[johno]

Yes as far as the experts are concerned remember how many years the poor mites had to live off the bees Haemolymph before they were allowed to consume bodyfat. This paper I keep refering to went into the difference between drip and vapor in great detail using the standard sugar OA solution and there was a definite loss in brood with the drip method. I generally try to bookmarkany stuff regarding OA but sometimes the computer does and sometimes it does not but I am still racking my remaining brain cell and keep searching.

 

[wildbranch2007]

took me a while to find this bee-l search leaves much to be desired even when it does work. see #4 4 hours afterwards, all the larvae that had been floating in jelly were removed
see 1. at 3x the vapor dose, larvae from 3-6 days were sacrificed, but replaced with eggs within hours.

Subject:
Why is Oxalic Acid Vaporization harmless?
From:
Ruth Zajicek <[log in to unmask]>
Reply To:
Informed Discussion of Beekeeping Issues and Bee Biology <[log in to unmask]>
Date:
Wed, 30 Oct 2019 18:17:39 -0600
Content-Type:
text/plain
Parts/Attachments:
text/plain (28 lines)
Two years ago, I put a nuc that was failing into my observation hive as a ‘Hail Mary’ effort to save the queen through the winter.

I found the bees covered in mites, with DWV and some progressive paralysis disease. So I used my OxVap to blast the colony with OAV. I tried smaller amounts at first, but that didn’t built enough pressure to shoot the vapor in. So I used the 1gram, 10-frame dose on my 3 frame observation hive. These bees got at least 3 times the recommended dose.

Things I Observed:

1. The bees near the vaporizer fanned, but the rest of the bees carried on as if they didn’t notice.
2. The queen did not pause in her egg laying.
3. Little crystals formed on the bees, comb, and brood throughout the hive.
4. 4 hours afterwards, all the larvae that had been floating in jelly were removed, except for some of the just-about-to-be-capped larvae. The capped brood and eggs remained.
5. By 6 hours, the cleaned out cells had newly laid fresh eggs.
6. The mites rained down over about 3 days time. And after I vacuumed the bottom board, I did not see another mite in that hive (it was winter).
7. The hive continued to limp along for a few more months, with me feeding them honey, and the capped brood and eggs that were covered with crystals hatched and appeared normal.
8. Even after all of the mites were gone, the diseases remained, and the queen probably got the paralysis virus. At first she started looking clumsy when bending her bottom into a cell, then two days later, she seemed to stumble and slip down the comb a bit. A few more days later, she ended up on the floor on her back with only her head and tongue still moving. In workers, it seemed to start with the back legs and move forward through the body. It was gruesome.

My take away:
1. at 3x the vapor dose, larvae from 3-6 days were sacrificed, but replaced with eggs within hours.
2. Even after all the mites are dead and gone, the viruses persisted and appear to be transferred sister to sister and sister to mother.
3. The down-fall of a hive to PMS is brutal to watch up close. What I read as bees suffering, (stuck on back with progressive paralysis) felt intolerable in my living room. And like Randy’s dog analogy, it just seems cruel not to do anything to prevent this fate. I am now an early and aggressive treatment advocate.
4. Keeping the viruses out in the first place is way, way better than treating afterwards. If your hive survives, it may take a full year to purge the viruses, if they ever get fully purged.

 

[Robert Holcombe]

Univ. of Sussex, Brighton, England - multi-year studies, large hive counts, identified proper amounts to apply, OAV better hive performance than Dribble, winter double OAV with 14 day spacing and 99.7% (memory) efficacy, do not remember larva mortality, would if significant - oxalic acid is my choice with spinach, no sugar.

 

[msl]

Univ. of Sussex, Brighton, England - multi-year studies

"towards integrated control of varroa" 1-5 IIRR Toufailia EtAl

OAV better hive performance than Dribble,

certainly what they said, not what their data showed
Towards integrated control of varroa: 2)comparing application methods and doses of oxalic acid on the mortality of phoretic Varroa destructor mites and their honey bee hosts Toufailia EtAl 2016... more or less the OAVers bible, this is the study that popularized OAV and quantified its efivecness.
sadly they manipulated the test conditions and cherry pick the data they use in their conulsution and miss represent findings as significant

as an example here is thier graft, shows dribble coming out on top at 2.25

they kept the OAV wand hot (against the manufactures direction) dumped in the oa and slid it in to the hive all ready smoking to make OAV "faster"
and they they come out saying OAV is much "safer" for the bees when the difference between the two 2.26g treatments was 16 dead bees ... 16 bees out of a full hive

sorry that one is a bit of a hot button lol, people say a lot of things about that study that just isn't true. OAV is GOOD stuff, but its not that much better, only a little

Johno toss this one in your notes
someone finally did an efecintily study on high capacity OA devices, they did very very well compared to traditional pan heaters (witch suprized me) showing that whatever the break down is its not causing a loss of mite killing power, we shale see what the replacates look like https://www.albertabeekeepers.ca/wp-content/uploads/2018/09/2019-Final-OA-vapourizer-report.pdf

 

[johno]

Msl, that does not surprise me as the control that one has and also the temperature information you get while sublimation takes place is far superior to wand technology. The often touted OA breakdown theory is a total falacy with the band heater vaporizer. One needs to know their vaporizer, sublimation temperature indicated is a gauge of the units efficiency provided the sublimation bowl with its thermocouple is light enough to show the quick change in temperature. I can show that the temperature will drop from above the 450's toaround 290 when all the conditions are correct and minimum sublimation time is then achieved, however with just a few microns of oxidization on the bottom of the bowl will find the OA subliming at330 degrees with a lengthier sublimation time but what is actually happening is that the OA is still subliming at the same temperature as in the first example but the oxidization layer prevents an immediate heat transfer. Also bear in mind that the OA sublimes to gas and water vapor and is already condensing into cryatals on the way out of the nozzle which I have proved and have produced a picture of the OA gathering on the hair

s of my arm at around 3" away so you can see why I say OA breakdown is a fallacy.

 

[msl]

The often touted OA breakdown theory is a total fallacy with the band heater vaporizer

Randy Oliver's current work suggests otherwise
and of course, I found why I felt the data was surprizing when I reread it, they weren't playing fair

The cumulative reduction in mite infestation levels of OA (efficiency) was 98%, 94% and 96% in colonies treated
with ProVap, Varroa Blaster and Varroa Cannon, respectively. Across all application methods,after four treatments,

they are comparing 4 provap treatments to get to 98% against studies that used one pan heater treatment (witch has a 50% breakdown, but that counts the 30% or so of the locked-in water ) and got a 97.6% kill rate, dirty pool.
It took 2 provap treatments just to hit a 90% or so kill rate
Devil is in the details, as always and It makes you wonder what there was no control group... seems they went out to prove that the high cap systems kill mites... but many people can tell them that they do kill mites

 

[johno]

In My opinion Randy Oliver is heavily biased against OAV, He once got a whiff of the vapor and is now convinced it is a dangerous material to work with. To make it even worse one of his B-L buddies had an accident with his vaporizer and had hot OA blown onto the face mask he was wearing so that did not help matters much. They will totally ignore the fact that some beekeepers are using only OAV and have been doing so for years with low over winter losses and mite counts. There is the old school that still teaches new beekeepers that mites can be controlled by IPM such as SBB and the Dowda method of sugar shake, and insist that OAV can only be used on broodless colonies during the early winter. Yet they still send their newbies to me to get nucs, so after a while you just give up and do your own thing as nothing changes except the needle to protect the record.

 

[Steve in PA]

Drizzle with glycerine...

The Glycerine Dribble Recipe

I have switched over to dribble. I read an EU study that made me comfortable with minimal brood loss. Another reason I'm comfortable is that Hiveclean and now VarroMed are approved for up to 11 treatments per year.

For me dribble is much easier than dragging out all the stuff for an OAV treatment. Just today I treated an outyard for the last time until I see a problem or pull supers. It's my 1st year switching exclusively to dribble so maybe I will see something that makes me change my mind. I started using it last fall and this is the best my hives have looked coming out of winter in the few short years I've been beekeeping.

If I find the study I read, an Italian one, I will post it later.

 

[msl]

If you read up on it you will find VarroMed is ruffer on bees then standard dribble https://www.ema.europa.eu/en/docume...varromed-epar-public-assessment-report_en.pdf
its main advantage is it shelf-stable (unlike dribble) so it can be sold on shelfs, that means $$ to push it threw approvals, poof it can be used supers on

 

[Juhani Lunden]

In My opinion Randy Oliver is heavily biased against OAV,

opcorn:

 

[crofter]

opcorn:

Juhanni I am uncertain of what your emoticon implies...

 

[Juhani Lunden]

Juhanni I am uncertain of what your emoticon implies...

Well, here in Finland if someone makes popcorn and sits down, it is a symbol for waiting for the coming debate. Maybe a very interesting debate indeed...



(In this particular matter a debate about weather Randy Oliver is biased in his OA opinions.)

 

[crofter]

Well, here in Finland if someone makes popcorn and sits down, it is a symbol for waiting for the coming debate. Maybe a very interesting debate indeed...



(In this particular matter a debate about weather Randy Oliver is biased in his OA opinions.)

Now we are on the same page.

Randy is a great contributor to bee research. A lot of people gain from his easily understood explanations and his well controlled trials. I have not read his recent position on OA but remember thinking some of his earlier work did seem just a little bit over cautious. And I mean just a little. He is not in the position to be encouraging cowboy behavior, so that is understandable.

I dont think many people convincingly argue against the effectiveness of OA during broodless conditions, but they needlessly give it a poor rating on phoretic mites due to the silly recommendation of seven day interval treatment. If mite load is high and brooding is ongoing much tighter schedules needed.

As far as some larval brood mortality I have never noticed it setting back a colony; heavy mite load sure as heck will though! People deliberately instigate broodlessness so why the great handwringing over some minor larval mortality. There is very low colony resource investment in a larva at this stage versus raising a full term bee compromised by varroa.

 

[johno]

In some of Randy Olivers writings he has mentioned that he would not like to expose himself or any of his crew to the dangers of oxalic acid vapor, so he rates the dangers pretty high which is the reason I mentioned the bias. Which basically boils down to the fact that if he feels that it is an undesireable treatment he will not be giving it its due, which is just my opinion. There are also those who will judge OAV against Apivar in treatment for treatment which is entirely unfair as you are equating a miticide that is in the colony for 42 days against a miticide that is in the colony for only 3 days so I would stick my neck out and say that 10 treatments of OAV every 4 days will give you the same results as Apivar without even opening the hive.

 

[Robert Holcombe]

"this is the study that popularized OAV and quantified its efivecness" - timing fits about when I dug-in, but that is not all that I looked at. I do like the critical, quesitoning comments. Europe was using OA dribble and OAV long before this time period, although OAV was late to the table. Italians did some interesting research - twice and influenced me. German field application safety study influenced me. I also go with Jennifer Berry's experience and decision resulting in selection of OAV (ABJ or was it Bee Culture?). Most opposition to OAV, I noticed, was fear of gases (and ignoring formic acid issues). This is not an issue for me and I notice Randy is changing his tune - pedal to he metal and all gassed up now. A fair amount of negative comments were put out there about OAV including by some research people. Besides I like the idea of attacking Varroa via deposition and horizontal spreading / contact. I get the competitive efficacy of both methods and a choice is typically made, few do both.

I admit to lightly reading the statistical part but did notice your comment, so my memory tells me. A bit of publish or perish going on? But reports fail to explain the statistical models, sensitivity analysis of same and they name so many model - programs my head spins. So I have not dug into that mathematical rabbit hole. It has been four years since reviewing and searching about OAV. Probably time to do it again but I prefer working the humidity - temperature issues of a hive's enclosure as I have "cleaning" it down pat for now.

Advantages of OAV from a novice's practical point of view;
1. OAV does not go through the gut of the bee like dribble does, takes a while, if I remember right, for isotopes to clear out of the bee when "dribbled" treated.
2. OAV cleans the hive too, (is it possible?)
3. OAV treatments in Fall and Winter without exposing the cluster,
4. Efficient application , fast, apply practically anytime ( except with supers on - an unsupported requirement from what I can find - copy job of Canadian requirements) based on a temperature - efficacy related issue. (It helps to have a few acres, John Deere Mower with a trailer and a barn to be efficient.)
5. Can be used on packages, ( I do not buy them anymore but people I help do.)
6. Dribble has EPA limited number of application ( gut issue?)
7. OAV is less concentrated per dose and but slower acting than dribble (but longer lasting?)
8. I now have a lot of observational experience OAV ( zero with dribble) - all good; nine for nine this year but a hive has a drone laying, 1st year, late summer Queen.
9. I refuse to use "chemicals" like Amitraz here, treatment free was a disaster, OAV and drone culling with Varroa inspection / counts in drone cells as an indicator works well for me. OA is ubiquitous, half life is short and essential for bowel movements .
10. Christmas to early Jan. OAV treatment(s) works well here - no treatments until Fall robbing season; drone culling and inspection in between. I can Fall feed syrup while treating and supers are off - perfect timing.
11. In either case, we still do not know exactly how oxalic acid kills Varroa (still true?)
12. How are thoracic mites killed? Efficacy for either method? (Not enough money in selling oxalic acid?)

Now that OAV is much more popular, I watch for new negative or supportive data as I can change my mind. I also make better observations now. The voting seems positive so far for OAV. In my area most do not use OAV but dribble as earlier comments about the dangers of OAV and wand cost drove newbies selection.

 

[Robert Holcombe]

:thumbsup: I asked my MD internist about OAV. He asked if I eat it! As it is free choice and my memory is failing as well as the German study i often forgt to bring 1/2 mask.

Funny the EPA never provided performance requirements for the 1/2 mask. I do wear wrap-around glasses or safety googles.

 

[Robert Holcombe]

Selling tickets?

 

[msl]

1- corect.. but dribble kills for 2 weeks not 2 days and going threw the gut may be bad for the bee, it seems to cause a shed of lineing cells to knock back nosema levels, espicaly in the next genuration
2 never hurd that
3 yes... but the "recommended" effective temp range for dribble is lower than OAV, so you can treat in colder conditions.
4 not really unless you drop $$ on a band heater system I can dribble a hive in under a min with a $1 syring and be back in the truck when treating a small yard before my band heater vap would have heated up
5 It can not by law, has to be dribble spray see label.... if you mean instaled packages dribble works just fine
6 often said, but internet BS, see the EPA lable https://www3.epa.gov/pesticides/chem_search/ppls/091266-00001-20151013.pdf Now I wouln't hit winter bees 3x with dribble... but there is no need to.. there are commercial opps in other countries doing 8 a year
7 reverse OAV dubble deep dose is 2g, dribble is 1.75g oav kills for 2-3 days dribble for 2 weeks OAV kills a tad bit more when bloodless, dribble significantly more brood on do to its longevity catching mite as they emerge for a longer period of time. brood on single dribble kills as many mites as 3 OAV treatments
8 I don't think anyone is saying it doesn't work
9 Amitraz has a MUCH shorter 1/2 life
10 yep, but for the reasons I give in #1 and #7 I use dribble for my late summer knockback to fight the mite bombs (in low-pressure yards I can get by with a spring split and single winter dribble) and knock back nosema, then rotate to OAV for winter use to avoid negative impacts on the long-lived winter bees
11 correct
12 I am not sure many care

Now that OAV is much more popular, I watch for new negative or supportive data as I can change my mind.

yep, that is the smart play

There are also those who will judge OAV against Apivar in treatment for treatment which is entirely unfair as you are equating a miticide that is in the colony for 42 days against a miticide that is in the colony for only 3 days so I would stick my neck out and say that 10 treatments of OAV every 4 days will give you the same results as Apivar without even opening the hive.

a fair argument, what is the difference between an extended-release strip constlily dosing the hive every day and aplying a treatment every 4 days?
Aside from it being illeagle pestiside abuse(witch can change) the issue would be the over the top OAV users tend not to rotate treatments and stick with a single mode of action. Time and time again this has proven a poor plan against the mites, and indeed most pests.

 

[johno]

Msl if you were doing that quick dribble in my yards I would expect you to be there for more than half the day and be pretty tuckered out when you are done as my colonies are that large that when I have removed my honey and start treatments most of my colonies are 3 boxes high, many have 4 boxes. My vaporizer will reach operating temperature in 2 minutes and while heating caps will go out onto the first 6 hives. The total time for a yard of 24 will be less than 25 minutes and I would not have had to spend maybe a half hour mixing up my dribble before hand. By the way I was born in the sub tropics so spent many years stomping on roaches and I believe the roaches have still not become resistant to being stomped on. As to whats legal or not I pay more attention to the laws of physics not so much the crap that comes out of Washington.

 

[JWPalmer]

I was going to post something about repeated mechanical damage, ie, stomping, being a bit different than poisoning. I have not found a fly yet that was immune to a flyswatter.