Once a hive has been OAV'd when does it go dormant? Undoubtedly less than seven days. Also is it the vapor only that kills them or the residue, i.e. crystals?
My understanding is that the vapor recrystalizes when it cools down. I'm not sure what you mean by dormant.
When does what go dormant? The oxalic acid or the hive? I don't believe the OA goes dormant at all.
As I understand it, as the vapor cools, it forms crystals, so if you see a puff of white coming from the hive while vaporizing, you're seeing crystals.
Don't know if this in any way answers the questions, but it's just what I can contribute from my meager knowledge of the subject.
What I'm trying to ask is at what time is the OA no longer any good for killing mites. I'm thinking if we have to repeat it every 7 days then there must be a life span on it. Otherwise we'd do it once and that'd be it. Just curious.
It only kills mites outside the cells and then the bees clean it up is my understanding so we have to reapply to regenerate new crystals for the next batch of hatch outs.
Quote from: KeyLargoBees on September 07, 2016, 04:36:26 PM
It only kills mites outside the cells and then the bees clean it up is my understanding so we have to reapply to regenerate new crystals for the next batch of hatch outs.
That's my understanding, as well -- that it has no effect inside cells and the bees take out the "trash," so we have to repeat the treatment.
After the above, I was rereading some of the articles Randy Oliver has written about OA. And found this written in 2007:
"Radetzki found that mite kill takes place in the first week, and tapers off for the next two weeks. One manufacturer claims: ?Without brood one vaporizer treatment is more than 95% effective (note: this is not much better than a good OA dribble) and with a follow up treatment, your bees should be almost mite free.? Some Europeans use it regularly during the summer. Sounds to me like a strategy to develop oxalic-resistant mites?"
i wonder if he still thinks mites could become oxalic resistant. It does throw the idea some of us have into question, but I don't see how something that's basically mechanical could stimulate resistance. Back to my earlier analogy (maybe in another thread) of smashing the mites with a brick, some mites might survive getting smashed, but the next time they meet a brick, they aren't tougher as a result of their first encounter.
My understanding is the OA is most effective on days 2 and 3 after a vapor treatment. The mites are phoretic for 5-11 days, so a 7 day cycle will get most of the just emerged suckers. Even drone brood that is capped for 14+-1 days is covered by 7+7+(2 or 3).
It is said the bees haul it out like trash, but it is a very fine crystal after vaporization and I'm sure it takes a while. It is considered safe to put supers back on after 10 minutes, so the crystals aren't floating in the air at that point.
It is my understanding that with some of the earlier mitecides tried, varroa developed resistance in the first season. Some others develop resistance in the 2nd season.
So far, I have not read about any evidence that varroa have developed any resistance to OA, whether dribble or vaporized, after being used for about 15 years, first in Europe, then in the U.S. I have not read of any evidence of varroa developing resistance to formic acid treatments, either. Perhaps I've missed the evidence. So what is all the hand wringing about OA resistance?
For the mites to build up 'resistance" to OA they would have to develop some sort of acid proof clothing like humans do... Kind of silly way to put it, but it would be similar to you trying to build up a resistance to sulfuric acid without protection from gloves or clothing, every time you pour it onto your skin it will react the same and destroy flesh.
Much different for medication type poison which over time your body can adapt to....
Quote from: Nugget Shooter on September 11, 2016, 04:05:01 PM
For the mites to build up 'resistance" to OA they would have to develop some sort of acid proof clothing like humans do...
Does the honeybee have this clothing? OA is a chemical that appears to give good mite kill results. It is not known to date how the acid works to achieve this result and it not know what the long term side effects are. We like the short term results so it's use has grown in popularity. A lack of knowledge is not a good reason to not be suspicious of the long term side effects.
Nope they do not.... And leaves one to ponder doesn't it? Is the damage the bees see minor enough to not cause the hive as a body more problems than the mites? Apparently so from what has been seen over many years use and as with the mites the damage is instant and not something that will lessen or build up over time. It is an acid and acids are very specific as to what they will dissolve, burn, or destroy.
So that said there is no real long term build up in the bees short lives, nor is there a build up of resistance in mites or bees to OA. What again is the damage to bees? Good question and I wonder if anyone has done a study to that affect and perhaps dissected a bee or two exposed. I searched online and see nothing so far, but years of use has shown very little problems with bees properly treated hives and instead the overall health of the hive improves as a result.
We are left with few choices then, no treatment, chemical poisons, or Oxalic acid... For me as a new guy with mites here in Arizona I choose for now to use OAV and once I fully understand managing my bees and understanding the full cycle feeling that not treating would result in disaster. As I learn and grow I may look at treatment free, but there is allot to learn before I will feel comfortable with that.
Interesting point you brought up Nugget shooter, I guess we would have to start with killing a few bees with OAV then look at them through a microscope to see the damage. After we do that then lessen the OAV with a different set of bees and keep going down until we kill mites only. Then we could compare what the first kill looked like compared to the bees who survived when the mites different.
Does any identity have any documentation on what a healthy mite looks like compared to those killed by OAV?
someone that has had experience with powdered sugar dusting tell me why this does not work on mites especially with an oil pan under the hive. I have been killing shb by the hundreds in oil with a double sbb, screen on top and under the oil pan bee proof,
Here's a tidbit from a post on my forum that may answer that question, acebird. That's why I belong to a half dozen or more forums. There's good info on all of them.
""The crystals sit on the hairs on the bees body they also sit on the hairs on the varroa
The bees can just groom them off (they do not eat them)
The varroa has sticky pads on its feet these collect the acid crystals
The varroa cannot groom the crystals from their body
If you put the varroa under a microscope after treatment you will see the crystals on the feet and body""
Quote from: iddee on September 12, 2016, 02:58:45 PM
Here's a tidbit from a post on my forum that may answer that question, acebird. That's why I belong to a half dozen or more forums. There's good info on all of them.
""The crystals sit on the hairs on the bees body they also sit on the hairs on the varroa
The bees can just groom them off (they do not eat them)
The varroa has sticky pads on its feet these collect the acid crystals
The varroa cannot groom the crystals from their body
If you put the varroa under a microscope after treatment you will see the crystals on the feet and body""
Thank you and this explains allot.... Man so much to learn.
paus, I can only guess, however I'm thinking that the powder sugar just doesn't kill a high enough percentage of the mites. Therefore their population recovery time isn't that long. With the OAV I've read that as much as 97% of the mites are killed.
All I can say for sure is that I've been doing it for 4 seasons and it's worked every time, not only worked but worked well.
The powdered sugar doesn't kill them. Only lessens their ability to hang on and they fall off.
well daaaahhh, thanks Psparr. I let that one get by me (lol)
Just call me still mixed up. The powered sugar makes the mites fall off. In a screen bottom board or in an oil pan as I use aren't the mites dead. Isn't the sugar a source of nutrition for the bees?
If they make it all the way to the tray. Good chance they will catch another bee on the way down.
Powdered sugar isn't healthy for bees.
You are correct, paus, EXCEPT, if the sugar removes 50 bees per day and the hive raises 75, what good does it do? Sugar helps, but is very inefficient.
Quote from: paus on September 13, 2016, 03:28:07 PM
Just call me still mixed up. The powered sugar makes the mites fall off. In a screen bottom board or in an oil pan as I use aren't the mites dead. Isn't the sugar a source of nutrition for the bees?
They will die if they fall into oil and they will die some time after they fall on a dry tray or bottom board because they can't get back on a bee. Ants and other critters will clean them up if you don't. Some ants can cause problems in a hive so the powdered sugar could be a bad thing.
Scientific Beekeeping:
Powdered Sugar Dusting
The practice of routinely dumping powdered sugar into beehives has become the rallying call of the Varroa impaired. Coat your bees with powdered sugar and Madam Mite will lose her grip and fall to her demise through the open screened bottom board, or so the theory goes.
In actual practice dusting with powdered sugar does only one thing. It removes somewhere between thirty and forty percent of the Phoretic mites from their temporary adult bee hosts. That?s it! During the active brood rearing months, approximately sixty percent of a colony?s mite load is in the capped brood, dusting has absolutely no affect on this segment of the population. The Phoretic mites that are removed through the dusting process are replaced as the colony?s mature brood emerges, hence the need to dust on a regular basis. It?s a vicious cycle, with literally no end in sight! A 2009 study out of Florida found that dusting colonies with 250 ml (1 cup) of powdered sugar at two-week intervals, over the course of ten months ?did not significantly reduce the total number of mites per colony, the number of mites per adult bee, or the number of mites per capped brood cell.? Furthermore, even though the test colonies were dusted throughout the relatively broodless winter period, there were still no ?significant differences in mite populations between dusted and undusted colonies.? In addition, the study appears to confirm earlier work by others ?that at lower mite densities, the reproductive rate of Varroa increases. Therefore, the mite may be able to compensate for population loss due to dusting by increasing its reproductive rate.?2
Powdered sugar dusting is at best a labor intensive short-term means of Varroa control. I refer to the dusting procedure as the here and now, or pay as you go method. Its only long-term benefit is a false sense of security, which will be replaced by disaster once you stop dusting. Like its predecessor, the screened bottom board, this method of controlling Varroa is an idea whose time has passed. Serious beekeepers need to advance their agenda and strive for realistic longterm solutions to the Varroa dilemma.
Bee Informed page:
Always be sure to monitor your bees for varroa mites so that you know the mite load before you prophylactically treat your colonies. If you treat with the same synthetic chemical at each treatment, this continual exposure may cause the mites to develop resistance to that specific varroacide.
Additionally, treatments can negatively impact honey bee larval development and adult life span and should be applied only after the mite levels have crossed the threshold for treatment. That threshold is different for different operations. It is not likely that mites will develop resistance to a naturally occurring compound such as formic or oxalic acid as these acids desiccate mites and it is difficult to see a resistance developed to this mode of action.
Quote from: GSF on September 12, 2016, 02:04:08 PM
Does any identity have any documentation on what a healthy mite looks like compared to those killed by OAV?
Here are the pics: I imagine a lot of the damage issue has to do with a bee having an exoskeleton and a mite being soft tissue...
(http://i65.tinypic.com/2ug09li.jpg)
Underside of varroa mite (one leg is missing) taken using a scanning electronic microscope Photo credit: Bee Informed Partnership
(http://i63.tinypic.com/2u6off7.jpg)
That bottom picture looks like what acid would do to skin.
Quote from: Psparr on September 13, 2016, 03:50:26 PM
If they make it all the way to the tray. Good chance they will catch another bee on the way down.
Powdered sugar isn't healthy for bees.
Store-bought may not be healthy for bees, but if you run granulated sugar through a blender to make it super-fine, it doesn't have the corn starch that the store stuff has, so it's just sugar. Is sugar not healthy for bees?
Quote from: Dallasbeek on September 21, 2016, 09:24:08 PM
Quote from: Psparr on September 13, 2016, 03:50:26 PM
If they make it all the way to the tray. Good chance they will catch another bee on the way down.
Powdered sugar isn't healthy for bees.
Store-bought may not be healthy for bees, but if you run granulated sugar through a blender to make it super-fine, it doesn't have the corn starch that the store stuff has, so it's just sugar. Is sugar not healthy for bees?
From what I understand powdered sugar whether it has corn starch in it or not. If it gets on the lava it will dry it out.
BEE HAPPY Jim 134 :)
Here's why no treatments work very well:
http://www.bushfarms.com/beesvarroatreatments.htm
Any treatment that is only marginally effective works even worse.
Quote from: Michael Bush on September 22, 2016, 10:05:25 AM
Here's why no treatments work very well:
http://www.bushfarms.com/beesvarroatreatments.htm
Any treatment that is only marginally effective works even worse.
And this makes no treatment good why? Maybe it is just my night shift brain fog or my ignorance... but I will admit... I don't get it :embarassed: Maybe I can read it when I am awake and understand....
With the varroa mite, there are basically 3 approaches to the problem:
The first is that being peddled by supporters of 'The Establishment' - that is, that only patented (and therefore expensive) products should be used, regardless of their efficiency, toxicity and so on.
The second is the opposite of this - that Vapourised Oxalic Acid (which, incidently, enters the hive as a fine crystalline powder produced by the action of vapourisation, and is NOT a vapour or gas as many believe), which - although the initial cost of the equipment is high - then costs mere pennies per treatment, safe (for the bees), non accumulative and thus non-toxic. But again - 'The Establishment' have decreed that in your country only Oxalic Acid Dihydrate with the right label (creating yet another monopoly) can be used - but not the regular, 'off the shelf' stuff which is exactly the same - and far cheaper.
The third approach is not to treat, and either a) select out hygenic queens and sell them at a good price (even though the hygenic characteristics are not guaranteed to persist, so it may be an expensive and temporary 'Band Aid' solution. Or, b) adopt a Typhoid Mary, 'I'm Alright Jack' approach, in which an apiary develops a working tolerance to Varroa, whilst continuing to harbour viable numbers of the mite, which then go on to spread Varroa infestation to neighbouring apiaries.
I don't have a mite problem - never have - but then I use VOA. I'm fairly sure that many of my colonies have developed hygenic behaviour, but I continue to use VOA on all colonies nevertheless, in order not to infect colonies outside of my own apiary.
LJ
Quote from: little john on September 23, 2016, 05:23:50 AM
non accumulative and thus non-toxic.
I am not convinced of either. The acid has to go somewhere and seeing as it is readily dissolved in water I think a lot stays in the hive and a whole lot is accumulating outside the hive.
Quoteb) adopt a Typhoid Mary, 'I'm Alright Jack' approach, in which an apiary develops a working tolerance to Varroa, whilst continuing to harbour viable numbers of the mite, which then go on to spread Varroa infestation to neighbouring apiaries.
I believe the opposite happens. If you cannot kill all the mites, and you cannot, then the stronger ones are left to go infest your neighbors hives. The "I'm Alright Jack" approach allows the weaker bees to die and doesn't build a stronger mite. LJ why are some "I'm Alright Jack" approach beekeepers succeeding? Why hasn't Europe been free of mites if OA really works? If OA did work it would not just be legal we would be forced to use it on every hive to exterminate the mite. But 30 or so years has proved that it is just another band aid that builds dependency AND is dangerous to the user which in many cases is unqualified to preform the task.
I run screened bottoms but leave my inserts in for a week after a treatment...i see fine crystals on the board that have fallen through the screens....so for me Ace the VOA drops down to the insert/ground and is blown or washed away....in a hive with a solid bottom i am not sure what would happen to it but I bet the bottom board will be squeaky clean with no stains on it :-)
According to some posts that I have read the bees carry out the crystals and dump them outside the hive, how far I don't know.
What I surmise is that the acid will not stay in the crystallized mode if it is in the presence of water. We know up here that condensation is quite prevalent in the spring and fall when this method of killing mites is mostly used. That suggests that some OA does not get carried out of the hive and then the question is well where does it go or get consumed?
What the brainiacs tell me. Some of the OAV reconstitute to formic acid. Who knows this is true or not.
BEE HAPPY Jim 134 :smile:
Quote from: little john on September 23, 2016, 05:23:50 AM
The second is the opposite of this - that Vapourised Oxalic Acid (which, incidently, enters the hive as a fine crystalline powder produced by the action of vapourisation, and is NOT a vapour or gas as many believe),
Agreed, which cause the respirator confusion if you use one. The OA goes through sublimation for a very short time and then quickly cools and becomes a particlate (so I have read) . The white cloud you see is indeed a particulate so a P95 cartridge should be good. But why not take the conservative approach if you are going to VAO and get a OV/P95/AG combination. Then there is no doubt. IMHO
Just completed my 1st OAV treatment on my 3 hives. Very happy with the results.
Uphere in the Yukon the queens have pretty much stopped laying so my hives were mostly broodless (less than 1/4 of one side of one frame). I had one infested hive (pre-treat mite drops of anywhere from 10-50 mites per 24h, the other two hives (1st years) had 0-5 mites per 24h)
Results: (the boards were cleaned after every check)
Hive 1 24h (500-700 dead mites after treat); 48h (+500 mites); 72h (300-400 mites); 96h (200-300 mites); 120h (30 mites)
Hive 2 24h (100 mites); 48h (140 mites); 72h (35 mites); 96h (25 mites); 120h (1 mite)
Hive 3 24h (17 mites); 48h (80 mites); 72h (20 mites); 96h (20 mites); 120h (2 mites)
I will be conducting a second treatment tomorrow to see how effective the treatment has been and too make sure most mites are dead. We've had frost every morning for the past 2 weeks with morning lows of -5C and daily highs of 12-16C. The hives are pretty much ready for winter with ~100lbs of honey and they will have a medium of with 1.5" of fondant as security. I use poly hives and I will put on an extra bubble foil wrap this year....I have a feel that it will be a cold one this winter.
Photo for day 5 and the setup. I use poly hive so I did the treatment through the screened bottom board. I will use slightly more OA as recommended as some of OAV crystallizes on the metal mesh of the screen board. I also run it for 3 mins instead of 2.5 mins as recommended.
Yukon said
"Photo for day 5 and the setup. I use poly hive so I did the treatment through the screened bottom board. I will use slightly more OA as recommended as some of OAV crystallizes on the metal mesh of the screen board. I also run it for 3 mins instead of 2.5 mins as recommended."
Please explain how you vaporize "through the screened bottom board". Do you have it sealed under the SBB or is it open?
If you look at the pictures of the hive painted red. I keep a piece of plywood underneath of the hive where I place the vaporizer and I use old t-shirts to seal the side and rear openings and the front entrances. You need to remove your insert.
Okay, I see it now. Do you leave the SBB on the hives all winter up there? Nice looking hives.
Yep... I also overwinter without the tray inserted. The condensation drains out of the hive through the SBB. I put piece of 2x4 to cover the sides though to keep the mice out from underneath the hive. Once snow falls I pile snow all around them for extra insulation/wind protection. I lean a piece of plywood on the front to protect the entrance from getting buried in snow.
Cozy. Does it warm up enough for cleansing flights after the snow gets piled up?
Maybe late Feb if we get a warm spell. They are pretty much stuck in the hive till late March with 1st willow pollens mid April (still snow on the ground though).
Quote from: Dallasbeek on September 21, 2016, 09:24:08 PM
Quote from: Psparr on September 13, 2016, 03:50:26 PM
If they make it all the way to the tray. Good chance they will catch another bee on the way down.
Powdered sugar isn't healthy for bees.
Store-bought may not be healthy for bees, but if you run granulated sugar through a blender to make it super-fine, it doesn't have the corn starch that the store stuff has, so it's just sugar. Is sugar not healthy for bees?
Pouring any sugar around my hives would bring ants from the next county and I battle them enough now with the local critters.