# OAV and the path to resistance



## Groundhwg (Jan 28, 2016)

Are you using OAV to treat mites? If so how is working for you? I do not know what is causing problems for others, though I have read a couple of threads here of folks having to treat several times. So far my OAV treatment have been very effective. Hope others keeping sharing what is or is not working for them as we can all learn from what other beekeepers are doing. 

If you are using OAV and it is working please share how you are treating. Thanks.


----------



## Charlestonbee (Mar 26, 2015)

I treated in august in 4 times in seven day intervals. In October I had high mite counts like over 25-35 per 300 bees. Just finished three treatments in seven day intervals and did a count. I had 6 mites/300 bees. It worked much better once the brooding slowed a bit. I think that was main difference. Next year I'll use maqs when queens are available and use oav in cooler times w no queens


----------



## beemandan (Dec 5, 2005)

I do a single...or occasionally two.... oav treatment during the dead of winter. I put sticky sheets on the bottom of some for about a week following treatment. It isn't uncommon to have 500 or so mites fall.

I do an end of season/prewinter bee production treatment using a conventional treatment. This year it was two rounds of Apiguard.

I think doing three or four rounds of oav as a primary treatment might be fine...although I'd still recommend some sort of treatment rotation. On the other hand, I'm reading about folks who're doing months worth...still finding mite drops, so they decide to continue for more months. That is the type of regimen that concerns me.


----------



## crofter (May 5, 2011)

Dan; mite resistance increasing, or mites carrying a heavier and more diversified assortment of viruses? 

Do we now need a lower mite numbers threshold than previously? Canadian Agriculture treatment threshold numbers have been reduced regardless of treatment method. I dont know what the significance is, if any.


----------



## TWall (May 19, 2010)

Without know the effectiveness of the treatment, pre- and post-treatment mite loads, it is hard to tell. Treating and then checking mite loads a couple of months later doesn't tell the story, too much time for something else to happen.

When something is 'easy,' like OAV is percieved to be, it can often not be done according to protocol so desired effects are not achieved.

But, the scenario described is a definite path to resistance to oxalic acid, if that is possible.

Tom


----------



## psm1212 (Feb 9, 2016)

beemandan said:


> A couple of years ago I thought that oav would be a durable mite treatment alternative. I understand the complex genetic mix that must change to create resistance and believed that the overcoming this was unlikely.
> 
> I'm having second thoughts today. It seems like I'm reading an epidemic of reports of long term, regular treatment regimens...that sometimes appear to be less than effective. My best guess is that the treatments are probably marginal or sub lethal doses. And the reporters' solution is to extended the protocol even longer. Keeping a pest under constant pressure with a sub lethal dose of any pesticide is a sure path to resistance.
> 
> Will we, once again, prove to be our own worst enemy?


If a treatment were marginal or sub lethal, I would expect to see little or no mite drop, the beek would be satisfied, and have a dead hive in Spring. If I am seeing over 1000 mites on the board within 24 hours of treatment, it is hard for me to label that treatment sub lethal or that the treatment was ineffective. I think a more logical culprit is the condition of the hive prior to or during treatment.

Let's make some assumptions. I have a hive with 40,000 mites with ample brood. My treatments kill 95% of all phoretic mites. 15% of the mite population is phoretic. Treatment 1 kills 5,700 mites. Looks like a blood bath, but did not really make a dent. You still have 34,300 mites in your hive and they are breeding faster than rabbits.

I do not see a way to kill even the majority of your mites with the standard 3 treatments at 7 days apart in this infested hive. You will be forced to move to more treatments and shorter intervals. I do not see this as a failing of the beek or the methodology.


----------



## CrazyTalk (Jan 27, 2015)

psm1212 said:


> If a treatment were marginal or sub lethal, I would expect to see little or no mite drop, the beek would be satisfied, and have a dead hive in Spring. If I am seeing over 1000 mites on the board within 24 hours of treatment, it is hard for me to label that treatment sub lethal or that the treatment was ineffective. I think a more logical culprit is the condition of the hive prior to or during treatment.


You're misunderstanding the terms. If there are 1500 mites in the hive, and your treatment kills 1000, you've just selected the 500 most resistant mites to reproduce (or the mites most likely to hide in places that they don't get dosed, etc). If the treatment isn't killing ALL of the mites, its sub-lethal, and is selecting the mites for resistance.


----------



## beemandan (Dec 5, 2005)

psm1212 said:


> If a treatment were marginal or sub lethal, I would expect to see little or no mite drop,


So that we are on the same page...sub lethal, in my opinion, is a level below the LD50 of a pesticide. So, there may still be a noticeable number drop....just less than 50% of the exposed pests.
Also...a hive with 40,000 mites collapsed a long time ago.


----------



## DanielD (Jul 21, 2012)

A concern I have with this thread is that it starts with the assertion that oav is a pesticide. My understanding is it mechanically harms the Varroa, not chemically.


----------



## psm1212 (Feb 9, 2016)

beemandan said:


> So that we are on the same page...sub lethal, in my opinion, is a level below the LD50 of a pesticide. So, there may still be a noticeable number drop....just less than 50% of the exposed pests.


In my scenario, I killed 95% of the exposed pests.


----------



## psm1212 (Feb 9, 2016)

DanielD said:


> A concern I have with this thread is that it starts with the assertion that oav is a pesticide. My understanding is it mechanically harms the Varroa, not chemically.


I suppose it makes sense to me that an insect can build a TOLERANCE for an acid over some period of time. I do not think it can be correctly compared to resistances built to pesticides. I can't say that it cannot happen, but I think it is an entirely different evolutionary ballgame.


----------



## Gumpy (Mar 30, 2016)

beemandan said:


> My best guess is that the treatments are probably marginal or sub lethal doses. And the reporters' solution is to extended the protocol even longer. Keeping a pest under constant pressure with a sub lethal dose of any pesticide is a sure path to resistance.


As of today, I've killed 12865 mites in one hive. What percentage of my mites do you suppose are receiving a sub-lethal dose?


----------



## dudelt (Mar 18, 2013)

DanielD said:


> A concern I have with this thread is that it starts with the assertion that oav is a pesticide. My understanding is it mechanically harms the Varroa, not chemically.


This has been my understanding as well. Varroa that survive treatment do not do so because they received a sub-lethal dose. They do so because they were not exposed in a manner that is lethal and it has nothing to do with the amount they are exposed to. It is like getting stabbed with a knife only you get stabbed with the handle end instead. There is no sharp point so it will not hurt you. OA treatment is also not uniform throughout the hive. Some areas get more, some less. If the varroa is in the area that got less, they stand a better chance of not being exposed in a lethal manner. I would guess that you could cover a varroa with OA but if none of it gets on the foot pads, the mite will survive.


----------



## Richard Cryberg (May 24, 2013)

beemandan said:


> Keeping a pest under constant pressure with a sub lethal dose of any pesticide is a sure path to resistance.


This oft repeated bit of folk lore is wrong more often than it is correct. It all depends on the genetics of resistance, the biochemical pathways that give resistance, transport properties of the pesticide and all kinds of other factors. There are very well demonstrated cases where the ideal kill to reduce resistance issues to a minimum can be as low as 60%. There are other cases where the ideal kill level will be 90%. There was a nice paper in one of the June issues of Science this year addressing this exact topic.

By the way, there are well documented examples of insects not developing resistance after 65 years of constant sub lethal pressure by a single insecticide. That still does not say it will never happen. Given time enough it will likely happen, if by nothing else horizontal gene transfer across species. The biggest problem with trying to anticipate resistance is you simply do not have the data to make rational choices until it happens. The one rational choice you can make is to forget the idea that sub lethal doses will speed resistance development. And once you do have resistance less than 100% kill doses can be the best way to manage the resistance.

The big problem with OVA is it only gets phoretic mites. If you have a mite bomb on your hands it is going to take a lot of treatments with OVA to get the problem under control unless the bees are broodless. If they have brood you should probably not use OVA on mite bombs. It is marginally effective and takes too many treatments to get control. There are better alternatives that are highly effective under those conditions such as MAQS or apivar. Not that those two are perfect either. MAQS is going to kill some bees and brood and may harm the queen. Apivar is known to have resistance problems in some areas already. So, your best management practices should be to do mite checks often enough you do not get a mite bomb. Until hobby bee keepers learn to do real mite counts regularly mite bombs will be a problem to both themselves and others. Perhaps the very worst invention in terms of mite control was the screened bottom board as it allows you to do sticky board counts on untreated colonies. All a low count tells you is the mites in the colony are healthy and not dying. By the time you get a big count the colony is a mite bomb.


----------



## Gumpy (Mar 30, 2016)

CrazyTalk said:


> You're misunderstanding the terms. If there are 1500 mites in the hive, and your treatment kills 1000, you've just selected the 500 most resistant mites to reproduce (or the mites most likely to hide in places that they don't get dosed, etc). If the treatment isn't killing ALL of the mites, its sub-lethal, and is selecting the mites for resistance.



Maybe you don't understand how mites operate, or how OAV works because your scneario is unrealistic, and your conclusion flawed. 

If there are 1500 mites in the colony, there will be about 225 phoretic mites, unless the colony is completely broodless. The remainder are sealed in brood cells, and OAV does not penetrate the wax. That's why multiple treatments are needed, spaced at intervals which accommodate the brood cycle and have more chance of reaching those remaining mites before they can enter another cell to reproduce. 

Are mites able to resist OAV? It doesn't seem like it, and there's no scientific evidence to the contrary. If OAV reaches them, they die. Are they able to hide? Well, if you consider they way they mate, I guess they can. Is that a genetic thing? Sure. They are said to crawl into the cell and hide below the larvae until the cell is capped. That's evolution, though. They are not hiding because of the OAV.


----------



## DanielD (Jul 21, 2012)

psm1212 said:


> I suppose it makes sense to me that an insect can build a TOLERANCE for an acid over some period of time. I do not think it can be correctly compared to resistances built to pesticides. I can't say that it cannot happen, but I think it is an entirely different evolutionary ballgame.


Like dudelt said, and, the acid isn't attacking them in a poisonous way, the acid solidified into sharp objects is what's happening with it's use. The crystals cut at the mites. I don't agree with the evolutionary theory (which means not factual, but mere theory), but adaptation of things to different conditions. They adapt or become resistant to something, but not change into something else.


----------



## CrazyTalk (Jan 27, 2015)

DanielD said:


> Like dudelt said, and, the acid isn't attacking them in a poisonous way, the acid solidified into sharp objects is what's happening with it's use. The crystals cut at the mites. I don't agree with the evolutionary theory (which means not factual, but mere theory), but adaptation of things to different conditions. They adapt or become resistant to something, but not change into something else.


Yikes. Theory means something very different in a scientific context than you think it does. We have more evidence and better understanding of evolution than we do of Gravity. (A scientific theory is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed, preferably using a written, pre-defined, protocol of observations and experiments)

Organisms evolve to survive physical trauma pretty regularly. If they're selectively surviving, they're being selected towards whatever allows them to survive, whether that's harder body parts, different behavior patterns, whatever. Evolution doesn't care - it just needs selective pressure.


----------



## Gumpy (Mar 30, 2016)

CrazyTalk said:


> Yikes. Theory means something very different in a scientific context than you think it does. We have more evidence and better understanding of evolution than we do of Gravity. (A scientific theory is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed, preferably using a written, pre-defined, protocol of observations and experiments)
> 
> Organisms evolve to survive physical trauma pretty regularly. If they're selectively surviving, they're being selected towards whatever allows them to survive, whether that's harder body parts, different behavior patterns, whatever. Evolution doesn't care - it just needs selective pressure.


:thumbsup:


----------



## Charlestonbee (Mar 26, 2015)

Gumpy keep on counting. I love the high number counts I just picture you losing count at like 986 and freaking out. Even if they are going to build a resistance should you just let your hives die from mites instead of using something that's working RIGHT NOW like today. I shouldn't have been using a gas powered vehicle all these years and just walked until electric gets affordable. For me it's what your best option right now until the optimal or better solution arrives in the future.


----------



## rangerpeterj (Dec 27, 2015)

Mites becoming resistant to OAV is like an ant becoming resistant to a hammer,OAV is an acid not a pesticide.The Europeans have been using OAV for 20 years and had no resistance problem yet. The acid damages their foot pads and internal organs through absorption.


----------



## beemandan (Dec 5, 2005)

A pesticide is a compound used to control a pest. The name 'pesticide' has nothing to do with the chemical composition. Formic acid and oxalic acid, when used to control varroa are both pesticides.

Have you ever used Frontline (fipronil) to control fleas on your dog? Did you also notice that, over time it lost its effectiveness? Then there was Apistan and Checkmite for varroa. Both lost their effectiveness. These are real world results of a mythical event...according to one poster. Repeated application of the same pesticide. There's a reason that rotating miticides is recommended.

I've heard the ant/hammer analogy. It sounds cool but I believe it to be an exaggeration. The Europeans have been using oxalic acid for quite some time. My understanding is that most of that has been a dribble application during a broodless period. I'd bet that even to this day they aren't hitting their hives on a scale that we are.

In North America during the last year we have embraced oxalic acid...especially oav. And I'm reading more and more about regular applications over extended periods of time. In a short period of time we've gone from treating with oxalic acid as a curiosity to using it as a mainstay and seem to have thrown all caution to the wind. I read a second hand report that one fellow has treated his hive practically every week for the past two years. I'm sorry....but this just doesn't sound like wise husbandry to me.

I have not suggested that oxalic acid is losing its effectiveness. I am only asking if we might be heading down that slippery slope. From the replies so far, it is evident that nobody shares my concern. I hope you folks are right.


----------



## clyderoad (Jun 10, 2012)

CrazyTalk said:


> Yikes. Theory means something very different in a scientific context than you think it does. We have more evidence and better understanding of evolution than we do of Gravity. (A scientific theory is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed, preferably using a written, pre-defined, protocol of observations and experiments)
> 
> Organisms evolve to survive physical trauma pretty regularly. If they're selectively surviving, they're being selected towards whatever allows them to survive, whether that's harder body parts, different behavior patterns, whatever. Evolution doesn't care - it just needs selective pressure.


the flip side is that organisms also go extinct because of their inability to evolve. 

please go on and expand upon your theory, but leave out the assumption that the mites under the cappings were 1. exposed to the oav treatment and 2. it was sub lethal.


----------



## beepro (Dec 31, 2012)

I did a little bee experiment earlier last month by moving the
cap broods from 8 nuc hives into one newly mated laying vsh daughter queen.
This mite bomb exploded and along with them many free running mites came out.
The thought about oav treatment came to mind but since it is an experiment I just let
the hive ride it out. So no treatment just frame manipulation on all of my hives in the same apiary. With the prolong Autumn
flow on now all hives are thriving with the big fat winter bees including the mite bomb nuc hive. The housekeeping
bees carried out the infected bees or bees not living to their standard. Many got dumped out on the ground in front
of the hive. A very sad scene like the hives that crashed reported by many members here lately. Still many healthy bees survived and carry on their daily task in this nuc hive. So don't forget that while the mites are
trying to evolve to resist certain chemicals we put in, the bees are evolving too in dealing with the mites. Hadn't I got the vsh genetics and allogrooming bees this season this mite bomb nuc hive will never stand a chance like on my 3rd season. It depends on how hygienic your bees are and they know what they are dealing with. Now I got the resistant bees I would like to get some of Carpenter's mite biting bees next season. Wonder how they deal with the mites once all the mite fighting genetics incorporated together? So rather than worrying about how the mites will eventually develop resistance to the oav why not focus on dealing with the mite using other methods? I rather go as natural as I possibly can. Reading last night that oav will burn tiny holes on the bee's exoskeleton while shorten the bee's lifespan. Many posts here said they treated over months but the hive still died now. Why? Is it because the operator error or something is at hands here? Not sure why the hive died if oav or oad can take care of the mites while sparing the bees.
When all hives are building up like it is early Spring time now I have to go inside for a complete hive check. Mainly it is to ensure that the big fat winter bee's population will not drop as much. They should be resting instead of going full force to collect resources now. At least I know my bees are not sick from the mites or DWVs.


----------



## DanielD (Jul 21, 2012)

CrazyTalk said:


> Yikes. Theory means something very different in a scientific context than you think it does. We have more evidence and better understanding of evolution than we do of Gravity. (A scientific theory is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed, preferably using a written, pre-defined, protocol of observations and experiments)
> 
> Organisms evolve to survive physical trauma pretty regularly. If they're selectively surviving, they're being selected towards whatever allows them to survive, whether that's harder body parts, different behavior patterns, whatever. Evolution doesn't care - it just needs selective pressure.


It's merely adaptation.


----------



## Nabber86 (Apr 15, 2009)

All this talk about sub lethal dosage and mites building resistance is ignoring the obvious. Fumigation is not a perfect technique. Vapor cannot get to all the nooks and crannies where mites may be hiding. Additionally, open areas within the hive may not be exposed to a high enough concentration of vapor to be effective. Therefore some mites simply are not exposed to enough OA to receive a fatal dose. Occam's razor people, Occam's razor.




beemandan said:


> It seems like I'm reading an epidemic of reports of long term, regular treatment regimens...that sometimes appear to be less than effective.


An epidemic? Can you provide any of these reports?


----------



## dudelt (Mar 18, 2013)

Beemandan, While I do defend the current use of OA, I also understand your concerns. Eventually, they might get some resistance to the OA but because of the mode of action, I believe it will be a very, very long time from now if ever. Yes, Frontline and Advantage no longer work here at all but their mode of action is poisoning, not physical damage. Most animals have an ability to fight off poisons as a part of our immune systems. Physical damage is not directly related to the immune system. My understanding is that mites bodies (just like honeybees) do not repair themselves when damaged. Thus, until, the mites bodies start repairing themselves, or the foot pads change their shape and / or method of functioning, resistance is unlikely. I believe that it is more likely that the mites will eventually become less lethal to bees than they are now. A parasite that almost always kills the host is creating its own extinction. A less lethal mite is a better choice for survival of the species. Unfortunately, humans created this problem but do not have the ability to correct it.


----------



## beemandan (Dec 5, 2005)

Nabber86 said:


> An epidemic? Can you provide any of these reports?


Epidemic is an exaggeration....but, I have seen a number of them. Are you telling me that you haven't?

Here's a most recent one:
http://www.beesource.com/forums/sho...tes-after-multiple-OAVs&p=1488252#post1488252

A quote from the same thread:


Arnie said:


> snl has a couple experimental hives that he has vaporized every time he goes to the bee yard to do some work. For two years running. According to him it's about every 7 to 10 days for two years.


There have been others but you can look for yourself, believe me or not. Your choice. I'm not going to make it my life's work to prove.


----------



## clyderoad (Jun 10, 2012)

BMDan, there does seem to be many posts lately but I attribute it to being a new treatment to most and thi9s being the appropriate time of year for the discussion. A few have gone overboard with the use, without exploring any of the possible reasons for needing so many treatments. Can't figure that one out, blinders maybe or that their methods are faulty and simply refuse to critically examine them.
My conversations outside of the forum leads me to believe the use of OAV, or OAD for that matter, is not widespread among the beekeeping masses. In fact, lack of any mite treatment seems to be more widespread.
The excessive OA users although small in number IMO will always exist.


----------



## Richard Cryberg (May 24, 2013)

DanielD said:


> Like dudelt said, and, the acid isn't attacking them in a poisonous way, the acid solidified into sharp objects is what's happening with it's use. The crystals cut at the mites. I don't agree with the evolutionary theory (which means not factual, but mere theory), but adaptation of things to different conditions. They adapt or become resistant to something, but not change into something else.


Show me one single scientific paper that demonstrates the crystals cut at the mites. I do not believe any such paper exists.

The theory of evolution, the theory of relativity, the theory of quantum mechanics and many other scientific theories are called theories because they have passed every single test they have been subjected to and are considered as proven as anything in science can ever be proven. In science the word theory means tested and proven correct in every single test and thus should be accepted as proven fact. An idea is called a hypothesis in science until it has been tested. Once tested it either passes the test and is a theory or fails the test and the job of science is then to find another hypothesis to test. This is not to say that a theory can never fail. Newton's theory of mechanics and time was ultimately proven to be a very, very good approximation, but failed miserably under some circumstances and had to be replaced with the theory of relativity. It is fortunate that we learned about this as if we had not your GPS would not work. To date relativity has never failed a single test. But, the same could be said of Newtonian mechanics for some 150 years after its inception and relativity is only 100 years old this year. Relativity is really just a fairly minor adjustment of Newtonian mechanics. There is a good chance at some point an adjustment will be required to relativity. After all, it does posit some very ugly physics that is hard to accept as being correct under conditions far beyond what can be tested today. Likewise someday we may have to rename evolution due to some minor tweak that is required by experimental data. But, even if that happens evolution will still be a 100% accurate description of the process that allowed single celled organisms to change and result in far more complex organisms today such as humans. If you do not like the idea that your ancestors were bacteria too bad because your ancestors were bacteria.

You are welcome to reject the theory of evolution and order God on how he had to do his job. Real scientists do not give God orders. Rather, they try hard to figure out how he did his job and accept that he is smarter at doing his job than us ignorant humans.


----------



## beemandan (Dec 5, 2005)

clyderoad said:


> there does seem to be many posts lately but I attribute it to being a new treatment


And that may be all there is to it. I do read the hammer vs ant analogy and I don't think that is the right mindset. I am hopeful that we don't find ourselves disappointed a few years from now. Just adding a bit of caution.


----------



## Nabber86 (Apr 15, 2009)

beemandan said:


> Epidemic is an exaggeration....but, I have seen a number of them. Are you telling me that you haven't?
> 
> Here's a most recent one:
> http://www.beesource.com/forums/sho...tes-after-multiple-OAVs&p=1488252#post1488252
> ...



No, I haven't seen any reports. That's way I asked. I am not asking you make it your life's work to prove, but at least you can provide something of value. 

"Look for yourself" is the lamest reply in internet history and has never helped anything.

Also, I am not seeing anything in the thread that you referenced that indicates OVA is not working, except for 1 anecdotal report by a beekeeper who isn't quite sure what the heck is going on. :scratch:


----------



## clyderoad (Jun 10, 2012)

Don't know how you missed this thread Nabber. Maybe it's one BMDan is referring to.
http://www.beesource.com/forums/sho...Varroa-mites-are-made-up-of-Oxalic-Acid-Vapor


----------



## Gumpy (Mar 30, 2016)

Charlestonbee said:


> Gumpy keep on counting. I love the high number counts I just picture you losing count at like 986 and freaking out.


I figured out a system after that happened. I have grid boards, so I just go back and forth on the grid rows counting. When I get back to the left edge, I write the number down and letter of the row I just completed. That way if I lose count, I only have to go back to the last completed row and start from there again. Works for me.

My numbers are coming down. I'm seeing improvement and the hives seem healthy. Time will tell.


----------



## clyderoad (Jun 10, 2012)

beemandan said:


> And that may be all there is to it. I do read the hammer vs ant analogy and I don't think that is the right mindset. I am hopeful that we don't find ourselves disappointed a few years from now. Just adding a bit of caution.


You asked "Will we, once again, prove to be our own worst enemy? "
I'd say it's possible. IMO depends more on the actions of OA than the actions of those using it.
I'd like to also say I hope we won't.


----------



## beemandan (Dec 5, 2005)

Nabber86 said:


> Also, I am not seeing anything in the thread that you referenced that indicates OVA is not working,


I don't believe that oav isn't working. In the one thread that I linked the op was stating that he was continuing to get significant drops. My statement was that it MIGHT be from sub lethal dosing. My concern is that repeated, regular long term treatment regimens...regardless of the reason..... may result in resistance.
That was all. If I wasn't clear....my apologies. If you misread...no problem.


----------



## SS Auck (May 8, 2015)

The sub lethal dose is a funny argument to me. The mechanism of action is not internal otherwise the bees would be affected. The reason why you vaporize is to thoroughly disperse the crystals in gas form through sublimation and heat causing convection currents through out the hive. Then as they cool it goes from gas to solid and crystallizes on all surfaces, including bees and mites. That is why larvae under cappings are not subjected to the tiny "killer" crystals. So by saying "dose" makes it sound like the oxalic acid is some how transmitted into the mites and not the bees. Further more you do not understand that an acid even in the gas form can not just go across membranes they are too polar. It might damage but then you would see bees die too. no way they could become resistant. 
If you need a better metaphor then maybe diatomaceous earth might be better.


----------



## Nabber86 (Apr 15, 2009)

clyderoad said:


> Don't know how you missed this thread Nabber. Maybe it's one BMDan is referring to.
> http://www.beesource.com/forums/sho...Varroa-mites-are-made-up-of-Oxalic-Acid-Vapor


It's a 3 page thread and I am still not seeing the part where OA is loosing effectiveness. Maybe my reading comprehension is incompetent, but can you point out a specific post? That is if it is not too much impact on your life's work. I don't want to bother you if you are too busy.


----------



## grozzie2 (Jun 3, 2011)

Richard Cryberg said:


> Show me one single scientific paper that demonstrates the crystals cut at the mites. I do not believe any such paper exists.


I dont have a scientific paper to link, but, if you go to the right place on beesource, located here: http://www.beesource.com/forums/showthread.php?322101-Let-s-talk-about-lega-vaporizer-unit&p=1388906#post1388906 , then you can see some photos of mites under a microscope, before and after an OA treatment.

I found those photos to be quite informative, even if the source is not a peer reviewed journal paper.


----------



## clyderoad (Jun 10, 2012)

Nabber86 said:


> It's a 3 page thread and I am still not seeing the part where OA is loosing effectiveness. Maybe my reading comprehension is incompetent, but can you point out a specific post? That is if it is not too much impact on your life's work. I don't want to bother you if you are too busy.


the thread is an example of prolonged usage related to the OP statement "It seems like I'm reading an epidemic of reports of long term, regular treatment regimens...that sometimes appear to be less than effective."
nothing more, nothing less.

Your statement-That is if it is not too much impact on your life's work. I don't want to bother you if you are too busy.- 
What? humor?


----------



## Nabber86 (Apr 15, 2009)

beemandan said:


> I don't believe that oav isn't working. In the one thread that I linked the op was stating that he was continuing to get significant drops. My statement was that it MIGHT be from sub lethal dosing. My concern is that repeated, regular long term treatment regimens...regardless of the reason..... may result in resistance.
> That was all. If I wasn't clear....my apologies. If you misread...no problem.


But I am still having a problem with the following message: 




beemandan said:


> I'm having second thoughts today. It seems like I'm reading an epidemic of reports of long term, regular treatment regimens...that sometimes appear to be less than effective. My best guess is that the treatments are probably marginal or sub lethal doses. And the reporters' solution is to extended the protocol even longer. Keeping a pest under constant pressure with a sub lethal dose of any pesticide is a sure path to resistance.
> 
> Will we, once again, prove to be our own worst enemy?


Second thoughts?
epidemic?
less effective? 
Probably marginal? 
Constant pressure? 
sub lethal dose? 
sure path to resistance?
Our worst enemy? 

Can you possibly insert any more platitudes


----------



## Arnie (Jan 30, 2014)

Beemandan, the beekeeper I was referring to in your quote is not treating his experimental hive because the treatments are ineffective, nor to determine if the mites will become resistant. He is treating to see the affect on the bee's health.......if it affects the queen or otherwise impacts the health of the colony. He does it to reassure himself that OAV does not harm the bees in any way.
That's my understanding. Just so you know...

I understand your concern about long term treatment regimens.. I don't have those concerns, mostly because of the experience of European beekeepers. 20 years, no sign of resistance. Works for me.


----------



## Fusion_power (Jan 14, 2005)

beemandan, to assert a position and then deny that you are taking a position is an oxymoron, kind of like a "racing snail". If you choose to post repeated statements that OAV resistance will develop, then at least post your bonafides so we know you are not just some crazy old beekeeper with an agenda. You perhaps have a degree in organic chemistry? insect pathology? even just plain old biology?


----------



## beemandan (Dec 5, 2005)

SnickeringBear said:


> to assert a position and then deny that you are taking a position is an oxymoron


I see three choices here. Either a couple of posters didn't read my entire first post or I didn't make my point clear or there are some folks with a reading comprehension problem.

From my first post:


beemandan said:


> Will we, once again, prove to be our own worst enemy?


You see....I am asking if the repeated regular long term use of oav will speed up the resistance process. I am asking....not claiming.

And the in a later post I said it again:


beemandan said:


> I have not suggested that oxalic acid is losing its effectiveness. I am only asking if we might be heading down that slippery slope.


Where did I assert a position? Is this not clear to you?


----------



## Daniel Y (Sep 12, 2011)

I have noticed an increase in reports of OAV not being effective as well. I also noticed a difference in equipment being used to apply it and a change in the requirements for application. To me it appears focus switched from effective treatment to time required to treat. and with that the development of equipment with the intent to reduce application time. I see this effort to go faster is resulting in less effective methods. I also noticed more concern about temperatures used to vaporize and measures to limit temperatures at the same time. it could be one the other neither or both. It could simply be more users more results. Btu I do not think that more use means OA is less effective. It would be far more likely more use results in more people messing it up. On of the most visible threads recently I have come to simply ignore. I don't know what is going on in that situation. I am not sure I care. but it is not mite counts as far as I am concerned. Sort of like throwing out the high and the low results in research. They are at the extremes most likely because they are the result of errors. I don't attempt to identify the error I just accept they are wrong. In all OA has a long history of use with no indication of resistance. Again I won't spend a lot of time investigating what is not happening. Assumption abound and for the most part are wrong. And this entire point is grounded on an assumption. Provide evidence that assumption is correct or you have not even supported every other claim beyond it. I have seen no evidence that anyone has applied inadequate doses. That survivor mites where not exposed is a far more likely scenario than mites are developing resistance. That recent development in equipment and temperature control is less than effective is also far more likely.


----------



## allniter (Aug 22, 2011)

I have 2 cents to put in the pot 

treatment days 
sun-day 1 ----0 days 

sun day 7-----7days 

sun day 14 ---14 days 

U have'nt been through BROOD CYCLE [21] days --yet but U did treat [3] times like it tells U 2 ---pluse the drone cycle is 24 days--- the mites like the drone cells better than worker cells


----------



## beemandan (Dec 5, 2005)

allniter said:


> I have 2 cents to put in the pot


If all I were reading were people who are doing three or four consecutive treatments...I would never have started the thread. There seem to be some who are doing so for much more extended periods. 

Once again...it appears that many people believe that varroa cannot ever become resistant to oxalic acid. I hope they are right.


----------



## psm1212 (Feb 9, 2016)

I am a little confused by what I consider to be the OAV guidelines. According to the instructions that come with the Varrox, you are to treat 3 times, 7 days apart. I don't really understand the 7 day interval. If the phoretic phase of the mite is or maybe less than 7 days isn't this a waste of effort? 

I am curious if the 7 day interval didn't simply coincide with the convenience of the beekeeper (especially part-timers) and ignored the life cycle of the mite. I would assume we should find -- to the extent we can -- the absolute minimum phoretic cycle of the mite and treat on that cycle until you have completed your brood cycle. 

I am not sure any study determined that 3 intervals is too much or not enough -- or that there is anything magic about 3 intervals. It seems that the goal when you start the treatment is to:

(1) make certain that the youngest capped brood cell in your hive ON THE DAY YOU START is hit with OAV the day after it hatches; and
(2) until that time, make certain that no mite emerges from a capped cell for greater than X days without being treated with OAV

"X" of course is the minimum phoretic period of a mite and is your interval.

If you hit these two goals, then you treated properly. If you did not, you treated improperly. 

I do not see how we determine that a beek treated too much or too little outside of this paradigm. Regardless of numbers of treatments. 

I have very thick skin and I am trying to get my head around all of this, so feel free to teach me something here. You do not have to be gentle.


----------



## Snaggy (Nov 24, 2015)

OAV is a fumigant, which have been used in Ag for decades. Some insects have developed resistance, but on the whole they've held up pretty well. The mechanism in phosphine resistance is that the insects have altered their respiration so less fumigant enters the body cavity through the spiracles. It also turns out insects with this adaptation just can't compete with their nonresistant brethren in the absence of the gas, likely because they just don't "breathe" as well. The anatomy of a mite is different, so that may or may not occur readily. Bees can close all their spiracles.

I've read Bruning's paper. It really is just an observation and a hypothesis, as he admits. It doesn't consider other mechanism of mite killing. If you've vaporized without a respirator, you know how irritating to the lungs the faintest whiff is. Given the choice between the crystals and foot thing, vs the idea that the gas enters the body through the spiracles and causes damage to the internal organs, the latter seems more plausible. Electron micrographs would tell the story.


----------



## crofter (May 5, 2011)

I think the 7 day period may be the belief that the OA deposit on the colony surfaces hangs around and is effectively killing mites for three or more days after application. Does anyone know of definitive data on this time frame? It seems that the phoretic period can be much shorter than the 4.5 day median time that is put forth. From what I have read an experienced female can jump back into a cell immediately and successfully cycle again; a first time out but mated female will be more successful with a longer phoretic period.

This possibility of jumping back into the cell immediately during the time the OA surface treatment has lost effectiveness could be a window of lost opportunity that could be happening with every 7 day periodic treatment.

Maybe the recommended periods are thoroughly tested to be optimum but I have not seen enough detail of how that was arrived at to give me confidence in it.
I am inclined to go with shorter periods and plan to do 5 repeats rather than allowing 7 day gaps and having to continue for a very large number of repeats. My mite counts are so low compared to what many of you are seeing that I am a poor testing control.

I realize that a large and ongoing reinfestation from external sources could confuse what actually is behind the affectiveness contradiction that Dan is homing in on. That and variations in temperature control of different devices. It is difficult solving a problem when there could be a number of unknowns not isolated.


----------



## clyderoad (Jun 10, 2012)

psm1212 said:


> I am a little confused.....


I don't think you are confused at all. 
Improper treatment timing results is lots and lots of ineffective treatments as does a poor method or tool or active ingredient (robbing of mite bombs will throw this as well). Seems to me to be a terminology issue most times, lots and lots of treatments is expressed as treating too much when it's actually describing a ineffective treatment regiment because of one or all of the above.
Attention to your points #1 & #2 results in a effective treatment using OAV in my experience.


----------



## dudelt (Mar 18, 2013)

allniter said:


> I have 2 cents to put in the pot
> 
> treatment days
> sun-day 1 ----0 days
> ...


Allniter, your math is wrong. Drones are capped on day 10 and emerge on day 24 so the mites are not accessible for only 14-15 days, not 24.


----------



## beemandan (Dec 5, 2005)

There are a number of variables....I surely don't know or understand them.

When I read where a beekeeper has dropped over 12,000 mites in one hive....I know that all of those couldn't have been native to that colony.

Three day or seven day cycle? I just don't know.

Rightly or wrongly I always thought that the Europeans were mostly using OA as a single application, broodless dribble. I am probably wrong about that. Does anyone know for sure?

Then...as a fumigant affecting their breathing....why doesn't it have a similar impact on the bees?

I know oav knocks down mites. I've done it. Mid winter single oav after a fall conventional treatment and I've dropped 500+ on many occasions. I remember seeing those photos posted by Glock with thousands of dead mites from a single treatment.

Having said all of that, when I read a post about someone treating weekly for months...for whatever reason....I wonder if we really know what we are doing.


----------



## psm1212 (Feb 9, 2016)

I understand you Dan. I have a problem hive that I am tracking on another thread. I am on my third treatment and I am still dropping a considerable amount of mites. I am definitely doing a 4th (4 day intervals) which should put me over the brood cycle mark. The question for me will be, what should I do if that 4th treatments drops 1000 mites? I am afraid to go with an alternate treatment, because I might kill my queen going into winter. I will also be afraid to leave that hive alone with that kind of mite population in it.

My guess is that I will probably OAV again . . . and then again . . . and then again, until I see the mites stop dropping in such large numbers. I think you are correct to wonder what the effects of that approach are. I wonder the same too. Maybe they are genetically inferior bees that should die. I have hives beside it that are dropping 2 mites a treatment (no more treatments for them BTW). I like the different ideas presented on this forum. It makes you think about it from a 30,000 foot view, instead of the one with your head in your hive.

If we had all the answers, we probably would not be here.


----------



## beemandan (Dec 5, 2005)

psm1212 said:


> My guess is that I will probably OAV again . . . and then again . . . and then again, until I see the mites stop dropping in such large numbers.


I'd probably do the same.
It is interesting that one hive continues to drop big numbers while its neighbors don't. Just helps convince me that there's a lot I don't understand. There may be any number of opinions but at the end of the day, that's all they are....opinions. 
I didn't start the thread to be critical of anyone....although some may have taken it that way.


----------



## snl (Nov 20, 2009)

crofter said:


> I think the 7 day period may be the belief that the OA deposit on the colony surfaces hangs around and is effectively killing mites for three or more days after application. Does anyone know of definitive data on this time frame?


Bees start carrying the crystals out almost immediately. A populous, flying hive can remove it all very quickly (a day or two) whereas in a in a non-flying hive (cold weather) it can remain weeks. So, there are many variables


----------



## Ian (Jan 16, 2003)

If it works, use it. Monitor its efficacy, don't rely on blind faith


----------



## beepro (Dec 31, 2012)

So many variables:
Know your bee cycle--newly emerged bees and the queen's egg laying stage on the bimonthly calendar.
Then time your oav treatment with those cycles. You have to catch them
from cycle 1 emergence along with the free running mites to the next bee
emergence cycle 2. Also whether or not the treatment is for a single deep, a
nuc or double deep or double nuc hives. Because some mites will be hiding on the
healthy nurse bees at the top hive box too. Four to 5 adult mites are congregating on 1 sick and deformed newly emerged bees sucking all the lifeline out of whatever is remainging. <<--This is my continued observation by following the 21 days bee emergence cycle for 2 seasons now. Then you still cannot catch them all because the queen will lay in small winter batches. Then you have the winter variables instead of the summer one: The center cells are cap first while the 2nd eggs cycle are on the outer edge next to the cap ones. So majority of the free running mites are hiding inside the 1st cap cells cycle. Then some queens will lay later say about 1 week behind the others. This also affect your treatment cycle and timing too from hive to hive. Know your winter bee cycle. What about the summer bee cycle and treatment strategy? There is a difference between the summer expansion mode and Autumn contraction mode. This is another topic for another day.
Oh, don't forget the winter drifters too. For survival especially in the low population hives they will accept any incoming foragers. If one hive is queen less for whatever reason all the flying bees will migrate to its neighbor hives less than a few days (3). And along with them are the mites too. Imagine if you made a mite bomb without treating then those are your spread out mites and bees infecting the neighbor hives that you're trying to clean out. 
So what is the real solution? Removed all the cap brood frames leaving only the pollen/nectar and honey frames and the replacement drawn frames. Brushed off all the attaching bees on the empty cells drawn comb frames for the replacement in the hive. Without the cap cells all the free running mites on the bees are susceptible to the oav treatment. This will give you 4 days ahead on the treatment without any developing larvae. Treat before the sunset on the 1st day after the brushed in bees where majority of the foragers are inside the hive. Many foragers will carry the mites on them because without any broods to take care the hive will sent out many foragers to the fields. You are looking at 1-2 days time frame. So treat later in the day. Also, the effective treatment is on a single deep or 5 frame nuc hive. The bee population will have an impact on your treatment too. A too populated bees will hinder the oav treatment. Less bees will make the treatment more effective. More oav covering the bees.
My proposal for futher little oav experiment: Also, treat in 3 days interval, 4 times total without the cap broods to get to as many bees as you can. You can also treat with sugar powder inbetween during the 3 days oav resting period. The OAC (oxalis acid crystals) producing unit can produce enough OACs to mix in with the sugar powder. Maybe a 10% sugar powder and 90% oacs mixture. 
So instead of treating many hives, my moved cap broods consolidation method will only treat 1 hive. This is the mite bomb hive from all the cap brood frames put inside. Now put all these cap brood frames into 1 vsh hive and watch majority of the infected cells uncap. Instantly you will have a mite bomb exploded inside. But the treatment will work to take care of this issue right away. The other hives with the cap broods removed will have less free running mites to deal with. You will remove them after knowing your bee cycle so that all the mites will be inside the cap broods going to the mite bomb hive. Knowing that the winter bees can live longer than the summer bees, removing the cap broods into the mite bomb hive will take care 99.5% of the mite issue after 3 cap brood cycles. Some hives I just moved it 1 time, some 2 x and some 3 x removal. The 2-3 x removal is the same result in less mites. 

We are here hoping to find an answer to the mite issue. Dan we understand your oav concern too. A little pest creating all these headache for us. Trying to go tf 2 seasons in a row though still too early to tell. More little mite experiment design will be done so that resistant will not develop, hopefully in time. It is no longer a concept or opinions but actual practical application we all can use here. I only removed the cap broods from 8 nuc hives into the mite bomb vsh hive this season. No oav or oacs so far! This is a good way to test out my little theory and tf concepts. And all hives are holding strong now. Seeing newly emerged bees without the mites attacking them or on them is a good accomplishment to me. Today, combined 2 strong nuc hives that got the moved cap broods manipulation since the prolong warmer than usual Autumn season sent them to the fields more. The local Loquat trees and wild mustard are still blooming strong. No need to continue with the oav treatment forever. You just have to interrupt them at the right bee cycle while finding the resistant bees to keep if you know where to look. 


No longer just a concept:


----------



## beemandan (Dec 5, 2005)

From a post today. I'm not going to link the post. My intent isn't to embarrass anyone. Just trying to make a point. 

*i been treating all season. Once a week weather permitting for fall.*


----------



## Daniel Y (Sep 12, 2011)

Dan, I agree that others seem to be going overboard. I also note that it is not accompanied with reports of bad results also. So in that I can recognize a possible positive based upon evidence of what did not happen. Okay flakey at best but it is actually what didn't happen. OR I can subscribe to the idea that tis may / or may not. result in something there is no evidence of any kind to be concerned about. Now is lack of evidence due to this being new? Possibly yeas and no. OA and OAV is not new. Being applied the way it is with what it is being applied with and possibly the overboard thing is, possibly. Do I think the reports of less effective treatments is the result of resistance? No, that possible cause would be well down my list. You have made your point. but you continue on it as if you are attempting to convince others to adopt it. I think they heard it. considered it and have filed it where they consider it being. and for most that is not very far up the list of priorities. temperature adjustments seem to be very near the top. I have argued against this entire overheating of OA claim since it started. To me it has now resulted in people trying to fix a problem that does not exist until treatment suffered. and they are now at least in part beginning to figure that out. I now see this issues as the next worthless thing to concern ourselves with. Keep fixing things that are not broken. No evidence they are broken or ever have been. take something that is working and alter it due to baseless concerns. Something that is derived out of an over active imagination. There are plenty of people out here that don't know enough and will think you do to buy it. I will no more promote that mites develop resistance to OA than I will promote that OA can be decomposed with the equipment we vaporize it with. Nether is even possible. if you think I am wrong then do it. go expose mites to OA and demonstrate that any of them survive. Produce formic acid from OA on a hot plate. go do what you say is being done. It cannot possibly be that difficult. the claims are everyone is doing it by accident. So go do it on purpose. It evidently is extremely easy to do.


----------



## Daniel Y (Sep 12, 2011)

SO here is my break down of why oa cannot be decomposed on a hot plate. the hot plate is well above the temperature to vaporize OA. I will go with 1200 degrees. Most of that heat is wasted. it goes into the air. into the body of the tool you are using. into the wood wax honey pollen and even bees of the hive. much of it goes into heating moisture that is in the air. not to mention other particles in the air. This wasted heat is known as inefficiency. And heat is notorious for being an inefficient energy. Now not all the OA on the hot plate vaporizes all at once. just like a pot of water does not boil all at once it starts slowely and builds up but each bubble from a boiling pot of water is just a small amount of water that was heated to the point it boils. once it reaches the boiling temperature that pocket or bubble of steam does not gain any more heat. it stays at 212 degrees rises to the surface and escapes the heat into the air. where it immediately cools into small droplets of water which we see as steam. IN fact what we se is no longer steam but steam that has returned to liquid state in very tiny droplets. SO why does the steam not gain any more heat. because it had to be right down at the bottom of the pot against the hot surface to even get hot enough to turn to steam. once it left that hot surface it was in cooler water for one. Another is that any additional heat goes to turning any remaining water to steam before it will ever go to making steam hotter. The same would be true about OA you have a pile of OA on a hot plate. it is vaporized not all at once but in tiny portions. and as long as any vaporized OA remains any additional heat will go to vaporizing that OA before any heat can go to making vaporized OA hotter. By far the majority of OA will have left the hot plate and be floating around in the hive long before the OA on the hot plate runs out. At most only that last tiny portion of OA to be vaporized leaving no OA behind could even possibly be heated to the point it is converted to formic acid. Even if the vaporized OA is trapped in a space that is at 1200 degrees it will not take on any more heat as long as there is unvaporize OA present.

The idea that OA can be decomposed into Formic acid is an ignorant fantasy that is doing nothing but causing ineffective results due to irrelevant concerns. Fix what is working until you assure it is broken. And then wonder what the problems might be with keeping bees.


----------



## Gumpy (Mar 30, 2016)

beepro said:


> Know your bee cycle--newly emerged bees and the queen's egg laying stage on the bimonthly calendar.
> Then time your oav treatment with those cycles. You have to catch them
> from cycle 1 emergence along with the free running mites to the next bee
> emergence cycle 2.


I don't understand this? Can you please explain what you mean. 

What is the queen's egg laying stage on the bimonthly calendar? 

As far as I know she doesn't lay in stages. She lays all the time. Every day. It's her full time job. Therefore, cells are being capped every day as they become ready, and bees are emerging every day. 

I must be misunderstanding what you mean.


----------



## Daniel Y (Sep 12, 2011)

Grumpy, Possibly and I would agree if the queen has unlimited brood nest area. But suppose a queen only has so much space and is able to fill it in say 10 days. what does she do for the remaining 11 days it takes for the first bee to emerge and provide an open cell?
YO may be able to see in a situation such as thee there would be a cycle of total capped brood cells.
Another is that each individual cell cycles form capped to uncapped. SO if you think of the hive as individual cells and that each needs to be treated while uncapped you again have a cycle that varies as to its range in the hive as a whole.


----------



## Arnie (Jan 30, 2014)

Well beemandan, this thread is about to go seriously sideways.

So, give us a 'Therefore what'?
Tell us what you would like to have us do to prevent mite OAV resistance, if you don't mind.


----------



## psm1212 (Feb 9, 2016)

snl said:


> Bees start carrying the crystals out almost immediately. A populous, flying hive can remove it all very quickly (a day or two) whereas in a in a non-flying hive (cold weather) it can remain weeks. So, there are many variables


Larry:
What state of OA is lethal to mites? Is it vapor form, crystal form, or both?


----------



## Daniel Y (Sep 12, 2011)

So if they carry out the crystals. What happens to the mite the crystal is attached to? I have not seen bees getting kicked out that have crystals on them and that is where I am most interested in them being. They at groom them off but then isn't grooming the idea behind other treatments like sugar dusting? Seems to me like with OAV you may be double or tripling up treatment methods. you get OA crystals, Formic acid gas, and grooming behavior. How could it miss?


----------



## Delta Bay (Dec 4, 2009)

I could see how a few undesirables could possibly take place with continuous OAV. This type of application is as far as I can tell new and not how the research describes application, so I'm sure with time something will be noticed. Is it inconceivable that the mites behavior could be selected to have a shorter phoretic stage as well as entering open cells earlier? I hear that the treatment has no effect on the bees but is that true. It could even be an insignificant side effect that no one even considers such as causing the bees develop time to be extended a day or two. I guess with the idea that more is better all it would take is a daily OAV and all will be good.


----------



## beemandan (Dec 5, 2005)

First...I DO *NOT* BELIEVE THAT OA IS LOSING ITS EFFECTIVENESS. There still seems to be some who haven't gotten this message.



Arnie said:


> Tell us what you would like to have us do to prevent mite OAV resistance, if you don't mind.


As a precaution I would suggest that:

Rotate miticides. Don't use oa over and over and over.

Limit the number of repeat treatments. If you are treating every 3 to 7 days and after four or five treatments you still believe that you have a significant infestation....try something else.

These would be the two biggies.


----------



## snl (Nov 20, 2009)

Once again per Jennifer Berry "resistance will not be an issue. It would be like like a ****roach becoming resistant to a hammer."


----------



## beemandan (Dec 5, 2005)

snl said:


> Once again per Jennifer Berry "resistance will not be an issue. It would be like like a ****roach becoming resistant to a hammer."


I bet if she heard that someone was treating hives with oav every seven days for the past two years...she'd withdraw that claim.


----------



## Nordak (Jun 17, 2016)

snl said:


> Once again per Jennifer Berry "resistance will not be an issue. It would be like like a ****roach becoming resistant to a hammer."


The analogy is a poor one in regard to the mechanism by which OAV works, by all accounts. If that level of blunt force were used on mites, it would certainly kill bees in the process. Need a better analogy for the argument is all I'm saying.


----------



## snl (Nov 20, 2009)

Nordak said:


> The analogy is a poor one in regard to the mechanism by which OAV works, by all accounts. If that level of blunt force were used on mites, it would certainly kill bees in the process. Need a better analogy for the argument is all I'm saying.


You'll need to take that up with Jennifer, I just quoted her.


----------



## Nabber86 (Apr 15, 2009)

Arnie said:


> Well beemandan, this thread is about to go seriously sideways.
> 
> So, give us a 'Therefore what'?
> Tell us what you would like to have us do to prevent mite OAV resistance, if you don't mind.



He he already said that it isn't his life's work to inform others. You are supposed to look for the information yourself.


----------



## Rader Sidetrack (Nov 30, 2011)

Nordak said:


> The analogy is a poor one in regard to the mechanism by which OAV works, by all accounts.


"... by _all_ accounts?" :scratch: Perhaps you'd care to tell us just what _that_ mechanism is?


Seems like there are several different theories floating around, and I, for one, have not seen that there is anything approaching a full consensus on exactly what the OAV mechanism of killing varroa is.


----------



## Mike Gillmore (Feb 25, 2006)

Rader Sidetrack said:


> Seems like there are several different theories floating around, and I, for one, have not seen that there is anything approaching a full consensus on exactly what the OAV mechanism of killing varroa is.


With that in mind ... how can we be certain that resistance may never develop? We don't know exactly what the actual mechanism is that kills the mites. Could it be something that mites eventually become resistant to? I don't think so ... but that's supposition on my part. 

With so many unknowns I think it's prudent to err on the side of caution in regards to treatment overexposure. Just in case.


----------



## Nordak (Jun 17, 2016)

Rader Sidetrack said:


> "... by _all_ accounts?" :scratch: Perhaps you'd care to tell us just what _that_ mechanism is?
> 
> 
> Seems like there are several different theories floating around, and I, for one, have not seen that there is anything approaching a full consensus on exactly what the OAV mechanism of killing varroa is.


That's kind of why I added the "by all accounts" part. All I've read on the matter are beekeeper accounts of how it works. You bring up a great point, and I have no answer for that. I doubt it works in the way a hammer works on a roach was the only point I was trying to make.

An even better point by Mr. Gillmore:

"With that in mind ... how can we be certain that resistance may never develop?"


----------



## Nabber86 (Apr 15, 2009)

Mike Gillmore said:


> With that in mind ... how can we be certain that resistance may never develop?


We can't. All we can do is play "what if" with a bunch of armchair chemists/toxicologists/geneticists/entomologists that inhabit BeeSource. 

Only time will tell and until we see start some some real evidence, I am not going to worry about it. I have better things to do like build and repair woodenware that I will need in about 5 months time.


----------



## crofter (May 5, 2011)

Mike Gillmore said:


> With that in mind ... how can we be certain that resistance may never develop? We don't know exactly what the actual mechanism is that kills the mites. Could it be something that mites eventually become resistant to? I don't think so ... but that's supposition on my part.
> 
> With so many unknowns I think it's prudent to err on the side of caution in regards to treatment overexposure. Just in case.


Just to stir the pot, Mike; I think it is also a possibility that in this hypothetical resistance development case, that under treatment with OA could be more conducive of resistance than treatment overexposure.  As Richard Cryberg has pointed out there are many quite different paths to the development of resistance and different levels of treatment affectiveness for optimum results vs resistance.

The situation certainly dose not appear to be a yes or no question. We certainly have made a mess with our own medical treatments and consequent loss of usefulness of many drugs. I also feel that the mechanics of OA exposure make the development of resistance less likely than with some of the previous bad experiments. I am thankful to be in conditions where there is apparently a very low background level of mites and if I knock them down they dont rebound like some other posters are experiencing.


----------



## crofter (May 5, 2011)

Nabber86 said:


> We can't. All we can do is play "what if" with a bunch of armchair chemists/toxicologists/geneticists/entomologists that inhabit BeeSource.
> 
> Only time will tell and until we see start some some real evidence, I am not going to worry about it. I have better things to do like build and repair woodenware that I will need in about 5 months time.



Hey Nabber; I resemble that remark! 

I guess we will just have to wait and see what plays out. We Canadians are doing the same in regards to what is playing out south of the border too!


----------



## clyderoad (Jun 10, 2012)

Nabber86 said:


> We can't. All we can do is play "what if" with a bunch of armchair chemists/toxicologists/geneticists/entomologists that inhabit BeeSource.
> 
> Only time will tell and until we see start some some real evidence, I am not going to worry about it. I have better things to do like build and repair woodenware that I will need in about 5 months time.


When does the real evidence start to show? How will we know?

Why don't you educate the armchair 'ists' then? That's the reason for all of the questions in these posts, asking for knowledge.
Instead the armchair bunch got a narcissistic and dismissive one-two punch. The old- I have better things to do than explain it to dumb bells.


----------



## Arnie (Jan 30, 2014)

beemandan said:


> First...I DO *NOT* BELIEVE THAT OA IS LOSING ITS EFFECTIVENESS.


I never said you do believe that.

However, you cannot escape the title of your thread and your musings that we may indeed be traveling the road to resistance and OAV ineffectiveness.
Hence my query. 

Thanks for the answer.


----------



## Mike Gillmore (Feb 25, 2006)

crofter said:


> Just to stir the pot, Mike; I think it is also a possibility that in this hypothetical resistance development case, that under treatment with OA could be more conducive of resistance than treatment overexposure.


Point well taken. 

For example, if hives are being treated with faulty vaporizers or methods ( under exposed ) week after week after week after week ....


----------



## Nabber86 (Apr 15, 2009)

clyderoad said:


> When does the real evidence start to show? How will we know?
> 
> Why don't you educate the armchair 'ists' then? That's the reason for all of the questions in these posts, asking for knowledge.
> Instead the armchair bunch got a narcissistic and dismissive one-two punch. The old- I have better things to do than explain it to dumb bells.


There nothing to explain at this point. You can't explain the unknown. We will know more and be able to explain things as we move forward with what seems to be one of the best varroa treatments that is currently available. If and when problems with resistance begin to develop, the data will have to be studied to determine how to deal with it. Right now we have no data. What we do have right now is a few people saying that they are not getting "enough results" so they apply more OVA than that recommended. Most of the people posting these anecdotes can not even define what "results" are and how to quantify them. 

The old, "I have better things to do than explain it to dumb bells." comment is way off base. I have no knowledge of what "it" is; therefore I cannot explain anything to anybody. My point was that personally, I don't worry about it.


----------



## crofter (May 5, 2011)

Mike Gillmore said:


> Point well taken.
> 
> For example, if hives are being treated with faulty vaporizers or methods ( under exposed ) week after week after week after week ....


Mike that angle really is a seemingly recent complication :scratch: The scenario you project certainly would seem to give the enemy too much opportunity to figure out our game!

I am not convinced a person can accurately evaluate visually the effectiveness of a plume that results from heating a quantity of OA crystals. In some reactions a very small change in one or more parameters can result in a totally different final product.

Some people are strongly convinced that OA *cannot* be decomposed in such a way to render the output ineffective! The problem with this is the fact that strength of conviction is not always proportional to the probability of accuracy. 

It does make truth an elusive game to hunt! Time will tell.


----------



## snl (Nov 20, 2009)

To know the effectiveness of a vaporizer, treat a hive you know has a high mite load and look at the drop in the 2nd 24 hours (when OAV shows it's greatest kill) that'll tell you.


----------



## Nabber86 (Apr 15, 2009)

Arnie said:


> I never said you do believe that.
> 
> However, you cannot escape the title of your thread and your musings that we may indeed be traveling the road to resistance and OAV ineffectiveness.
> Hence my query.
> ...


After re-reading this thread a couple of times, I think I understand what beemandan was trying to say initially. However things went down hill when many where accused of lacking reading comprehension. When the level of comprehension decreases for many people, the chances of poorly expressed thoughts increases. 

Beemandan, can you tell me if this is your approximate stance? 

There are several reports of people claiming that they have to over-treat with OVA because they "think" it isn't working. (I agree)

Over-treating is a bad thing. (I agree)

Could over-treating lead to problems? (Not sure if I agree or disagree, but it is something to think about)


----------



## Nabber86 (Apr 15, 2009)

Mike Gillmore said:


> Point well taken.
> 
> For example, if hives are being treated with faulty vaporizers or methods ( under exposed ) week after week after week after week ....



What are your thoughts on the difference between under exposed for week, after week, after week and over exposed for week, after week, after week?


----------



## Daniel Y (Sep 12, 2011)

Nabber86 said:


> He he already said that it isn't his life's work to inform others. You are supposed to look for the information yourself.


he seems pretty intent about informing others to me.


----------



## beemandan (Dec 5, 2005)

Nabber86 said:


> However things went down hill when many where accused of lacking reading comprehension. When the level of comprehension decreases for many people, the chances of poorly expressed thoughts increases.


Actually....if you go back a reread what I believe I clearly said...I suggested that it was likely one of three things. Did you miss the other two?




Nabber86 said:


> Beemandan, can you tell me if this is your approximate stance?
> 
> There are several reports of people claiming that they have to over-treat with OVA because they "think" it isn't working. (I agree)
> 
> ...


Somewhat. I don't think, from what I've read, that it is only people who 'think' that it isn't working. It seems that some are continuing to treat...for reasons I don't understand and they don't always articulate....and I wonder if it might be related to the oft repeated claim that varroa will never become resistant to oav.


----------



## beemandan (Dec 5, 2005)

Arnie said:


> I never said you do believe that.


It wasn't directed at you. I should have made it a separate post....


----------



## Daniel Y (Sep 12, 2011)

beemandan said:


> and I wonder if it might be related to the oft repeated claim that varroa will never become resistant to oav.


where have you seen this said. I haven't, but then I don't see everything that is posted.


----------



## Mike Gillmore (Feb 25, 2006)

Nabber86 said:


> What are your thoughts on the difference between under exposed for week, after week, after week and over exposed for week, after week, after week?


The only thing I can offer is my own experience with OAV over the past 9 years or so. I've done 3 or 4 treatments a week apart at the correct time of year, Aug-Sept, when the mite load in the hive is peaking and brood being reduced. Then, one more treatment when broodless in the winter months between Thanksgiving and Christmas. I use a Varrox vaporizer and fresh Savogran wood bleach, and find this routine to be very effective, even when treating hives with very high mite loads. 

The need to treat for weeks on end is foreign to me, I simply don't understand how that can be. Maybe it's the thought that "every" mite in the colony has to be terminated in order for OAV to be a successful treatment. OAV has seasonal limitations to achieve maximum effectiveness, just as Formic treatments must only be administered in certain temperature ranges. 

I don't know if OAV resistance will ever be seen, we're all just guessing one way or the other at this point in time. But, if it "could" happen, overexposure is one sure way to shorten that time line. Lengthy exposure with normal doses, or continued under dosing worries me. Not just in regards to the resistance issue, but the long term effect that constant acid exposure might have on colony health in general. 

I am not meaning to criticize or second guess those who are treating more often than the general guidelines suggest. I just don't understand it. Something else has to be in play in these cases and I think it's important to determine the root cause rather than continue treating endlessly. Faulty equipment or acid, improper application methods, treating at the wrong time of year, mite bombs, who knows. If a series of 3 or 4 OAV treatments does not seriously knock down the mite load then something else should be used. OAV has it's limitations based on brood volume and is not the year round cure all silver bullet for Varroa mite management. I'm not sure this part of OAV is fully understood. 

Anyway, these are some of my thoughts. I know, not very scientific. But sometimes don't you just get a gut feeling that something isn't quite right?


----------



## crofter (May 5, 2011)

snl said:


> To know the effectiveness of a vaporizer, treat a hive you know has a high mite load and look at the drop in the 2nd 24 hours (when OAV shows it's greatest kill) that'll tell you.


First; snl, I am a user and proponent of OA and points I make are not an attempt to discredit it. There does seem to be a relatively recent increase in reports suggesting the possibility of reduced effectiveness that I would like to see cleared up or explained. This thread is chasing two ideas, one about the possibility of resistance developing to OA, and the other to the question of the relative effectiveness of different vaporization methods and whether more critical temperature controls are warranted during the *entire* process. It suggest that visual assessment alone, may not be adequate.

In most of the literature it has been pointed out that a colony with a lot of capped brood even a perfectly delivered OA dose is not the most effective treatment. The workaround has been to do repeat treatments to incrementally reduce mite percentage levels each time.
Unless the actual number of mites is known (high is not an accurate number) and the ratio of bees under capping vs phoretic, the dead mites counts after a treatment dont tell us the percentage kill rate so I will suggest that that cannot be used to definitevely assess the treatment effectiveness.

The present recommendations of treatment frequency and number of reps are based on an expected kill rate of 95% on exposed bees. Because of the exponential growth rate of mites, _anything less in terms of effectiveness may result in only maintaining absolute numbers rather than reducing them_.
In simple terms if a colony has a large amount of brood under cappings and is laying heavily and has a high mite load, the present recommendations may not take the numbers down quickly enough. This brood and mite scenario describes the booming, high producing hive that "mysteriously" collapses in the fall.

If some compromising factor is also creeping into the exercise, eg. OA breakdown into less effective sub components, or being blown in on water vapor during initial water of hydration boil off, then the actual kill rate on exposed bees may be less than we are counting on.

Yes Beemandan your thread has kind of gone sideways but at least we are still on bees. I admit to being one of the first posters that lead to the diversion.


----------



## Daniel Y (Sep 12, 2011)

This entire conversations is founded on one persons "Gut Feeling". I have no interest in anyone now trying to introduce Scientific anything to it. I also have little interest in anyone requiring scientific anything until I see at least some appropriately apply the concept of Hypothesis. A fancy word for educated guess, suspicion or conclusion with no investigation to support it. I suppose you could call it a Gut Feeling as well.

From what I have seen myself I have a suspicion that large amounts of OA. Such as would be used with the intent of treating 10 or more hives at a time. are presenting many of the problems with these new devices not being effective. I will offer this actual result as an example of what I think may be happening. I do not think this is the only problem these new devices produce. just an example of one possible one.

I made up and used a very simply vaporizing device. the OA was placed in a tiny cup barely 1 inch in diameter about 3/4 of an inch deep made of very thin metal. not much more than aluminum foil. With a dose large enough to treat one hive box it worked fine. but any attempt to vaporize a double dose resulted in the OA vapor collecting at the top of the cup in a dome. additional vapor simply crystalized on this dome and the actual dose applied to the hive was inadequate. Such results where completely unexpected and resulted in me taking a closer look at how OA vaporizes what causes it to cool and crystalize. what sort of timing is involved and exactly why more OA would crystalize more poorly than less.

In large my concern with some of these devices recently has been. they are trying to vaporize to much OA at a time. At too cool of a temperature. I then read how they have to take the unit apart and clean it out every so often. Clean it out of what. all the OA that did not remain vapor long enough to reach the hive? Some of these are not killing mites because they never get the OA in the hive in the first place. it is still stuck in the gun. just like the OA in my double dose was still stuck on the cup.

Now I don't know about anyone else. but there was no Gut feeling of any kind that I would see these results. it is as far as I am concerned a nearly random result of a seeming inconsequential difference.

IN this case it comes down to these new devices don't work. OA works. the devices don't. I am not real interested in why. I suspect it is to much device, to much OA and not enough heat.


----------



## beemandan (Dec 5, 2005)

Daniel Y said:


> where have you seen this said. I haven't, but then I don't see everything that is posted.


From this thread alone. 



rangerpeterj said:


> Mites becoming resistant to OAV is like an ant becoming resistant to a hammer,





SS Auck said:


> no way they could become resistant.





Arnie said:


> European beekeepers. 20 years, no sign of resistance. Works for me.





snl said:


> Once again per Jennifer Berry "resistance will not be an issue. It would be like like a ****roach becoming resistant to a hammer."


----------



## beemandan (Dec 5, 2005)

Daniel Y said:


> This entire conversations is founded on one persons "Gut Feeling".


What gut feeling?
I said that I was reading reports of extended treatments. No gut feeling there.
I asked if this might cause resistance in varroa. No gut feeling there. 

Simply asking opinions. 
From my first post.


beemandan said:


> Will we, once again, prove to be our own worst enemy?


From another.


beemandan said:


> I don't believe that oav isn't working.


And this.


beemandan said:


> First...I DO *NOT* BELIEVE THAT OA IS LOSING ITS EFFECTIVENESS. There still seems to be some who haven't gotten this message.


Where do you see a gut feeling in this????????


----------



## costigaj (Oct 28, 2015)

This thread is getting as hot as a hive in dearth


----------



## beemandan (Dec 5, 2005)

From a thread today.

*i have been treating nonstop since augest*


----------



## beemandan (Dec 5, 2005)

costigaj said:


> This thread is getting as hot as a hive in dearth


I'm guessing that you missed fireworks years on Beesource. Some mean spirited, name calling....seriously hot threads. This is tame.


----------



## Arnie (Jan 30, 2014)

So my takeaway from this is:

Dan is warning us....Look we have a good thing here with OAV; let's not ruin it by throwing caution to the wind and going overboard with use bordering on abuse.

Point taken.

I would add this:
If you are starting out with OAV get yourself a commercial wand so you know how it is supposed to work.
Then , when you are familiar with the results, go ahead and 'hillbilly' yourself a homemade rig. That way you have a point of reference to make comparisons.


Since I made the switch to OAV as my primary mite killing technique my bees look like they did in the pre-mite days. I do the OAV on a schedule, I do not wait until samples show I have a problem. Keep the mites under control all year and your bees will reward you with booming hives and a nice honey harvest. 
(I'm assuming good bee husbandry... )

Thanks for the discussion.


----------



## beemandan (Dec 5, 2005)

Arnie said:


> Thanks for the discussion.


Stimulating a discussion was my primary intent.


----------



## johno (Dec 4, 2011)

It would appear to me that there might be problems with the administrating of OA, If you do not get sufficient coverage of the vapor due to what ever system you are using there would be mites that do not come into contact with the fine crystals and therefore do not get the kill expected. This could be caused by many reasons as I would consider clouds of vapor exiting the hive would mean loss of the required dose. Some of the forced air driven systems could be guilty of this, so you get quicker but unmeasurable doses. There is also the fact that we could have more mites in the brood than expected so after harvest it could take more treatments to clear them up. Clearly the most important part of the exercise is to do mite counts a couple of weeks after the four treatments are completed. In 2014 I completed 4 treatments and 2 weeks later my mite count was still unacceptable so I had to start again. With some tests I did on a new home built vaporizer I found that during vaporization the latent heat required to boil of the water of crystallization and the sublimation was quite high so the heated device would drop more than 20 degrees during the vaporization. I would then feel that there is little chance of OA degradation unless a great deal of heat was applied as with a large propane torch or something of that order. Just a few thoughts to throw out there to be pulled apart by the experts no doubt. You may consider that the experts who set up beginner classes still advocate for the treatment of mites with the Dowda sugar shake method and will tell you that OAV can be administered only once a year.
Johno


----------



## Daniel Y (Sep 12, 2011)

beemandan said:


> Where do you see a gut feeling in this????????


That any of this will lead to resistance.


----------



## beemandan (Dec 5, 2005)

Daniel Y said:


> That any of this will lead to resistance.


My thinking isn't that it will....only that it might.


----------



## beepro (Dec 31, 2012)

Gumpy said:


> I don't understand this? ....
> I must be misunderstanding what you mean.


Because during the Autumn and winter months the queens will lay in
smaller brood batches. She will first lay right in the center of the
frame toward the top a bit surrounded by the pollen and nectar rings. As these larvae in the center mature and about to be cap in 2-3 days, the queen will laid some more eggs in a 2nd patch this time further out on the frame filling more empty cells and right up next to the pollen ring. This is typical of the 2-3 months old later mated Autumn queens' laying pattern. Every week I do hive inspection to track every hive's progress. These young queens have no boundary in laying and I don't even know if they know that winter is approaching. We do have warmer than usual weather here in the valley. Other years after Halloween there will be fogs and cold wet weather. This year almost 70F everyday with the Loquat trees and wild mustard blooming now. Down in L.A. (Los Angeles) they have consistent 90F weather now. So all my hives are building up like this is their first normal Spring weather headed by a young queen. As the bees forage more bringing in hive resources the queens laid more to further expand their brood nest. I don't mind because they will build up a larger bee population leading to our Spring flow. This will benefit my hive expansion even more comes Spring time. It is hard to believe until you see it yourself. The first cap brood patch have less bees than the 2nd patch which have 3x more developing larvae. So basically I can transfer the cap broods frame into the vsh hive without interfering with the hive population that much. This will lessen the mite load over this winter. Why they laid like that? Maybe it was from the abby-normal weather we're having trying to test out the expansion phase a bit just before the winter sets in. <<--Just my guess!?
You can clearly see the first and second brood laying pattern in the following pics. Outside full of eggs extending almost toward the bottom--3x.


1st patch 2" diameter next to the 2nd eggs pattern:


----------



## aunt betty (May 4, 2015)

Opinion: Don't think varroa will develop resistance to OA. 
You might as well breed up some people who have developed a resistance to dying in a vacuum. NASA could use some of those people.


----------



## Rader Sidetrack (Nov 30, 2011)

Wouldn't the equivalent of "_people_ who have developed a resistance to dying in a vacuum" be "_varroa_ who have developed a resistance to dying in a vacuum"? :scratch:

I don't see how a vacuum even enters into consideration.


----------



## beemandan (Dec 5, 2005)

Daniel Y said:


> where have you seen this said. I haven't


And another from this thread.



aunt betty said:


> You might as well breed up some people who have developed a resistance to dying in a vacuum.


----------



## camero7 (Sep 21, 2009)

I am one of the overtreaters. I use 4-5 gms/hive and treat 4X about a week apart. I will deal with resistance when it comes, if it ever does.


----------



## Nordak (Jun 17, 2016)

Rader Sidetrack said:


> I don't see how a vacuum even enters into consideration.


Or a hammer, or any number of other bad analogies that have been made to argue resistance is not possible. I'd like to know exactly how it works. Analogies are easy to throw around. I'm pretty sure I could come up with a cool sounding one myself.


----------



## dudelt (Mar 18, 2013)

camero7 said:


> I will deal with resistance when it comes, if it ever does.


By the time resistance comes, the makers of the Flowhive will have come out with the Varroa Deathray Hive. It will be a computer operated hive with scanners and lasers that scans every bee periodically. When a bee has a mite on it, the laser turns on and vaporizes the mite. I want to see the little buggers develop resistance to that! Perhaps they will and someone will create the varroa killing nanobot for my hives. 

I am beginning to think I have been watching too much syfy channel...


----------



## Daniel Y (Sep 12, 2011)

Nordak said:


> Or a hammer, or any number of other bad analogies that have been made to argue resistance is not possible. I'd like to know exactly how it works. Analogies are easy to throw around. I'm pretty sure I could come up with a cool sounding one myself.


OA burns the feet of the mite. for the mite this is lethal. Maybe there is a small percentage of mites that are fire walkers. If you are so intent on knowing exactly how OA works, Why not more research on your part to discover that? Are you waiting for someone else to tell you? SO that you can then discount their findings as well? You want people to tell you about OA but then argue that they are wrong. How would you know? Because someone else told you to think they are wrong?

Here is a fact for you. after decades of using OA mites have not developed resistance and there is no evidence that they ever will. So why do you choose to concern yourself with a contrived problem yet not rely on a contrived solution? Or imagined evidence. the problem is imagined. You choose to believe that.

I would suggest you apply your same standard of evidence to the question. Is there even a problem with mites developing resistance. once you do that I suspect you will not require any further answers. Analogies or not.


----------



## Rader Sidetrack (Nov 30, 2011)

Daniel Y said:


> OA burns the feet of the mite. for the mite this is lethal.


Funny how Randy Oliver is much more careful about oxalic acid 'mode of action' ... 



> *Q:* A reference from X said that due to the mode of action of OA, it is impossible for mites to gain resistance to it.
> 
> *A:* [HIGHLIGHT]_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. [/HIGHLIGHT] 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!
> 
> ...




(bolding, italics and highlighting of Randy's quote are mine)


----------



## Nugget Shooter (Mar 28, 2016)

Simple fact is one can not build up a resistance to a corrosive acid.... Drip some sulfuric acid on your thumb once a day and see if it ever stops destroying your flesh. Acids are not like internal or external drugs/poison in that it will always attack and destroy the same organic compound without it being covered by some sort of added protection made of a non-organic material. So unless Varroa develop rubber protective gear over time (tongue in cheek) it will continue to destroy them generation after generation.


----------



## Rader Sidetrack (Nov 30, 2011)

Both bleach and vinegar are corrosive acids! And yet ... bleach is widely used in home laundry and cleaning, and vinegar is willingly ... *EATEN*!  

Does the flesh on your thumb come off from dipping in vinegar? :scratch: ...what does your tummy say about vinegar? 


... perhaps things are a bit more complicated than they might appear on the surface! 





EDIT: Oops, as Nugget Shooter points out below, ordinary bleach is not acid - it is a strong base, with a ph around 11. However ordinary bleach is certainly corrosive, capable of damaging stainless steel.


----------



## beemandan (Dec 5, 2005)

Nugget Shooter said:


> Simple fact is one can not build up a resistance to a corrosive acid....


Strange that bees seem to be unaffected by this same corrosive acid. I wonder what sort of rubber protective gear they've gotten.


----------



## Nugget Shooter (Mar 28, 2016)

Rader Sidetrack said:


> Both bleach and vinegar are corrosive acids! And yet ... bleach is widely used in home laundry and cleaning, and vinegar is willingly ... *EATEN*!
> 
> Does the flesh on your thumb come off from dipping in vinegar? :scratch: ...what does your tummy say about vinegar?
> 
> ...


The key with acids is dosage and vinegar is a much diluted form of Acetic Acid.

A bleach is a chemical that removes color or whitens, often via oxidation. Bleach is typically a strong base. However, there are oxidizing and reducing bleaches, so it can be either. One example is Sodium dithionite, which is used as a powerful reducing agent in some bleaching formulas. But the typical bleach under your sink is a strong base.

Diluted acids are often used on skin and otherwise for cleaning solutions that will not dissolve your fingers, but undiluted they would mess ya up. Dosage is the key and again there is no resistance built up to it's corrosive abilities by an organic the desired dosage once established.


----------



## Nugget Shooter (Mar 28, 2016)

beemandan said:


> Strange that bees seem to be unaffected by this same corrosive acid. I wonder what sort of rubber protective gear they've gotten.


Dosage is the key and the beauty of an acid being usable as treatment, once the proper application and dilution rate, Oxygen, water, or other, is established the dosage will remain stable. I am sure some bees paid the ultimate price in testing years back in learning how much to use...


----------



## crofter (May 5, 2011)

Every once in a while I see something like this snippet 

"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!

that takes away my faith in anything that has an overarching _appeal to authority_ as authentication. Oxalic Acid vapor is generally considered to have a very _large lethality margin_ on bees vs mites.

I will put my money on the very specialized mucous membranes of the mite footpads as being their prime vulnerability to Oxallic Acid vapor.

I think as a general course of action that rotation of methods is advisable from more aspects than only resistance development. Oxalic acid certainly is not "instant pudding" when the bees are rearing brood.


----------



## beemandan (Dec 5, 2005)

crofter said:


> I will put my money on the very specialized mucous membranes of the mite footpads as being their prime vulnerability to Oxallic Acid vapor.


This seems the most plausible explanation to me as well Frank. Having said that, just because the path to resistance isn't obvious doesn't mean we won't be surprised. The more folks insist that it won't happen....the more likely it will....in my opinion.


----------



## crofter (May 5, 2011)

beemandan said:


> This seems the most plausible explanation to me as well Frank. Having said that, just because the path to resistance isn't obvious doesn't mean we won't be surprised. The more folks insist that it won't happen....the more likely it will....in my opinion.


Dan is this the inverse to, "You have to believe in something to make it happen"?


----------



## Nordak (Jun 17, 2016)

Daniel,
I have researched, and can not find a direct answer. When I see analogies being thrown around, it tells me that people probably don't actually know how it works. OAV isn't quantum mechanics, so telling someone how it works shouldn't result in an answer equivalent to sharks developing resistance to helicopter blades, for example. It burns the feet of the mite...how hard was that?
At least you tried, and gave an actual answer to the question. I'm sorry you seem bothered by something that isn't unanimously agreed upon. 



Daniel Y said:


> I would suggest you apply your same standard of evidence to the question. Is there even a problem with mites developing resistance.


This is simply a response from someone with no answers. In order for me to understand if there was a problem with mites developing resistance, I'd kind of have to understand exactly how it worked......


----------



## Gumpy (Mar 30, 2016)

Wait! Sharks are resistant to helicopter blades? When did that happen?


----------



## Nordak (Jun 17, 2016)

Gumpy said:


> Wait! Sharks are resistant to helicopter blades? When did that happen?


Lol! What I should have said was "would be like sharks becoming resistant to helicopter blades." Sounds like a Sharknado scenario.


----------



## 1102009 (Jul 31, 2015)

Musing:
Oxalic acid kills some microorganism and fungi
This the bees need to ferment pollen, prevent nosema or for general strength.
The bees are weaker and so are susceptible to sickness and not able to defend very well, not foraging very well too.
Means mite impact seems stronger.
Looks like the mites are resistant.
In the long term the visual impact is on the bees.
( I don´t think there is resistance to OA)


----------



## psm1212 (Feb 9, 2016)

SiWolKe said:


> Musing:
> Oxalic acid kills some microorganism and fungi
> This the bees need to ferment pollen, prevent nosema or for general strength.
> The bees are weaker and so are susceptible to sickness and not able to defend very well, not foraging very well too.
> ...


If any research or studies support anything in your "Musing," I would be very interested in it. Please cite or link. Thanks.


----------



## clyderoad (Jun 10, 2012)

Nordak said:


> Daniel,
> I have researched, and can not find a direct answer. When I see analogies being thrown around, it tells me that people probably don't actually know how it works. OAV isn't quantum mechanics, so telling someone how it works shouldn't result in an answer equivalent to sharks developing resistance to helicopter blades, for example. It burns the feet of the mite...how hard was that?


What are the chances of you accepting the simple answer "it burns the feet of the mite"?
Zero to none I suspect.


----------



## beemandan (Dec 5, 2005)

crofter said:


> Dan is this the inverse to, "You have to believe in something to make it happen"?


I'm thinking along the lines of 'you'll see it when you believe it'.


----------



## crofter (May 5, 2011)

clyderoad said:


> What are the chances of you accepting the simple answer "it burns the feet of the mite"?
> Zero to none I suspect.


Occam's Razor!


----------



## crofter (May 5, 2011)

beemandan said:


> I'm thinking along the lines of 'you'll see it when you believe it'.


I believe that Dan.


----------

