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Author Topic: How does oxalic acid dribble work?  (Read 3639 times)

Offline Hethen57

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How does oxalic acid dribble work?
« on: November 03, 2009, 01:11:23 PM »
I have read the various studies and posts regarding this method, the effectiveness, and the various concentrations, but was wondering how this method kills the varroa, ie, does it kill the varroa by contact only, or do the bees ingest the sugar water with OA to kill the varroa from the inside out?  If it kills by contact only, why the sugar solution and why doe the sugar concentration appear to be a significant factor in effectiveness in the studies? 
-Mike
-Mike

Offline Hethen57

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Re: How does oxalic acid dribble work?
« Reply #1 on: November 04, 2009, 02:28:22 PM »
In case anyone else was wondering, I did a little research on this subject and will try to answer my own question as best I can, based on what I found.  It appears that the OA solution kills the mites on contact, but they die a slow death.  The drop occurs from 24 hours to 2 weeks.  The sugar solution is thought to slow down evaporation of the solution and to help adhere to the bees where it will kill the mites.  The bees probably don't eat the syrup at higher OA concentrations.  By moving around in the cluster, the bees transfer the solution to each other.  The Nebraska study concluded that the 3.5-4.2% solution was not very toxic to the bees, but very effective at mite control.  There was little difference between spraying and dribbling, although dribbling was a quicker method to perform.  Note that this is currently not an approved method of mite control in the US, but it is in Canada and Europe.

Source - 2008 study by Nicholas Aliano, University of Nebraska at Lincoln.  Thanks to Finsky for the many authoritative references that he provided.
-Mike

Offline David LaFerney

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Re: How does oxalic acid dribble work?
« Reply #2 on: November 05, 2009, 12:34:14 PM »
I know that this method is used in late fall when hives are broodless.  It seems like intentionally dribbling liquid onto bees during cold weather would chill them to death.  Is this concern unfounded?

What is the recipe for the solution?    IE - 1 liter of water + X grams of sugar + X grams of OA dihydrate?

What time of day, and what conditions do you need?

"It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." Samuel Clemens

Putting the "ape" in apiary since 2009.

Offline Hethen57

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Re: How does oxalic acid dribble work?
« Reply #3 on: November 05, 2009, 01:38:55 PM »
David, here is what I found: Treat in November or December, when bees are in winter ball, but on a day when temps will be above freezing, use luke warm liquid (but I share your concern about the cold), treat with 5ml per seam of bees, or about 30ml for a single 10 frame or up to 50ml for double deep.  The simplest recipe I have found is 35-45g OA in a liter of 50:50 sugar syrup, which should be 3.5-4.5% w:v.  I'd like to find a recipe in cups and oz's, but haven't yet. 

Caveat - this is a summary from someone who has not done this yet (so anyone who knows more, please chime in), but one of the best practical explanations of this approach that I have found, and other methods as well, is at www.scientificbeekeeping.com   There is also at least one Youtube video of someone treating with this method in Germany (I think), and it looks very simple and quick.

I am going to try this method of treatement on my worst varroa infested hive (which was also my most prolific split and honey producer) in a few weeks.  I hope to report good results, but I feel like I have nothing to lose, and worst case, I will learn something.
-Mike

Offline Hethen57

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Re: How does oxalic acid dribble work?
« Reply #4 on: November 05, 2009, 01:54:37 PM »
Here is a good YouTube video of the procedure....it brings up a bunch of other related videos as well.....Oxalsyrebehandling (may have to cut and paste into your browser)

-Mike
-Mike

Offline Cindi

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Re: How does oxalic acid dribble work?
« Reply #5 on: November 06, 2009, 12:14:03 AM »
Just a quick reply, Mike, good you have done your research, that is a good thing to do.

Worrying about a small amount of sugar syrup, such as a small amount that is used with the trickling, will not chill the bees.  The syrup is applied warm.  The small amount of syrup that is distributed over the bees would not have a chance to cool.  The warmth from the cluster would keep the bees warm.  Don't worry about chilling the bees with the warmed syrup.  And it only takes a moment to do the drizzle, so having the lid open for a few minutes won't do any harm either.  Good investigating on your part.  Have a wonderful and most awesome day, to love and live this life, health. Cindi
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Offline David LaFerney

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Re: How does oxalic acid dribble work?
« Reply #6 on: November 06, 2009, 09:53:29 AM »
Thanks for the research and good info Heathen (are there really 56 other Heathens on here?)  I think this is going to me my plan B in case the OA vapor treatments that I've already done don't do the trick.  Probably what I should have done to begin with.

And Cindi - thanks for your input too.  It's reassuring to hear from someone who knows what they are talking about from personal experience.
"It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." Samuel Clemens

Putting the "ape" in apiary since 2009.

Offline Bee-Bop

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Re: How does oxalic acid dribble work?
« Reply #7 on: November 07, 2009, 12:07:28 PM »
Mike;
Thanks for the video.
A couple things I did notice, he was us, what appeared to be a solid piece of Plexiglas as a innercover.
I've heard talk of this but I wonder about the humidity ? :stayontopic:

Also did you notice his top cover boards were flush with the hive box top, no overhang.   

I know this is off topic, but it appears to be a long winter coming.   

Thanks Again
Bee-Bop
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Offline David LaFerney

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Re: How does oxalic acid dribble work?
« Reply #8 on: November 07, 2009, 05:59:12 PM »
Mike;
Thanks for the video.
a couple things I did notice, he was us, what appeared to be a solid piece of Plexiglas as a innercover.
I've heard talk of this but I wonder about the humidity ? :stayontopic:

Also did you notice his top cover boards were flush with the hive box top, no overhang.   

I know this is off topic, but it appears to be a long winter coming.   

Thanks Again
Bee-Bop


If you look close you can see that the outer cover telescopes down over a tenon that runs around the inner edge of the hive body.  It looks like those might be polyurethane hives to me.
"It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." Samuel Clemens

Putting the "ape" in apiary since 2009.

Offline Hethen57

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Re: How does oxalic acid dribble work?
« Reply #9 on: November 08, 2009, 01:35:08 PM »
Bee-Bop:
It looks like the plexiglass has ventilation slits cut into it....the plexiglass (with ventilation)be helpful to quickly assess the strength of the hive and the size of the ball, without fully opening the thing up.  Also, based on the thickness of that outer cover, I would imagine that it has some ventilation holes or an upper entrance (I think I see one, but can't tell for sure).  I would be curious as well.
-Mike
-Mike

Offline Finski

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Re: How does oxalic acid dribble work?
« Reply #10 on: January 24, 2010, 01:35:58 PM »

In video there is a polystyrene hive. It has a well insulating outer cover. So many use plastic folio that burr does not attach to the real cover.

Probably the hive has 20 x 20 cm floor mesh patch and in that case there is no upper entrance.

Here you see the idea of plastic sheet
einhängen einer Zuchtlatte in ein Startervolk
« Last Edit: January 24, 2010, 02:36:22 PM by Finski »
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Language barrier NOT included

Offline David LaFerney

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Re: How does oxalic acid dribble work?
« Reply #11 on: January 24, 2010, 08:39:33 PM »
Very cool.  Thanks for sharing the video.  I was looking at other videos from the same person and right away I have a couple of questions about this one:

abstoßen der Bienen

It looks like he is collecting nurse bees - I'm guessing to build up a starter hive or mating nuc for queen rearing.  

1) Does it not dangerously weaken a hive to remove so many nurse bees at one time?

2) Is that just sugar water that he is spraying on them to keep them in the bucket?

Or, am I completely wrong about what is going on here?  These are interesting videos - I wish I understood the language.
"It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." Samuel Clemens

Putting the "ape" in apiary since 2009.

Offline Finski

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Re: How does oxalic acid dribble work?
« Reply #12 on: January 25, 2010, 01:47:30 PM »
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The guy is rearing queens and just put queen larva cups into the hive.
This is a starter hive. Perhaps he puts queen cells after 3 days into bigger hive to be finally reared.
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Language barrier NOT included

 

anything