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Saltybee "A dribble for a single nuc appeals. Pop, squirt, walk."

Randy - "It is critical to mix and apply oxalic dribble correctly (5 mL between each frame of bees), or you risk seriously harming your bees! Be sure to read:"

You don't have 6 minutes per hive for OAV? No, buy multiple vaporizers and daisy chain power in parallel.
 

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Discussion Starter #3
Working on nucs with brood. Is V much better than D? Plenty of observations, no so much data. Neither is doing the capped.
So I am weighing 3 days x 7 and the likelihood of keeping to that schedule with OAV.
 

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You don't have 6 minutes per hive for OAV? No, buy multiple vaporizers and daisy chain power in parallel.
I got sick of too many incomplete vapes. I'd pull the wand out and it would have a crust on top with half the OA, then I'd have to do it again, even with new OA from the package. I think it was causing my hives to carry too many mites.

I just came in from doing a dribble on a mixture of nucs and full size hives in my home yard. 6 nucs and 2 full sized 8-frame deeps. Done in about 15-20 minutes and I'm confident about the application. I was never confident about the AOV applications and that is why I switched. Time was completely secondary.

Salty, I've only done dribble with sugar and glycerine. I started late last fall with the dribble. My last OA of the year and 1st of spring were both with sugar. If it wouldn't have been for 2 separate bear attacks I probably would have had zero winter losses.

I didn't start using glycerine until I pulled the supers in July. If you search on here I started a thread about VarroMed which is a premix they use in Europe. The glycerine mix in Randy's link above is the same thing minus the Formic acid and colorants, if memory serves correct. Or, Varromed has sugar in it instead of glycerine. I found the ingredients and posted them in that thread.
 

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Working on nucs with brood. Is V much better than D?
nope, other way around
Dribble kills for 2 weeks, vape for 3 days so you get a higher kill with dribble brood on(or incoming fall mites) and you don't have to hold as tight a schedule

A dribble for a single nuc appeals. Pop, squirt, walk.
yep, try a spray bottle
In this video I do 8 nucs in about 3 min
Same Idea as the pump up garden sprayer randy Oliver uses, but with much better control...
1.25ml per pump, 4 pumps gives you 5ml per seam of bees
https://www.youtube.com/watch?v=c3cKxGR5By0
 

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Saltybee "no so much data" - look to European data bases. England's Univ. of Sussex has published using large numbers of hives to compare V versus D. V wins! Especially when looking at Spring build up. They also provided the study to support winter treatments, 14 days apart. I am not sure this works, attaches, but here is a OAV plot for my apiary from last year.

Screen Shot 2020-06-18 at 11.19.15 AM.jpg
 

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msi "nope, other way around" - got a reference or is it observations by you. Also the EPA label has restrictions for number of times to use this method, I believe.
 

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Steve in PA "I got sick of too many incomplete vapes" you have a hardware or process problem. My Varrox never fails, over 1,000 applications. I carry bucket of water with me, cool by dunking my Varrox in between vapes. During my 3minute wait in cooler weather I cool off and wipe clean the Varrox and then repeat. Also be carefu lof the OA you use, some off-the-shelf have other stuff in them. If I had two Varrox OA applicators I could cut my overall time for approximately 10 hives by about 25%, I think, but I do not move as fast anymore.
 

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Discussion Starter #9
msl and Robert,

Going to do a dribble. Amount of sugar is the uncertainty. If I have your graph correctly (bad eyes too) High initial kill and along taper kill. What would be expected.
As an aside, making the assumption that the capped cell mite emergence is a constant, any substantial lasting kill would have a longer lasting steady state kill as each day would have a significant emergence of mites.

http://scientificbeekeeping.com/oxalic-acid-questions-answers-and-more-questions-part-1-of-2-parts/ 2019 update :

More recent studies indicate the the main effect of oxalic upon mites is direct absorption into the mites’ bodies via either the empodia (the sticky inflatable pads on their feet– likely the main route), or directly through their exoskeleton. Absorption through the exoskeleton appears to be dependent upon their being a humectant associated with the acid to allow it to better penetrate a mite’s cuticle — sugar or glycerin appear to serve this purpose. But recent work by Toomema indicate that by simply increasing the amount of dribble applied to the bees, one can decrease the concentration of acid, forego the humectant, and still get a good mite kill (Kalle Toomemaa (2019) The synergistic effect of weak oxalic acid and thymol aqueous solutions on Varroa mites and honey bees, Journal of Apicultural Research, 58:1, 37-52).

I doubt the theory that water only OA is not ingested. Spray a bee with plain water and the others will groom it. Sugerless would be a lot less messy and spraying sugar around has it's own drawbacks. Apparently weak sugar does not work as well, though there would be a sugar/ OA dosage sliding scale I would think.
 

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Saltybee: My opinion - Randy who was anti-OAV, took up a South American idea ( based on low cost) and the idea of a slow release to develop a product that failed.

Second Opinion: The chart is a mix of varroa mite emergence from capped cells and horizontal spreading primarily by robbing. I believe the horizontal robbing dominates in the Fall season.

Third Comment: Data I have read implied Dribble was faster acting than OAV, faster dead drop counts, OAV slower and both essentially useless after 10 days but both having equivalent overall efficacy. The problem is dribble kills more brood and thus restricting multiple applications over time - hard to use theis agaisnt horizontal spreading of Varroa. If you want long lasting effects use APIVAR with supers removed. I just will not do that here. Organic acids are as far as I go with chemical controls, bees, veggie and fruit farming activities. I prefer wasp, snakes, toads and physical barriers, mechanical traps.
 

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Discussion Starter #11
There will be a population drop dribble or no dribble. That is what they do this time of year, not to sure brood kill matters much. Brood weakening, another story. A common treatment story over many methods.

I have found sugarless info, but mostly direct spray of the comb face. Not a true dribble.
 

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Discussion Starter #12
Leaning towards a very weak sugar free dribble/spray. There are other studies that say a heavier saturation of 60 ml per seam has no brood loss short or long term.

https://www.researchgate.net/profil...roa-mites-and-its-influence-on-honey-bees.pdf

In the spraying experiments, 0.5% OA in aqueous solution was as effective as 1
and 1.5% solutions for mite control (Fig. 1) but less toxic to bees (Table 1). Spraying
once or twice with 0.5% OA in aqueous solution, in September 2005, showed equally
high efficacy on mite control (Fig. 2) and little toxicity to bees. We conclude that a
single spray of this concentration and at a dose of ca 25 ml per comb should be used
for effective Varroa control.
 

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got a reference
several were in the video

""The macroCT analysis demonstrated a rapid and consistent distribution of OAD involving a reduction of the individual dosage over time. Even after 14 days, the density of the bees was still significantly higher than prior to treatment, indicating a potential efficacy of at least up to 14 days.
The results from the field trials, where the maximum efficacy against mites was reached ten days after treatment, support this assumption"
https://www.mdpi.com/2075-4450/8/3/84...


In this study with brood we see Dribble killed 49.36% over control and OAV killed 6.76% over control
https://www.apimondia.com/en/compon...UWhxjxLrLtrL6mtB02YHpYuh7vlBa2WE0lxTg9w8DtoAy


outher works commonly show about a 3 day drop window for OAV


http://scientificbeekeeping.com/the-varroa-problem-part-15/
 

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Sugar in the mixtures makes the bees consume the dribbled oxalic acid – which in turn leads to a "leaky gut". Impressive pictures can be found here: https://www.apidologie.org/articles/apido/pdf/2004/05/M4027.pdf

So sugarless is much bee-friendlier.

I use Varromed which does not have sugar in it, but propolis. Sugar was used to make the oxalic acid sticky, so it sticks to the bees and increases contact to the mites. But the sugar is problematic. Varromed uses propolis to make the mixture sticky. With little sugar in it, it is much better on the bee health and multiple treatments can be make without much dead bees. The small portion of formic acid in Varromed prolongs the half-time of the oxalic acid, which makes it more effective for a longer time. I really like the idea behind Varromed. Good engineering.

Another way to stick the oxalic acid to the bees is glycerine as in the recipes from Argentina.

Whatever, I strongly recommend sugarless applications of oxalic acid. Much better on bee health.


PS: The manufacturer of Varromed was forced to produce disinfectants instead of bee medicine...which is why the supply is zero at the moment. :scratch:
 

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In this study with brood we see Dribble killed 49.36% over control and OAV killed 6.76% over control
I've no idea how you came by those figures, but anyway - the document linked to appears to contain a flaw.

Sublimation:
G1 - OA sublimation with Q caging. Yellow - 98.55%
G2 - OA sublimation with brood present. Pink - 14.22%
G3 - Queen caging. Blue - 43.38%
G4 - Control (natural mite fall) Khaki - 13.30%

Dribble;
G1 - OA dribble with Q caging. Green - 89.40%
G2 - Queen caging. Blue - 44.30% (shown as G3)
G3 - OA dribble with brood present. Pink - 23.60% (shown as G2)
G4 - Control (natural mite fall) Khaki - 15.80%


Note: the order of procedures G2 & G3 have been reversed in the listing, but NOT on the graph. Colours are those shown on the bar chart.

Dribble-with-brood (at 23.60%) does contrast with Sublimation-with-brood (at 14.22%), but is 'balanced' by broodless-Dribble (at 89.40%) vs. Broodless-Sublimation (at 98.55%).

Queen-caging and the Controls are near enough identical, and so can safely be ignored.
LJ
 

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Killed my first two nucs doing an OAD series in August. Too hard on the brood. They never recovered. Highly favor OAV. Very different result.
 

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Discussion Starter #18
Killed my first two nucs doing an OAD series in August. Too hard on the brood. They never recovered. Highly favor OAV. Very different result.
At what dose and method?
 

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At what dose and method?
Read Randy Oliver articles and calculations and followed those. It was not done lightly or casually. I used a large shringe to apply at the right amount on the seams. If I remember correctly I did 4 or 5 treatments every 5 days to cover a brood cycle (just like OAV)
 

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Discussion Starter #20
There is a lot of info, including studies that vary in results. Multiple AOD or OAS do result in brood death at any of Randy's dosage levels.
 
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