How many of you fellow beekeepers think OAV is a benign substance in your hives?

[lazy shooter]

First off, let me state that this question is not to evolve into a heated argument between treated and untreated philosophies.  I have read so many pros and cons on this issue that I am perplexed.  I would like to think that OAV will kill mites in my beehives without leaving a harmful residue and without killing too many beneficial organisms.  Some of my bees are into their third year without treatment of any kind, other than feeding sugar syrup.  This is the year that mites most often kill untreated hives, hence my questioning of OAV.

Will OAV breed more resistant mites?

[iddee]

Go to the last post on "types of treatment" by Marbees.
http://www.worldwidebeekeeping.com/forum/index.php/topic,557.0.html

The important thing is, treating hives with oav will not lead to resistant mites. The amount of oa in honey does not increase with oav treatment. If oa is going to strengthen mites, it will happen naturally, with or without treatments.

[Jen]

Thanks Iddee, that's a good confirmation. When I found my one and only hive had a dangerous mite level late last fall, I took one week of serious butt time to figure how to treat or not treat. Randy Oliver, scientist, was my greatest help. Youtube, he is fascinating, and traveling the world to help with the dismal bee situation.

Oxalic Acid, Formic Acid, and Thyme/Thymol were the treatments that were the most successful at dropping mites 'right now', and not harming the bees, wax, or honey.

My first treatment was NOD formic acid sticky strips, very easy to use, and very effective. Then I bought a oa vaporizer and that will be the tool for me from here on out.

[robo]

Oxalic Acid, Formic Acid, and Thyme/Thymol were the treatments that were the most successful at dropping mites 'right now', and not harming the bees, wax, or honey.

Formic Acid is the "better"  choice as it can penetrate capped brood and kill the mites,  whereas OA does not get the capped mites.   Formic Acid is much more expensive since your only real option is the Mite-Away pads thanks to formic acid now being a controlled chemical due to it's use in illegal drug manufacturing.    With that said,  OAV performed exceptionally well for me when I used it.

[Jen]

Rob- ""Formic Acid is the "better"  choice as it can penetrate capped brood and kill the mites,  whereas OA does not get the capped mites.""

The one thing about formic acid is it needs to be applied in temperatures around 60-70. And yes it's great in getting the mites out of the cells and off of the larvae. But it does kill the bees that have a lot of mite damage and it kills some larvae. You will find this in front of your hive after the 7 day treatment.

Website instruction with oxalic acid say to do treatments when the hive is broodless. So an early fall treatment, and a treatment just before brooding kicks in again in the spring is a perfect way to treat and not worry about the bee and larvae kill.

Both are effective and natural tools for mite kill, I would choose either depending on the circumstances, like the time of year.

Rob ~ always appreciate your input!

[Crofter]

That might be late fall and very early spring to catch the bees broodless. In warmer climates there might be no totally broodless time. You should still do very early mite counts in case you have to do multiple OA treatments before honey supers go on. If you do hve supers on, I have heard of pushing the bees out of supers with fume board and bee escapes then pull the supers, cover and do a vaporization. You can put the supers back on in a few hours and your honey will be good to go. You cant do that with thymol or Formic strips or pads.

[Perry]

Actually, with the MAQS you don't even have to remove your honey supers.

[GLOCK]

There's a lot of guys that treat with OAV with the honey supers on but I would not plus you should treat when there's low brood  or no brood and that's early spring and late fall so no honey supers to worry about.
One thing is to make sure ya get a good vapor .

[Perry]

Up here where we are allowed to use Oxalic, it is not allowed with honey supers on.
Funny how rules can be so different for neighbours.

[GLOCK]

Up here where we are allowed to use Oxalic, it is not allowed with honey supers on.
Funny how rules can be so different for neighbours.

Funny not approved here but I told my inspector I was OAV and he asked how it was working out and was going to give it a try .

[Jen]

Yes! I have heard of beekeepers telling the inspectors that they use OA and none of them have made an issue about it. Come On US!

[Slowmodem]

Funny not approved here but I told my inspector I was OAV and he asked how it was working out and was going to give it a try .

That sounds like what our state inspector told me last year about BT.  It works great but it's illegal.

[Perry]

I knew a keep up here, a friend actually, and we both got a surprise visit from Health Canada department. (you know, the big dark suburban vehicle!).
(I thought) they got to me first, asked questions at my home, had me show them where I stored my treatments in the basement, took pictures, etc. Then he asked me to take him to my closest yard, and open up 2 random hives, took pictures, said everything was good and left!
When I got home there was a message on my answering machine from my friend "warning" me they were on their way to see me! (just a little late!  )
Anyways, when they went through his hives with him, he had been using something allowed in the states but not up here.
All they said was "You do know that's not approved up here?". When they were done, they said everything was good and left!
This had nothing to do with any beekeeping inspection or anything, although the guy did have his own suit. I think it was just some kind of snap health thing to see if anything untoward was going on.

[DLMKA]

The inspector in my region will not officially tell you to use OA but when he's not wearing his inspector cap swears how well it works. I don't treat my hives and I've got better survival rate than most of the folks around here that do treat. All my bees are from swarms and "survivor" stock too where just about everyone else I know just gets queens mail-order out of CA or down south. 

[lazy shooter]

First things first, thanks to all you for responding.  Secondly, it appears to be a benign substance, but I do note that many regions of the US and Nova Scotia have some restrictions on its use.  That's a red flag to me.  I don't think the various governments are necessarily correct.  In fact, I am mostly a contrarian to what the feds in our country believe.  Still, the governments aren't always wrong.  This coupled with so many opposing views, makes me wonder.  To me the jury is still out.

One positive that has come out of this thread is that apparently there is good evidence that the OAV does not contaminate the honey.

Again, thanks to all of you for the many replies.

[ShepherdsWatchFarm]

The 3 studies I've read say formic doesn't penetrate brood cells. It would have to be brushed on the cappings in order to penetrate the cells.

[Crofter]

The 3 studies I've read say formic doesn't penetrate brood cells. It would have to be brushed on the cappings in order to penetrate the cells.

Are you referring to oxalic acid perhaps? I agree OA does not penetrate cappings but I have only seen the odd post and no studies saying that formic acid needs brushing on cappings to be effective on capped brood.

[Jen]

Hey Shep- From what I have read extesively is that formic does penetrate the cells, which is good because it kills the mites that are living on the larvae. So formic is good to use in the summer. Then use the OA in the fall and spring when the hive is broodless.

[ShepherdsWatchFarm]

It's just what I've read. I've never conducted any experiment myself:

http://apisenterprises.com/papers_htm/BC2003/Formic_acid1.htm
"Formic acid appears to be a good candidate because it is a relatively small compound with a molecular weight of 46.03, which may be responsible for reports that it can penetrate brood cappings and kill mites sealed in the cell (Mr. Ruzicka says it actually must be brushed on the cappings to be effective). "

http://www.biosecurity.govt.nz/pests-diseases/animals/varroa/paper/varroa-treatment-options.htm#9
"It is suggested that formic acid is able to kill varroa in capped brood cells as well as on adult bees. Tests where brood combs were fumigated in closed plastic foam boxes at 50ml for 1 hour killed 100% of mites in the brood cells with 90% of brood surviving the treatment48. However, vapours may not be sufficient to produce similar results in field conditions.

 "Adverse Effects: Use of Formic acid gel resulted in removed drone eggs, delayed drone production and reduced adult drone survival (24% survival at 10 days old vrs. 49% for controls). Unlike fluvalinate, formic acid did not reduce drone weight or weight of glands.

 "Surviving drones had higher levels of sperm than controls33. Formic acid may also have adverse effects on open brood and hatching bees, depending on ambient temperature and device used, although loss of brood did not have a negative effect on colony overwintering in mid-European conditions92. Formic acid produced the highest rate of adult bee mortality (35.3 bees/hive/day) of 6 substances tested52. "

http://scientificbeekeeping.com/the-arsenal-natural-treatments-part-1/
"Formic vapors dissipate throughout the hive, killing phoretic varroa mites (but few in capped cells)..."

[Jen]

Okay Shep, I'll take a look at these. I like to see what others are reading. I'll get to ya.