baton Rouge. 

(_Note:_ Dr. Hunt's description is slightly confusing. If you find a cell with a mite family--immatures and adult female mite, that counts 

as a reproductive mite--the optimum is to find a majority of solo adult mites in capped cells: non-reproductive mites). 

This is the sign you have VSH behavior from VSH expressing bees.


And, yes, if you have VSH behavior _and_ Mite Grooming behavior, your bees are going to be hardy and mite resistant!


Adam
http://vpqueenebes.com


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## AstroBee (Jan 3, 2003)

adamf said:


> "Mite Biting" falls under "grooming behavior".


Thanks Adam. Very nice input.


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## Phoebee (Jan 29, 2014)

adamf said:


> Hi there--
> 
> AstroBee is correct. "Mite Biting" falls under "grooming behavior". Adult bees will groom other bees and themselves, potentially removing and inhibiting parasites (Varroa) from infesting the colony.
> 
> ...


Supposedly, Africanized bees are pretty good at grooming, but I was pleased to hear that Europeans can as well. But durn the lazy videographer, just left the camera running in the back of the room and did nothing to incorporate the slides! I've videoed a number of presentations, and always try to get the slides and put them into the video, full screen and full resolution, so they can actually be read! Now I'll need to do some extra homework to find out what chewed mites look like.

I will say, following the formic acid treatment, the girls spent a lot of time dragging out dead pupae. I don't know if this was pupae killed by the formic acid treatment, or removal due to the varroa, but it was definitely hygenic behavior (removing pupae for one reason or another). So at least I know these bees have THAT trait.

I use the green drone frames. If I remove them to freeze, I always check some cells for varroa, and have photographed some under an inspection scope. 

Anesthetizing bees with CO2, eh? I've got a bottle I use for storing frames (it can kill wax moths in all life stages if concentrated enough). I may have to try that.


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## adamf (Jan 28, 2006)

Phoebee said:


> I will say, following the formic acid treatment, the girls spent a lot of time dragging out dead pupae. I don't know if this was pupae killed by the formic acid treatment, or removal due to the varroa, but it was definitely hygenic behavior (removing pupae for one reason or another). So at least I know these bees have THAT trait.


Yes! That's another set of traits you can select for when breeding bees: Hygienic Behavior. This is different from VSH Behavior. People who select for hygienic behavior will often use

the freeze killed brood assay:

http://www.extension.org/pages/21762/testing-honey-bee-colonies-for-hygienic-behavior#.VNoz0US9r5A


Here's some background on general hygienic behavior:

http://www.beekeeping.com/articles/us/hygiene_queen.htm


Sadly, selecting for hygienic behavior does not indicate if the bees will also show VSH behavior. We skip testing for general hygienic behavior and opt for the VSH Non-reproductive

test described earlier. 

Adam
http://vpqueenbees.com


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## Phoebee (Jan 29, 2014)

OK, YouTube video of a discussion by Greg Hunt on the topic. The first part is on pesticides, but the varroa part starts at 17:00. At 27 minutes there is a short clip of a chewed mite made under a microscope. One member of the audience said he's found he can spot chewed legs by comparing legs on opposite sides of the mite. If one leg looks a lot shorter, it is probably chewed.

https://www.youtube.com/watch?v=ChiA5-J-sPo


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## deknow (Jul 17, 2006)

Astro...thanks for clarifying. I had a hard time reading "...manipulating brood in various ways to manage varroa." as referring to manipulations by the bees rather than manipulations by the beekeeper.

Adam...I'm no expert on how these traits are classified or linked, but I think of 'grooming behavior' as referring to adult bee to adult bee, and the general term 'hygienic behavior' referring to how the bees clean comb and deal with cleaning out diseased brood (and perhaps removing mites), and nursing behavior referring to how the bees are fed and kept warm.

I don't know if mite leg biting is considered (or linked) to grooming behavior, but it is certainly not 'brood manipulation'.

I looked at the link you posted above for "Mite "Biting" / Mite Grooming Behavior". 


> Mite-grooming behavior has been described as the ability of the adult bees to remove Varroa mites during grooming and has been associated with mites that have been chewed by the bees’ mandibles, but the proportion of chewed mites is extremely tedious to measure.


I'm not sure exactly what 'associated with' means, but probably not 'falls under'.


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## deknow (Jul 17, 2006)

adamf said:


> Several breeding programs around the world now use this test to select for VSH in addition to the USDA bee lab in Baton Rouge.


Adam, what breeding programs (or breeders) are using this assay besides the work at Baton Rouge?


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## Phoebee (Jan 29, 2014)

johno said:


> Hi Phoebee I have used the Amrine and Noel system for some time and I have found that the results vary from hive to hive depending a lot on the size of the cluster and the ambient temperature. Also I have made only 2 fume boards and have tried to treat 6 hives at a time, 2 with fume boards and 4 with FA soaked meat pads and find that the fume boards out perform the meat pads so the design of the fume board does help a lot. By the way there is no EPA label for the use of FA unless you use Quick strips, so I also use OAV after harvesting Honey and late in the season when the bees are broodless. But in the end the only way to find out whats happening are mite counts before and after treatments.
> Johno


Johno,

The difference between my quilt box and their fancy fumigator is the queen escape passages that I suspect they put in when they experienced queen balling. I'm not convinced they help ... I think they may just be left over from an earlier experiment. But the quilt boxes do have a layer of #8 hardware cloth that holds the pad about 3/4 inch off the frames below, so they should do the same thing to the vapor as the WVU method suggests. And the next time I try this I'll put the HBH on a separate pad. As soon as you add it to the formic acid solution it begins to react and turn brown. The HBH is supposed to be the real key to prevent balling.

What are the odds the queen would even find the escape passages?


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## johno (Dec 4, 2011)

Phoebee from what I can gather the HBH dilutes the acid to about 45% and that is where the queens are not damaged, the gaps on the sides of the fume board is to allow bees to get above the board if they are distressed by the acid. the top of the board has aluminum above the absorbent pad which is supposed to trap the rising heat from the cluster and thereby evaporate the acid, so less heat less evaporation.
Johno


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## Phoebee (Jan 29, 2014)

johno said:


> Phoebee from what I can gather the HBH dilutes the acid to about 45% and that is where the queens are not damaged, the gaps on the sides of the fume board is to allow bees to get above the board if they are distressed by the acid. the top of the board has aluminum above the absorbent pad which is supposed to trap the rising heat from the cluster and thereby evaporate the acid, so less heat less evaporation.
> Johno


Oh, yeah, I forgot ... I do use a piece of aluminum flashing to get that surface to put the pad on.

If you look down in that paper they will say the HBH does dilute the FA further, but they also say that it is there to prevent balling, and that you must only add it at the last minute due to the fact that it degrades fast.

I never leave the formic acid concentration to chance. I use a hydrometer to set it, and on my next round I probably will set it to 45%.

As for escaping the fumes, the bees hate the fumes, and you can expect them to beard like crazy when the pad is first put in. Workers won't run from much, but they run from formic acid fumes. I see no reason why the queen can't leave for a little fresh air. The question is, would she and could she find those escape passages? She would have to climb to where the fumes are strongest. And the procedure has you button up the hive ventilation, so there probably is not much fresh air above the pad. The paper makes an incorrect statement about the "weight" of formic acid fumes. The fumes may tend to drop somewhat since the molecule is heavier than oxygen or nitrogen, but the compound is volatile as all get-out and the fumes go up, down, sideways ... it is a much lighter molecule than oxalic acid (about half the molecular weight).


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## enjambres (Jun 30, 2013)

@Phoebe,

You wrote:



> For a strong colony, let's guess 60,000 bees, after a treatment that is supposed to kill 80% of the mites, to drop 700 should put the level of infestation at a bit less than 2%. That's roughly consistent with 2 mites on a sugar roll, if the sugar roll catches about half the mites present in the sample..


I think that's one of the statistical fallacies surrounding mite drops: You can't back-calculate the percentage of infestation from sticky board collections, whether from normal drops or treatment, to correlate that number with any published "infestation rate" arrived at by doing a sugar roll. 

Even estimating the hive populatin doesn't help do that.

This is also why intermittent sticky boarding has given the technique such a mixed reputation. It gives almost no valid information about the amount of mites alive (or previously alive in the case of a post-treament count) in the hive, on any one test. It's best use is to tell you whether the mites levels in the hive ar increaing, or decreasing, and at what pace relative to a recent previous test. So it really is about the dynamics of your mite population rather than the actual number of mites. 

Enj.


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## Phoebee (Jan 29, 2014)

Enjambres,

I agree with you more than you think, now. At the time I was getting all sorts of advice from various people, but my gut said the sugar roll data was probably my best measurement, and that what the drop rate (pre-treatment) was telling me was that you can't tell squat from drops onto an IPM board. 

Had I dropped 3000 mites due to the treatment, THAT would have had me wondering. And an effective FA treatment on a badly infested hive would have produced that kind of numbers, but should have also produced higher numbers on the sugar rolls. The main point I was making is that the treatment drop made me trust that I was doing sugar rolls right, and that the previous drops were totally bogus.

Beyond a sugar roll, one could do an alcohol wash, which may give somewhat higher numbers on the same size sample of bees. But I'm too big a softie to do that without a really good reason, and I did sugar rolls on that hive roughly once a month, just getting the hang of it, but would have been highly reluctant to do repeated alcohol washes.

The only truly reliable method would be to kill the entire population and pick thru them, which ain't gonna happen in my apiary.

But this is getting away from the original topic: obviously I was getting bogus information from IPM board counts, pre-treatment, and the question is, why was this happening. My other hive, "hygenic" Carniolans, had similar sugar roll values and very low drop rates. Something my "VSH" girls were doing was making them drop a lot of mites. I suspected better grooming but had not heard that this was a VSH trait ... I'd read just what was said above, that VSH meant pulling infested brood.

Anyway, I'll keep doing the IPM board and/or oil tray exams, but will see if I can learn to identify mutilated mites (ooooh, I like the sound of that). I'll put no trust in the counts, but I'll get the satisfaction of seeing dead mites, beetles, etc, and there is some information to be had from cappings if I can learn to read it.


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## adamf (Jan 28, 2006)

deknow said:


> Adam, what breeding programs (or breeders) are using this assay besides the work at Baton Rouge?


Here are the programs and breeders:


http://www.nelsonhoney.com/queen-breeding-programme/


http://blogs.msucares.com/honeybees/


http://aristabeeresearch.org/


http://www.harbobeeco.com/vsh/


http://vpqueenbees.com


Adam
(see closest link above)


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## SRatcliff (Mar 19, 2011)

I've put in a request to test a couple of these queens this summer. It will be interesting to see how they do.


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