# OAV Resistance?



## blackandtan (Aug 20, 2014)

I've noticed more and more beeks are switching to OAV for mite treatments. It seems as though it will just be a matter of time before mites build up sort of resistance to the treatment. I know they have been using OAV and OAD in Europe for some time. Has there been any sign of mite resistance?


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## dudelt (Mar 18, 2013)

No, there is no sign of resistance and the argument that it will be a long time coming, if it ever happens, is due to the way the mites are killed by OAV/OAD. The OA does not poison the mites. It does physical harm to them.


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## FlowerPlanter (Aug 3, 2011)

We are breeding for it right now, selecting the most OA resistance mites and breeding them, over and over again. Mites have already developed resistance to other treatments.

What was once a one time per year treatment is now being routinely used twice a year. Winter mortality across the board has never been higher.

My hope is feral survivor stock will replace treatments before we are successful at breeding a stronger mite that is also OA resistance.

http://www.beesource.com/forums/showthread.php?318123-Varroa-shouldn-t-develop-resistance-to-OA


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## 1102009 (Jul 31, 2015)

blackandtan;1479584 I know they have been using OAV and OAD in[U said:


> Europe[/U] for some time. Has there been any sign of mite resistance?


As I see it the problem starts with the formic acid treatment in summer which weakens the bees and often kills the queens.
The hives are weak in winter and winter bees short lived, so when the oxalic acid comes there are not many bees left. 
In our winters the bees have no brood brake so when oxalic acid is used, this kills the phoretic mites but not those in brood.
While treating some bees come out of box and die of freezing.

So it´s not always a question of mites getting resistant but of weak bees.
Those who want to aid the bees but treat try to do only oxalic acid.

The mites are getting more virulent though.
Nucs survive but production hives are much infested by virus disease what I hear. They talk of CCD, too.


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## gtwarren1966 (Jul 7, 2015)

blackandtan said:


> I've noticed more and more beeks are switching to OAV for mite treatments. It seems as though it will just be a matter of time before mites build up sort of resistance to the treatment. I know they have been using OAV and OAD in Europe for some time. Has there been any sign of mite resistance?



Have humans evolved a resistance to being hit over the head with a large rock? OA kills mites physically not via poison.


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## Nordak (Jun 17, 2016)

SiWolKe said:


> The mites are getting more virulent


This is one worry when it comes to blind treatment. How are the viral aspects of this relationship adapting? My guess is mites may not ever adapt to OA, but the viral aspect may get much worse. Who's to say while we're killing mites we're not creating the next super virus? Everything comes with a cost.


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## jkard883 (Sep 17, 2014)

Spoke with a entomologist about this and he basically said there isn't a way to develop a resistance to it. Basically the same as humans developing a resistance to fire. Evolution is a powerful thing, but this is acid, it physically burns them, you don't quickly evolve to resist burns.


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## FlowerPlanter (Aug 3, 2011)

gtwarren1966 said:


> Have humans evolved a resistance to being hit over the head with a large rock?


The is the very fact why you have skull in the first place.


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## clyderoad (Jun 10, 2012)

in many of these discussions a little bit of knowledge turns into being an expert on all things 'bee'.
extremely rare that one of our resident brainiacks just says "i just don't know".


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## Groundhwg (Jan 28, 2016)

dudelt said:


> No, there is no sign of resistance and the argument that it will be a long time coming, if it ever happens, is due to the way the mites are killed by OAV/OAD. The OA does not poison the mites. It does physical harm to them.


Agree that there is no way for mites to develop resistance to OAV treatment. Have never lost more than 2 or 3 bees per OAV treatment and only then if they got to close to the hot wand. Have never treated via OAD but OAV has not harmed my queens or slowed down their laying.


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## Nordak (Jun 17, 2016)

clyderoad said:


> in many of these discussions a little bit of knowledge turns into being an expert on all things 'bee'.
> extremely rare that one of our resident brainiacks just says "i just don't know".


I freely admit, "I don't know." Your comment made me laugh, Clyde, and there's a lot of truth to it. 

But I think by overlooking the main problem with mites, the viruses associated with them, we're not looking at the whole picture in the relationship. Sure, it kills mites, and they may never gain resistance, but the pressure for viruses to replicate increases, and viruses can have extreme adaptation measures.


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## blackandtan (Aug 20, 2014)

I was under the impression that we were not sure of the mechanism by which OA kills mites. If it is a mechanical mechanism it is possible to develop resistance via a thicker exoskeleton etc. 
I must admit that in terms of mites I'm out depth. Has there been observed resistance to thymol or Formic acid treatments?


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## clyderoad (Jun 10, 2012)

Nordak said:


> I freely admit, "I don't know." Your comment made me laugh, Clyde, and there's a lot of truth to it.
> 
> But I think by overlooking the main problem with mites, the viruses associated with them, we're not looking at the whole picture in the relationship. Sure, it kills mites, and they may never gain resistance, but the pressure for viruses to replicate increases, and viruses can have extreme adaptation measures.


I just don't know if/how viruses will adapt. I don't know if viruses will become more or less virulent to honey bees or just disappear. 

From my seat at the back of the class I also don't know of a single experienced beekeeper who overlooks the viruses associated with mites.
Do you?


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## Dave Burrup (Jul 22, 2008)

Clyde I know a beekeeper of 40 plus years that claims the virus issue does not exist. He blames it all on pesticides.


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## Nordak (Jun 17, 2016)

clyderoad said:


> From my seat at the back of the class I also don't know of a single experienced beekeeper who overlooks the viruses associated with mites.
> Do you?


Nope. I think if there's room, I'm headed to the back myself.


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## clyderoad (Jun 10, 2012)

He is probably forgetting what ailed the bees 20, 30, or 40 years ago when he started versus now.
He is probably having some trouble recalling how he kept his bees then as compared to now, also.


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## Duncan151 (Aug 3, 2013)

clyderoad said:


> in many of these discussions a little bit of knowledge turns into being an expert on all things 'bee'.
> extremely rare that one of our resident brainiacks just says "i just don't know".


The people that do not know, almost never bother to make a post with that statement! LOL


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## Fusion_power (Jan 14, 2005)

The original question was phrased to suggest that resistance will eventually develop. Several subsequent posts went along with that paradigm mostly because they don't know how acids works. An entomologist who studies bee parasite relationships recently commented that OA is like killing mites with a 5 pound sledge hammer. Pests don't easily develop resistance to 5 pound sledge hammers. It does not matter if the hammer is made of copper, iron, or even wood, it will still kill the mites. The reason it does no major harm to the bees is because they have thick exoskeletons that are more resistant to the acid.


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## shinbone (Jul 5, 2011)

_While true that __given enough time mites could probably adapt to having their feet and mouth parts burned off with acid, such a statement ignores the long timescales that such an adaptation would take. In the mean time, it is just as likely that mites could go extinct for other reasons, bees could go extinct, humans could go extinct, humans could evolve to no longer being able to tolerate or use honey in any form, humans could create a process whereby a superior product is more cheaply produced, etc., etc.

It is for the above reasons that I think a statement to the effect that "mites will probably someday adapt to being chemically burned" is a silly statement, that, at least, should have a few qualifiers noting the long times scales involved, etc., added to make it have any real world meaning.

(sorry for the unnecessary italics)_


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## Nabber86 (Apr 15, 2009)

FlowerPlanter said:


> That is the very fact why you have skull in the first place.


Evolution doesn't work that way; it is much more passive. Humans evolved thick skulls because humans born with thick skulls lived longer than humans with thin skulls. The takeaway is that we don't have thick skulls because our ancestors got beat over the head (active force) all the time.


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## IAmTheWaterbug (Jun 4, 2014)

Groundhwg said:


> Have never lost more than 2 or 3 bees per OAV treatment and only then if they got to close to the hot wand.


If the wand heated up slowly, over the course of 5-10 seconds, instead of going instantly from OFF to BLAZING HOT, that might give bees a chance to get far enough away to avoid harm.


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## IAmTheWaterbug (Jun 4, 2014)

Nabber86 said:


> Evolution doesn't work that way; it is much more passive. Humans evolved thick skulls because humans born with thick skulls lived longer than humans with thin skulls. The takeaway is that we don't have thick skulls because our ancestors got beat over the head (active force) all the time.


But the corollary is that selection pressure only works if there's pressure. There needed to be a reason for humans with thicker skulls to outcompete/outbreed humans with thinner skulls, and large rocks may have had something to do with that.

Otherwise, growing and carrying a thicker skull has a biological cost that doesn't pay off.


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## Groundhwg (Jan 28, 2016)

IAmTheWaterbug said:


> But the corollary is that selection pressure only works if there's pressure. There needed to be a reason for humans with thicker skulls to outcompete/outbreed humans with thinner skulls, and large rocks may have had something to do with that.
> 
> Otherwise, growing and carrying a thicker skull has a biological cost that doesn't pay off.


Has been quite a while since Cain popped Able and does not seem to be much happening as far as thicker skulls, :scratch: yet.


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## Groundhwg (Jan 28, 2016)

IAmTheWaterbug said:


> If the wand heated up slowly, over the course of 5-10 seconds, instead of going instantly from OFF to BLAZING HOT, that might give bees a chance to get far enough away to avoid harm.


It heat slowly. Most likely the one or two I get are caught against the wand as I pull it out of the hive.


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## beepro (Dec 31, 2012)

The mites just like us don't know when the acid is coming.
They cannot tell and be prepared to do so. It is a physical adaption if they can at all.
After so many times of oav trials I still cannot adapt to the toxic vapors. If I cannot then
my offspring cannot too. Only if somehow my lungs can filter out the poison on the burn that
I can adapt. So far I cannot! 
I doubt it that my offspring can find a way to adapt to the acid burn. If they can then our entire
genetics have to be rewritten and so are the mites. When they burn they burn!


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## 1102009 (Jul 31, 2015)

> Has there been observed resistance to thymol or Formic acid treatments?


Why always be so scientific? Use your eyes and you observe that there is no resistance of mites and bees to those treatments but other facts why treatments are in vain or mites surviving.

A hive which has no virus tolerance will die of a small amount of mites. A hive with no defense behavior or a weak one will die quickly after mites outbreed the bees.

We have the wrong thinking. We fight the symptoms instead of rearranging our bee managements to have stronger bees. 

Every treatment has side effects. When you treat, you have to put up with this. Don´t blame it on resistant mites!


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## Nabber86 (Apr 15, 2009)

IAmTheWaterbug said:


> But the corollary is that selection pressure only works if there's pressure. There needed to be a reason for humans with thicker skulls to outcompete/outbreed humans with thinner skulls, and large rocks may have had something to do with that.
> 
> Otherwise, growing and carrying a thicker skull has a biological cost that doesn't pay off.



Humans and mites are evolving every day. Small mutations occur all the time, _without any outside influences._ The vast majority of mutations are insignificant, some are really bad, and very very few result in a good trait. Over millions and millions of years some humans were born with thin skulls and some were born with thick skulls. This is due to sheer chance and is not the result of any outside influence. The ones with thick skulls just happened to survive better because the ones with thinner skulls tended to die off quicker. This does not mean that we _developed_ thicker skulls because we kept getting bonked over the head with rocks. Just as mites are not going to develop resistance to OVA by getting nuked with OVA over and over.


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## IAmTheWaterbug (Jun 4, 2014)

Nabber86 said:


> Humans and mites are evolving every day. Small mutations occur all the time, _without any outside influences._ The vast majority of mutations are insignificant, some are really bad, and very very few result in a good trait. Over millions and millions of years some humans were born with thin skulls and some were born with thick skulls. This is due to sheer chance and is not the result of any outside influence. The ones with thick skulls just happened to survive better because the ones with thinner skulls tended to die off quicker. This does not mean that we _developed_ thicker skulls because we kept getting bonked over the head with rocks. Just as mites are not going to develop resistance to OVA by getting nuked with OVA over and over.


Yes, we are in violent agreement. Rock bonking doesn't cause thicker skulls to grow. Rock bonking causes those who happen to have thicker skulls to survive.

If humans did not encounter significant head trauma on a fairly significant basis, there would be no benefit to those who randomly grew a thicker skull, and therefore they would likely be outcompeted by those who _didn't_ randomly grow thicker skulls and who hadn't paid the weight/energy penalty for doing so.

By analogy there may be some mites out there who are marginally less susceptible to OAV, either because their exoskeletons are thicker or their hemolymph chemistry has more X or less Y or ?????. In the absence of OAV pressure these random variations could have no effect or a negative effect on their survivability and ability to breed.

But regular OAV treatments _might_ cause differential survivability of these traits, especially if the treatment kills less than 100% of breeding mites. So poor treatment practices and light dosages could accelerate the propagation of adaptive traits, much as partial treatments of antibiotics accelerate the development of resistant bacteria.

By analogy, if you were to hit every human in a population with a well-placed, 100 lb. rock, you would wipe out that population, and there would be no advantage to having a slightly thicker skull. But if you were to launch a shower of 2-5 lb. rocks at them, periodically, you would kill a few and injure many, and over time you would be selecting for those who had randomly developed thicker skulls (or faster reflexes, or the brains to manufacture helmets).


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## crofter (May 5, 2011)

'sa bunch of trumped up catastrophizing ; go split some wood or something! 



_Grant me the serenity to accept the things I cannot change,
Courage to change the things I can,
And wisdom to know the difference_


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## IAmTheWaterbug (Jun 4, 2014)

I'm afraid I'll get hit on my thin skull if the axe head flies off.


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## Snaggy (Nov 24, 2015)

There's always a flipside to evolution. As skulls got thicker, a price was paid. Maybe smaller brainpans, maybe the extra calcium needed to thicken the skull, AND redesign the neck and rest of the skeleton to bear the weight meant an excess demand on nursing mothers or left less calcium for other bones. Maybe it's because important nerves exit through small holes in the skull and thicker bones were a problem. This is why thick and thin skulls reached equilibrium. In nature it's all about balance and compromise.

What price would varroa pay to tolerate corrosive chemicals? A thicker less flexible chitin shell might have implications in molting or hitching a ride on the bee. It the spiracles are the point of entry into the mites body, changes would require extensive changes to respiratory mechanisms. The mite can't grow too large and heavy with add-ons and still parasitize a little critter like a bee. If humans had to evolve to tolerate airborne acids, we'd surely look and act a lot different than humans today.


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## crofter (May 5, 2011)

Here is a link to an interesting take on the mites reliance on their very specialized and delicate feet and how oxalic acid hits their figurative, "Achilles tendons".

http://www.moraybeedinosaurs.co.uk/Varroa/weakest_link.htm

Some adaptations such as releative thickening or thinning of an existing structure would be a very simplistic adaptation to aquire; something as specialized as the varroa feet would need some serious engineering work around in the presence of a substance that immediately renders them incapable of making a living. 

Many are taking the position that varroa must, as of some law of nature, evolve to successfully thwart humans and their OA. Adaptation _can_ happen when a species faces novel environmental resistance but the most common result in deep time, has been extinction of the severely challenged organism.

The information commonly available makes me think that the people forecasting certain (or even most likely) resistive adaptation to OA by the mites, are catastrophizing big time. Too much weight is being given to ideologic values rather than supportable and statistically sound probable outcomes.


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## Kuro (Jun 18, 2015)

Maybe mites can get away from weekly OAV by shortening the phoretic stage, even if they are still susceptible to the acid… The flipside in this scenario is that such mites would have less chance to spread to other hives. So I am hoping it will not happen.


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## IAmTheWaterbug (Jun 4, 2014)

crofter said:


> Here is a link to an interesting take on the mites reliance on their very specialized and delicate feet and how oxalic acid hits their figurative, "Achilles tendons".
> 
> http://www.moraybeedinosaurs.co.uk/Varroa/weakest_link.htm
> 
> ...


The article sounds plausible, but it's ultimately a guess. Proving it would require a well designed experiment, probably involving some highly controlled application of OA to the feet of immobilized mites, followed by assay of mite soup. (I can imagine some of you laughing maniacally as you celebrate the execution of these mites). 

This is something that the U.S. Dept of Ag can and should fund. We just need a bunch of grad students and an entomology professor!

And I'm not predicting the success or failure of some eventual mite adaptation; I'm just trying to dispel some myths about how evolution works. And to note that life has performed some pretty miraculous evolutionary feats throughout history.


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## Nabber86 (Apr 15, 2009)

IAmTheWaterbug said:


> But regular OAV treatments _might_ cause differential survivability of these traits, especially if the treatment kills less than 100% of breeding mites. So poor treatment practices and light dosages could accelerate the propagation of adaptive traits, much as partial treatments of antibiotics accelerate the development of resistant bacteria.


Evolution is not as simple as _cause and effect_. OVA treatment will not cause anything to happen. Mites may naturally happen to develop thicker foot pads, or some other attribute that makes them less susceptible to OVA, but that could happen with or without OVA treatment. OVA has no affect as to whether this happens or not. If they develop thicker foot pads naturally, then those mites may be less susceptible to OVA. They could just as easily develop thinner foot pads making them more susceptible to OVA. Treating with OVA only makes a difference _after _some mutation naturally occurs. There are literally millions of random mutations that can occur and it could take millions of years for a single mite to develop thicker foot pads. There is no reason why they would develop thicker foot pads over any other of millions of mutations. They could grow 2 heads and a tail before they get thicker foot pads. So it they may happen to develop thicker foot pads some day, but the chances of this happening are as slim as a 2 headed mite.


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## IAmTheWaterbug (Jun 4, 2014)

Nabber86 said:


> Evolution is not as simple as _cause and effect_. OVA treatment will not cause anything to happen. Mites may naturally happen to develop thicker foot pads, or some other attribute that makes them less susceptible to OVA, but that could happen with or without OVA treatment. OVA has no affect as to whether this happens or not.


Yes, I understand that completely. OAV will not affect whether or not a trait randomly develops. OAV _might_ affect whether or not a randomly developed trait becomes beneficial, and therefore whether that trait becomes an advantage. If it does become an advantage, then it may become more and more prevalent in the population as it differentially out-competes other traits.


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## crofter (May 5, 2011)

Conviction that something must be so, and the creating of a compendium of coercive analogies, is not scientific proof of concept. That package is about on the same level as politics!

When I sense something is loaded with suggestive language I am pretty sure the audience is being led.


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## Nabber86 (Apr 15, 2009)

IAmTheWaterbug said:


> Yes, I understand that completely. OAV will not affect whether or not a trait randomly develops. OAV _might_ affect whether or not a randomly developed trait becomes beneficial, and therefore whether that trait becomes an advantage. If it does become an advantage, then it may become more and more prevalent in the population as it differentially out-competes other traits.


Agreed. It is an if/then scenario. If a mutation naturally occurs, then OVA may have some impact. I think too many people are hung up on a cause and effect relationship. Rereading your posts I see where we agree. 

To me it then becomes a question of what are the odds and when it may happen. I am guessing on the order of million of years as opposed to tens of years. Realistically, the chances of bees mutating so that they are less susceptible to the viruses that mites carry is just as probable (or more so) than mites developing thicker foot pads. But who really knows?


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## bucksbees (May 19, 2015)

Dont we thinner skulls compared to Neanderthals, Cro-Magnons?


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## beepro (Dec 31, 2012)

And don't forget that we have other mite treatment options as well.
Even if they evolved to have thicker pads the other treatment will get
them at an earlier stage. That is why it is so important to rotate your
treatment option every season. Give them a natural brood break too like I did.
After all these years if they develop the resistant then we all have it by now. Besides,
a highly infected colony will be crashed at early Spring time so how can any resistant be developed, huh?
We often hear about the tf hives dying and the new beekeepers don't know why and asking for the right
answer. Too late by then!


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## FlowerPlanter (Aug 3, 2011)

Developing acid resistant pads is only one of many things they might do to improve their chances (already 4% of the mites beat OAV and 10% beat OAD). How long before this number goes up to 4.1%... Or has it already? An increasing number of treatments per year, higher than ever winter mortality?

OAV only kills the phoretic phase of mites, we are currently selectively breeding the mites that can get back into a cells the quickest. 

And viral loads, since it has jumped species this mite has made quite the deal with DWV. 

What about a better hiding place on the bees? Is there less exposure to vapors if the mite hides between scales or body segments? Even just enough so 4.1% mite survive? 

We are killing weak mites, to keep weak bees alive.


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## crofter (May 5, 2011)

Maybe a few of the foregoing items could use bit of a disclaimer that they may be assumptions or predictions rather than hard fact.

I dont think there are any mite treatments that are 100% effective so that point is perhaps a bit of a strawman in relation to the question of OA resistance developing.

The alternative to treating is not treating, and that could conceivably get around this present point of time problem, varroa. We all know that is only a dream of being possible to enforce so lets get on with reality of the situation being faced; that is that treatments *will* continue and work will continue to see if a non treatment regime is possible on anything like a widespread commercial scale.

Remember Apis Mellifera is an introduced species and the varroa mite is an exotic parasite from yet another location that has jumped species. Events here that have fast forwarded and broken the rules of long term adaptive relationships. You simply cannot invoke the rules in the old handbooks and predict so accurately.

I think it is a good idea just as a matter of course to use a rotation of the non accumulative treatments that appear not to be highly conducive to establisment of resistance. Formic acid, Thymol, perhaps the hops compounds etc., are useful tools to keep in our kit.

I am definitely no fan of the organophosphate miticides: we have come a long way since they came on the picture.


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## IAmTheWaterbug (Jun 4, 2014)

Nabber86 said:


> Agreed. It is an if/then scenario. If a mutation naturally occurs, then OVA may have some impact. I think too many people are hung up on a cause and effect relationship. Rereading your posts I see where we agree.


We don't just agree; we're both correct! 



> To me it then becomes a question of what are the odds and when it may happen. I am guessing on the order of million of years as opposed to tens of years. Realistically, the chances of bees mutating so that they are less susceptible to the viruses that mites carry is just as probable (or more so) than mites developing thicker foot pads. But who really knows?


Natural selection happens faster when there is increased selection pressure, and also when the selection pressure is highly specific for certain traits. Both are true for varroa mites facing OAV treatments, so I would not be surprised to see it happen in tens of years, or even faster.

As a corollary, look at what has happened with highly hygienic bees. In the absence of varroa mites the ankle-biter trait and the infested-brood-cleaning trait would be rounding errors, and might not be selected for in natural honey bee populations. Right now humans are accelerating the selection of this trait throughout the populations of managed populations.

Regarding mite adaptions, one can think of many possible routes, including altered physiology, altered chemistry, altered lifecycle (as mentioned above). If an altered life cycle seems implausible, look at some of these convoluted parasite life cycles and think about what bizarro mutations must have occurred under bizarro selection pressures to select for them.


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## Nabber86 (Apr 15, 2009)

FlowerPlanter said:


> Developing acid resistant pads is only one of many things they might do to improve their chances (already 4% of the mites beat OAV and 10% beat OAD). How long before this number goes up to 4.1%... Or has it already? An increasing number of treatments per year, higher than ever winter mortality?
> 
> OAV only kills the phoretic phase of mites, we are currently selectively breeding the mites that can get back into a cells the quickest.
> 
> ...


Where did you get the 4% figure?


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## FlowerPlanter (Aug 3, 2011)

The 4% is not scientifically proven (that I know of). Have read OAV kills anywhere from 92 to 96 percent depending on source, R Oliver says OAD kills around 90%. 

Lots of variables may coming to play for the differences. The mites may find one they can take advantage. They may already have; increased their survival by 0.1 percent and we wouldn't even know it. 

As MB said if you cull only drone brood you're selecting mites that breed on worker brood. 

Alternate treatment is the key in preventing resistance. This has been proven over and over in the medical field. R Oliver also states this on his site when using OA. Also mentioned above.


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## crofter (May 5, 2011)

FlowerPlanter said:


> The 4% is not scientifically proven. Have read OAV kills anywhere from 92 to 96 percent depending on source, R Oliver says OAD kills around 90%.
> 
> Lots of variables may coming to play for the differences. The mites may find one they can take advantage.
> 
> Alternate treatment is the key in preventing resistance. This has been proven over and over in the medical field. R Oliver also states this on his site when using OA. Also mentioned above.


I wonder if that high a percentage of the mites are actually surviving the oxalic acid or it is a matter of other ones being carried into the hive from outside sources. Are these effectiveness tests being done on captive bees?

There does seem to be evidence of increasing virulence of the mite vectored species but I dont think we can automatically assume that is due to mites developing resistance to Oxalic acid (which is question of the original post).


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## igottagetalife (Feb 19, 2012)

I have friends in Belgium and France they are having a problem with resistant mites. They have bumped up concentrations of OAV/D to the "hot" (4.5%) and still the mites survive. In essence the beekeepers developed OA resistant mites... rather than mite resistant bees.

OA is good for the initial treatment but you must swap to something else or we'll end up with the same problem.

It seems the silver bullet can be defeated.


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## clyderoad (Jun 10, 2012)

igottagetalife said:


> I have friends in Belgium and France they are having a problem with resistant mites. They have bumped up concentrations of OAV/D to the "hot" (4.5%) and still the mites survive.


please be more specific.


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## igottagetalife (Feb 19, 2012)

In what regard?

I'll post the note I received from Belgium if you wish. It is from a beekeeper who lost 90% of his hives. It was purely mites.


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## jonsl (Jul 16, 2016)

One anecdotal story doesn't prove this. There are plenty of stories of people who lost their bees because they waited too long to treat. It was the treatment that lead to that. Was this person doing routine mite counts?


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## shinbone (Jul 5, 2011)

A subset of treatment free beekeepers are so firmly committed to not treating that they want all beekeepers to adopt a no treatment strategy. OAV causes great concern for these "anti-treaters," because it works so well and doesn't harm the bees. 

Since OAV is so effective and doesn't harm the bees, the anti-treaters in the U.S. furthered their agenda by arguing OAV was not approved for use in the U.S. But, with recent approval by the EPA, that argument evaporated.

Without the "its illegal" threat to waive around, the anti-treaters had to find another argument to suppress use of OAV, and that argument is that the mites will become resistant. That there is no evidence to support that argument is immaterial to these folks because it aligns with their world view and advances their personal agenda.

Just the latest scare tactic by such extremist.

JMHO




.


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## Slow Drone (Apr 19, 2014)

Though I'm a tf beekeeper common sense tells me resistance to Oxalic acid isn't possible it is an acid after all. Personally I'm glad there finally is a treatment for ya'll that doesn't cause the problems the more harsh chemicals do.


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## crofter (May 5, 2011)

igottagetalife said:


> In what regard?
> 
> I'll post the note I received from Belgium if you wish. It is from a beekeeper who lost 90% of his hives. It was purely mites.


I look forward to reading about the circumstances that led up to the conclusion that it was _developed resistance_ on the part of the varroa mites that caused ineffective treatment.

I dont know if single treatment OA dribble is any more effective than vaporization during ongoing brood rearing or robbing from untreated hives. These effects could easily cast doubt on effectiveness and lead to undue conclusions.


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## Michael Bush (Aug 2, 2002)

My problems with OAV have nothing to do with resistance. There is the microbes. There is damage to the bees. And there is the fact that you are trying to solve a problem I don't have.


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## clyderoad (Jun 10, 2012)

Michael Bush said:


> My problems with OAV have nothing to do with resistance. There is the microbes. There is damage to the bees. And there is the fact that you are trying to solve a problem I don't have.


What about your concern for microbes? which ones do you have in your hives?
If you don't use the stuff, what's the issue then?


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## Gumpy (Mar 30, 2016)

Michael Bush said:


> My problems with OAV have nothing to do with resistance. There is the microbes. There is damage to the bees. And there is the fact that you are trying to solve a problem I don't have.


What damage does OAV do to bees, and where is it documented? I've not come across any. Please elaborate.


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## crofter (May 5, 2011)

Gumpy, my bees seem to spend a fair bit of time in my horse yard; topping up their microbes I guess. If my OA vaporizations deplete their microbes at all, they apparently balance their books quite quickly.


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## Gumpy (Mar 30, 2016)

crofter said:


> Gumpy, my bees seem to spend a fair bit of time in my horse yard; topping up their microbes I guess. If my OA vaporizations deplete their microbes at all, they apparently balance their books quite quickly.


Now I'm concerned. I don't have any horses! 

Although the place I'm planning on placing hives this spring does, so maybe they'll become super bees!


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## Michael Bush (Aug 2, 2002)

While on the topic of resistance, Randy Oliver points out that we don't even know what the mechanism is, so how can we even speculate on whether the mites will develop resistance?
http://scientificbeekeeping.com/oxalic-dribble-tips/

>What about your concern for microbes? which ones do you have in your hives?

According to Martha Gilliam and the USDA about 8,000 different ones that I would like to keep...
http://www.ars.usda.gov/is/ar/archive/aug98/bees0898.htm?pf=1

>If you don't use the stuff, what's the issue then?

I don't understand the question. I listed my issues. Which is the "why" I don't use it.

>What damage does OAV do to bees, and where is it documented? I've not come across any. Please elaborate.

When damage from oxalic acid is discussed it's usually measurement of damage to the colony that is being attempted. In other words did the colony die. I'm talking about damage to the bees. We know oxalic acid is fatal at high enough dosage to arthropods (including insects and mites). We know the fatal dosage is lower for Varroa than for Apis mellifera. But how much damage does it do to an individual worker at sublethal doses? How much to the queen? It's not a question of whether it damages them. That is obviously true. The question is only how much. They are built pretty much the same. Similar chitin in their exoskeletons. If it eats the legs off of mites, as is usually suspected with vaporization, then it's bound to damage the exoskeleton of the bees and thinner, smaller parts would be more damage. It's only a matter of scale. I have no reason to damage my bees.


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## crofter (May 5, 2011)

>If it eats the legs off of mites, as is usually suspected with vaporization, then it's bound to damage the exoskeleton of the bees and thinner, smaller parts would be more damage.<

This is gross exaggeration of any serious examination of damage to the mites. It is the extremely filmy and delicate footpad of the mite that is damaged. Bees have a different claw like foot with hard chitin. 

As for Oxalic acid vaporization damage overall to the bees I will put my survival rates up against any one elses, treated or not. That is not survival numbers supported by a high ratio of splitting either.


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## IAmTheWaterbug (Jun 4, 2014)

Michael Bush said:


> While on the topic of resistance, Randy Oliver points out that we don't even know what the mechanism is, so how can we even speculate on whether the mites will develop resistance?
> http://scientificbeekeeping.com/oxalic-dribble-tips/


Here's the quote from R. Oliver's site:



> The above is a good example of someone talking out of their [hat]. No one even knows for sure what the mode of action of OA is against varroa, nor how it is absorbed. And no matter, I can assure you that some mites will be more resistant than others, which implies that some degree of resistance is possible. Remember, *there is only a small margin of safety between the dose that kills mites, and the dose that kills bees*. That means that varroa only needs to develop a slight degree of resistance until OA is as toxic to the bees as it is to the mites. Rotate treatments!


(emphasis mine)

I think that points pretty plainly to _some_ effect on the bees, even when sublethal. It would be extremely rare for any substance to go quickly from "completely benign" to "lethal" without an intermediate "damaging, but not lethal" dose between.

By contrast, selamectin flea medications are lethal to fleas at the prescribed dosage, but measurably harmless to puppies and kittens at *10x the prescribed dosage*. With that kind of margin you can safely conclude that there is no appreciably harmful effect on the host at the intended dosage.

You can't say that about OAV given the narrow safety margin.


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## clyderoad (Jun 10, 2012)

Michael Bush said:


> >What about your concern for microbes? which ones do you have in your hives?
> 
> According to Martha Gilliam and the USDA about 8,000 different ones that I would like to keep...
> http://www.ars.usda.gov/is/ar/archive/aug98/bees0898.htm?pf=1
> ...


I asked, what about your concern for microbes? which ones do you have in your hives?
I still ask in a thread titled "OAV Resistance"- what's your concern for microbes? that OAV will harm them?
8000 microbes collected and id'd from hives all over the world- which ones do you have?
All are beneficial?, some?, only the few mentioned in the paper you reference? 
here is the working link to the paper https://agresearchmag.ars.usda.gov/1998/aug/bees/


Seems like you are screaming FIRE in a crowded movie theater.


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## clyderoad (Jun 10, 2012)

IAmTheWaterbug said:


> You can't say that about OAV given the narrow safety margin.


That 'narrow safety margin' you point out has been identified in previous discussions. If I recall correctly its in the same range as your example.


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## crofter (May 5, 2011)

IAmTheWaterbug said:


> Here's the quote from R. Oliver's site:
> 
> *there is only a small margin of safety between the dose that kills mites, and the dose that kills bees.*
> 
> ...




I am surprised at that portion of the quote that you highlighted. I have remarked on that on another post. That is the first and only reference I have seen to there being a narrow range of treatment effectiveness vis a vis mortality of bees when used to treat them for varroa mites. I would like to see the results pro and con of an unbiased search on this point. 

Unless the general concensus is very wrong, oxalic acid especially by vaporization is one of the least disruptive and contaminating of available treatments.


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## IAmTheWaterbug (Jun 4, 2014)

crofter said:


> I am surprised at that portion of the quote that you highlighted. I have remarked on that on another post. That is the first and only reference I have seen to there being a narrow range of treatment effectiveness vis a vis mortality of bees when used to treat them for varroa mites. I would like to see the results pro and con of an unbiased search on this point.
> 
> Unless the general concensus is very wrong, oxalic acid especially by vaporization is one of the least disruptive and contaminating of available treatments.


It's possible that I've conflated toxicity of OA dribble to that of OAV, and that they are different. R. Oliver has his OA Dribble PowerPoint presentation available, and the notes on Slide 17 read:



> There is little margin for error with oxalic. Accidentally doubling the dose will _hurt your bees_.


Later in the presentation he writes as an advantage of vapor vs. dribble, "Perhaps gentler to the bees."

Apologies if this was a red herring.


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## shinbone (Jul 5, 2011)

I use a 1/4 teaspoon measuring spoon to scoop out the OA dosage when OAV'ing. The OA powder is "clumpy," and I don't take the time to do a precise measurement. Scooping powder with a small spoon is not precise, anyway. Plus, the generally accepted dosage for a hive is one gram per brood chamber, and one gram is "about 1/4 teaspoon". And this regardless of whether running 10-frame or 8-frame brood chambers. All this to say that the entire dosing process for OAV is imprecise, but, yet, credible reports of hives dying from the OAV itself are rare-to-nonexistent.

This does show anecdotally that there is a big difference between an OAV dose that will kill mites and an OAV dose so large that it will kill bees. I don't have experience with OAD, but would not be surprised that coating bees with an acidic liquid would have a different effect than a vapor depositioning onto surfaces as solid crystals.

Randy Oliver does great work and provides a huge service to the bee keeping community. I have tremendous respect for him, but, just like anyone else, just because he says something doesn't make it true. Based on his rigorous application of the scientific method, I would guess he probably has no expectation of people accepting unsupported proclamations, as well. Accordingly, without some type of supporting or clarifying information that there is little margin for error when using OA, his bare statement has little worthwhile meaning.

JMHO




.


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## crofter (May 5, 2011)

There has been at least one post here on the forum where someone deliberately chose to use huge overdoses of OA vapor on some colonies whose queens he didnt value anyways, and saw no signs of bee damage or mortality. That is not something to be pursued though as the effectiveness is virtually unchanged by increasing volumes above present recommendations.

I have read though, a number of different sources warning against exceeding the strength or total volume applied by dribble or spray method. The wet vs dry factor as Shinbone refers to may be a factor there.


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## Nabber86 (Apr 15, 2009)

> *there is only a small margin of safety between the dose that kills mites, and the dose that kills bees*



I don't buy that statement for one minute. If that were the case it would be easy to prove just by treating bees with varying amounts of OA and developing a dose response curve, just like any other toxicity study. Where is the data that shows this? 

Also the OA application rate varies hugely by the user. I have heard 1 tsp is recommended, but measuring by volume is ridiculous way to go about it. Where did that that come from? Trial and error I guess. Teaspoons are not exactly calibrated and the specific weight of OA varies depending on the moisture content of the OA and how tightly you pack the teaspoon. 

How many brood boxes are on when you treat? One, two, or three? If you treat a 2-box hive with 1 tsp and then treat a 1-box hive with the same amount, the 1-box hive received double the dose. 

And lastly, the bees don't ingest the OA. There is only so much vapor that can go into a hive once the atmosphere is saturated. Is your hive sealed complete, or is some of the OA vapor leaking out? I don't think there is any way to to figure out how many milligrams each bee was exposed to; which is exactly what you need to find out how much OA is harmful to bees. 

Microbes? That is a pretty broad term. Which microbes are susceptible and how much OA does it take to kill which microbe?


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## John Davis (Apr 29, 2014)

Nabber, there have been studies done in Europe in which hives were treated with a large range of doses and frequencies that have shown no toxic effects on bees with OAV. The dribble method causes the bees to injest the acid, an overdose can have negative effects with that method, which is why the directions are for only one dribble treatment per year in the brood less period. One of the German Beesource members has posted photos of the structure of the varroa feet which have a direct tubular entrance up into the body, honey bee feet don't so the OA crystals stay external to the bees body.


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## Nabber86 (Apr 15, 2009)

I guess I should say that my comments are related to vapor. Of course I would like to see how they measured the amount of OA was igested by the dribble method. 

Can somebody explain to me why somebody would use the dribble method anyway? It doesn't make much sense to me when vapor is much easier.


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## IAmTheWaterbug (Jun 4, 2014)

Nabber86 said:


> Can somebody explain to me why somebody would use the dribble method anyway? It doesn't make much sense to me when vapor is much easier.


p. 74 of the linked PowerPoint presentation.


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## clyderoad (Jun 10, 2012)

Nabber86 said:


> Can somebody explain to me why somebody would use the dribble method anyway? It doesn't make much sense to me when vapor is much easier.


it's much faster. easy too.


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## John Davis (Apr 29, 2014)

The dribble is much faster per hive, lift the lid or box above the brood chamber and squirt the amount needed on each seam of bees, close the lid and you are done. No closing the hive and carrying around a power source, only one visit instead of three. Makes a no brainer for commercial folks.


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## jonsl (Jul 16, 2016)

You don't have to worry about vapors either with OAD. I used this method and found it very easy and quite effective.


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## BadBeeKeeper (Jan 24, 2015)

shinbone said:


> I use a 1/4 teaspoon measuring spoon to scoop out the OA dosage when OAV'ing. The OA powder is "clumpy," and I don't take the time to do a precise measurement. Scooping powder with a small spoon is not precise, anyway. Plus, the generally accepted dosage for a hive is one gram per brood chamber, and one gram is "about 1/4 teaspoon". And this regardless of whether running 10-frame or 8-frame brood chambers. All this to say that the entire dosing process for OAV is imprecise, but, yet, credible reports of hives dying from the OAV itself are rare-to-nonexistent.


I don't think that precision is absolutely necessary, as long as you have a sufficient volume to saturate the volume of atmosphere within a hive of a given size. Too little will be insufficient and the results would not be efficacious. More than necessary is mainly a waste of the material, within normal margins of error. It should be easy to test what effect an extreme excess dosage would have- simply load up a 10X dose and see if it kills a hive.



> This does show anecdotally that there is a big difference between an OAV dose that will kill mites and an OAV dose so large that it will kill bees. *I don't have experience with OAD, but would not be surprised that coating bees with an acidic liquid would have a different effect than a vapor depositioning onto surfaces as solid crystals.*


One would presume so. Further testing might be interesting.



> Randy Oliver does great work and provides a huge service to the bee keeping community. I have tremendous respect for him, but, just like anyone else, just because he says something doesn't make it true. Based on his rigorous application of the scientific method, I would guess he probably has no expectation of people accepting unsupported proclamations, as well. Accordingly, *without some type of supporting or clarifying information that there is little margin for error when using OA, his bare statement has little worthwhile meaning.*


I am not aware of what credentials Randy may or may not have as a 'scientist', however, putting forth a hypothesis is one thing, testing and verifying the truth or falsity of a hypothesis is something else. One must not mistake a hypothetical projection as truth, without testing and verification. A lot of ideas may sound reasonable initially, but reality proves different in practical application.


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## antonioh (Oct 15, 2014)

The first time (about twelve years ago) I used OAD I use anhydrous, convinced I was using dyhidrate (error caused by the lab that sold me the oxalic). I carefully weighted the amount (as if it was dyhidrate) , made the dilution and the treatment. The mistake made a concentration higher by about 30 %. Though no hive or queen died, I had very heavy losses on adult bees. There are studies made in Europe that compare different concentrations of oxalic on dribling . I can´t recall as it was long ago but maybe by Nanetti or Imdorf. There is also at least a study that compares dribling and vapor, and found that in short term ( 1~2 month) vapour has higher residues than dribling . I´l try to find them an put the link here. 

As for resistence, here in Europe we have already varroa colossalis, that even attacks beekeepers as you can see here :

http://montedomel.blogspot.pt/2011/04/varroa-colossallis-hora-da-verdade.html


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## antonioh (Oct 15, 2014)

And to whom it may interest:

http://revistas.inia.es/index.php/sjar/article/view/270


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## 1102009 (Jul 31, 2015)

> http://montedomel.blogspot.de/2011/04/varroa-colossallis-hora-da-verdade.html


:lpf:



> http://revistas.inia.es/index.php/sjar/article/view/270


Yes, it could be the sugary solution, because the bees are cleaning this off their fellow bees. Vaporizing was prohibited so far because of the dangers while working, but now is used more and more.


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## johno (Dec 4, 2011)

As far as time taken to treat a hive, with the band heater type of vaporizer the hives can be treated with the exact dose of OA without opening the hive in about 45 seconds. This with maybe 3 hive boxes, I would like to see the dribble method beat that time.
Johno


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## Ian (Jan 16, 2003)

John Davis said:


> The dribble is much faster per hive, lift the lid or box above the brood chamber and squirt the amount needed on each seam of bees, close the lid and you are done. No closing the hive and carrying around a power source, only one visit instead of three. Makes a no brainer for commercial folks.


A dribble and vapour treatment require all the same internal hive conditions to work. 
One dribble does not equal 3 vapour treatments during brood. 
Non brood conditions one dribble equils one vapour treatment


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## Gumpy (Mar 30, 2016)

antonioh said:


> As for resistence, here in Europe we have already varroa colossalis, that even attacks beekeepers as you can see here :
> 
> http://montedomel.blogspot.pt/2011/04/varroa-colossallis-hora-da-verdade.html


Those are the organisms from Star Trek original series, "Operation: Annihilate!" Just shine some ultraviolet light on them and they will die!


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## jonsl (Jul 16, 2016)

shinbone said:


> I use a 1/4 teaspoon measuring spoon to scoop out the OA dosage when OAV'ing. The OA powder is "clumpy," and I don't take the time to do a precise measurement. Scooping powder with a small spoon is not precise, anyway. Plus, the generally accepted dosage for a hive is one gram per brood chamber, and one gram is "about 1/4 teaspoon". And this regardless of whether running 10-frame or 8-frame brood chambers. All this to say that the entire dosing process for OAV is imprecise, but, yet, credible reports of hives dying from the OAV itself are rare-to-nonexistent.
> 
> This does show anecdotally that there is a big difference between an OAV dose that will kill mites and an OAV dose so large that it will kill bees. I don't have experience with OAD, but would not be surprised that coating bees with an acidic liquid would have a different effect than a vapor depositioning onto surfaces as solid crystals.
> 
> ...


OAD uses a sugar syrup base. This causes the bees to ingest the OA which I would think would cause some different issues for them. Everyone needs to keep in mind that Randy is talking about OAD not OAV.


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## IAmTheWaterbug (Jun 4, 2014)

jonsl said:


> Everyone needs to keep in mind that Randy is talking about OAD not OAV.


Yeah, that's probably my fault for citing him incorrectly.


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## shinbone (Jul 5, 2011)

IAmTheWaterbug said:


> Yeah, that's probably my fault for citing him incorrectly.


Don't feel bad. The statement itself is not necessarily clear. Others have also cited to the same statement, not understanding which form of OA treatment was being referenced.


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## squarepeg (Jul 9, 2010)

plb provides a reference on the topic here:

http://community.lsoft.com/scripts/wa-LSOFTDONATIONS.exe?A2=BEE-L;de5f58e7.1704


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## shinbone (Jul 5, 2011)

Interesting article. Thanks for posting.


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