[1954Lincoln]

I have all the equipment for applying the OA to the hives. I did a test to see how long it takes to completely sublimates and it took 4.5 min for a 1/2 tsp for 2 brood chambers. Because of the hot temps 95+ we are starting dearth.
I just have a couple of questions:

1. What is the best time of day? Does anyone apply it right before sundown?

2. Do I start the application 8 weeks before first frost (Nov4) and add 21 days to it (Aug22)?

3. For the 21 day application I read a post where they talked about it. The poster replied that he did one extra on the 25th day and then [email protected] Christmas. I can't remember the span between applications. I could not find the post I read because I came across it by accident. What span of days is recommended?

People have recommended that I try to hook up with a club. (Montgomery county) I have a crazy work schedule where it is hard to be off when clubs hold meetings. There used to be a Honey salesman along 105 a couple years back but I have not seen him lately. I will keep reading.

Thanks everyone for helping on this site! By the way I haven't spotted the blue drone lately.lol
Both queens are laying tho and i just look for eggs and get out.

Mike

 

[ericweller]

FWIW, I started out using OAV as my mite treatment and was still having 60%+ losses. I knew that OAV was most effective only on phoretic mites and less effective on capped brood but I kept hoping that it would decrease my losses. After 3 years of using OAV changing the number of treatments and frequency, I still had terrible losses. I finally changed my treatment regimen to a thymol-based product and moved my treatments to the beginning of August and greatly improved my loss percentage (20%). I still do my OAV treatments in December when the hives are mostly broodless but the thymol based product in August was the game changer for me.
My suggestion is to modify your plans to one of the formic or thymol based products in the fall and use OAV when there is little or no brood (winter).

 

[Tim KS]

My OAV treatment is every fifth day for a series of 5 treatments.....evening is fine. Tuesday will be my second round.

 

[dudelt]

As with everything in beekeeping, ask 3 beekeepers and get 4 different answers. When I do fall treatments with OAV, I do 4 treatments, 5 days apart. The reason for that is two-fold. Drones have the longest period being capped (about 14 days). Doing 4 treatments 5 days apart cover 15 days so any mites that were sealed under the cappings just before the first treatment will hatch out just before the last treatment is performed. The second reason is that treatments 5 days apart are close enough that any mite that hatches out after a treatments will not have the time to get under the cappings again before the next treatment occurs. The phoretic period tends to be longer than 5 days and most literature states it is 5-11 days.

Every area of the country has unique beekeeping conditions. OAV in the fall may be a very poor choice. Ericweller sure thinks so. In my area I find it works great with the timing I stated above. I have only lost 1 hive in the last 2 years to varroa thanks to OAV and I keep between 15 and 25 hives at all times. That 1 loss was my fault, not the treatment failing. I do the 4 treatments starting the first week in August and 1 treatment just before Christmas. Finally, the best time of day to do the treatment is when it is most convenient for you. However, I do believe that it works best when done in the middle of the day. My reasoning is that mites supposedly prefer nurse bees over foragers. If that is true, treating when the foragers are gone will give better coverage to the nurse bees because there will be much less surface area inside the hive with fewer foragers in the hive.

 

[johno]

I have a friend who has just started using OAV for mite control, did mite checks before starting a regimen of 5 treatments 5 days apart. Most of his hives showed low mite infestation but one had more than 30 mites per half cup of bees, that hive got 6 treatments and when he again did mite washes the high hive was still above 30 mites per half cup of bees. I know when I started OAV about 6 years ago I had to do a couple of courses of treatments to get my mite levels down but to do 6 treatments and not make a dent in the infestation troubles me a little. As he had solid bottom boards he could not verify if there was any mite drop. Has anyone come across this before. I always do 2 courses of treatments of 5 at 5 days apart and never look back but 6 treatments with no good result what is going on.

 

[1954Lincoln]

Are the mites showing signs of resistance in those cases?

 

[R_V]

.........snip....
I just have a couple of questions:

1. What is the best time of day? Does anyone apply it right before sundown?

2. Do I start the application 8 weeks before first frost (Nov4) and add 21 days to it (Aug22)?

3. For the 21 day application I read a post where they talked about it. The poster replied that he did one extra on the 25th day and then [email protected] Christmas. I can't remember the span between applications. I could not find the post I read because I came across it by accident. What span of days is recommended?

......snip....

Mike

I have a ProVape110 so it takes about 20 seconds per hive. I bought it last year and attribute my last winter's 100% survival rate to it.

1. whenever the most bees are inside the hive. Coolest point of the night/early morning.
2. I start the first of August, just after the suppers come off.
3. I vape generally on the 1st, 6th 11th, 16th, 21st, and maybe the 26th.

Are the mites showing signs of resistance in those cases?

it's hard to develop a resistance to an acid.

 

[dudelt]

I think when you see huge mite drops after each treatment, the treatment is clearly working. If you still have large mite counts after treatment, my best guess is that you are getting re-infested from robbers bringing back the mites. I have seen this happen with all mite treatments, not just OAV. If you scan this forum, you will see instances of people who used MAQS, Apivar and other treatments stating that their hive is still over run with mites and asking if they should do another round. If you have a troubled hive, treat with OAV and put a piece of cardboard or an election sign on the bottom board afterwards and see what the 2 day mite drop is. Better yet, do that every time for confirmation. If you see lots of mites, you can be sure the OAV is working and there is some other factor in play that is causing the mite load to stay high. Don't do the treatment with the cardboard in the hive. It will catch on fire.

 

[SS Auck]

resistance to OAV is very improbable due to it being a physical kill rather than internal kill.

 

[Fivej]

Mike: I assume you are using a wand. What brand? 4.5 minutes seems like a long time. My Varrox takes 2.30 minutes, sometimes up to 3 . Might want to be sure your OA is dry. As for the timing, I will leave that to people near you but will say that you want a couple of brood cycles of relatively mite free bees going into "winter", whenever that is for you. Remember that mite loads increase just as bee population decreases which makes timing critical. J

 

[crofter]

resistance to OAV is very improbable due to it being a physical kill rather than internal kill.

It appears quite well supported that it is mechanical damage to their very specialized feet. If you remove an organisms prime mode of transportation to its unique food and reproduction source, it is going to take more than a minor adaptation to become resistant.

Perhaps in eons of time it could happen! If we want to truly be that far thinking, we have many more pressing issues we should address with our visionary abilities!

 

[johno]

I am wondering that in a heavily infested hive you could have quite a number of those mites feeding under the belly scales of bees and are perhaps not affected by the OAV as they are protected by the scales. There has to be some reason 6 treatments do not bring the count down. I have also heard some beekeepers claim that after some years of OAV treatment it seems to result in less and less mites every year as if there is something residual about OA

 

[1954Lincoln]

Mike: I assume you are using a wand. What brand? 4.5 minutes seems like a long time. My Varrox takes 2.30 minutes, sometimes up to 3 . Might want to be sure your OA is dry. J

I heated the oxalic acid till it was completely gone in an open air test on a cinder block using a 12 volt 1000cca boat battery. I was concerned if the material was going to splatter, it did not. It does not have the plume like the provap110 has.

 

[Fivej]

Not familiar with that brand. What do the instructions say as far as time? You should def see a "plume" no matter what type of delivery system you are using. When applying it to the hives, you should see it coming out of the cracks. So, where did you get the OA? I can't tell from your pic. J

 

[1954Lincoln]

The directions said it would take 2 to 5 min. They stated to do a test sample to verify the time to complete sublimation. The longer time could have been from the wand slightly tilted away from the heating element.

 

[JWPalmer]

Not a problem with the oxalic acid. That is the Florida Labs material, same as I use.

 

[1954Lincoln]

10 lbs was cheap on Amazon 26 bucks.

I will do another test tomorrow and video it.

 

[John Davis]

Looks like a wand design issue. Too much mass for the heat source and not good distribution.
I like the Varrox. More expensive but really works well.

 

[1954Lincoln]

I retested the wand today on a flat surface and had a plume. The total time was 4min 13sec. I have a video but this site does not have a video function.

 

[amatol]

Mike,

I'm doing a repeat combination of OA and Apiguard. I was able to successfully get my hives through the winter. I started off by vaping on 30 June and then again on 10 July. I just started my first round of Apiguard on 16 August and will apply the second round in about 10 day. I'll then I vape them twice in January. I also find the following article interesting and worth considering. https://backyardbeekeeping.iamcount...de Extra&utm_campaign=Extra_1-14-19_MillerBee