# Any studies on OAV's affect on queen health?



## snl (Nov 20, 2009)

No known studies. But those who have regularly used it report no queen loss.


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## enjambres (Jun 30, 2013)

And good mite control protects the queen from viral pressure. A hive that has mite-vectored viruses can "grow out" of the problem over time (after treatment to kill the mites) as the affected, short-lived workers and drones naturally die off in six weeks or so. The queen is a different story because she lives so much longer, and in some seasons in the north is replaceable..

In addition, a broodless period treatment in the late Fall/early winter has the potential to leave the hive with such a low-level of mites that no further treatment is needed in the spring time. This protects the brood - and that includes new queens being started then - from being exposed to treatment chemicals during their early (larval/pupal) stages of development. And I think that would likely have an good follow-on effect on long-term queen viability and fertility.

Enj.


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## Beeathlon (Jul 28, 2015)

http://www.researchgate.net/publica...roa_destructor_in_honey_bees_(Apis_mellifera)

http://connection.ebscohost.com/c/articles/56546051/effect-oxalic-acid-honey-bee-queens


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## Arnie (Jan 30, 2014)

Excellent. Thank you Beeathlon!


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## BernhardHeuvel (Mar 13, 2013)

Do those studies really cover vaporized oxalic acid?! The effects of dribbled and sublimated oxalic acid are completely different.


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## Arnie (Jan 30, 2014)

Bernhard,
What are your thoughts on dribble vs OAV? I would think that the dribble would be harder on the bees since they eat the syrup that contains the oxalic acid. What say you?


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## BernhardHeuvel (Mar 13, 2013)

Exactly so. There is a microscopic study that shows how the oxalic acid (dribbled) damages the gut of the bees. After the treatment without dribbled oxalic acid you always find dead bees in the front of the hive and the lifespan of the surviving bees is significantly reduced.

You don't find any of those effects when sublimating the oxalic acid. Simple because the fine oxalic acid crystals can't enter neither the sticky pads at the end of the bees' legs nor they are able to enter the tracheal system of the bee.


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## Michael Bush (Aug 2, 2002)

>It has been suggested that treating for mites causes the queen's health and longevity to deteriorate. 

Only in the case of lipophilic insecticides that are being used as acaracides. They build up in the wax and affect the queens' longevity and fertility. Organic acids are not lipophilic i.e. they do not build up in the wax. They are water soluble. They may get in the honey, but not in any amounts exceeding natural levels of those same organic acids. (assuming of course that you are doing recommended dosages of recommended acids...) The mode of action between the systemic acaracides (such as Amitraz, Fluvalinate and Cumaphos)and the organic acids is quite different.


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## Arnie (Jan 30, 2014)

Thank you, Bernhard and Michael.


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## Michael Bush (Aug 2, 2002)

And, yes, I was referring to vaporized and not dribbled. I don't know anything at present about dribbled OA and queen longevity but it shortens the lives of the workers so it would not be surprising if it shortens the lives of queens.


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## Eduardo Gomes (Nov 10, 2014)

Michael Bush said:


> The mode of action between the systemic acaracides (such as Amitraz, Fluvalinate and Cumaphos)and the organic acids is quite different.


From readings I've done I think I know the modes of action of amitraz and fluvalinate to the level of neurotransmitters in varroa mites. What is the mode of action of oxalic acid on varroa mites? I can not find literature that addresses this issue. Thank you Michael or others for your patience enlighten me.


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## Michael Bush (Aug 2, 2002)

>What is the mode of action of oxalic acid on varroa mites? I can not find literature that addresses this issue. 

The two prevailing theories are that the bee can handle a more drastic systemic change in pH than the mites (this is the prevalent theory for dribbling especially). The prevailing theory on vaporization is that it damages the feet of the Varroa and they fall off and starve. I know of no proof of either but the mites do die.


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## Eduardo Gomes (Nov 10, 2014)

Thank you Michael. With these clues I will direct my research of literature in a more focused way.


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## snl (Nov 20, 2009)

Michael Bush said:


> The prevailing theory on vaporization is that it damages the feet of the Varroa and they fall off and starve. I know of no proof of either but the mites do die.


Actually, the prevailing _theory_ on OAV is both; that it damages their feet and that it (OA) enters through the pads of the mite into the mite killing them. 
And yes, it certainly kills them.........


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## crofter (May 5, 2011)

Here is an enlarged view of the mites feet. The very delicate footpad surface is what enables them to travel from bee to be and cling like velcro. The bees have a hard claw like foot that is not attacked the same way by the OA micro crystals.

https://www.google.com/url?sa=i&rct...VaOPTyIztrfnmFUaB1Wm9FYA&ust=1444342147241154


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## Eduardo Gomes (Nov 10, 2014)

Thank you very much snl and Frank for your help.


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## Mike Gillmore (Feb 25, 2006)

Arnie said:


> , so I am wondering if anyone knows of study/studies that address the issue of queen vitality specifically regarding OAV treatments.


I'm curious how such a study could even be performed. What do you use as a control group? If you use colonies with sister genetics, and the control group is not treated with OAV, they will probably be battling a much higher number of mites in the colony. The treated and untreated groups would be facing totally unrelated stresses, apples and oranges. The queen in the untreated colony could perhaps have a higher vitality rating, but if the colony crashes, it doesn't mean anything. Just thinking out loud here.


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## Arnie (Jan 30, 2014)

Mike,

You'd have to do averages. Study the longevity and health of groups of queens treated with OAV verses queens untreated and/or treated with other things.

But, as you say, they would not be dealing with the same issues. I hadn't thought of that.

Someone smarter than me will have to figure out how to do the study.


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## Mike Gillmore (Feb 25, 2006)

Someone smarter than me too, this is way above my pay grade.


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