# Those who advocate OA as a summer treatment, what do you make of this?



## Mike Gillmore (Feb 25, 2006)

cervus said:


> This was OA liquid treatment, but one can infer the same results via vaporization.


Not really. Liquid has a much more negative effect on open brood than vaporization. I don't know of very many who advocate multiple "dribble" treatments in the summer on colonies with brood. 

OAV administered in multiple treatments 5 to 7 days apart in the summer can produce good results reducing the mite load. It's not the best time of year, but it works.


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## cervus (May 8, 2016)

I'm not advocating one way or the other, just trying to make some sense of the options. I'm sure you read the dissertation, so you know he did conduct 3 treatments, 1 week apart and found "no harmful effect on bees" brood or otherwise and with the liquid method. What they did find, was a "paucity of significant mite population suppression". That indicates to me that it is not as effective as we would like it to be...in the summer. Is there any peer-reviewed papers or studies that indicate otherwise, or is that something people like to keep hush-hush since the label also states "Use only in late fall or early spring when little or no brood is present"? I'm not trying to start a label/off-label firestorm. I'm seriously trying to learn.


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## rv10flyer (Feb 25, 2015)

Your mostly brood-less time will be in December. If you want good healthy long-lived winter bees, when should you start treating? Not November. I start OAV Aug 1-15. I treat once every 5-7 days for four times. I then wait one week to do a mite check. I want them under 1%. I treat one more time Dec 1-15. 100% through last winter.


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## Mike Gillmore (Feb 25, 2006)

There are studies everywhere with varying conclusions. All I know is what I have learned from personal experience, trial and error. If I perform a series of OAV treatments in late Summer/early Fall when the broodnest is contracted and the mite load is at it's peak, it knocks down the mite population significantly. Another single treatment later when broodless (Nov-Dec) and they are good to go next Spring. No additional treatments needed in Spring or Summer. 



> Does trickle or vaporization work better? A recent study at Sussex University examined the effectiveness of different doses and application methods on mite and bee mortality. The experiment involved 110 hives. The results showed sublimation (vaporization) was far better at reducing mite populations and showed no increase in bee mortality.


http://www.beeculture.com/oxalic-acid-effective-easy-on-bees-but/


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## rbees (Jun 25, 2012)

The author states that his results did not signaficantly reduce the number of varroa during the three week period. Ok fine...but did it suppress growth of Varroa? According to his data...yes....which is important to note when one considers during summer..mid July brood slows down and Varroa numbers increases past the lag stage. * "I reject my hypothesis that repeated applications of OA would significantly reduce Varroa mite populations in colonies containing brood. There was an overall
percentage reduction in the Varroa mite populations on adult bees regardless of treatment" * If his data is correct..then dribbling OA will buy the beekeeper a month of population suppression during the time when levels would explode.


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## Saltybee (Feb 9, 2012)

I am not clear on his methods. Hives were single deeps with 2? medium? supers on. (no I did not do the math, it only changes the description not the question). Treatment sounds like deep only was treated with supers left on. (All frames were covered with bees) Were the supers packed with bees or lightly populated? 
Does that mean only half of the bees were treated? 80%, 90%?
Maybe covered in the pages I did not read?
Logic says that if mites were able to sustain population in spite of kill rate on adults there would not be the typical population curve as typically graphed. There would be virtually no delay in the steep late spring upward climb.

"Summer" treatment is itself a rather useless description. With multiple frames of brood under an excluder, that is either late spring or early fall to me. Well, maybe a rainy summer.


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## johno (Dec 4, 2011)

This particular paper was published 8 years ago, since that time some other studies have shown sublimation to be superior to the drench method. I believe some studies have found the drench method to be detrimental to the bees health if dosed more than once. Practical experience from a number of beekeepers have shown that multiple use of OA vapour to have no ill effect on queens bees or brood even if the recommended dosage is doubled. So at the end of the day OA vapour can be used over and over again until mite counts are brought down to a respectable level. It might take a lot of time, but the treatment is cheap also considering the formic acid treatments which tends to be some times unreliable, queen loss and brood loss and the difficulty with temperatures at the time of treatment are some of them not to forget expensive. OA sublimation has been used quite safely by many beekeepers in the USA as late summer treatments of varoa. There are many threads recording its use on this forum.
Johno


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## Saltybee (Feb 9, 2012)

I do not think anyone with a vaporizer looks at it and says; "I think I'll use my squirt bottle today."


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## rbees (Jun 25, 2012)

Saltybee said:


> I do not think anyone with a vaporizer looks at it and says; "I think I'll use my squirt bottle today."


True...but if one doesn't have a vaporizer and going through hives during summer they can give a quick squirt of the bees while it's open


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## cervus (May 8, 2016)

Good points, but I'm still looking for published studies that demonstrate that OA vaporization in* summer* is a viable treatment option. They are hard to find. And if it is a viable treatment option I can't help but wonder why the label specifically restricts it's use during the very season when, according to a lot of people, it's use is critical for mite control. One would expect that the emergency registration process would seek to maximize the efficacy of the proposed treatment not restrict it's use during a time when it's needed. Must be the government. 



rv10flyer said:


> Your mostly brood-less time will be in December


 Nope, November


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## Arnie (Jan 30, 2014)

OA vaporization , used with a plan, will knock down the mites such that you should be able to get through the summer without treatment. 
That means a one-time treatment in winter when the bees are broodless and a series after the supers come off, 4 times, a week apart.... end of summer usually. Since I am paranoid I also add a series in May, just to be certain. 3 times, a week apart.

If your bees are currently infested with mites you can do a series of treatments just as long as you block the vapors so they don't work their way into the supers, or take the supers off before treatment and replace them after.

Don't wait to treat while looking around for scientific research and lose your bees. You can look for studies during the winter.


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## rbees (Jun 25, 2012)

Also..dribble is MUCH MUCH safer to the user


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## shinbone (Jul 5, 2011)

Every single time I OAV a hive, I see a HUGE mite drop (unless, it is the last treatment in a series of treatments). I didn't read the dissertation, but if the author says OAVing in the summer doesn't kill mites, he didn't OAV correctly or he didn't count mites correctly. Since OAVing is extremely effective at killing mites, multiple treatments at the correct interval can't help but reduce the mite population regardless of the time of year.

Not all aspects of beekeeping has been subjected to a scientific study. Sometimes, to move forward your only option is to listen to those with lots of experience (and I am a rookie beekeeper, so I don't put myself in the "lots of experience" category) to decide what to do.

Obviously each beekeeper is free to rely on whatever information he chooses, to, though.

JMHO


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## cervus (May 8, 2016)

I have a vaporizer and OA. I also have a packet of Api-var that I can put on one time and forget it until 28 August. Then I could treat with OA, per the label , starting somewhere around mid to late October. I don't have any honey in the supers to speak of, made too many splits this spring and summer. What they make in the fall will be left for them. I'm not seeing mite levels high enough to treat...yet. Just weighing options for the inevitable. If I'm going to treat with anything inside the hive, I want the most bang for the buck.


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## rv10flyer (Feb 25, 2015)

Open a hive on a warm day Nov 1-15. Open a hive Dec 1-15. Then tell me which one has a bigger patch of brood.


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## rv10flyer (Feb 25, 2015)

All I can say is that before I started my above OAV regime, I lost 36% every winter. I used Apiguard and Apivar before. I lost zero last winter after knocking them down below 1% with OAV. They are your bees, do as you wish. 49 double deep hives presently.


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## cervus (May 8, 2016)

Brood laying wanes here in November. November is late fall. OA label says treat in late fall. Don't know what else to say.


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## e-spice (Sep 21, 2013)

Arnie said:


> Don't wait to treat while looking around for scientific research and lose your bees. You can look for studies during the winter.


:thumbsup::thumbsup::thumbsup: Great advice!

I do several series of OAV treatments throughout the summer and monitor the drop counts. I sometimes get 300 or so mites after a treatment. I would think that has to have an effect on the overall mite count.


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## Arnie (Jan 30, 2014)

cervus, whatever you do, good luck.


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## Saltybee (Feb 9, 2012)

cervus said:


> Good points, but I'm still looking for published studies that demonstrate that OA vaporization in* summer* is a viable treatment option.
> r


Not a scientific study but respected. If you are considering a brood filled treatment chances are you have nothing to lose.
http://scientificbeekeeping.com/oxalic-acid-questions-answers-and-more-questions-part-1-of-2-parts/


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## clyderoad (Jun 10, 2012)

cervus said:


> Brood laying wanes here in November. November is late fall. OA label says treat in late fall. Don't know what else to say.


You want strong, fat, healthy, long lived winter bees. If you wait to treat the colony in late fall the winter bees are already present in the hive and they will not be strong, fat or healthy but weak, skinny and likely carrying a virus load that will make them short lived.
And that's if the colony makes it to Thanksgiving.


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## Daniel Y (Sep 12, 2011)

cervus said:


> _
> 
> This was OA liquid treatment, but one can infer the same results via vaporization.._


_

You can if you wish, But I wouldn't. effectiveness of dribble vs vaporization are not the same. Not to mention other differences. Why would I suddenly assume results in this matter are comparable?
There is no mention of the frequency of repeated applications. In fact there is little detail about anything claimed to have been done. I did this and then I did that but nothing to evaluate how he went about doing it. overall the idea that treating while broodless is more effective is nothing new. but it does not make the case that treating repeatedly with brood present is not effective enough. You don't need better methods when the ones you use already work. More work and time consuming yes. so this would be the advantage I see in a one shot fix. But I don't see the idea that dribble in any manner is a one shot fix. It is an easier less time consuming compromise. Better than nothing but far from the best. So comparing an inadequate compromise to an effective method is in no way comparable._


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## jim lyon (Feb 19, 2006)

People that assume dribbling's only effective application is as a late fall treatment are missing out on my favorite use, which is treating a nuc made with a queen cell at that 20-21 day "sweet spot" just before brood is capped over. One can give an effective treatment in a few seconds that can pretty much buy you a whole season before varroa can significantly recover.


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## cervus (May 8, 2016)

> Why would I suddenly assume results in this matter are comparable?


Same compound, same mode of action. Vaporization is just a mode of dispersal. 



> There is no mention of the frequency of repeated applications. In fact there is little detail about anything claimed to have been done.


What?! He did 3 treatments, 1 week apart. In addition, his procedures are well documented. It's all in the dissertation, you must have missed it.



> but it does not make the case that treating repeatedly with brood present is not effective enough


Yes, it does. That's the whole premise of that section of his thesis. He rejected his hypothesis that it was effective in the summer. His data proved otherwise.


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## AHudd (Mar 5, 2015)

cervus said:


> Same compound, same mode of action. Vaporization is just a mode of dispersal.


That sounds like saying you will get the same results by throwing a can of paint against a wall as you will by using a modern airless spray rig. 

Alex


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## cervus (May 8, 2016)

clyderoad said:


> You want strong, fat, healthy, long lived winter bees. If you wait to treat the colony in late fall the winter bees are already present in the hive and they will not be strong, fat or healthy but weak, skinny and likely carrying a virus load that will make them short lived.
> And that's if the colony makes it to Thanksgiving.


 My point exactly, why would the EPA handcuff us with that label restriction? Unless....OA is not effective in the summer.


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## cervus (May 8, 2016)

AHudd said:


> That sounds like saying you will get the same results by throwing a can of paint against a wall as you will by using a modern airless spray rig.
> 
> Alex


Not really. Using your example, if I saw both walls, I could _infer_, that someone wanted paint on the wall in both cases. And that was the result. We're talking about an organic acid spread in a hive.


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## Mike Gillmore (Feb 25, 2006)

cervus said:


> Brood laying wanes here in November. November is late fall. OA label says treat in late fall. Don't know what else to say.


Clyderoad has given you some solid practical advice regarding treatment timing, you would be wise to take that into consideration.

I think you might be getting hung up on some of the "label" wording. Keep in mind that the label never advocates doing multiple treatments of either method. It says to use the product "only in late fall or early spring when little or no brood is present". The instructions are geared toward a single treatment with OA, in addition to other miticides. 

Check the directions for Solution Method. 


> Under certain unfavorable conditions (e.g. weak colonies, unfavorable overwintering conditions ), this application methods may cause some bee mortality or overwintering bee loss.


There are no such warnings under the Vaporization Method. 

Read between the lines a little and you may find some of the answers you're looking for. If you are determined to follow the label directions to the letter you should probably use other miticides during the year and stick with a single OA treatment in November as a clean up.


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## cervus (May 8, 2016)

I appreciate practical advice and I do consider it. My background also requires me to consider the scientific method. I'm not hung-up by the label, as I originally stated, I'm weighing options. I understand the fan-boy mentality when it looks like a new silver bullet has arrived.


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## jim lyon (Feb 19, 2006)

cervus said:


> Same compound, same mode of action. Vaporization is just a mode of dispersal.


I think there is reason to believe that the mode of action of dribbling is more systemic as you are, in effect, treating the cluster. If you are applying with the notion of getting treated syrup on each individual bee then you are grossly overdosing them.


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## Daniel Y (Sep 12, 2011)

cervus said:


> Not really. Using your example, if I saw both walls, I could _infer_, that someone wanted paint on the wall in both cases. And that was the result. We're talking about an organic acid spread in a hive.


Not even close. In such a cases I would infer in the one case that someone painted a wall. in the other I would infer vandalism. Not to mention the issue of. Did each method achieve the desired result. Now I can readily agree that dibble method in summer is not effective. But that is because I would also agree that dribble method is not effective at any time. To compromise with apposing opinions I will relent and say that dribble is not as effective. I will not agree that it is ever effective enough. So in all this paper is an effort to document what is readily obvious to me. A method that is claimed to be adequate largely by those that cannot distinguish maintenance from vandalism.


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## johno (Dec 4, 2011)

Cervus you must realize that OA dribble and OA vapour were brought to the beekeeping community by beekeepers not pointy headed intellectuals those are the guys who brought us fluvalinate and caumophos and look where that took us. As for the Employment Prevention Agency they put on their labels what the pointy headed intellectuals tell them to put on. But you are free to do as you please with your bees but I will tell you this, if you do not control your mites they will kill your bees.
Johno


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## clyderoad (Jun 10, 2012)

cervus said:


> My point exactly, why would the EPA handcuff us with that label restriction? Unless....OA is not effective in the summer.


contact them and ask.

there is a long history of OA use to control varroa. 
I suggest you research it for yourself.


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## Mike Gillmore (Feb 25, 2006)

I just emailed Brushy and requested links to studies on both application methods. If I get a response tomorrow I'll post it.They have been at the center of the US registration process so I'm confident they will have the best resources to share with us.


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## cervus (May 8, 2016)

My this escalated quickly. I was hesitant to post due that very reason. Bottom line is I am going to treat when my monitoring indicates it is required. I will most likely be using OAV because I have the tools and it is just so darn easy. I was just surprised at the summary dismissal of it's seasonal efficacy both at the scholarly and regulatory level. Hopefully it's not like the addage, "when the only tool you have is a hammer, everything begins to look like a nail".



> pointy headed intellectuals those are the guys who brought us fluvalinate and caumophos and look where that took us.


I respectfully disagree. It was the cavalier overuse and misuse of those compounds that brought us where we are. The attitude that if a little works, a lot will be that much better. It is those "pointy-headed intellectuals" who are sought out when things get tough. It's the same in conventional agriculture. The whole university extension system is based on that.


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## cervus (May 8, 2016)

clyderoad said:


> contact them and ask.
> 
> there is a long history of OA use to control varroa.
> I suggest you research it for yourself.


Clyde, I have been researching. And like I said, I've found a grand total of one peer-reviewed, scientific study. And that study showed that OA is not effective in summer. And this seems to be in direct contradiction of the practical experience of hundreds (thousands?) of beekeepers.


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## cervus (May 8, 2016)

Mike Gillmore said:


> I just emailed Brushy and requested links to studies on both application methods. If I get a response tomorrow I'll post it.They have been at the center of the US registration process so I'm confident they will have the best resources to share with us.


 Thanks Mike. Hopefully we can put this to bed. It would be a great project for a graduate student, it it hasn't already been done.


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## clyderoad (Jun 10, 2012)

cervus said:


> Clyde, I have been researching. And like I said, I've found a grand total of one peer-reviewed, scientific study. And that study showed that OA is not effective in summer. And this seems to be in direct contradiction of the practical experience of hundreds (thousands?) of beekeepers.


more information is available from those "across the pond". both scientific and the methodology of those who practice the craft.
as mentioned, there is a long history of its use to draw from. here, we are late comers to the party.


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## cervus (May 8, 2016)

clyderoad said:


> more information is available from those "across the pond". both scientific and the methodology of those who practice the craft.
> as mentioned, there is a long history of its use to draw from. here, we are late comers to the party.


Agree, about 99% more from Europe. Hopefully Mike's inquiry to BM will shed some more light.


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## sakhoney (Apr 3, 2016)

> My point exactly, why would the EPA handcuff us with that label restriction? Unless....OA is not effective in the summer


EPA - because there not beekeepers - have you seen anything the government is involved that is right? SS messed up, USPS messed up, Balanced budget - now that really messed up - EPA approving nicks before knowing what it does in the food chain - messed up. Shall I continue?


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## cervus (May 8, 2016)

sakhoney said:


> Shall I continue?


No, you've made your point. 

But it will all change come November.


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## aunt betty (May 4, 2015)

clyderoad said:


> You want strong, fat, healthy, long lived winter bees. If you wait to treat the colony in late fall the winter bees are already present in the hive and they will not be strong, fat or healthy but weak, skinny and likely carrying a virus load that will make them short lived.
> And that's if the colony makes it to Thanksgiving.


This is what I was going to post. You can't wait until winter to breed up your good winter bees so you might want to treat in September. That way you have some healthy strong bees going into winter. That's my logic anyway.


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## sakhoney (Apr 3, 2016)

> But it will all change come November


Sure hope your right


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## TalonRedding (Jul 19, 2013)

http://scientificbeekeeping.com/varroa-management/treatments-for-varroa/

Read everything here twice a day for three days, anyone who has questions will walk away with some pretty good answers if they do. It's very good information and I have put much of it to work, and yes....it works.


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## Stephenpbird (May 22, 2011)

clyderoad said:


> more information is available from those "across the pond". both scientific and the methodology of those who practice the craft.
> as mentioned, there is a long history of its use to draw from. here, we are late comers to the party.




A good review of OA, with references to scientific studies, can be found at http://www.apidologie.org/articles/apido/pdf/2006/01/M6010.pdf


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## cervus (May 8, 2016)

Stephenpbird said:


> A good review of OA, with references to scientific studies, can be found at http://www.apidologie.org/articles/apido/pdf/2006/01/M6010.pdf


 Thanks for that link! A little dated, but the bibliography is great stuff!


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## Saltybee (Feb 9, 2012)

cervus said:


> Same compound, same mode of action. Vaporization is just a mode of dispersal.
> 
> 
> What?! He did 3 treatments, 1 week apart. In addition, his procedures are well documented. It's all in the dissertation, you must have missed it.


Yeah I did miss it. He did not clearly state where he applied just seams. Did not state total bees in hive. Total volume is enough for treating lower brood frames as stated. so were the other 7 frames of lower hive empty or packed with bees? were supers empty or packed? Major questions of effective dosing. If supers and all lower frames were packed that dose is too low and probably did little to treat.


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## cervus (May 8, 2016)

Saltybee said:


> Yeah I did miss it. He did not clearly state where he applied just seams. Did not state total bees in hive. Total volume is enough for treating lower brood frames as stated. so were the other 7 frames of lower hive empty or packed with bees? were supers empty or packed? Major questions of effective dosing. If supers and all lower frames were packed that dose is too low and probably did little to treat.


_The experimental hives were single story Langstroth beehives (24.4 cm deep hive body) with a queen excluder and 1 or 2 supers
(16.8 cm deep). The experimental colonies contained 3 to 6 frames of brood, a young Carniolan or Italian queen, and all frames were covered with bees._

He used 50ml solutions of 2% OA, 3.5% OA, and 6% OA. I think that 50ml was at that time, the maximum safe level as reported in his literature search. 

_When spraying or trickling OA, the maximum dose is 50 mL per hive, whether the bees are in nucs, single, or multiple brood chambers._

It's the same levels that did show great efficacy when the hive was broodless, just not so much in the summer. Someone now needs to do a study on OAV, following the same procedures. Hopefully an enterprising grad student in entomology will do just that.


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## usngunr (Feb 21, 2013)

cervus said:


> It's the same levels that did show great efficacy when the hive was broodless, just not so much in the summer. Someone now needs to do a study on OAV, following the same procedures. Hopefully an enterprising grad student in entomology will do just that.


Let us know how it comes out. :applause:


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## Saltybee (Feb 9, 2012)

cervus said:


> _.
> 
> When spraying or trickling OA, the maximum dose is 50 mL per hive, whether the bees are in nucs, single, or multiple brood chambers. _


_

I got that. What I do not see is how that statement matches with pg 54 in any conclusive manner; 

"For the OA treatments, I trickled 50 mL of either a 2.0%, 3.5%, or 6.0% OA sugar
water (sugar:water) (1:1) (w:w) solution over the cluster of bees using a 100 mL syringe.
I trickled 5-6 mL of the OA solutions between each occupied bee-way and made an effort
to maximize contact with the adult bee population."

If the lower body was packed, which is the only way to reach 50ml using 5 ml per beeway, is the beeway count a quantity of 9 or plus two outer halves at 2.5ml each making 10 beeways. if 2 half frames were treated that should have been stated as such.That does not allow any treatment for an unknown population of bees in the supers. My statement is the parameters of the experiment were either not controlled or an important variable, the bee population, was not addressed, at least in chapter 3. 

I am left with more uncertainty in the methods than I would find to be a reliable treatment determinant. The brood frames are stated, the bee population is not. I would find the bee population as an important variable, needing to be addressed. One may assume that all behives had the same number of "beeways" or the description of the experiment is flawed. If the hives were balanced in "beeways" why would you not balance brood frames as that was the basic question being investigated?

I would have given a "c" at best and would not rely on the conclusions to determine my actions.

He may have found the 50 ml to be the max per any size hive, I find that much more of a variable then mixture strength. Why would you find that belief to influence your treatment decision today. Over treatment for a nuc, under for the equivalent of a double deep.


Contrast that with Randy Oliver"s; 
At the University of Nebraska, Ellis and Aliano (2005) found that a single treatment of 5-6 ml of 3.5% syrup dribbled per seam of bees resulted in about a 90% mite kill. They also found that a 2% oxalic solution was far more effective than Sucrocide® (62% compared to 32%) at killing mites on package bee_


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## snl (Nov 20, 2009)

Those who doubt the late summer efficacy of OAV treatments, merely need to look at the mite drop on their sticky board after the 1st 48 hours..... It is beyond me (after viewing those mite drops) that one can state that those treatments are not effective.


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## beepro (Dec 31, 2012)

Using my homemade oav gadget under the hive is effective all year long even in the
cold winter rainy days. So when oav kills it will on any season. My little oav 
bee experiment is not scientific in nature but full of experience to know what I am doing
to control the mites tracking them in a yearly bee cycle. Remember that my only 2 hives got
crashed by the mites 2 years ago?
And here is the real answer: When you need to treat then do it!
Wait until Oct or Nov you may not have a live hive to treat anymore. You cannot wait until the
brood less period because as long as the bees are capping so are the mites with them. It does not matter
in the late summer or early Autumn time. What matters the most is your hive condition and the level of infestation in the
present.


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## Bigmachine (Jan 4, 2015)

hello everyone, I ordered me the Varrox Vaporizer the other day and it should be arriving within the week. I wanted to ask how many mites should I have on my sticky board that would tell me that I need to treat? I have 2 hives and after 3 days I count 32 on hive #1 and 50 mites on hive #2. Any advice is appreciated, I lost my one and only hive last year in early winter and want to give my 2 current hives a fighting chance this year!


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## cervus (May 8, 2016)

Bigmachine said:


> hello everyone, I ordered me the Varrox Vaporizer the other day and it should be arriving within the week. I wanted to ask how many mites should I have on my sticky board that would tell me that I need to treat? I have 2 hives and after 3 days I count 32 on hive #1 and 50 mites on hive #2. Any advice is appreciated, I lost my one and only hive last year in early winter and want to give my 2 current hives a fighting chance this year!


Everything you ever wanted to know about sticky boards and mites. http://scientificbeekeeping.com/fighting-varroa-reconnaissance-mite-sampling/


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## snl (Nov 20, 2009)

Bigmachine said:


> hello everyone, I ordered me the Varrox Vaporizer the other day and it should be arriving within the week. I wanted to ask how many mites should I have on my sticky board that would tell me that I need to treat? I have 2 hives and after 3 days I count 32 on hive #1 and 50 mites on hive #2. Any advice is appreciated, I lost my one and only hive last year in early winter and want to give my 2 current hives a fighting chance this year!


I see 20 mites, I treat. I do one treatment of OAV and look at the mite drop on the 2nd day. That tells me if I need to treat. I do not like to see over 20 mites as I have a low tolerance for mites.


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## jwcarlson (Feb 14, 2014)

Saltybee said:


> I do not think anyone with a vaporizer looks at it and says; "I think I'll use my squirt bottle today."


I do if they're broodless. I can do a dribble in seconds or stand around vaporizing in a hive for several minutes and lug a heavy battery around.


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## Mike Gillmore (Feb 25, 2006)

snl said:


> I see 20 mites, I treat. I do one treatment of OAV and look at the mite drop on the 2nd day. That tells me if I need to treat. I do not like to see over 20 mites as I have a low tolerance for mites.


I would like to add another thought to this if I may. 

Moving into this time of year when the mite population typically escalates, if you do a single treatment to determine the need to continue with a series of treatments, do not rely on the results of a single test to plan the balance of the year. 

If the counts after 48 hours are low do not assume you are out of the woods for the season. Sometimes when the brood nest contracts in late summer (especially in booming hives) there are a lot of mites under cappings which are not impacted by the OAV treatment, and 3 or 4 weeks later you might have an explosion in the mite population in the colony when these bees emerge. If you do a treatment and things look good, plan on another one in 3 or 4 weeks just to be sure and then re-evaluate.


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## snl (Nov 20, 2009)

Mike Gillmore said:


> If the counts after 48 hours are low do not assume you are out of the woods for the season. Sometimes when the brood nest contracts in late summer (especially in booming hives) there are a lot of mites under cappings which are not impacted by the OAV treatment, and 3 or 4 weeks later you might have an explosion in the mite population in the colony when these bees emerge. If you do a treatment and things look good, plan on another one in 3 or 4 weeks just to be sure and then re-evaluate.


True Mike, but when as the brood nest contracts, it means that there are more phoretic mites as there are less and less cells about to be capped for the mites to jump into...... You're right, another OAV test in a couple of weeks is a good idea..


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## shinbone (Jul 5, 2011)

snl said:


> Those who doubt the late summer efficacy of OAV treatments, merely need to look at the mite drop on their sticky board after the 1st 48 hours..... It is beyond me (after viewing those mite drops) that one can state that those treatments are not effective.


Ha! Everyone knows that if it isn't reported in a peer reviewed publication authored by _real_ scientists, then it doesn't happened.


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## AHudd (Mar 5, 2015)

And how can you tell the real bee scientist? Are they the ones with the bee beards?

Alex


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## BeekeepingIsGood (Aug 12, 2012)

It is all very confusing the chasm between what is researched, what people say to do, and what people might actually be doing. This leads to the frustration around figuring our what works and when, and what will contaminate honey and what will not. The summer is particularly confounding for beekee

Everyone making recommendations to beekeepers suggests to remove the supers before dribbling. It's probably prudent to do so, but the limited published research on the subject seems to suggest it doesn't have much impact on oxalic levels in honey. So one must wonder.




> Single or repeated treatments with oxalic acid do not lead to accumulation of residues in honey (Mutinelli et al., 1997; del Nozal et al., 2000; Bernardini and Gardi, 2001; Radetzki and Bärmann, 2001; Prandin et al., 2002; Bogdanov et al., 2002a; del Nozal et al., 2003; Moosbeckhofer et al., 2003).






> a l o w risk of i mpo rta n t contami natio n in t he h o n e y intende d for extraction.


Perhaps the problem is simply that it's very difficult to be absolutely certain of anything? Nobody wants to be responsible for a mistake?


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## Mike Gillmore (Feb 25, 2006)

snl said:


> True Mike, but when as the brood nest contracts, it means that there are more phoretic mites as there are less and less cells about to be capped for the mites to jump into...... You're right, another OAV test in a couple of weeks is a good idea..


If there are less open brood cells when the nest contracts then there will be a much higher percentage of bees emerging with mites during the next cycle. The phoretic mites will find open cells to jump into, and less cells means more of the available cells will have mites in them. 

Anyway, I think it's a good idea to treat again in a few weeks even if the counts look good. Mite populations can change very quickly sometimes. Another factor that can blindside is the number of mites hitchhiking a ride if your bees are robbing out a weak hive overloaded with mites. It's about that time of year.


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## Daniel Y (Sep 12, 2011)

BeekeepingIsGood said:


> It is all very confusing the chasm between what is researched, what people say to do, and what people might actually be doing.


There is a considerable difference between saying and doing at all. Doing requires many skills that saying does not require. and those skills need to be practiced. observations must be conducted, conclusions must be made and corrections implemented. I can show you how to make realistic pencil drawings of people. Your first attempt I expect to be extremely poor. they would also be expected to improve with additional attempts. Until with enough attempts enough improvement and enough adjustments to your specific methods and understanding they will be good.


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## BeekeepingIsGood (Aug 12, 2012)

> Until with enough attempts enough improvement and enough adjustments to your specific methods and understanding they will be good.


The problem is most beekeepers don't have the ability to test oxalic acid content of their honey. I don't even know where to begin to gain experience with that.


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## Daniel Y (Sep 12, 2011)

BeekeepingIsGood said:


> The problem is most beekeepers don't have the ability to test oxalic acid content of their honey. I don't even know where to begin to gain experience with that.


Do you know what such tests would require? and if not how do you know if most beekeepers have the ability or not. Again the difference between saying and doing. it is easy to say beekeepers can't do it. Have you taken the effort to know they can't do it. I say they can. it only requires a test kit. Now I only spent a couple of mintues on this so the reliability would not be high.


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## aunt betty (May 4, 2015)

Daniel Y said:


> Do you know what such tests would require? and if not how do you know if most beekeepers have the ability or not. Again the difference between saying and doing. it is easy to say beekeepers can't do it. Have you taken the effort to know they can't do it. I say they can. it only requires a test kit. Now I only spent a couple of mintues on this so the reliability would not be high.


Am in a very large bee association and from my observations "most beekeepers can't keep their bees alive more than one season". 
There are less than ten of us who don't buy bees every year. The others and I mean a few hundred are bee havers/replacers. 
They come to meetings and rarely have anything to say. The core-group of 5-10 of us are the real beeKEEPERS around this area.

I think it is a sound assumption to say that "most of us can't monitor the OA levels in our honey". Have never used OA so why would I wish to monitor it? Just take the supers off, OA, then put them back. Seems like a no-brainer.


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## BeekeepingIsGood (Aug 12, 2012)

aunt betty said:


> I think it is a sound assumption to say that "most of us can't monitor the OA levels in our honey". Have never used OA so why would I wish to monitor it? Just take the supers off, OA, then put them back. Seems like a no-brainer.


I looked into OA kit costs. One I found seems rather pricey with a short shelf life. That will also deter even the keeners.

There's many advantages to being able to treat during the summer without taking off the supers. I'm in a dearth right now and all the honey is in the supers on many hives. I'd like to see that the fall flow comes through before I remove them. It's also unpleasant to harvest during a dearth. Treating with the supers on is used as a selling point for MAQS so I imagine there are those other than myself who see the benefit. I imagine maqs is approved while other formic applications are not because they spent the money on the research to create the evidence for their particular product? Unfortunately it's often too hot for maqs during the summer here. Summer options are limited.


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## BigBlackBirds (Aug 26, 2011)

Saltybee said:


> Not a scientific study but respected. If you are considering a brood filled treatment chances are you have nothing to lose.
> http://scientificbeekeeping.com/oxalic-acid-questions-answers-and-more-questions-part-1-of-2-parts/



He publishes the only information I bother reading; good science background and an actual beekeeper. 

Personally I do like dribbling better than vaporizing. Works good for me when everything is broodless.


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## GerrieRPh (Mar 10, 2015)

OAV - would it improve the kill rate if applied when all the bees are home for the evening? i.e. after sunset, but before dark?


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## cervus (May 8, 2016)

GerrieRPh said:


> OAV - would it improve the kill rate if applied when all the bees are home for the evening? i.e. after sunset, but before dark?


The more bees the better, IMO. But, in reality, the OA vapor condenses on the hive surfaces. Just the bees moving it around the hive should disperse the active ingredient sufficiently. I treat in the evening.


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## Mike Gillmore (Feb 25, 2006)

cervus said:


> Just the bees moving it around the hive should disperse the active ingredient sufficiently.


That probably occurs, but for the most effective treatment you want the vapor to settle "on" as many "bees" as possible. That's why standard instructions suggest sealing off all entrances and openings while vaporizing. If you are going to go through the effort of vaporizing, it would make sense to wait until "all" the bees are in the hive before treating and get the most bang for your buck.


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## usngunr (Feb 21, 2013)

Mike Gillmore said:


> That probably occurs, but for the most effective treatment you want the vapor to settle "on" as many "bees" as possible. That's why standard instructions suggest sealing off all entrances and openings while vaporizing. If you are going to go through the effort of vaporizing, it would make sense to wait until "all" the bees are in the hive before treating and get the most bang for your buck.


That is my theory and what I do as well. I'll smoke a touch to get them back in, block the door, and then I vaporize from the top or if it's a screened bottom from under the screen. Which ever is easier to access, both work well.

Vince


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