# oa dribble freqency



## Jadeguppy (Jul 19, 2017)

I find myself looking to dribble OA. I've ready that the dribble method kills for three days. In my area we barely get a brood free time, if any. What is the best frequency for dribble? Will three treatments three days apart harm the queen? Temp today is 84 and the golden rod has barely bloomed due to drought.


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## msl (Sep 6, 2016)

it kills for 2 weeks+, 3 days is likely vapor


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## Mike Gillmore (Feb 25, 2006)

Based on studies I've read, OA "dribble" is really rough on open brood. Most recommend only using it one time when the colony is broodless. Vaporization can be administered multiple times while the colony is brooding without a negative effect on the brood, but any mites under cappings are not impacted.

In Florida my suggestion would be to use a product like Formic Pro if the temperatures cooperate. It's a more costly treatment but will kill mites under cappings too.


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## LAlldredge (Aug 16, 2018)

Please don’t make my mistake. I didn’t want to put out the money for a wand and this among other mistakes led to losing both of my colonies last year. It was too hard on the brood. Queens survived but the population never recovered. Bought the Varrox wand and vaporize OA. Much different experience.


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## Steve in PA (Jan 26, 2015)

Following...

I have a wand but after doing dribble recently to about half of my hives I very much like it more.

We are nearly bloodless now. I'm trying to figure out if I can do dribble again between Thanksgiving/Christmas or if that will be too soon.

Winter mistakes are mostly unforgiving.


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## Michael Bush (Aug 2, 2002)

>Based on studies I've read, OA "dribble" is really rough on open brood.

From what I've seen it's really rough on adult bees. Usually they don't recommend more than one treatment.


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## Fivej (Apr 4, 2016)

Agree with above that only one single treatment is recommended. People around me who dribble do it in the winter when they are broodless. J


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## Jadeguppy (Jul 19, 2017)

LAlldredge said:


> Please don’t make my mistake. I didn’t want to put out the money for a wand and this among other mistakes led to losing both of my colonies last year. It was too hard on the brood. Queens survived but the population never recovered. Bought the Varrox wand and vaporize OA. Much different experience.


What mix did you use? Could it have been that the treatment came to late?

I'm looking to use the mix listed on scientific beekeeping.


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## Juhani Lunden (Oct 3, 2013)

Michael Bush said:


> >Based on studies I've read, OA "dribble" is really rough on open brood.
> 
> From what I've seen it's really rough on adult bees. Usually they don't recommend more than one treatment.


:thumbsup:


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## msl (Sep 6, 2016)

> Usually they don't recommend more than one treatment.


I am not sure who "they" are. 
There seems to be a bit of internet lore out there with most of the issues seeming to be climate dependent and some at a much higher % then is used in modern times.
When I am forced to I do a round of 3 weekly treatments as a rescue to knock back levels post harvest of hives that have high counts and are in danger of bombing out(replace queen in the spring). I am sure its a bit harsh on them, but they bounce back and winter well( to be fair I would NOT do that to winter bees) Its hot here in Aug, options are limited if I want to stay away for systentnics. 

4 treatments
Bacandritsos, Nicolaos & Papanastasiou, Iosif & Saitanis, Costas & Nanetti, Antonio & Roinioti, Erifylli. (2007). Efficacy of repeated trickle applications of oxalic acid in syrup for varroosis control in Apis mellifera: Influence of meteorological conditions and presence of brood. Veterinary parasitology. 148. 174-8. 10.1016/j.vetpar.2007.06.001. 
"


> Oxalic acid field trails for the control of varroosis (Varroa destructor) were carried out in an apiary located on the Mt. Imittos (Attica, Greece). The colonies received four successive applications (approximately one every 16 days) with 4.2% oxalic acid (OA) and 60% sugar solution by trickling method with two alternative types of syringes (an automatic self-filling dosing and a single-use) from the broodright to broodless period. The results indicate that the first three applications (from 6th October to 25th November-broodright period) resulted in 65.3% cumulative mite mortality, while only the last application (after the 26th November-broodless period) resulted in 77.3% mite mortality. Very low outern temperatures reduce to the minimum the bee movability, which may result into a slower development of the OA efficacy. No poor colony growth or queen loss were observed even if the bee colonies were received the four successive OA applications with the last one taken place at a very low outern temperature (6.2 degrees C)."


4 treatments
Acaricidal effect of oxalic acid in honeybe(apis mellifera) colonies
Aleš Gregorc, Ivo Planinc
Apidologie 32 (4) 333-340 (2001)
DOI: 10.1051/apido:2001133


> Treatments were applied to twenty-fourcolonies on August 12 as follows: (1)six colonies received a 3.4% OA and 47.6%sucrose in water solution (w/w) using oxalicacid dihydrate (Riedel-de Haën), sucrose(sugar) and de-mineralised water, (2) sevencolonies received 3.7% OA and 26.1%sucrose (w/w) (Nanetti, 1999), (3) sevencolonies received 2.9% OA and 31.9%sucrose (w/w), (4) four-control coloniesreceived de-mineralised water only. Treat-ments were repeated on August 21, August30, when the brood was present, and on October 28 during a broodless period





> In OA treated colonies no queenlessnesswas recorded and worker bee mortality(3.25 ± 1.25 bees/day) five days after Augusttreatments were not significantly differentfrom control colonies (2.5 ± 0.58 bees/day,P> 0.1). Mean bee mortality after OctoberA. Gregorc, I. Planinc336Figure 1. Natural mite mortality per day observed in three pre-treatment periods (groups A, B, C), mitemortality following three oxalic acid (OA) applications in August (group D), post treatment mitemortality per day (group E), one 3.7% OA/26.1% sucrose application on October 28 (group F) andmite mortality following two Perizin applications to all colonies (group G). Groups D and F give themite mortality per 4 days and group G the total mite mortality. Bars indicate standard deviations.
> OA treatment was on average 1.63 (± 1.32)bees/day and was significantly lower thanthat observed after Perizin treatments (11.54± 3.49 bees/day). Over-wintering coloniesand early spring development in the year2000 were normal without visible change



4 treatments 
Gregorc A, Planinc I. (2012) Use of thymol formulations, amitraz, and oxalic acid for the control of the varroa mite in honey bee (Apis mellifera carnica) colonies. J Agric Sci. 56(2): 123–129.


> Experiments were conducted in three apiaries to assess the comparative effi cacy of: Thymovar (Andermatt BioVet AG); Apiguard (Vita Europe Ltd., UK); an oxalic acid solution (OA) which consisted of 2.9% oxalic acid and 31.9% sugar in water; and amitraz fumigation, for controlling the honey bee mite Varroa destructor. Mite mortality increased signifi cantly (p<0.001) in the Thymovar, Apiguard, OA or amitraz treated colonies. The relative mite mortality after: four OA applications, two Thymovar or two Apiguard applications during August and September in the Senično apiary was 41.80% (±14.31), 14.35% (±10.71), and 18.93% (±13.56), respectively.


8 treatments a year for 8 years 
Maggi, Matías & Damiani, Natalia & Brasesco, Constanza & Szawarski, Nicolas & Mitton, Giulia & Mariani, Fernando & Sammataro, Diana & Quintana, Silvina & Eguaras, Martin. (2016). The susceptibility of Varroa destructor against oxalic acid: A study case. Bulletin of Insectology. 70. 


> A commercial apiary composed by 54 colonies of a re-gional ecotype of A. mellifera located at Federal (30°57'4.42"S 58°47'55.78"W: Entre Rios province, Ar-gentina) was selected as biological model for the assays. In this apiary, the OA was topically applied as the sole option for Varroa control during eight consecutive years (2000-2008). Thus, this V. destructor population was considered as the „focal‟ population in our study. An average of eight treatment applications (± one) per year was made


Here is the treatment chart for Varromed, a pre mixed OA dribble aproved in the EU 







It suggests up to 5 treatments in a row and a max of 9 per year


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## LAlldredge (Aug 16, 2018)

Jadeguppy said:


> What mix did you use? Could it have been that the treatment came to late?
> 
> I'm looking to use the mix listed on scientific beekeeping.


I did the same. The mix I used with in keeping with his solution. It wasn't too late. It was in August after my spring/summer treatments. You will find conflicting information about whether or not it's safe. Enough that you may want to try it. I did and will never do it with brood again. It's very effective with no brood.

The biggest difference between this and vapor is in the mechanics of how it's dispersed. Dribbling on the seams puts it right over the bees and brood and potentially right into the cells before capping. So if you imagine a nurse bee trying to feed the larvae, she is having something dripped on her while trying to feed the brood. She is either eating it because she's coated with it, or it's making it's way into the cells of the baby bees. 

The mechanics of vaporizing are different. They fan it, have less opportunity to eat it and it doesn't drip onto the brood. Hey, I know you're seeing articles that make it seem okay. But you don't want to be wrong on this one. Especially at this critical juncture before winter. This is when the culmination of everything you've worked for matters most.


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## Mike Gillmore (Feb 25, 2006)

From Randy Oliver's website.



> As far as winter broodless dribbling, it is absolutely critical to treat them only once, with exactly the right amount and concentration of OA. More than one winter treatment clearly hurts the bees. Charriere and Imdorf (2002) found that colonies treated with 5-6 ml/seam of 3% OA were only 85% the strength of controls by April 25.





> Heinz Kaemmerer of Heilyser Technology says:
> “You can treat your colonies with a liquid mixture of OA and sugar but be careful. The liquid acid shortens the life of the bees. There is no problem during summer because the bee’s life not longer than approximately 6 weeks. The problem starts with winter bees–do not treat your winter bees more than one time with liquid OA. When using liquid OA bees get wet and have to clean each other. The result is, the acid ends up in their stomach and during winter without a cleaning flight it shortens the life of the bees. Two treatments on winter bees might kill the colony. Liquid OA is a slow killer and bees will probably die after a few weeks or month instead reaching the next season.”


http://scientificbeekeeping.com/oxalic-acid-questions-answers-and-more-questions-part-1-of-2-parts/


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## Steve in PA (Jan 26, 2015)

So much conflicting information. No wonder I'm confused.

I only did about half of my hives with dribble. I will do a 2nd round between Thanksgiving and Christmas as well. There are still a decent amount of flying days and they are sure to be broodless. I obviously don't want to lose that half because it is my spring nucs I hope to sell but we'll see what happens. There will be almost 3 months between treatments.


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## Mike Gillmore (Feb 25, 2006)

Steve in PA said:


> There will be almost 3 months between treatments.


You should be fine. Those bees are all gone now.

I certainly understand your concerns about conflicting information. I try to use what little common sense I have and err on the side of caution to keep me out of trouble.


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## Jadeguppy (Jul 19, 2017)

msl, that is great information. Thank you!


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## beebad (Mar 28, 2019)

The company i work for want to do the dribble method in about a month. It is nov.1 today. This morning was 45. In a month it could be COLD. how smart is it to dribble liquid into a hive when it is pretty cold outside?


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## johno (Dec 4, 2011)

Here are some interesting findings from tests carried out by the University of Essexhttps://www.tandfonline.com/doi/full/10.1080/00218839.2015.1106777


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## johno (Dec 4, 2011)

Sorry that did not work out to well https://www.tandfonline.com/doi/full/10.1080/00218839.2015.1106777


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## johno (Dec 4, 2011)

I find the chart with colony strengths 4 months after treatment rather interesting and also the time taken for treatments as the OAV was done with a varrox and the time could be cut at least by a half using the band heater type of vaporizer thereby making it much quicker than any other method especially if the hives are more than a single box.


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## beebad (Mar 28, 2019)

that article was written in 2015. i will read it When I get back to the office to hard to read it on my phone has anyone done the dribble method when it’s cold outside


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## crofter (May 5, 2011)

johno said:


> Sorry that did not work out to well https://www.tandfonline.com/doi/full/10.1080/00218839.2015.1106777


Thanks johno; That was a good long read. My feeling is that their research methodology was top notch. Their final conclusion leaves little doubt that there is considerable advantage to the sublimation method. I have done many high repetitions at close intervals without observing any mortality but would be very reluctant to bodily spray the bees with the liquid at cold temperatures and having them ingest a fair bit of it in the process of getting their affairs back in order. Probably more than a bit of my own emotion in that vision  but I am sold on the vaporizers.

In the experiment they give the application time factor using a tray/wand appliance and it took a bit longer than for dribbling. With the band heater external source device that difference would be far in the other direction!


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## Adamd (Apr 18, 2009)

beebad said:


> that article was written in 2015. i will read it When I get back to the office to hard to read it on my phone has anyone done the dribble method when it’s cold outside


See my reply to your question on another thread. I have been dribbling for 10 or 12 years.


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