# OAV treatment in honey producing hive



## jwhiteker (Apr 1, 2013)

I live in south central Kansas and typically keep a few colonies of bees for honey production. After several seasons of heavy loss due to varroa, my partner and I decided to invest in a vaporizer to treat our colonies. My question is timing. I've read material by Randy Oliver and others, and while it all makes sense to treat a new colony at 5-7 days and older colonies after a 14-21 day caged queen cycle, I'm still wondering when to treat our surviving overwintered colonies this year. We have crazy spring weather here in KS. We've seen brood in the hive as early as late February, but yet our nectar flows don't typically ramp up until well into May from my observations. 

I've heard that the hive should not be subjected to OA while honey is present, and treatment is not nearly as effective if there is capped brood. So, would I be better off doing treatments very late in the season (after pulling supers in late August), and possibly very late winter (early Feb)? I like the idea of a caged queen/brood break at the end of the season, but I'm not sure that a queen in KS would have enough time to lay sufficient overwinter population between the time supers are pulled and they typical stoppage of egg laying cycle for the season according to weather and other factors. Just curious if any others here in the Midwest have found a good schedule for OA treatments.


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## Dan the bee guy (Jun 18, 2015)

There are many post here about OAV you should be doing a sugar roll so you know what your mite levels are and looking at your mite fall after teatments. I do minimum of 4 treatments 5 days apart in the spring, sugar roll after that round and every month after.

Treating late August is to late for me by then it's to late for healthy winter bees in my area.


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## Mike Gillmore (Feb 25, 2006)

Every region will have different treatment windows for best results with OA. 

If you are using OAV as your only form of mite treatment you should plan on treating once in the winter when your hives are broodless, and then a series in the Fall months before the hives begin raising their final rounds of winter bees.

In my area the broodless period is some time between Thanksgiving and Christmas. You will need to talk to your local beekeepers and get their feedback on what time frame this might be in your region.

A series of treatments in the Fall after removing supers, when the mite population will usually be at it's peak, will knock down the mites before the colony starts raising a couple cycles of winter brood. Here that is usually mid to late August. I do a series of 3 or 4 treatments at 7 day intervals, but others treat at 5 day intervals. I think either way will work fine.


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## Grady Stanley (Jul 7, 2017)

jwhiteker said:


> I've heard that the hive should not be subjected to OA while honey is present


I've too have read this and heard it from others, that honey supers should be removed before doing any OA treatments. I also read an article in in the American Bee Journal, September 2016, “Keeping Honey Bee Colonies Safe From The Varroa Mite” by Meghan Milbrath, Ph.D. It the article she includes a chart that states whether honey supers can be left in place for various treatments. Her chart shows OA can be used with honey supers on. 

So, which position is the right one? Can you or can't you leave honey supers on during OA treatments? What is it that OA does to the honey?


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## snl (Nov 20, 2009)

The EPA label clearly states that OA should NOT be used when honey supers are in place. Easy enough to get around. Either remove them or place a barrier between the supers and brood chambers. When there is brood a 3 treatment regimen (every 7 days) works however I like the 4-5 treatment regimen (every 5 days). That covers the brood cycle and it gets those mites that don’t read the book that says they are to stay phoretic the 4 day or longer period after emerging with the bee. 
If just starting with oav now, I’d do a regimen prior to super placement, another regimen after pulling supers then a one time treatment late fall, early winter.


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## Bee Arthur (Mar 21, 2015)

Like snl said, the way around the labeling problem is to put a barrier between the honey supers and the brood boxes (see pic). The downside is the bees in the super don't get treated, but it hits most of the bees in the hive.


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## msl (Sep 6, 2016)

Never mind the fact the manufacturer states supers can't go back on till 2 weeks post tx :lookout:
The idea that the bees that have been treated won't go in to the supers after you unbloc them, carrying the OA with them, is laughably..They are literally covered in OA dust and it presicests in the hive for weeks


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## clyderoad (Jun 10, 2012)

msl said:


> Never mind the fact the manufacturer states supers can't go back on till 2 weeks post tx :lookout:
> The idea that the bees that have been treated won't go in to the supers after you unbloc them, carrying the OA with them, is laughably..They are literally covered in OA dust and it presicests in the hive for weeks


please direct us to the references for these claims.


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## msl (Sep 6, 2016)

> CAN YOU TREAT DURING A HONEY FLOW?
> It has not been approved for use during a honey flow. If you have honey supers on the hive you must remove them before treating and leave them off for at least 14 days to give the Oxalic Acid treatment time to be fully cleansed from the hive to avoid contamination of the honey.


http://brushymountainbeefarm.blogspot.com/2015/09/oxalic-acid-faqs.html

OA dust on a bee










> The distribution of oxalic acid dihydrate within a colony was shown by macro-computed tomography; it was rapid and consistent. The increased density of the individual bee was continuous for at least 14 days after the treatment indicating the presence of oxalic acid dihydrate in the hive even long after a treatment. Rademacher 2017


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## psm1212 (Feb 9, 2016)

clyderoad said:


> please direct us to the references for these claims.


The only place I have seen that 2 week reference is a Brushy Mountain FAQ about using OA you can find on its website. However, Brushy does not put that restriction on the label for the OA it sells under the Directions for Use. Perhaps msl meant Distributor and not Manufacturer? If it is the manufacturer, I would like to see that as well.


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## msl (Sep 6, 2016)

As the label holder BM is the "manufacturer" of the product as far as the EPA
Here is the EPA approval. Its intent is clear, a treatment range of Late fall to early spring... a time when there is little brood and no supers.
No summer treatments, no treatments with supers on 








back to the OA dust on the bees subject








you can read the whole document here https://www.regulations.gov/document?D=EPA-HQ-OPP-2015-0043-0119

blocking of the supers for a few hours is out side both the letter and sprit of the approval and is wholey inadequate measure to prevent the OA from ending up in the supers


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## Mike Gillmore (Feb 25, 2006)

Grady Stanley said:


> Meghan Milbrath, Ph.D. ...... Her chart shows OA can be used with honey supers on.
> 
> So, which position is the right one? Can you or can't you leave honey supers on during OA treatments? What is it that OA does to the honey?


I certainly don't have a Ph.D, so take this with a grain of salt. I'm looking at this question from a purely common sense perspective.

When a hive is treated with OAV a cloud fills the hive cavity and OA crystals settle on every surface inside the hive ... the wood, the bees, the comb. The crystals that settle on the bees, cappings, or solid surfaces inside the hive remain solid, and for the most part are cleaned up by the bees within a few days. 

What happens when that cloud of OA settles on nectar or honey in "open cells"? It is absorbed into the liquid, and becomes part of it. It is no longer a crystal on a solid surface that can be scrubbed away during the bees housekeeping activities. 

I really don't understand what is so difficult to comprehend about this. Do you want to sell honey to your customers that has been exposed to, or has possibly absorbed, OA? 
There is a good reason that we are instructed to NOT use OA with supers on the hives. As far as I'm concerned, it's just common sense guidelines promoting safe practices. I don't want to sell honey to my customers and later have them ask me why the honey has a "peppery" taste to it.


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## Bee Arthur (Mar 21, 2015)

msl said:


> Never mind the fact the manufacturer states supers can't go back on till 2 weeks post tx :lookout:
> The idea that the bees that have been treated won't go in to the supers after you unbloc them, carrying the OA with them, is laughably..They are literally covered in OA dust and it presicests in the hive for weeks


I don't see anything in the reference you posted about waiting 2 weeks before putting supers on after an OA treatment. Maybe I missed it?

I do know of a 3-year study in Switzerland that showed no increase in the oxalic acid content of honey after multiple treatments, with honey supers on the hive. Granted, the study is for spraying and dribbling applications, but directly spraying honey supers with oxalic acid would surely have a greater affect on the honey than re-installing the supers a few hours after an OAV treatment. And even so, the impact to the honey was zero.

https://www.researchgate.net/public...formic_and_oxalic_acid_under_field_conditions


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## msl (Sep 6, 2016)

> I don't see anything in the reference you posted about waiting 2 weeks before putting supers on after an OA treatment. Maybe I missed it?


1st item post 9 


> I do know of a 3-year study


Thanks for the link,, that alwsy makes things easer for dissution
Perhaps I am missing somthing but it doesn't seem to support your comments , perhaps you were flipping the OA and FA treatments? 

The hives in the study in the link were treated with OA while brood less in nov/dec, no flow, and one would assume no supers 
_Oxalic acid treatments by spraying were carried out during the broodless period between beginning of November and end of December._

The honey samples were taken spring/summer...mouths later 
_Most trials samples were taken from the first honey harvested in spring. However under some cir-cumstances (e.g. lack of a sufficient spring honeyflow) beekeepers in Switzerland harvest the first honey in summer. For that reason we had to include summer honeys in the trial _

_There was no in-crease of oxalic acid in the honeys from apiar-ies which had been treated during the preceding autumn_

This is tippical of the published study's out, use as directed and the OA doesn't end up in the honey the next season.
it is not however backing for treating with supers on or during an active flow


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## baybee (Jan 10, 2016)

Mike Gillmore said:


> ... I don't want to sell honey to my customers and later have them ask me why the honey has a "peppery" taste to it.


 Peppery? Some people have tasted it:


> It’s no big deal to get either the crystals or solution on your skin—simply wash off with water. If you suspect that there is some oxalic syrup on your skin, taste it (it tastes like strong lemonade). Don’t worry–you eat plenty of oxalic acid in common vegetables.


The question of whether or not OA accumulates in uncapped honey or nectar after repeated OAVs can be resolved by a straightforward experiment, which must have been done many times.


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## viesest (Jul 13, 2016)

OAV is very good as fall treatment, and exclusively the best as winter treatment. In summer formic acid is better choice (anyway).


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## clyderoad (Jun 10, 2012)

msl>>>
The Rademacher 2017 quote applies to oral and dermal application methods using a OA sugar solution. " OAD (Caelo, Hilden, Germany) dissolved in sucrose solution (50% w/w) was applied to bees individually using two application forms: trickling 5 µL OAD solution onto the abdomen (dermal) or feeding 10 µL OAD solution (oral)".

The macro-computed tomography was used after treatment by trickling. "Internal structures of a bee hive can be demonstrated by computed tomography [7]. Two honey bee nucleus colonies (A. m. carnica) were used for a distribution test with a macro-computed tomography scanner (macroCT). The colonies consisted of approximately 4000 individuals and had already formed a winter cluster. The treatments were conducted in November without brood. OAD (3.5% w/v in sucrose solution 50% w/w) was applied in the recommended dosage (according to package instructions for use-Oxuvar®) by trickling onto the bees in the bee space".

The use of this study to argue against OA vaporization seems misguided.

Yes the EPA document is straightforward with regards to when and how OA is used. There is no mention anywhere in the EPA document of
the following BM faq statement, "If you have honey supers on the hive you must remove them before treating and leave them off for at least 14 days to give the Oxalic Acid treatment time to be fully cleansed from the hive to avoid contamination of the honey". What is the basis for this precaution?


"blocking of the supers for a few hours is out side both the letter and sprit of the approval and is wholey inadequate measure to prevent the OA from ending up in the supers".
In your opinion it is outside the spirit and intent, but may in fact be adequate.


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## msl (Sep 6, 2016)

> The Rademacher 2017 quote applies to oral and dermal application methods


So does the EPA label it dosn't make exemptions for OAV 


> The use of this study to argue against OA vaporization seems misguided.


if 50cc of liquid starting on very few bees gets spread quiclky and evenly and all threw out the hive, you can bet a a coating of OA dust on all the bees and surfaces moves as well. If it didn't, you wouldn't get the bees in side the cluster with cold weather treatments and it wouldn't be effective...but it is 
The nectar needs to be carried in the fount door threw the nest and bees covered in OA and up to the supers. Add in the dust moving on all the air currants used to evaporate the nectar and climate control the hive and for sure the OA is getting up there... just think about how cappings travel stain... 



> The question of whether or not OA accumulates in uncapped honey or nectar after repeated OAVs can be resolved by a straightforward experiment, which must have been done many times.


Yet no published study seem to exist and there in not a single developed country that I can find that alows OA with supers/flow on. The EPA didn't do one do the OA being fast tracked and they just copied the CAN label. 

I don't think the question is does it end up in the supers when used with them on, the question is does it matter . There is hope that Randy Oliver's EPA study last summer will shed some light and pave the way for mid summer use


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## grozzie2 (Jun 3, 2011)

Bee Arthur said:


> I don't see anything in the reference you posted about waiting 2 weeks before putting supers on after an OA treatment. Maybe I missed it?


The EPA approved label is available to see here: https://www3.epa.gov/pesticides/chem_search/ppls/091266-00001-20150310.pdf

Page 3 of that pdf is the actual label, with blanks for inserting batch code and net contents, to be filled in at time of manufacture. In the use restrictions section, this is the relavent paragraph:



> Use only in the late fall or early spring when little or no brood is present. Oxalic Acid Dihydrate might damage bee brood. Oxalic Acid DiHydrate will not control Varroa mites in capped brood.


The label is very clear, to be used late fall or early spring when hives are broodless, or nearly so. If treating in the fall, then it's months before supers go back on. If doing it at broodless time in the spring, it'll be at least 6 weeks (2 brood rounds) before supers are set on the hives. This is as per the EPA approved label.

The FAQ from Brushy appears to be an acknowledgement that folks are using OAV outside of the correct time frames, and provides some guidance for folks doing so.


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## clyderoad (Jun 10, 2012)

msl said:


> So does the EPA label it dosn't make exemptions for OAV
> 
> if 50cc of liquid starting on very few bees gets spread quiclky and evenly and all threw out the hive, you can bet a a coating of OA dust on all the bees and surfaces moves as well. If it didn't, you wouldn't get the bees in side the cluster with cold weather treatments and it wouldn't be effective...but it is
> The nectar needs to be carried in the fount door threw the nest and bees covered in OA and up to the supers. Add in the dust moving on all the air currants used to evaporate the nectar and climate control the hive and for sure the OA is getting up there... just think about how cappings travel stain...
> ...


msl>>> pure conjecture without a OAV study.


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## msl (Sep 6, 2016)

> pure conjecture without a OAV study


If we accept this point as valid, then is its also pure conjecture that it doesn't get in the supers with out a study.

We are dealing with a food product, so absentee of any proof to challenge the validity of the label, I argue we should follow the law and protect our product from pesticide contamination.


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## clyderoad (Jun 10, 2012)

msl said:


> If we accept this point as valid, then is its also pure conjecture that it doesn't get in the supers with out a study.
> 
> We are dealing with a food product, so absentee of any proof to challenge the validity of the label, I argue we should follow the law and protect our product from pesticide contamination.


Decisions based upon hard data, right msl ?


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## msl (Sep 6, 2016)

Yes
Plenty of hard data to support that OAV is not effective with brood on. 
Plenty of hard data to support that the other two OA application methods can end up in honey when used in the spring/summer or when mutpul winter treatments are done
Mean whole there is no hard data and only internet speculation that OAV doesn't get get in the honey when used when supers are on, much less with the 3,4,5 Tx it takes to get mite control with brood on.


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## gww (Feb 14, 2015)

Randy oliver has based his decision on other studies and is making his own but is already confident of what the results will be before proving those results. Basicaly repeating previous proof. 
Here is another of the previous studies but there are a few.
http://www.apimondia.com/apiacta/articles/2004/enzo_1.pdf

What is funny about these discussions is that mqas does leave residues but those residues are below the danger rate. It leave more residue then olixic does regaurdless of application method. To Mike G's point on open cells, the honey that has been tested is still not showing up with higher rates then is natural in all honey. So maby there is small residue but it is small enough that it does not really change what is normal for honey.

Here is another one taken from open cells eight days after treatment and tested.
https://www.apiservices.biz/en/arti...c-acid-in-honeybee-colonies-as-varroa-control

Several vaperisor sellers give instructions of just placing a seperating sheet between the honey supers and brood chambers during treatment and then removing it.
It is enough to convince me that the claims of olixic not being fat solible makes it not gether in honey and comb.

Enough actual measurments have been taken to make me feel very comfortable with the olixic treatments not causeing honey to go out of bound of what the bees themselves would naturally add to the honey. there is another study somewhere that show where the olixic vapor ends up after treatment with percentages of where and how long before it leave the hives after treatment. If a guy wanted to do the math base on what it said, if you were doing 5 treatment 3 days apart at 2 grams each, You might have a gram left somewhere in the hive whenit was all done. I did not put the math to the study or feel like spending all day trying to find it again but do remember enough of it that my math is proby close.

Hopsguard and mqas are both worse for residue then olixic but all seem to be safe levels.

Msl is correct that randys studies when released will probly be one more that will prove the same thing the previous ones have proven.
Cheers
gww


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## Mike Gillmore (Feb 25, 2006)

OA Vaporization has been used in Europe and Canada for quite some time, yet there are still restrictions from the vaporizer manufacturers to not use this method with supers on the hives. I wonder why those limitations were put in place to begin with. Is there conflicting data from other tests that would require the warning to not apply OA with supers on. 

I'm not disputing test reports which seem to indicate that it's safe to vaporize with supers on and not impact the honey. It just seems odd that it's taken decades for someone to take a closer look at this and focus on disproving the fear of OA contaminating the honey in open cells.


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## gww (Feb 14, 2015)

Mike
I know this may not answer your question but, I think it cost money to get approval and wonder if it might be more a question of who would bennifit enough to spend that money for that approval. I know it would not be me. Randy has decided to but has been given some donations for some of the work he does. I don't think it is as easy to get stuff done through the government. olixic was done here even though everyone was using it already because the government decided to go ahead and accept canadas test. Would we even be able to legally been able to use olixic if the government would not have waved the testing required? Would someone have stepped to the plate knowing that beekeeper can go to the lumber yard and buy wood bleach? Not much incentinve to jump through hoops if you can't get a return on your effort.

I think that is how things work and not the other way around where once we know it should be common sense. Ask randy how easy it is to do even if you are right. The gov does not do thier testing they just grade yours.
Cheers
gww


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## Tim KS (May 9, 2014)

What foods are high in oxalic acid?
High Oxalic Acid Foods. Lists of foods high in oxalic acid vary greatly from source to source. The body is known to absorb oxalic acid from only a handful of foods, according to the University of British Columbia, including peanuts, pecans, wheat bran, spinach, rhubarb, beets and beet greens and chocolate. (NOTE...honey is not included)

...so if you eat any of the above list...WATCH OUT!


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## viesest (Jul 13, 2016)

Mike Gillmore said:


> I'm not disputing test reports which seem to indicate that it's safe to vaporize with supers on and not impact the honey. It just seems odd that it's taken decades for someone to take a closer look at this and focus on disproving the fear of OA contaminating the honey in open cells.


The instructions are correct. The assumption is wrong; that instructions are in that form because OA residues in honey are health risk.


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## fatshark (Jun 17, 2009)

Bee Arthur said:


> I don't see anything in the reference you posted about waiting 2 weeks before putting supers on after an OA treatment. Maybe I missed it?
> 
> I do know of a 3-year study in Switzerland that showed no increase in the oxalic acid content of honey after multiple treatments, with honey supers on the hive. Granted, the study is for spraying and dribbling applications, but directly spraying honey supers with oxalic acid would surely have a greater affect on the honey than re-installing the supers a few hours after an OAV treatment. And even so, the impact to the honey was zero.
> 
> https://www.researchgate.net/public...formic_and_oxalic_acid_under_field_conditions


As msl states ...

This paper is often quoted as indicating that it's OK to treat with honey supers on. *It doesn't indicate anything of the sort*. It simply shows that OA does not persist for months in the hive.

And in response to baybee ...

I'm not aware that the experiment has been done once, let alone many times, and it's not straightforward. If it has been done, it's not been peer-reviewed and published anywhere visible. It's not straightforward because of the cost of OA testing and because the OA content of honey varies significantly anyway (45-89mg/kg in this study). It would have to be a study with multiple replicates to reproduce a range of field conditions.

Interesting to note that *OA was stable in honey* over a 3-6 month period in this study. Therefore, once 'contaminated' with OA added exogenously it would likely linger.

For me, that's one of the most compelling reasons NOT to treat with honey supers in place (or temporarily removed for <14 days).


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## psm1212 (Feb 9, 2016)

Is powdered sugar a pesticide when it is sprinkled into a hive to manage varroa? Is it legal for me to use powdered sugar as a pesticide without the approval of the EPA and my state?


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## psm1212 (Feb 9, 2016)

msl said:


> blocking of the supers for a few hours is out side both the letter and sprit of the approval and is wholey inadequate measure to prevent the OA from ending up in the supers


The label is the law. Period. The label says: "Do not use when honey supers are in place to prevent contamination of marketable honey." My honey supers are "in place" when they are affixed to the upper brood chamber making a contiguous space with that brood chamber. If I put a piece of luann between my honey supers and the brood chamber, my supers are no longer "in place." That is the law. Your interpretation only differs from mine. We can argue about that, but you are incorrect when you say that I violate the "letter" of the law. As to the "spirit" of the law, that is pure fiction. There is no such thing.


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## gww (Feb 14, 2015)

Here is link number four in this thread replicating the results of the previous three testing results.
https://www.apidologie.org/articles/apido/pdf/2006/01/M6010.pdf
Cheers
gww


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## Groundhwg (Jan 28, 2016)

psm1212 said:


> The label is the law. Period. The label says: "Do not use when honey supers are in place to prevent contamination of marketable honey." My honey supers are "in place" when they are affixed to the upper brood chamber making a contiguous space with that brood chamber. If I put a piece of luann between my honey supers and the brood chamber, my supers are no longer "in place." That is the law. Your interpretation only differs from mine. We can argue about that, but you are incorrect when you say that I violate the "letter" of the law. As to the "spirit" of the law, that is pure fiction. There is no such thing.



:applause::applause: Ding, Ding, Ding, We have a winner. Careful you are be logical and making sense so most will disagree.


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## Tim KS (May 9, 2014)

The directions on my "Wood Bleach" doesn't say anything about removing honey supers............:scratch:


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## psm1212 (Feb 9, 2016)

Tim KS said:


> The directions on my "Wood Bleach" doesn't say anything about removing honey supers............:scratch:


And I assume you are only attempting to bleach the wood on the interior of your hive bodies, right?


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## baybee (Jan 10, 2016)

fatshark said:


> ... and it's not straightforward. If it has been done, it's not been peer-reviewed and published anywhere visible.


Fatshark (or "Horizontally Gifted" shark as they now say here across the pond), I was thinking about a simple experiment when one quantifies OA in samples of open nectar or sugar syrup before and a few hours after an OAV. Yes, natural OA varies widely in different honeys. The question however is how much OA is added to open nectar with a typical OAV treatment.

Frames with plastic comb could be filled with syrup, or frames with open nectar could be borrowed from a hive and then treated with OAV in a mock hive without bees or in a full-scale test hive with bees. I know there are commercial kits for quantitation of oxalates from Sigma which could be used for measuring the before and after concentrations. It can't be done at home but should be a straightforward (one day?) experiment for a chemistry or biotech lab. After all, they can extract and sequence DNA from microgram samples of tissue.


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## crofter (May 5, 2011)

If you _blanche_ when you taste the honey you will know it picked up some additional OA! If you cant taste any extra _tang_ it will not have unsafe levels compared to, say, carrots or other normally consumed daily fare. Locations that have a high percentage of blueweed or leafy spurge that the bees are concentrating on, produce honey that will leave a fair tingle on your tongue for quite a while too; different chemicals though.

At such a time when flow and supers are on, brood rearing will be happening and it then takes a lot of repeat back to back treatments with OA to get mite numbers down. You might get under the taste test radar with one shot but perhaps not with the six or eight vaporizations of a double series.


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## baybee (Jan 10, 2016)

crofter said:


> ...but perhaps not with the six or eight vaporizations of a double series.


Yes, this is the question which I believe isn't super-hard to answer with an experiment. One? Eight? Or twenty eight?


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## gww (Feb 14, 2015)

baybee
I wish you would do the experment and tell us how it went. I would be interested but don't want to do the work.
Cheers
gww


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## baybee (Jan 10, 2016)

gww said:


> baybee
> I wish you would do the experment and tell us how it went. I would be interested but don't want to do the work.
> Cheers
> gww


Well, I definitely could provide the before and after samples. Would still need a budget to buy chemicals, glassware and rent a space in a chemistry lab with appropriate equipment.

The questions still are: Has it been done before here or in Europe, or in Argentina? And would beekeepers with a background in analytical chemistry approve this particular approach?


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## psm1212 (Feb 9, 2016)

baybee said:


> The question however is how much OA is added to open nectar with a typical OAV treatment.


A related question, and one I have sought an answer to for some time, at what levels or amounts does OA become harmful when ingested by humans? 

My wife juices spinach, kale, carrots and an apple every day. I can't help but believe that she gets a heck of a lot more OA in that glass of juice every day than I would get from a table spoon of honey that was exposed to 4 treatments of OAV at 1 gram a honey super.

4 grams of OA sublimated into a medium 9-frame super of honey. Let's say that NONE of the honey is capped during any of the treatments, that the bees do not remove a speck of the crystals and it all absorbs into the honey and NONE of it dissipates over the 20 day treatment process, NONE of it adheres to frames or woodenware. All of it is absorbed by the open honey.

1 super of honey = 27 pounds = 12,247 grams of honey. 

4 grams OA/ 12,247 grams of honey = a .000326610 concentration of OA in the finished product.

100 grams of honey = roughly 4.5 tablespoons. 

23 grams of honey = 1 tablespoon

23 grams x .000326610 = .75 grams of OA per tablespoon or 750 milligrams/tablespoon.

A 100 gram serving of spinach just happens to = 750 milligrams.

For those that, like me, are metrically challenged that is about 3.5 ounces of spinach. 

Either my math is wrong (a very strong possibility), my reasoning is wrong (a stronger possibility) or we are just making a whole lot out of nothing (which never happens.)

Help.


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## Biermann (May 31, 2015)

But??? Why risk it?

Do the fellows that want to use OA with supers on also drive drunk because 99.8% of drunk drivers have made it home safe in the past 100 years?

I am rather 'save than sorry' and a beek has so many options with OA(V) not to risk it when the supers are on. The last thing in that sentence was a period, also known as 'full stop'. 

Why always push the envelope?

Or, am I missing the point here?

Joerg


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## psm1212 (Feb 9, 2016)

Biermann said:


> But??? Why risk it?


Posting a question on a message board risks nothing.


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## gww (Feb 14, 2015)

Joerg
I really do not see your "save or sorry" point? When the question is, "is it safe or not and is there enough info to use to try and make that determination. If it is safe, then how can you be sorry. Yes, you don't have to go that route if you take a differrent route but that would not make olixic either leave residue or not. It either does in amounts that matter or it doesn't.

Baybee
There are four studies linked already that answer the question that you say are easy to find out. Randy is doing another one that will someday be published. there are poeple that no amount of proof could be given. Then there are other poeple who, when the government decides it is ok to do something that will say it is right even if there is risk that has to add up till the gov decides to change. Look at the diet pill fen fen or what ever it is called that was causing heart attacks. 

We all admit that legally, the lable says don't treat with vapor with the supers on. It also says 3 treatments every 7 days or so. If we break down the push back on how to use it properly, do we also go after that?

Formic acid does leave a residue in honey but it leaves the honey at more then ten times below the recomended danger level reconized by the gov. The differrance is that mqas was requested to be authorized to be used with the supers on. 

Does being legal or illegal change how much residue is left?

I would not recomend everyone just do what they want regaurdless of safety. I just say that there is enough testing to feel pretty confident that you are not causing an issue with olixic acid with supers on. 

If you decided that it doesn't matter if it is safe, you were only going to use stuff that somebody has made the effort to make legal so they could also make a profit, There is nothing wrong with that. If you are one of those guys that used olixic for ten years before it was legal or 5 time insted of three like the lable says cause it worked, you have some studies to base a decision on as for as residue in honey goes and you are not shooting blind.
Cheers
gww


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## gww (Feb 14, 2015)

psm
If you have kidney stones, very little could hurt you. If you were a heathy person wikipiedia says 11 pounds of rubarb might kill you and some smaller amounts may make you feel not so good.
Cheers
gww


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## psm1212 (Feb 9, 2016)

gww said:


> psm
> If you have kidney stones, very little could hurt you. If you were a heathy person wikipiedia says 11 pounds of rubarb might kill you and some smaller amounts may make you feel not so good.
> Cheers
> gww


2 gallons of water can kill an adult human. Water is still considered safe for human consumption. 

3 bites of rubarb that is not coated in sugar and other things to hide the fact that it is rubarb will make me sick.


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## Tim KS (May 9, 2014)

From the Daily Garden...."At high concentrations, oxalic acid really is deadly. According to the National Institutes of Health, lethal doses range from 15 to 30 mg, though an oral dose of 5 mg has been fatal. In each of these cases, it is the amount of oxalic acid being ingested that is the problem. The levels found in our food are too low to cause problems. Bottom line, a 150 pound person would need to eat approximately 12 pounds of rhubarb leaves for it to be dangerous. And spinach leaves contain more oxalic acid than rhubarb leaves. And that’s why your teeth may feel funny after eating spinach. It’s oxalic acid crystals binding with any nearby calcium to create calcium oxalate crystals. These crystals stick to your teeth for several minutes to an hour.

Oxalic acid is found in a surprising number of food plants that we eat every day. The trick is in the concentration. In fact, oxalates can be toxic to plants, too, but plants bind those oxalates up in crystals that they then use as tiny spears to defend themselves against herbivores. These specialized cells are called idioblasts. Oxalic acid is formed when plants burn sugars and carbohydrates as fuel. Oxalates are also used to balance calcium levels within the plant by binding to calcium molecules. This is why some people say eating high levels of oxalic acid can interfere with healthy bones and teeth, but, again, you would have to eat an awful lot, over a long period of time, to cause any real problems. By the way, our bodies produce oxalic acid out of Vitamin C., on purpose. Also, cooking plants that contain oxalic acid has not been shown to reduce oxalate levels."


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## Grins (May 24, 2016)

Tim KS said:


> From the Daily Garden...."At high concentrations, oxalic acid really is deadly. According to the National Institutes of Health, lethal doses range from 15 to 30 mg, though an oral dose of 5 mg has been fatal. In each of these cases, it is the amount of oxalic acid being ingested that is the problem. The levels found in our food are too low to cause problems. Bottom line, a 150 pound person would need to eat approximately 12 pounds of rhubarb leaves for it to be dangerous. And spinach leaves contain more oxalic acid than rhubarb leaves. And that’s why your teeth may feel funny after eating spinach. It’s oxalic acid crystals binding with any nearby calcium to create calcium oxalate crystals. These crystals stick to your teeth for several minutes to an hour.
> 
> Oxalic acid is found in a surprising number of food plants that we eat every day. The trick is in the concentration. In fact, oxalates can be toxic to plants, too, but plants bind those oxalates up in crystals that they then use as tiny spears to defend themselves against herbivores. These specialized cells are called idioblasts. Oxalic acid is formed when plants burn sugars and carbohydrates as fuel. Oxalates are also used to balance calcium levels within the plant by binding to calcium molecules. This is why some people say eating high levels of oxalic acid can interfere with healthy bones and teeth, but, again, you would have to eat an awful lot, over a long period of time, to cause any real problems. By the way, our bodies produce oxalic acid out of Vitamin C., on purpose. Also, cooking plants that contain oxalic acid has not been shown to reduce oxalate levels."


Silly goose, let's not confuse facts with policy. There is no data suggesting OAV used in colonies with supers on has any health risk whatsoever. But policy lags data by years all too often. And it is policy that we need to adhere to to avoid legal and ethical entanglements.
Lee


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## gww (Feb 14, 2015)

Lee


> But policy lags data by years all too often.


Most data is gethered by those who don't follow policy for years before policy decides it is good or bad.
It is all pretty circular.
Cheers
gww


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## psm1212 (Feb 9, 2016)

Tim KS said:


> From the Daily Garden...."At high concentrations, oxalic acid really is deadly. According to the National Institutes of Health, lethal doses range from 15 to 30 mg, though an oral dose of 5 mg has been fatal. In each of these cases, it is the amount of oxalic acid being ingested that is the problem. The levels found in our food are too low to cause problems. Bottom line, a 150 pound person would need to eat approximately 12 pounds of rhubarb leaves for it to be dangerous. And spinach leaves contain more oxalic acid than rhubarb leaves.


That is 15 - 30 grams, not milligrams that can be fatal. You get 15 - 30 mg of OA when you eat a single leaf of spinach. 

So we have the answer though. 15 to 30 grams of OA is a fatal dose. Good find.

5 pounds of sugar is a fatal dose.

So if I sat down with a gallon of honey that had been exposed to OA, a spoon and a death wish, what do you think would kill me first: the sugar or the oxalic acid?


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## viesest (Jul 13, 2016)

psm1212 said:


> That is 15 - 30 grams, not milligrams that can be fatal. You get 15 - 30 mg of OA when you eat a single leaf of spinach.
> 
> So we have the answer though. 15 to 30 grams of OA is a fatal dose. Good find.


Yes, and in your calculation; 4 grams per 10 kilograms is 0.4 grams per kilogram of honey or 400 milligrams per kilogram or 10 milligrams per tablespoon.


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## psm1212 (Feb 9, 2016)

viesest said:


> Yes, and in your calculation; 4 grams per 10 kilograms is 0.4 grams per kilogram of honey or 400 milligrams per kilogram or 10 milligrams per tablespoon.


I knew I was messing something up there. Thank you. The metric system is so superior to our empirical system. I wish we had converted decades ago.


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## BadBeeKeeper (Jan 24, 2015)

grozzie2 said:


> The EPA approved label is available to see here: https://www3.epa.gov/pesticides/chem_search/ppls/091266-00001-20150310.pdf
> 
> Page 3 of that pdf is the actual label, with blanks for inserting batch code and net contents, to be filled in at time of manufacture. In the use restrictions section, this is the relavent paragraph:
> 
> ...


The label has absolutely NOTHING to do with the amount of time before supers can be replaced. The ONLY thing that this addresses is the EFFICACY of the treatment- in that the product is not effective in eliminating varroa from capped brood cells.

The treatment is ONLY effective at eliminating phoretic mites and will not kill mites in capped brood cells. It is for this reason, AND THIS REASON ALONE, that the recommendation is to treat when broodless.

Replacing the supers (or removing the blocking material) as little as 10 minutes after treatment is not a violation of the label requirements.

The only reason that it is contraindicated to leave supers exposed to the treatment at the time of application is because it has not been PROVEN safe to do so (though this is in the works). They are erring on the side of caution (as is prudent) until such time as it is proven safe.

-----------------------------------------------------------------------------------

What is it with people reading crap into stuff that actually isn't there?


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## Fivej (Apr 4, 2016)

Do any of our European or Canadian members know if there has ever been a study concerning OA use and residuals in honey? In other words, has this ever been studied or was it approved because it worked to kill mites and "they" proscribed that it not be used with supers on because they did not study that? So to be safe, "they" said not to use with supers on.
I know that here in the US, the EPA expedited approval of OA and used the Canadian government's studies in order to do that. I have a feeling that OA and honey safety has just not been studied. This is an example of something that the government(s) are suited to do as there is no money in it for private industry. Wouldn't this be a great opportunity for the EU and US to do a joint study?


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## viesest (Jul 13, 2016)

Fivej said:


> if there has ever been a study concerning OA use and residuals in honey?


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## Beebeard (Apr 27, 2016)

I don't feel there is a need to treat with OAV while honey supers are on anyway. Supers are on during a flow, and at a maximum building time for the bees, which is hands down the LEAST effective time to use OAV. Additionally, a big stack of supers is a bigger hive with way more surface area, which the applicator has to overcome by using even MORE OA in hopes of getting good coverage. The stuff works best in the early spring, as an extended round in late summer when the brood nest contracts, and the absolute best in late fall/early winter when the hives are (nearly) broodless. If you are controlling the mites during these other times, there is no need to treat during the main flow. Follow the label, even if there isn't one.


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## Fivej (Apr 4, 2016)

Beebeard, while not optimal, it would be useful to have the option of using OAV at other times. For example, when it is too cold or hot to use other treatments, and when there are no queens available. This happens here (VT) in the fall when we have supers on for goldenrod/aster and can happen in the spring (but not this year!) J


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## psm1212 (Feb 9, 2016)

Beebeard said:


> I don't feel there is a need to treat with OAV while honey supers are on anyway. Supers are on during a flow, and at a maximum building time for the bees, which is hands down the LEAST effective time to use OAV. Additionally, a big stack of supers is a bigger hive with way more surface area, which the applicator has to overcome by using even MORE OA in hopes of getting good coverage. The stuff works best in the early spring, as an extended round in late summer when the brood nest contracts, and the absolute best in late fall/early winter when the hives are (nearly) broodless. If you are controlling the mites during these other times, there is no need to treat during the main flow. Follow the label, even if there isn't one.


I have honey supers on from April until October. I have two flows with a dearth in the middle. Far too much work putting supers away in June and putting them back on in late July. I just slap on robbing screens. OA is not ideal during the summer months, but it is quick, easy and cheap. It keeps my mites knocked down until I can get the supers off for a hard treatment (Apiguard or Apivar) in the Fall. I presently treat them with OAV with a piece of luann inserted between the supers and the brood chamber.


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## fatshark (Jun 17, 2009)

baybee said:


> Fatshark (or "Horizontally Gifted" shark as they now say here across the pond), I was thinking about a simple experiment when one quantifies OA in samples of open nectar or sugar syrup before and a few hours after an OAV. Yes, natural OA varies widely in different honeys. The question however is how much OA is added to open nectar with a typical OAV treatment.
> 
> Frames with plastic comb could be filled with syrup, or frames with open nectar could be borrowed from a hive and then treated with OAV in a mock hive without bees or in a full-scale test hive with bees. I know there are commercial kits for quantitation of oxalates from Sigma which could be used for measuring the before and after concentrations. It can't be done at home but should be a straightforward (one day?) experiment for a chemistry or biotech lab. After all, they can extract and sequence DNA from microgram samples of tissue.


Those Sigma kits are about £500 for 100 tests ... they're also highly variable in their readout with the standards.


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## Beebeard (Apr 27, 2016)

PSm1212, just curious, when do you harvest? I use that summer dearth to harvest the spring honey, and get a treatment window. I guess I technically have honey supers on through the season as well, but the ones that are on are ones that I leave for the bees and won't extract anyway. They usually have some brood in the middle anyway. For that matter, with bees moving honey around in the hive, and OA staying in exposed honey, I guess the only way to make sure no OA ends up in the honey that gets harvested is to treat a hive with zero honey in it.

Everyone is free to manage their own way. Other areas with different flows will have different management. For me, I'll sample and treat right after I pull my spring/summer supers, and before I put on fall supers to hopefully catch the fall flow. Then I'll treat again after those are off (if needed). Here, in the month of august, they are bringing in nothing, so that's my ideal window. Again, there may be 1 or 2 supers still on, but they are bee food, I'm not harvesting those. I keep it separate using either different color boxes, or the handfull of shallows I've collected over the years. Point being, I manage my treatment schedule around when I'm harvesting, and around when a particular treatment is most effective. With keeping the mites down during my windows of opportunity, I haven't had the need to treat when they are making the honey I'm taking. Now, If i suddenly find a mite bomb that's not following my schedule...


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## psm1212 (Feb 9, 2016)

I harvest twice a year as well. I only harvest fully capped frames and I usually have partially capped frames at the time of the first harvest. So I leave them until the last harvest at the end of the year. I don't have any good storage method for wet comb here, so I stack them all back on the bees to clean them up and keep them safe. Small hive beetles would slime me in a week if I did not keep them on my bees during the dearth. I swap honey supers around to avoid having too much space to defend for a weak colony. I also have a deep freezer if my bees just can't handle the SHB, but I can only fit about 100 frames in it.

If you do not use OA during the summer months, I assume you use thymol or a formic product during your dearth? I can't use either of those in the middle of summer due to heat. I would think that Apivar would take too long and you could not fit them in between harvests. I am pretty much stuck with using OA during that time.

I had drones in my hives in the last week of January this year. I had my first swarm cells in the last week of February. So by mid-summer, I have had a whole lot of brood cycles which have generated a whole lot of varroa. 

My hope is the Randy Oliver works out an ideal substrate for the delayed release of OA and gets it approved for use with honey supers in place. That would be a non-temperature sensitive solution. Doesn't look like shop towels are going to be it. At least not for the humid Southeast.


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## Beebeard (Apr 27, 2016)

I've used the series of OAV during the dearth and it worked fine, but was a lot of labor. Last year I used MAQS at full strength ( 2 pads) and even though we had a week of temps within range, and I kept the hives as open as I dared, I lost 3 queens. I have a theory that its not the formic itsself that kills the queen, but the fact that it harms/kills the open brood and the hive blames the queen and supersedes her. Just my theory, not going to stand by it real hard, my queens are just as gone either way. This upcoming year I'm planning to give the thymol products a go. I don't know if I will ever settle on a plan year in and year out because there is just too much variability in this craft, but the bones of a monitoring and management plan are fairly established for me here. Guessing you aren't likely to see a break in temps where you are, so I see how your treatments are limited. All beekeeping is local.


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## psm1212 (Feb 9, 2016)

Your theory makes sense. There is no massive bee die off, so it does not stand to reason that the queen, of all the bees in the hive, is somehow more fragile and directly targeted by the MAQS. Thymol will kill a small amount of brood as well, but my experience is only a dozen or so pupae being pulled and taken out to the bottom boards. I have not lost a queen, with the exception of the nuc that absconded. I blame that nuc on myself though.


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## baybee (Jan 10, 2016)

> I have a theory that its not the formic itsself that kills the queen...


So many backyard beekeepers seem to blame themselves for not applying MAQS correctly, while the actual reason might be poor design/manufacturing of the product, which, even if one follows the instructions to the letter, results in a flash release of a very strong acid -- this kills the queen.

I would carefully examine MAQS packages next time before application. Do the paper wraps look or feel wet? Are there cracks or tears visible on the paper wraps? If yes, then, whatever the temperatures are, there is a great risk of flash release.


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## BadBeeKeeper (Jan 24, 2015)

psm1212 said:


> Your theory makes sense. There is no massive bee die off, so it does not stand to reason that the queen, of all the bees in the hive, is somehow more fragile and directly targeted by the MAQS. Thymol will kill a small amount of brood as well, but my experience is only a dozen or so pupae being pulled and taken out to the bottom boards. I have not lost a queen, with the exception of the nuc that absconded. I blame that nuc on myself though.





baybee said:


> So many backyard beekeepers seem to blame themselves for not applying MAQS correctly, while the actual reason might be poor design/manufacturing of the product, which, even if one follows the instructions to the letter, results in a flash release of a very strong acid -- this kills the queen.
> 
> I would carefully examine MAQS packages next time before application. Do the paper wraps look or feel wet? Are there cracks or tears visible on the paper wraps? If yes, then, whatever the temperatures are, there is a great risk of flash release.


I have been using MAQS since 2011 and I have never, I repeat, NEVER, lost a queen while using it (nor any time reasonably afterward where it could be considered to be a factor). I may be a bad beekeeper, and have lost hives due to NOT using MAQS (or other treatment), but I pay strict attention to the temperature requirements and placement of the strips, as well as providing extra space during the initial application period. I have not found that there is any danger of queen loss when used as directed.

I keep seeing these stories/rumors of queen loss, but it doesn't happen to me. Why is that? Am I just 'lucky'? Or is it more likely to be due to the fact that I am very, very careful with it?


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## baybee (Jan 10, 2016)

BadBeeKeeper said:


> I keep seeing these stories/rumors of queen loss, but it doesn't happen to me. Why is that? Am I just 'lucky'? Or is it more likely to be due to the fact that I am very, very careful with it?


Yes, following the instructions helps. But could it be also because you are only a few hrs drive from where MAQS are made? Or because your MAQS retailer also stores them as recommended?


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## Beebeard (Apr 27, 2016)

BadBeeKeeper said:


> I have been using MAQS since 2011 and I have never, I repeat, NEVER, lost a queen while using it (nor any time reasonably afterward where it could be considered to be a factor). I may be a bad beekeeper, and have lost hives due to NOT using MAQS (or other treatment), but I pay strict attention to the temperature requirements and placement of the strips, as well as providing extra space during the initial application period. I have not found that there is any danger of queen loss when used as directed.
> 
> I keep seeing these stories/rumors of queen loss, but it doesn't happen to me. Why is that? Am I just 'lucky'? Or is it more likely to be due to the fact that I am very, very careful with it?


I too was very, very careful with it. Brand new box from the manufacturer, applied well within the temp range, label followed. If the product failed in some way, it was not by my action or inaction. Did the treatment kill the queen? I don't know. Correlation is not causation. My theory stems from the fact that I never see any sort of die off of adult bees when using MAQS. I find it very hard to believe that the product is any harder on one particular bee (the queen) than the thousands of others in the hive. But i do see some brood mortality. Perhaps the queens had some underlying issue I don't know about, and the sudden brood 'failure' as the hive saw it was enough to push them over the edge and supersede. I don't know. The hives in question superseded, one had to be combined, the other two recovered enough to overwinter and are still good hives today, which to me is just in a days work of beekeeping. I will still use the product. Perhaps you could send some of your 'luck' my way.

From the product label: "Some brood mortality is to be expected early 
in the treatment, treatment may trigger supercedure of fragile queens."


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## psm1212 (Feb 9, 2016)

BadBeeKeeper said:


> I keep seeing these stories/rumors of queen loss, but it doesn't happen to me. Why is that? Am I just 'lucky'? Or is it more likely to be due to the fact that I am very, very careful with it?


I think there could be a lot of factors. You likely live in a very favorable climate for MAQS. In addition to heat, there seems to be a humidity concern for some treatments. There is suspicion that this humidity factor may be showing up in the the UGA/Auburn University trials of the OA shop towel extended release method. They are not getting the same results as Randy Oliver in Northern California. I simply can't use MAQS at all, at least not within the manufacturer's recommendations. Some beekeepers in my area will place a single MAQS application across the top bars between brood chambers for what they call a "knock down" treatment when they feel that they have to treat with honey supers on. But that gets varying results and they will sometimes gas their hives. I can use thymol, but only in 1/2 doses -- which is advised on Apiguard's website under the FAQS posted there. However, I have often had to cancel the second treatment due to spikes in temps. 

But from all I have read of MAQS issues with queen loss, I do think that it is MORE likely the combination of many of these external factors and differing environments that are causing negative results and far less likely that it has to do with your unique abilities to be careful.


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## viesest (Jul 13, 2016)

psm1212 said:


> there seems to be a humidity concern for some treatments.


Just to mention, OAD has higher efficiency in higher humidity. What would be result if you apply OAD-s instead of OAV-s?


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