# How does verroa die from Oxalic treatment?



## Tenbears (May 15, 2012)

It is toxic to them. Simply contacting it they absorb it and whammy. However it is the fumes that do the majority of the damage to them. The uptake of the compound in it's gaseous form is instantly fatal to the mites. You will see an increased fall in a few days because the bees begin to shed the corpses. destroys their ability to breath!


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## JTGaraas (Jun 7, 2014)

The website for Oxa Vap indicates the oxalic acid vapors enter the soft pads on the feet and then into the bloodstream of the varroa mite to cause death. Check out the "Information" tab under the following link: http://oxavap.com The company should be able to identify the source of their information, if asked.

I vaporize (from the top) as one aspect of mite control - always use the proper respirator/eye protection, and stand upwind and away -- it helps assure humans will prevail over mites!


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## Daniel Y (Sep 12, 2011)

Tenbears said:


> It is toxic to them. Simply contacting it they absorb it and whammy. However it is the fumes that do the majority of the damage to them. The uptake of the compound in it's gaseous form is instantly fatal to the bees. You will see an increased fall in a few days because the bees begin to shed the corpses. destroys their ability to breath!


How do you get the mite to survive the 270 degree temps required for OA to be a gas? Or is it that once you have made OA into a gas it just stays a gas? That sort of punches a hole in the whole recrystallization thinking. Maybe the temp to vaporize OA is different than the temp it recrystallizes. Something like it vaporizes at 270 degrees but then remains a gas until it cools to say 70 or so.


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## snl (Nov 20, 2009)

JTGaraas said:


> Check out the "Information" tab under the following link: http://oxavap.com The company should be able to identify the source of their information, if asked.


That information comes from BioVet the manufacturer of the Varrox in Europe. If you look in the "picture" tab on OvaVap.com (under information) it provides some additional information.


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## Steve in PA (Jan 26, 2015)

Daniel Y said:


> How do you get the mite to survive the 270 degree temps required for OA to be a gas? Or is it that once you have made OA into a gas it just stays a gas? That sort of punches a hole in the whole recrystallization thinking. Maybe the temp to vaporize OA is different than the temp it recrystallizes. Something like it vaporizes at 270 degrees but then remains a gas until it cools to say 70 or so.


It's the same thing that happens with frost/fog. It becomes a gas at that temp but once in the air it doesn't instantly recrystalize until it comes in contact with something. That something is anything inside the hive. What doesn't crystalize on the bees, wax, frames settles to the bottom as a thin film of white dust.

That white dust is the same as the frost you see on the lawn or your windshield on a fall morning.


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## Daniel Y (Sep 12, 2011)

Steve in PA said:


> It's the same thing that happens with frost/fog. It becomes a gas at that temp but once in the air it doesn't instantly recrystalize until it comes in contact with something. That something is anything inside the hive. What doesn't crystalize on the bees, wax, frames settles to the bottom as a thin film of white dust.
> 
> That white dust is the same as the frost you see on the lawn or your windshield on a fall morning.


So what is all the white stuff floating around and pouring out of the cracks of a hive. I'm thinking it is recrystallized OA. If so, what did it come in contact with? Or is that just how OA as a gas looks? I have not seen many gases that are that visible.


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## Tenbears (May 15, 2012)

Other compounds within the Oxalic acid mix make smoke moisture add some steam. Just as Carbon monoxide gas is colorless, odorless and tasteless. When present with the compounds burned the smoke can be seen tasted and smelled


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## Daniel Y (Sep 12, 2011)

So we have "Compounds" now that get burned in the process of vaporizing the OA. okay I follow you that far. But I am a bit concerned about these compounds. Now if I recall correctly OA vaporizes at around 270 degrees. It will be decomposed at 320 or so. both of those temps are Fahrenheit. Now what compounds is it that will burn at some temperature lower than that? Now keep in mind that the temperature that Gasoline burns is 495 degrees. I'm just thinking this must be some really unstable stuff.


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## TNValleyBeeK (Oct 3, 2012)

Steve in PA said:


> It's the same thing that happens with frost/fog. It becomes a gas at that temp but once in the air it doesn't instantly recrystalize until it comes in contact with something. That something is anything inside the hive. What doesn't crystalize on the bees, wax, frames settles to the bottom as a thin film of white dust.
> 
> That white dust is the same as the frost you see on the lawn or your windshield on a fall morning.


I disagree with this. If you ever get the chance burn off a pan in the sunlight you'll see the smoke is actually made up of the crystals. Looks like insulation floating through the air if you've ever seen that.


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## Steve in PA (Jan 26, 2015)

TNValleyBeeK said:


> I disagree with this. If you ever get the chance burn off a pan in the sunlight you'll see the smoke is actually made up of the crystals. Looks like insulation floating through the air if you've ever seen that.


Actually you are agreeing. I'm trying to describe the process using water and fog is what everyone is familiar with. This is a good picture of fog that shows the droplets of water or ice









Because of temperature difference in states of acid and water a better example would be Frozen Fog but it's the same thing essentially. This image of frozen fog is exactly what happens in the hive


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## Riverderwent (May 23, 2013)

volker said:


> Does anybody know of a scientific study about the cause and effect of how verroa actually dies when using OAD or OAV ?
> Nothing specific found when searching it on Google.
> Thanks, Volker, San Rafael, CA


The vapor causes the varroa's spiracles to contract which interferes with the varroa's ability to breathe and, more significantly, likely inhibits the varroa's ability to transpire water vapor through the tracheal tubes causing a fatal build up of fluid in the gut and possibly in the trachea. Bustin' a gut or drowning in sweat. The damage to the foot pads is indirectly related or post mortem. Just my thoughts.


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## Mike Gillmore (Feb 25, 2006)

The question still remains .. where's the scientific study?


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## RAK (May 2, 2010)

Oxalic burns the feet and mouth so the mite can't hold or suck on the bees.


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## Himmel-Hund (Aug 1, 2015)

I really can't remember the last time I read so much speculation and nonsense.
Sorry I had to say that.


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## BernhardHeuvel (Mar 13, 2013)

Still living in Viersen? Thought you moved down south?

I posted some pictures some time ago, and added some wild speculations, too, on how oxalic acid vapor kills the mite.

No studies yet, as far as I know.


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## BernhardHeuvel (Mar 13, 2013)

Himmel-Hund said:


> I really can't remember the last time I read so much speculation and nonsense.


He's the expert when it comes to nonsense and speculations. 

Update your profile, Andre, first year beek with ten years internet beekeeping experience. :lookout:

We are the best buddies, the German version of Charlie and Ollie.


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## Rader Sidetrack (Nov 30, 2011)

See post #16 here:
http://www.beesource.com/forums/showthread.php?322101-Let-s-talk-about-lega-vaporizer-unit

and post #173 here:
http://www.beesource.com/forums/sho...Acid-Vaporization-Questions-and-Answers/page9

for some of Bernhard's varroa microscope photos and comments.


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## JTGaraas (Jun 7, 2014)

The pictures displayed in the two (2) threads as posted by BernhardHeuvel are much appreciated. Thanks to Moderator Rader Sidetrack for reminding us of these past postings. The scientists may have yet to determine the sequential biological consequences of oxalic acid on varroa mites, but I am satisfied these pictures (and the tests performed by many others, and personal experience) display circumstantial evidence that oxalic acid kills - beyond a reasonable doubt! The "magic bullet" to conquer varroa may never be known until we know more about the mite itself; for instance, why are mites that poop on the bee pupae (as compared to pooping on the wall) ending up sterile? See comments in http://articles.extension.org/pages/65450/varroa-mite-reproductive-biology for my source document. Is there a chemical that will sterilize mites in our future?


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## Riverderwent (May 23, 2013)

BernhardHeuvel said:


> He's the expert when it comes to nonsense and speculations.
> 
> Update your profile, Andre, first year beek with ten years internet beekeeping experience. :lookout:


Bernhard, I hate to risk disrupting the German volksgeist by coming to the defense of your countryman and foil, but there may be a hint of less than total error in his comments and a bit of concern for other diligent hunds who may stumble upon this trail and be mislead.


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## volker (Dec 7, 2010)

Mike Gillmore said:


> The question still remains .. where's the scientific study?


Thanks you to for every bodies knowledgeable reply. 

So may be the question should be: 
"Why don't we have a scientific study?"
"Or is it deemed unnecessary to find scientific evidence?"
"Or do mite researchers no have $ or other reasons not to find out?" 
"Or do we not want to know about possible future resistance?"

Seam to me that there were some scientific recommendations, and why not scientific prove, at the time the EPA approved OA usage on EHB!?

Bee well,
Volker


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## volker (Dec 7, 2010)

Bernhard,
Danke - for the those wonderful microscopic pictures you posted on OAV (thanks Rader for the link). I am now reading the Gerhard Brüning www.varroamilbe.ch reports. 

Volker, originally NRW, Germany


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