# What percent of a mite load is too high?



## rbees (Jun 25, 2012)

So...a little back story.

I treated my hives with Formic Pro last week of July. Around the middle of August I did alcohol washes to determine if it was effective and what infestation percent was present. I sampled prolly 60-65 percent of a total of 30 hives to get a realistic sampling. The highest percent I got was 4 mites/300 bees with most just one or two per 300 bees sampled. I was quite happy with what I saw.

Today I sampled 6 and got a high 8/300 bees which in my mind seems pretty good considering the brood nest consist now of 2 center frames in single boxes of nine frames.

I also have 10 five frames that were not treated and one came back with a 7 percent mite load. In those hives I would guestimate maybe 100 - 150 sq2" of brood covering both sides of the center frame with very little open brood. I did not see any signs of brood cannibalization but one DWV bee. I plan to OA dribble all of those soon.

So my main question is, what percent of a mite load is too high when the queen has practically stop laying as she preps for winter? and a side question can I dribbles soon and then again say early December? It is not uncommon to have mild spells late November early December where I have the bees.

I'm 30 miles south of Seattle.


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## ifixoldhouses (Feb 27, 2019)

1%, you probably broke out the big treatments too early.


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## GregB (Dec 26, 2017)

10g ~ 100 bees

Source:


http://www.bregalnica-ncp.mk/wp-content/uploads/2020/08/Alternativni_metodi_Varroa_ENG.pdf


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## rbees (Jun 25, 2012)

ifixoldhouses said:


> 1%, you probably broke out the big treatments too early.


The one percent level was observed in mid August after I treated in July, I didn’t to counts prior to treating as historically that has been when I see increasing mite levels. Late July or early August is when the summer nectar dearth arrives snd that is when I do my summer treatment.


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## ifixoldhouses (Feb 27, 2019)

I do OAV 3 times in the Summer, and wait on the pricey treatments till late Aug early Sept., or they will just get reinfested.


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## crofter (May 5, 2011)

ifixoldhouses said:


> I do OAV 3 times in the Summer, and wait on the pricey treatments till late Aug early Sept., or they will just get reinfested.


Problem with that is you are allowing mites to keep spreading virus in the mean time. It has been often said that it takes two rounds of brood clear of virus effect before the winter brood is nursed. Quoted as time needed for the viral titre to drop after mite removal.

I agree that reinfesting after you think they are all gone could lead to the winter bees to be carrying a damaging level of varroa.

Why limit summer treatments to 3? To heck with the expense; give it to them!


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## dtpeck (Sep 16, 2021)

In a sense, you obviously want as few mites as possible at all times. However, you're exactly right that higher mite levels at this time of year are expected as the amount of brood in the colonies goes down. Your mite monitoring method only counts the phoretic mites, and with fewer brood cells you can expect a larger percentage of the moderate mite population to be in the phoretic stage. You could certainly treat now, but the published treatment thresholds generally would suggest that October mite levels of about 2.7% are not high enough to predict that your bees will likely die from mites and mite-associated viruses this winter. However, I would say those hives are great candidates for a winter oxalic acid vaporization or oxalic acid dribble, since either method will let you clean up those mites while they're riding the winter bees, and will prevent them from causing trouble (and starting to grow their numbers) next spring.


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## ifixoldhouses (Feb 27, 2019)

crofter said:


> Problem with that is you are allowing mites to keep spreading virus in the mean time. It has been often said that it takes two rounds of brood clear of virus effect before the winter brood is nursed. Quoted as time needed for the viral titre to drop after mite removal.
> 
> I agree that reinfesting after you think they are all gone could lead to the winter bees to be carrying a damaging level of varroa.
> 
> Why limit summer treatments to 3? To heck with the expense; give it to them!


Well honeys on till late July, then I oav 3 times over 3 weeks, and put Apivar or Apiguard etc on to where it ends treatment at the end of Sept when the Bees that raise the Winter bees are emerging.
been working so far. That stuff is expensive for 25-30 hives.


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## username00101 (Apr 17, 2019)

Anything getting above 3/300 bees in the fall is bad.

A few years back, when other mite bombs were in the area, a solid % of them were 5% in the fall, none of them perished in the winter.

They were down to 0% by November.


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## crofter (May 5, 2011)

3 OAV's 7 days apart? Yes the Apivar is pricey. With your shorter winters you can probably tolerate a higher % mite load but the lower the mite levels average, it helps keep viral levels from rising. This can sneak up over a period of several years. Dont get complacent. Some operators have been hit with the 5 year collapse. Some several times. There has been a fair bit of chatter about the paralytic virus occurances being on the rise.


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## ifixoldhouses (Feb 27, 2019)

crofter said:


> 3 OAV's 7 days apart?


Yes, then I OAV on Thanksgiving, Christmas, and 3 times in the Spring, then they are good to go till the supers come off, plus I try and use VSH bees as well.


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## crofter (May 5, 2011)

The adherence to the 7 day spacing, is that adherence to letter of the law or do you feel that is optimum bang for the buck? I would feel I was leaving a lot of money on the table.


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## ifixoldhouses (Feb 27, 2019)

crofter said:


> The adherence to the 7 day spacing, is that adherence to letter of the law or do you feel that is optimum bang for the buck? I would feel I was leaving a lot of money on the table.


Meh, it knocks them back till I get the big treatment on.


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## rbees (Jun 25, 2012)

dtpeck said:


> In a sense, you obviously want as few mites as possible at all times. However, you're exactly right that higher mite levels at this time of year are expected as the amount of brood in the colonies goes down. * Your mite monitoring method only counts the phoretic mites, and with fewer brood cells you can expect a larger percentage of the moderate mite population to be in the phoretic stage. * *You could certainly treat now, but the published treatment thresholds generally would suggest that October mite levels of about 2.7% are not high enough to predict that your bees will likely die from mites and mite-associated viruses this winter. * However, I would say those hives are great candidates for a winter oxalic acid vaporization or oxalic acid dribble, since either method will let you clean up those mites while they're riding the winter bees, and will prevent them from causing trouble (and starting to grow their numbers) next spring.


That's kind of what I'm thinking as I fully expected to see an increase in the wash as the brood nest has significantly reduced. I am, however, a bit nervous at that one fiver that came back with a 7 percent load. 

Anyahoo...I did a OA dribble on the five frame nucs today, and even though its contradictory to you should not OA dribble more than once a year I plan to do another OA dribble sometime mid November when little to no brood should be present.


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## rbees (Jun 25, 2012)

username00101 said:


> Anything getting above 3/300 bees in the fall is bad.
> 
> A few years back, when other mite bombs were in the area, a solid % of them were 5% in the fall, none of them perished in the winter.
> 
> They were down to 0% by November.


If I'm reading your post correctly, you had many in the 5% range after late September, but knocked the back to a close to zero, with out any ill effects stemming from the mites?


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## Lee Bussy (May 28, 2021)

dtpeck said:


> Your mite monitoring method only counts the phoretic mites


That's not correct. Mites infest the nurse bees, they are not phoretic at that time. As a matter of fact, there's a fair argument that they are never phoretic willingly.

When you do a wash, you are getting a count of any mites found in the sample; both actively feeding, and those seeking another gig. It is a representation of the infestation rate, not a count of those moving around.



rbees said:


> Anyahoo...I did a OA dribble on the five frame nucs today, and even though its contradictory to you should not OA dribble more than once a year I plan to do another OA dribble sometime mid November when little to no brood should be present.


The reason OAV is generally considered safe is that bees do not ingest the OA. Multiple dribbles can kill a significant number of your bees:


Oliver said:


> 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.


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## crofter (May 5, 2011)

_"That's not correct. Mites infest the nurse bees, they are not phoretic at that time. As a matter of fact, there's a fair argument that they are never phoretic willingly."_

Here I think you are quibbling about semantics. 

I think the term phoretic, in its strict definition does not entirely convey the significance to varroa and bees. The general take away seems to mean that whenever they are _not under cappings. _ While they are not under cappings, whether they are moving on their own power or hitching a ride, they are greatly susceptible to treatments.

_"When you do a wash, you are getting a count of any mites found in the sample; both actively feeding, and those seeking another gig. It is a representation of the infestation rate, not a count of those moving around"_. This I agree with.


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## username00101 (Apr 17, 2019)

We base treatment on the # of mites/300 bees.


it's not a way to determine the exact # of mites in every cell on every larva in the entire colony.


Based on that metric, we prescribe treatments.

Sort of like doing a lice test on humans, see a few lice? Well that's bad, time to treat - they don't go in and count every single lice to determine exactly what % of lice are on the entire skull....


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## GregB (Dec 26, 2017)

rbees said:


> should not OA dribble more than once a year


What about - one should not dribble the *same *bees more than once?
Think of the population turn over.


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## rbees (Jun 25, 2012)

LBussy said:


> The reason OAV is generally considered safe is that bees do not ingest the OA. Multiple dribbles can kill a significant number of your bees:


Yes...I realize the literature states that multiple dribbles hurts the bees, but high loads especially will likely kill them off by late winter. I don’t like having to treat twice, but I like having empty boxes in late winter much less. I’ve looked for information about how much harm there really is to the bees with multiple dribbles spaced 30 days, but didn’t find much other than uts not recommended. If anyone can shed lightbin how bad it is to multiple dribble kate in the year, that would be great


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## rbees (Jun 25, 2012)

GregV said:


> What about - one should not dribble the *same *bees more than once?
> Think of the population turn over.


I have thought of this aspect but the bees currently in the hives are what will be there for the winter until new bees begin to hatch


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## GregB (Dec 26, 2017)

rbees said:


> I have thought of this aspect but the bees currently in the hives are what will be there for the winter until new bees begin to hatch


Well, exactly.
Ideally you want to dribble them once AFTER they stopped brooding.
The whole point of the OAD - it should be applied while brood-less for the least possible damage and the most possible efficacy (90%).

So seems to me (and something I would do myself) the proper OAD application is:

sometimes in early/mid summer - while working on the rebuilding/expansion of your apiary and conveniently having brood-less colonies
sometimes in late fall when the colonies already stopped brooding.
This should rather be normal planned activity which just happens along the flow and NOT an after-thought/catch-up hassle.


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## Lee Bussy (May 28, 2021)

crofter said:


> Here I think you are quibbling about semantics.


Well, maybe? And here I am arguing semantics about semantics.  I think though that we should endeavor to use the proper terms because they indicate different things. If you really see phoretic mites, it probably means they can't find enough places to eat in your hive and that's a whole other crisis. However, where I made my point was to be careful to point out it's the ones buried in like a tick we are counting as well. Maybe we need new words.


rbees said:


> I’ve looked for information about how much harm there really is to the bees with multiple dribbles spaced 30 days, but didn’t find much other than uts not recommended. If anyone can shed lightbin how bad it is to multiple dribble kate in the year, that would be great


I linked you to Randy Oliver, generally considered authoritative, and he provided a reference to peer-reviewed research.


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## Lee Bussy (May 28, 2021)

Interestingly, I just came across this article with guidance on how and when to treat:

_Can Honey Bees Survive Varroa Mites? The Challenges, the Tactics, the Future_, by Leslie Mertz, Ph.D. and Cameron J. Jack, Ph.D.


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## crofter (May 5, 2011)

I get a different impression about how _buried in like a tick, _they really are. Mite washes with alcohol, dawn dish soap water tsp per gallon, Oxalic acid dust, icing sugar dust, all seem to knock them off dependably for count. Could you be making an assumption that is not borne out in fact? I am not claiming authority here by any means. I just sense preconception, on either my part or your part, is tugging at the picture

As far as using proper terms.......... what do you do if the common terminology is not precisely correct for an isolated situation? My feeling is that different contexts are being taken on the term phoretic. Until that point is defined ( common defining terminolgy), debate is non productive.


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## clyderoad (Jun 10, 2012)

Is all this dribble talk assuming sugar syrup and oxalic acid solution?
It is worth noting that using glycerin as the solvent instead of sugar syrup has a very different effect on the bees when dribbling OA for varroa control.


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## crofter (May 5, 2011)

clyderoad said:


> Is all this dribble talk assuming sugar syrup and oxalic acid solution?
> It is worth noting that using glycerin as the solvent instead of sugar syrup has a very different effect on the bees when dribbling OA for varroa control.


Yes it appears that the bees are not fooled by something we think is sweet! Glycerin does not get ingested by the bees or stored in honey. I have not calculated what cost it would add to a dribble vs using a sugar syrup carrier. Anyone?


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## GregB (Dec 26, 2017)

crofter said:


> Yes it appears that the bees are not fooled by something we think is sweet! Glycerin does not get ingested by the bees or stored in honey. I have not calculated what cost it would add to a dribble vs using a sugar syrup carrier. Anyone?


$25/gallon
Cheap for a small scale hobby setup.
Kosher too. 









Amazon.com: SMPLY. 99.7% Pure USP Vegetable Glycerin - Food Grade, Kosher Certified (1 Gallon) : Industrial & Scientific


Buy SMPLY. 99.7% Pure USP Vegetable Glycerin - Food Grade, Kosher Certified (1 Gallon) on Amazon.com ✓ FREE SHIPPING on qualified orders



www.amazon.com


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## crofter (May 5, 2011)

GregV said:


> $25/gallon
> Cheap for a small scale hobby setup.
> Kosher too.
> 
> ...


Oxalic Acid Treatment Table - Scientific Beekeeping Link to article by Randy Oliver. Info on mix of glycerin to water to replace the sugar syrup component of the more familiar sugar syrup OA dribble. Quck figures less than an ounce glycerine for a 50 ml dribble so 20cents or so per dribble. Someone else please check those figures.


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## GregB (Dec 26, 2017)

crofter said:


> Oxalic Acid Treatment Table - Scientific Beekeeping Link to article by Randy Oliver. Info on mix of glycerin to water to replace the sugar syrup component of the more familiar sugar syrup OA dribble. Quck figures less than an ounce glycerine for a 50 ml dribble so 20cents or so per dribble. Someone else please check those figures.


So, 1 gallon ~ 3800 ml.
$25/3800 ~ 0.66cents/ml - for GLY.

Let's call it 1cent/ml of ready mix to include everything that costs (OA, GLY, work) - before water added.
So a penny/ml of GLY is probably a good estimate

(GV: this was a mistake; should be much less; 20-25cents per 50ml of final mix) 
50ml --> 50 cents to treat a hive 

OR: ~$4 to make this batch - "35 grams OA + 600 ml warm H2O + 400 ml GLY."
400ml GLY + OA --> ~$4.
Water is free.

You can treat a lot of hives with this little batch for $4.
All in all - it is cheap; no matter how you shave this.

The recipe is taken from:








Oxalic acid with Glycerin dribble


I am planning on doing the oxalic acid with Glycerin dribble per Randy Oliver to my new nucleus colonies at the appropriate time when there is no cap brood. I would like to hear from anybody who has done this.




www.beesource.com


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## rbees (Jun 25, 2012)

clyderoad said:


> Is all this dribble talk assuming sugar syrup and oxalic acid solution?
> It is worth noting that using glycerin as the solvent instead of sugar syrup has a very different effect on the bees when dribbling OA for varroa control.



I am not familiar with the use of glycerin as a delivery for OA dribble and its effect on bees. Is it much easier on the bees and can they tolerate successive applications?


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## Lee Bussy (May 28, 2021)

crofter said:


> I get a different impression about how _buried in like a tick, _they really are. Mite washes with alcohol, dawn dish soap water tsp per gallon, Oxalic acid dust, icing sugar dust, all seem to knock them off dependably for count. Could you be making an assumption that is not borne out in fact?


I did not mean to imply that they would not be washed/rolled off. I was using that term to apply to those actively feeding vs those mobile for whatever reason. I think the test is effective on those as well given the little experience I have and the research I've been able to do.

Yes, I have individually examined all of the bees after a couple of washes, and I was unable to consistently demonstrate that the wash was not effective (and I have no desire to go through that tedium again.) Mites I found on the bees and not in the feeding location were free-floating and found on the bees only as a result of the wash being less than 100% effective due to the manner in which I did it.



crofter said:


> As far as using proper terms.......... what do you do if the common terminology is not precisely correct for an isolated situation?


Rage against the machine?  I guess we just hope that the smart folks doing this research recognize that the term is not (always) correct, and make a distinction that will fit and become used.

I wonder if it's important to us (the terms)? I think in some cases it is. If a large number of mites are migratory on the bees, then that suggests the colony is just a dead bee walking. The classic picture everyone has seen with a mite on a bee's head is scary if you think about it. It means that mite was unable to successfully feed on that bee and needs a new host. That mode _is_ phoresis, and in my mind, that's the scariest situation.

We can probably assume that the poor bee in the picture already is being fed upon by a different mite, and the mite on its head is looking for a host not actively being fed upon. In that ultra-small sample of one, that's a 200% infestation rate. Again, not scientific, not accurate for the superorganism, but (probably) accurately describes that classic picture.



rbees said:


> I am not familiar with the use of glycerin as a delivery for OA dribble and its effect on bees. Is it much easier on the bees and can they tolerate successive applications?


Read the article Crofter shared. It gives the information available now and also suggests that OA dissolved in water may be simpler and more effective. The point being "we think" the bees will not consume it and then further hypothesize that it will be less harmful to the bees. The fact is, we don't know right now. It's also not an approved treatment in the US.

In my head, I would think a dribble even without sugar would be consumed in part as the bees groom themselves. They do not want to be wet. They don't want to eat it because there's no sugar but neither do they want to take feces in their mouths but they do to clean the hive. My guess (not a hypothesis, I'm not that smart yet) would be that it would be at least marginally more dangerous to the bees than vaporization.

Why are you against vaporization? It seems you are dead set on using the OA, and likewise plan more than one treatment. Why not use the method found to be the least harmful so far?


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## crofter (May 5, 2011)

The article Greg linked to by peterthebeekeeper suggest no consumption of the oa / gly drench by the bees or contamination of honey. I can project a vision of them getting that or feces in their mouth and spitting it out, wiping their lips and hands on their sleeves and shaking their little heads. This has to be just as good as your imagined vision. We have to be careful with our visions that they dont become part of the virtual reality, when as you said, we dont know right now. Dont lead the jury.

I dont know who is referred to as being dead set against OAV; certainly not me. It could be a decent alternative to someone who did not have vaporizing equipment. I think it a possibility that it may hang around on the bees a bit longer than the effects of the vaping. Pretty commonly accepted that OAV effectiveness gets somewhat dodgy after about three days. Would the water borne OA dribble be as effective / enduring as the glycerine content vehicle?


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## Lee Bussy (May 28, 2021)

crofter said:


> We have to be careful with our visions that they dont become part of the virtual reality, when as you said, we dont know right now. Dont lead the jury.


Well, I make sure my profile indicates my experience ... being very little at this point. I might be leading the jury, but that assumes the jury is here. As Randy Oliver would say, more research is necessary. 



crofter said:


> I dont know who is referred to as being dead set against OAV


I was referring to rbees.

On that note, let me put a plug in for anyone here who has gotten any information off Randy's website to drop him some money for a cup of coffee: Contact Me - Scientific Beekeeping You can set up a recurring donation as well.



crofter said:


> Would the water borne OA dribble be as effective / enduring as the glycerine content vehicle?


I think all we know is what's in Randy's page that you linked us:


Randy Oliver said:


> A recent study by Toomema (https://doi.org/10.1080/00218839.2018.1486695), suggests that the oxalic dribble can be equally effective if a more dilute solution of OA _*in water alone*_ (5 g OA dihydrate/1 L water) is applied at the greater rate of 20 mL/comb space of bees, rather than 5 mL.


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## jim lyon (Feb 19, 2006)

A good discussion here with lots of well thought out opinions. I’ve come to the conclusion the surest way to good winter clusters are a good late flow and an effective mite treatment/treatments put on as early as possible. Even with that, it seems some years are worse than others and it’s not always in direct proportion to mite loads. I’ve come to blame it on viral loads though lack of nutrition can play a part and I would never totally discount pesticide exposure. In short, anything that unduly stresses hives, coupled with varroa has a synergistic effect.


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## GregB (Dec 26, 2017)

LBussy said:


> Why are you against vaporization?........ Why not use the method found to be the least harmful so far?


Care about *your own* health maybe? 
Besides OAD dirt cheap and low tech (vs. the OAV).

The difference is huge at the application level while the bee impact is marginal if any.


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## Lee Bussy (May 28, 2021)

GregV said:


> Care about your own health maybe?


Hold your breath and close your eyes, vape, run. Simple.


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## GregB (Dec 26, 2017)

LBussy said:


> Hold your breath and close your eyes, vape, run. Simple.


Default answer - use the PPE (which too costs money).
A common issue - people don't and every one knows it.

There was a recent talk where most every one came out and told their own story of taking in a "lungs full" of oxalic. So yeah.
Here, found it for you:








 Oxalic Acid protocol


This morning I went to start an Oxalic Acid Vaporization treatment. I recently go a new band vaporizer. It has little cups that you put the oxalic acid into before you start the treatment. I made the mistake of thinking that because I wasn't heating up the unit it was OK to not don my face mask...




www.beesource.com





But I am sure you will be different. LOL.


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## Lee Bussy (May 28, 2021)

GregV said:


> But I am sure you will be different. LOL.


I hope I am. I’m not going to say I’ve never made a boneheaded move, but I do have the proper PPE and plan to use it.


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## johno (Dec 4, 2011)

You have to be something else to get lungs full of OAV, Those who do had better not go swimming. at the first whiff of OAV exhale and move away then you can breathe when you are in clean air, simple as that barring accidents but the same applies. 77 years old and have been using only OAV getting on for 9 years now with no ill effects form the few whiffs I have got over the years. Common sense is required for this kind of work and if you do not have any you should not be beekeeping anyhow. I would expect that there would be far more dannger of developing a sudden allergy and going into shock than being seriously damged by OAV. There have been no fatalities to date fom OAV I believe, but there have been fatalities to from bee stings, so for all you folks who are concerned with OAV I take it you all carry an epipen around.


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## AHudd (Mar 5, 2015)

Speaking of mites, I just ran across this today; https://entomologytoday.org/2019/02/21/inside-look-how-varroa-mite-diet-discovered/

Alex


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## jim lyon (Feb 19, 2006)

AHudd said:


> Speaking of mites, I just ran across this today; https://entomologytoday.org/2019/02/21/inside-look-how-varroa-mite-diet-discovered/
> 
> Alex


That is fascinating to see but whether their diets are hemolymph or fat I’m not sure that it changes anything from a treatment perspective. The best treatments are always those that affect a pest’s ability to reproduce.


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## ursa_minor (Feb 13, 2020)

johno said:


> There have been no fatalities to date fom OAV I believe, but there have been fatalities to from bee stings, so for all you folks who are concerned with OAV I take it you all carry an epipen around.


Epipen, yup I do carry one in my bee box, they are cheap insurance and the one I currently have does not go out of date for 3 years. I carry it not for myself but for those, including grandkids, who might be allergic. We are many miles from help and I have been well schooled in how to protect those around me.

Fatality is not the only issue. As we age lung or esophageal conditions such as cancer, COPD, chronic pneumonia and a host of others could be waiting in the wings. I marvel at people who see immediate health incidents as the only threat from a substance such as the vapour from OAV.

I don't doubt that you are fine doing OAV and have incredible knowledge about it. But for other people the risk to their health is not worth a method that seems to be needed repeatedly in quick succession to gain any control over the mite population, which, I might add, increases the beekeepers exposure and the chance of accidents.


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## AHudd (Mar 5, 2015)

jim lyon said:


> That is fascinating to see but whether their diets are hemolymph or fat I’m not sure that it changes anything from a treatment perspective. The best treatments are always those that affect a pest’s ability to reproduce.


It made me think of the mode of action the flea pill I give my dog utilizes. The poison is stored in the fat layer, not her blood. Someone may come up with something that can be fed to bees that is stored in their fat bodies instead of hemolymph to kill the mites or to possibly render the mites sterile. Who knows.

Alex


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## Lee Bussy (May 28, 2021)

Maybe - the first thing that comes to my mind is what else relies on the fat body, namely vitellogenin synthesis. A mammal's fat is just stored energy, a bee's fat body is more like our liver.


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## rbees (Jun 25, 2012)

LBussy said:


> Read the article Crofter shared. It gives the information available now and also suggests that OA dissolved in water may be simpler and more effective. The point being "we think" the bees will not consume it and then further hypothesize that it will be less harmful to the bees. The fact is, we don't know right now. It's also not an approved treatment in the US.
> 
> In my head, I would think a dribble even without sugar would be consumed in part as the bees groom themselves. They do not want to be wet. They don't want to eat it because there's no sugar but neither do they want to take feces in their mouths but they do to clean the hive. My guess (not a hypothesis, I'm not that smart yet) would be that it would be at least marginally more dangerous to the bees than vaporization.
> 
> Why are you against vaporization? It seems you are dead set on using the OA, and likewise plan more than one treatment. Why not use the method found to be the least harmful so far?


I’m not against vaporization, I just don’t have a power source where I have the bees. Being that I live in Seattle snd the bee yards are a good drive away, frequent trips are time consuming and due to my schedule can only be done on the weekends.
Ok so if I read the article correctly, multiple dribble of OA/Gly does not harm the bee appreciably. I’m I reading that correctly or am I missing something?


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## clyderoad (Jun 10, 2012)

rbees said:


> I’m not against vaporization, I just don’t have a power source where I have the bees. Being that I live in Seattle snd the bee yards are a good drive away, frequent trips are time consuming and due to my schedule can only be done on the weekends.
> Ok so if I read the article correctly, multiple dribble of OA/Gly does not harm the bee appreciably. I’m I reading that correctly or am I missing something?


You are reading it correctly. 
It has proven so in my experience with using glycerin.


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## rbees (Jun 25, 2012)

LBussy said:


> Maybe - the first thing that comes to my mind is what else relies on the fat body, namely vitellogenin synthesis. A mammal's fat is just stored energy, a bee's fat body is more like our liver.


I would say that is the primary purpose of the fat body is to produce yolk and perhaps other precursor proteins needed for metabolism.


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## rbees (Jun 25, 2012)

clyderoad said:


> You are reading it correctly.
> It has proven so in my experience with using glycerin.


Thank you


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## Lee Bussy (May 28, 2021)

rbees said:


> I’m not against vaporization, I just don’t have a power source where I have the bees.


Not that it's as convenient as an extension cord, but the majority of the more budget-prived vaporizers use 12V. Even if you don't have another battery, I assume you drive up there and could use your car/truck battery.



rbees said:


> Ok so if I read the article correctly, multiple dribble of OA/Gly does not harm the bee appreciably. I’m I reading that correctly or am I missing something?


You read it right, I think you stopped before you got to the end:


Randy Oliver said:


> A recent study by Toomema (https://doi.org/10.1080/00218839.2018.1486695), suggests that the oxalic dribble can be equally effective if a more dilute solution of OA _*in water alone*_ (5 g OA dihydrate/1 L water) is applied at the greater rate of 20 mL/comb space of bees, rather than 5 mL. The above dose applies about half as much OA to the bees, but the greater amount of solution likely results in better dispersal.


So if you're going to go the dribble route, you don't necessarily need to use the glycerine.

I found the article Randy linked to be pretty interesting as well. It's worth a read.

Also, please do pay attention to the ranging he gives:


Randy Oliver said:


> _*This application method is not currently registered for use in the United States.*_


It's something to be aware of either way.


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## rbees (Jun 25, 2012)

LBussy said:


> Not that it's as convenient as an extension cord, but the majority of the more budget-prived vaporizers use 12V. Even if you don't have another battery, I assume you drive up there and could use your car/truck battery.
> 
> 
> You read it right, I think you stopped before you got to the end:
> ...


I have thought about purchasing a vaporizer and am...I just haven’t pulled the trigger. The last few years my go to mite treatment has been Apivar but it has lost its effectiveness. Last year was pretty hard and this year I focused on colony health were everything else was secondary. I gave come to the conclusion that the needs of the bees come first.

Regarding the OA dribbling I’ve never heard of a different delivery system other then sugar syrup and now I reading that successive dribble applications may not be as detrimental as previously thought and for those who responded including you I thank you.


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## Lee Bussy (May 28, 2021)

rbees said:


> I have thought about purchasing a vaporizer and am...I just haven’t pulled the trigger.


They are inexpensive if you can wait a few weeks for delivery:









11.6US $ 10% OFF|Bee Keeping Oxalic Acid Vaporizer Treatment Varroa Mite Beekeeping Vaporiser Supplies For Beekeeper Hive Tools - Beekeeping Tools - AliExpress


Smarter Shopping, Better Living! Aliexpress.com




www.aliexpress.com





You'll notice the picture in that listing is (I'm pretty sure) the Varrox branded item. The one they are selling there does not have the flat "ears" that the Varrox has. You might want to keep that in mind, but for $10 and a couple of bucks shipping, it may be worth it to experiment.

I like to support local (or at least in the same country) business when I can, but sometimes it pays to try more things for less. Then when you settle on a direction, you can invest in quality.


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## jim lyon (Feb 19, 2006)

rbees said:


> Regarding the OA dribbling I’ve never heard of a different delivery system other then sugar syrup and now I reading that successive dribble applications may not be as detrimental as previously thought and for those who responded including you I thank you.


Having done quite a bit of OA dribbling let me say it seems to stress a hive in relation to its size. Large hives shrug it off without any apparent affect while small hives don’t tolerate it well at all and have a wet appearance even a couple days post treatment.


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## LAlldredge (Aug 16, 2018)

I have a different threshold for winter. Too many is over 1%. My winter bees have to live longer with less brood being raised. I also prefer testing using a dead drop count with my sticky boards after a single dose of OAV. Then I go to mitecalculator.com to translate that to a percent. I also don't like going into the stack when they want to propolize and seal it up. I'm under 1% (.08 was the highest) for all so no late series needed for October. I keep an eagle eye out though so if I pull a board and see more mites it means they are going after a mite bomb. The late fall is the trickiest since they can look clean in August.


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## crofter (May 5, 2011)

LAlldredge said:


> I have a different threshold for winter. Too many is over 1%. My winter bees have to live longer with less brood being raised. I also prefer testing using a dead drop count with my sticky boards after a single dose of OAV. Then I go to mitecalculator.com to translate that to a percent. I also don't like going into the stack when they want to propolize and seal it up. I'm under 1% (.08 was the highest) for all so no late series needed for October. I keep an eagle eye out though so if I pull a board and see more mites it means they are going after a mite bomb. The late fall is the trickiest since they can look clean in August.


My philosophy on mites certainly falls in line with this. My last test OAV on one colony a couple of weeks ago showed 3 mites on a sticky board. I may do one more vape since I am not absolutely sure all brood had emerged at the time of the last shot. To heck with the expense. They may have picked up a hitchhiker or two!


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## Zippy69 (Sep 5, 2021)

rbees said:


> I’m not against vaporization, I just don’t have a power source where I have the bees. Being that I live in Seattle snd the bee yards are a good drive away, frequent trips are time consuming and due to my schedule can only be done on the weekends.
> Ok so if I read the article correctly, multiple dribble of OA/Gly does not harm the bee appreciably. I’m I reading that correctly or am I missing something?


There is a lithium battery module available for oxalic acid. Per the site can treat 10 hives on one charge. It’s a bit pricey for me as I’ve power cord availability. Varrox Eddy :: OxaVap – Your Source for Oxalic Acid Vaporizers


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## Zippy69 (Sep 5, 2021)

LBussy said:


> Hold your breath and close your eyes, vape, run. Simple.


Or get a quality respirator and for gods sake…..shave the beard😉


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## bricknerdn (Dec 5, 2020)

crofter said:


> Problem with that is you are allowing mites to keep spreading virus in the mean time. It has been often said that it takes two rounds of brood clear of virus effect before the winter brood is nursed. Quoted as time needed for the viral titre to drop after mite removal.
> 
> I agree that reinfesting after you think they are all gone could lead to the winter bees to be carrying a damaging level of varroa.
> 
> Why limit summer treatments to 3? To heck with the expense; give it to them!


If you can find the February issue of the American Bee Journal, read the article "Mite Control While Honey is on the Hive - Part 4" by Randy Oliver. Within his article, he posts the results of mite treatments via vaporization by a Florida beekeeper, Edward Lutman. Lutman's trial showed that he could not get control of the mite population until he did the vaporization treatments every 2 days, not 3 times a summer. This means whether you did dribble or vaporization, you would have to treat a colony every 2 days for 11 consecutive applications, which provides exposure to the emerging mites over a 21 day female brood cycle.

The formic acid treatments should be the last treatment of the season.


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## bricknerdn (Dec 5, 2020)

GregV said:


> $25/gallon
> Cheap for a small scale hobby setup.
> Kosher too.
> 
> ...


You can buy a 5 gallon pail from Bulk Apothecary a whole lot cheaper than $25 per gallon.


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## GregB (Dec 26, 2017)

bricknerdn said:


> You can buy a 5 gallon pail from Bulk Apothecary a whole lot cheaper than $25 per gallon.


Sure.
The point still is - cheap.

5 gallon maybe too much for a small hobbyist too.
Besides standard storage frame for glycerin is 24 months.


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## ursa_minor (Feb 13, 2020)

bricknerdn said:


> This means whether you did dribble or vaporization, you would have to treat a colony every 2 days for 11 consecutive applications, which provides exposure to the emerging mites over a 21 day female brood cycle.


Talk about tied to the hive, that sounds like a lot of work and dedication and no summer holidays if you are a hobby keeper LOL.


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## username00101 (Apr 17, 2019)

it's definitely a lot of work, hence why 50% overwintering survival is not unusual in these parts.


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## William Bagwell (Sep 4, 2019)

GregV said:


> 5 gallon maybe too much for a small hobbyist too.
> Besides standard storage frame for glycerin is 24 months.


Freezes well for long term storage. Plus there are other 'hobbyists' besides beekeepers who use glycerin. Can think of two, soap makers and DIY vapers. (nicotine not oxalic acid) Should be easy to find someone to split an order with.


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## Lee Bussy (May 28, 2021)

bricknerdn said:


> If you can find the February issue of the American Bee Journal, read the article "Mite Control While Honey is on the Hive - Part 4" by Randy Oliver.


If you have a digital subscription, that article is here.



GregV said:


> Besides standard storage frame for glycerin is 24 months.


I believe that's because being "food safe" it's considered a good product and subject to expiration dates where none may really be needed.


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## bricknerdn (Dec 5, 2020)

GregV said:


> Sure.
> The point still is - cheap.
> 
> 5 gallon maybe too much for a small hobbyist too.
> Besides standard storage frame for glycerin is 24 months.


You are right. I buy in larger quantities and resell to our bee club members at cost. That way we all get our supplies at the lowest prices. Some products can be stored (maybe not glycerin) for a very long period in a freezer without degradation, like the Mite Away Quick Strips. We picked up a supply of 2019 and 2020 vintage strips at a bargain this year that had been stored in a freezer. I weighed them and they weighed the same as the new 2021 strips I also bought and they had not lost any weight and were as pungent as the 2021 strips when opened.

The oxalic acid purchased in 10 pound quantities on Amazon from Florida Laboritories drops the per pound price below $3 a pound compared to the same product Mann-Lake is selling at 10 times the price.


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## GregB (Dec 26, 2017)

ursa_minor said:


> Talk about tied to the hive, that sounds like a lot of work and dedication and no summer holidays if you are a hobby keeper LOL.


This is why I am testing a single OAD application this season.
Broodbreak combined with OA - a single hit.
And the broodbreak is nothing but a part of regular splitting/queen raising process anyway.

I have no time or desire to be running around treating, treating, treating.
Ain't no time or desire.
There has to be economical threshold beyond which the busy work just does not pay anymore.


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## GregB (Dec 26, 2017)

LBussy said:


> I believe that's because being "food safe" it's considered a good product and subject to expiration dates where none may really be needed.


Good point.
Only makes the vegetable, food grade glycerin even a better option.


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## GregB (Dec 26, 2017)

William Bagwell said:


> Freezes well for long term storage.


I was not aware; need to double-check this.
Well, then I like this glycerin thing even better.


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