# Mite count and OA vaporization



## cristianNiculae (Jul 2, 2013)

Hi,

... new beekeeper from eastern Europe.

Last week I've made an mite infection evaluation using jar and sugar method. I have 2 hives.

Results:
1. ~50 bees - 1 mite (10 frames of bees)
2. ~50 bees - 5 mites (6 frames of bees)

Did an OA vapor treatment the same day and put the sticky board the same day on #2.
The day after the treatment only 2 mites fell. After the 3rd day about 10 mites/day. I'm not sure if the OA was correctly administered as I don't have a professional tool. I'm not sure if 10 mites/day is caused by OA or is a natural drop 

Any thoughts on this? Maybe do a jar sampling again later this week? 

I forgot to mention that I still have brood in the hives and that I see some ants on the sticky each time I pull it out to count. The only thing I'm worried about is the efficiency of the treatment.


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## FlowerPlanter (Aug 3, 2011)

How did you administer the OA?

Do some searches on utube for "Oxalic bees" some very simple OA atomizers

I took a piece of copper pipe 12", folded one end over about 1/2" hammered it flat several times. I think its 1 gram per deep, I use a little bit more cause some condensates in the tube. 

I made one with a glow plug but don’t like it cause of a small bee kill, I think it get hot to quick and cause too much OA at the same time.

When brood is present once a week for 3 weeks.

Ants can carry the mites away, but if they are getting stuck I don’t think they are removing them.


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## cristianNiculae (Jul 2, 2013)

I have a copper pipe thing that I've made just that in my opinion is very hard to control the temperature and it most probably gets too hot and destroys the acid. The temperature must be between 315°F and 372°F.
For the treatment I've used a customized soldering iron (40 W).
I did another jar mite count today on about 200 bees and there were only 3 mites. So it seems the acid has worked fine just that I haven't seen that reflected on the sticky board, probably because of the ants. I should have monitored the mites a little bit earlier before the treatment and then I could have told the difference. My mistake.


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## Glen H (Aug 17, 2013)

Welcome to the forum!
hope to hear more from you on your results.


Glen


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## cristianNiculae (Jul 2, 2013)

Thanks.

In our country probably one or two people use OA, at least from the forums but I found enourmous amount of info on US sites. I wouldn't be that obsesed with counting but I need to know the results so that I tune up the treatment. 
We have a standard form of treatment that is officially recomended and everybody uses it: amitraz + taufluvalinate but I don't want to use that because of contamination and other reasons.
If God helps my bees pass the winter I also want to gradually use foundationless frames starting from next Spring flow.

Regards,
Cristian


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## Glen H (Aug 17, 2013)

When I started out this spring with two hives I used foundation sheets alternated with foundation-less frames. So one sheet of foundation then next to it an open frame then another sheet of foundation..... This helps the bees to draw the foundation-less frames out straighter.
I also cut a strip of the foundation (plastic sheet) along it's longer edge about 1.5 inches (4cm)
wide. And used that as a starter strip attached to the top of the frame. This helps to get the bees drawing their own wax straighter.

Glen


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## cristianNiculae (Jul 2, 2013)

60 W vaporizer - 2g in 5 minutes
I've made this today and it satisfies me. I have a small rectangular opening on the bottom board for ventilation, not varroa screen that's why that wood. I evaporate the acid through them.


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## Glen H (Aug 17, 2013)

Nice.
What did you use to attach the copper cup to the tip of the soldering iron?
Silver solder, Brazing?

Glen


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## cristianNiculae (Jul 2, 2013)

It was silver solder. The tip of the soldering iron was also copper and I made it flat on the side that touches the cup. I used a torch to fuse them together.


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## cristianNiculae (Jul 2, 2013)

Yesterday there was 1 mite on the sticky and it's been 5 days since last treatment.
As far as I've read the sticky board is not that recommended in Fall.
Is it because the bees are more lethargic due to cold and mites don't fall that often because there's not much movement?
Tomorrow I'll do another treatment with the new device.

Cristian


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## Glen H (Aug 17, 2013)

How about doing a before and then after sugar roll test mite count?



Glen


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## cristianNiculae (Jul 2, 2013)

Yes, it would be a good procedure.
He he... this hive was definitely my "learning dead corpse"  I'm trying not to be very intrusive but I never succeeded in that. Anyway, I have to establish some work procedure (and this includes treatments) before I start expanding my apiary. The risks are low for now.

Cristian


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## cristianNiculae (Jul 2, 2013)

I did the treatment on Friday. I couldn't open the hive as it was too cold so I just put a new sticky(A4 sticky paper) under the brood area.
24 hours - 4 mites.


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## Glen H (Aug 17, 2013)

Cristian,

After doing the vaporization, are you finding sludgy gray residue left in the cup?

I'm going to run some temperature trials today with a temperature measuring gun and see what happens running the vaporizer at different temperatures. The first two times I used the vaporizer it had no residue at all left in the cup. The last three times I used it it did have the gray residue.


Glen


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## Glen H (Aug 17, 2013)

So today I did some dry runs of OAV I did it ten times with 3 grams of OA.
Each time I did it I used different shut of temperatures and timed them.
I have found that no matter what temperature I shut the vaporizer off at, or no matter how slowly I bring the temperature up I'm finding that my Axolic acid will not sublimate. The crystals will melt to a liquid first before it would turn to a vapour. So I'm not sure why Randy is saying that the OA will Sublimate. I can't get mine too!?!?!? :scratch: And only really start getting vapor once it has turned to liquid. 

("Sublimation is the transition of a substance directly from the solid to the gas phase without passing through an intermediate liquid")

Also I'm not getting the crystals to not leave some sort of residue. 

Glen


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## crofter (May 5, 2011)

I believe sublimation is also the transition from a gas to a solid without a liquid state. The Oxalic acid that gasses off goes throughout the hive and is deposited as fine oxalic acid crystals. It is killing the mites, ain't it? stop quibbling about the description! I notice a bit of ash too but I dont even bother scraping it! Sometimes I get some ladder comb drop in and a few barbecued bees. It is all good!


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## Glen H (Aug 17, 2013)

crofter said:


> It is killing the mites, ain't it? stop quibbling about the description!


LOL YA I can be a bit critical and detail oriented most of the time.


Glen


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## WBVC (Apr 25, 2013)

Glen H said:


> I have found that no matter what temperature I shut the vaporizer off at, or no matter how slowly I bring the temperature up I'm finding that my Axolic acid will not sublimate


What vapourizer are you using?
What oxalic acid source are you using?
Why did you test with 3 gm...rather than 2 (for double deeps)or 1 (for single deep)

These variables may have some impact on your results.


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## JRG13 (May 11, 2012)

Sublimation is solid to gas, gas to solid is deposition.


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## Glen H (Aug 17, 2013)

WBVC said:


> What vapourizer are you using?
> What oxalic acid source are you using?
> Why did you test with 3 gm...rather than 2 (for double deeps)or 1 (for single deep)
> 
> These variables may have some impact on your results.


I have a deep and two mediums on, so just a bit more then two deeps.
And any way I'm doing the testing dry,no hives involved. Oxalic acid source is EBay.
And the Vaporizer is one I made using two glow plug heaters. Its the second one I've made so far. Pictured below.









Glen


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## crofter (May 5, 2011)

JRG13 said:


> Sublimation is solid to gas, gas to solid is deposition.


It has been a while since my chemistry classes! If I remember some substances have an intermediate stage that is rather subtle such as a thin wet surface on the solid. I have not delved into whether oxalic acid is a classic example of sublimation or a rather poor demonstration of the effect.

Oxalic acid does pull in moisture from the air if it is not well sealed and how much water has been absorbed into the crystals probably does have an effect on how it appears to go off in the cup. I never patiently waited for all the water of hydration to boil off to see if a solid would appear in the cup before gassing off. I have found if you push it hard initially it will boil over. 

I really was joshing Glen H about quibbling but perhaps there *is* something here that needs better defining; if someone wants to have a go at, fill your boots!


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## Glen H (Aug 17, 2013)

Crofter,
When I did the ten trial dry runs today out side, the air was cools and very moist. Two days of rain and a break in the rain while testing. So the moisture level in the air was high.
This test was basically used to entertain my curiosity and to see if the OA reacted differently at different temperatures. I have learned one thing from todays test. I need to shut off my vaporizer earlier then what I have been running while vaporizing in the hive, to keep the cup temp below 280 deg. F. Todays tests showed cleaner vapours at 215 to 230 deg. F with less residue.

Glen


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## cristianNiculae (Jul 2, 2013)

Glen H said:


> Cristian,
> 
> After doing the vaporization, are you finding sludgy gray residue left in the cup?
> 
> ...


Hi,

Yesterday I tried that water heater thing - http://www.beesource.com/forums/sho...ade-oxalic-acid-vaporizer&p=991675#post991675). 

The one that I have is far to powerful at 500W/220V but some guys put me out of my misery... finally. I should have thought about this earlier. I didn't know that the principle behind professional vaporizers is to shut them off before reaching their max. temperature.

So I've made some tests.
As I don't have a thermometer I used water(and AO later) in my tests. The water boils at 100C and the AO at 150C. The whole idea is not to overheat.
I now think that any vaporizer would do, just that you need to find it's particular use. In my case I found out that I need a first push of 15 seconds then after each minute another push of 3-4 seconds. In my case I used copper again(3/4 cup). I also think that the best "tray" for it, is a more inert or thick material like Glen has, to keep the heat for longer time and not heat too quickly.

About residue: this happens when using lower temperature(towards the end of the process) - the acid condenses back to the tray.

So to come back to the idea behind this topic: I probably have used less amount of vapor than I should have because of the weak powered vaporizer (the one with the soldering iron) and also not optimal heat dispersion.

I just seen some other topics on using VW glowplugs (at first I didn't know what they were). Awesome! Probably in my case is not really necessary as I have electrical power near the hives but I will definitely build one in the near future.

Cristian


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## Glen H (Aug 17, 2013)

Found this statement on another site.

"The physical properties of oxalic acid may be of interest in this connection. The stuff one buys is usually oxalic acid dihydrate, which is a crystal which has two water molecules attached to each oxalic acid molecule. The CRC Handbook of Chemistry and Physics gives the following properties for oxalic acid dihydrate: 

On heating: 

1) The water of hydration leaves at 101.5° C (214.7° F) The water boils off leaving anhydrous oxalic acid crystals. 
2) At 157° C (314.6° F) the oxalic acid starts to sublime (goes directly from solid to gas) 
3) At 189° C (372.2° F) the oxalic acid which has not yet sublimed decomposes to formic acid and carbon monoxide."

Too me this makes sense for what I am seeing. It's the water boiling off at 217 - 280 deg. F I'm seeing. and The sublimation takes place after that occurs. So actually by not going over 280 deg. F I'm not getting the crystals to vaporize.

Time for more trial runs. 

Glen


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## crofter (May 5, 2011)

Originally Glen I thought you were funning us but I see what you were after. I think you fellows are going about it in a good way. Trying to rush the process results in surface temperatures much too high and you build up a layer of insulating steam that throws contents around but actually lowers overall heat transfer into the mass of the contents. Think of dropping water onto a hot stove top as compared to a surface around 250F. At 5 or 6 hundred degrees it just dances around and sizzles.

I think with the lowered air circulation and reflected heat inside the hive you may even have to hold back a bit compared to observations in open air. From a cold start mine takes over a minute to start boiling off the water and I cut the current off and on about every 20 seconds for a minute. From that point on I cut the power and there is enough heat stored in the mass of the unit to finish driving off the oxalic without overheating it.

The advertising literature seems to want to stress how quick their units are and I dont think speed is you friend from what I have seen. It takes X number of BTUs to effect a change of state of a given weight of material. Oxalic acid has a certain window of temperature with the upper limit being undesirable and ineffective gas instead of sublimed OA. 

Maybe that is overthinking it a bit (or overstating it) but a few trial runs are well advised.


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## Glen H (Aug 17, 2013)

More

Oxalic Acid Dihydrate, C2H2O4•2H2O 


CAS #: 6153-56-6 
IMIS #: 1970 
Molecular weight: 126.07 
Melting point: 101.5°C 
Sublimes: 157°C 
Appearance: Although colorless, and odorless both forms may appear to be white and consists of monoclinic granules 
Vapor pressure: <0.001 torr


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## crofter (May 5, 2011)

Looks like the melting and boiloff of water of hydration could well overlap and mask the sublimation. Material in direct contact with the bowl could be starting to fume off while the liquid portion is still bubbling away.


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## Glen H (Aug 17, 2013)

Yes I would think so that is what is happening, but only partial sublimation is occurring for me. But I'm guessing most of that vapour we are seeing as it boils is just water vapour and a small amount of Oxalic vapour.
I'm now thinking because I was shutting the heat off, trying to keep the temp below 280F, 
(because I thought that above 280F was the point were it would release Formic and monoxide. I had my temperature numbers all messed up in my mind.) that It never got to a high enough temperature to actually totally vaporize the crystals (Sublimate). Need to get hotter 315F to get total vaporization with no left over ash (crystals).

Glen


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## Glen H (Aug 17, 2013)

Did three more tests tonight and now that I have my head screwed on frontwards, I'm getting the crystals to totally vaporize. I ran the temperature up to 315 deg. F and it does work and there is no residue at all. Not sure where I was getting the 280 deg. F figure from and that it would be to hot and would turn it into Formic acid and Monoxide!?!?!?! DUH!
So all is well in my little world and I can go, discover and pondering my next scientific fact of life. 

Glen


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## cristianNiculae (Jul 2, 2013)

I think the treatment works fine and probably we are a bit too worried about the results as we never did it before.

Earlier this summer, I've made a test using a 40W soldering iron in an empty hive and I think it could be another good way on double checking the results: a thin layer of crystals on the walls, which is condensed acid and what we want.

I've got 20 mites in 48h on #1 but as I've said it before I have small infestation.
I need more mites 

Just as a curiosity: 
One guy on another forum said that after fogging and having tons of mites fallen, he took the tray away from the hive and came back 2 days later. He pretended that after 2 days there were many live mites on the tray, meaning that the vaporization doesn't kill the mites, only knocks them down, and if one has no SBB then vaporization is of no use.
I haven't found this to be true anyway. I also don't use SBB.

Cristian


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## cristianNiculae (Jul 2, 2013)

Hi again,

On the more seriously infected hive I have 0 mites now after 2 rounds of vapor OA.
Remember I had about 10% mites using jar-sugar method before the treatments.
I took a sample of about 300-400 bees from a frame with very little capped brood.
I haven't seen more than 100 on the A4 sticky.

Where did those mites go?

I guess sticky board sucks... or am I just plain nuts? I hate things I cannot explain or control as I'm getting kind of obsessed.
Not to mention that I am also suspicious on loosing the queen now . Almost no brood, just a few capped. I'll look for the queen tomorrow. I hope I didn't shake her together with the other bees.

Hive #2 - 8 deep frames of bees in single hive body

Did you guys encountered this kind of mystery?

Cristian


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## Glen H (Aug 17, 2013)

I'm not overly happy with the bottom board as a means of counting Mites.
My bottom board shows low numbers. But when I did the sugar roll in the jar the mite numbers were up. 3/4 plus cup of bees had 30 mites. :-(

What was your mite count from doing the roll with the jar was it 30-40 mites? 300-400 bees that is what a 1/2 cup?
Was this count you did with the jar, before the treatment or after?

Glen


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## cristianNiculae (Jul 2, 2013)

\

Ufff... these units 

It was more then half as in this kind:
http://www.borcane.ro/Borcane-mici-370-ml/Borcan-212-ml-Fateta--cID3--pID3.html
...probably 200 bees

Before treatment:
Hive #1 ~50 bees - 1 mite (10 frames of bees)
Hive #2 ~50 bees - 5 mites (6 full frames of bees)

After treatment:
Hive #1 I haven't sampled
Hive #2 ~200 bees 0 mites

This inexact science of beekeeping is driving me crazy . I hope to get better in time.

Cristian


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## cristianNiculae (Jul 2, 2013)

Anyway more then 200 bees:
http://www.youtube.com/watch?v=fDAErFAIneY


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## Glen H (Aug 17, 2013)

I was doing it that was, as the video shows to measure the bees.
In another thread Michael Bush suggested a better way of measuring bees with out using a measuring cup each time. His method is to measure a full cup of water and to then pour it into your empty clean bee sugar roll jar. Set it on a level surface and mark the outside of the jar with a permanent marker. Empty the water out and dry. You now have a one cup measure on the jar.
He went on to say don't worry about the odd bee trying to climb up the sides.
That's what I use now.

Glen


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## cristianNiculae (Jul 2, 2013)

It has been a learning year for me. Now the weaker hive lost it's mites and the queen.
There were too many sugar rolls perhaps. Probably in the future I will mark the queens.
Anyway one of my friends has to unite 3 families so I will have a mated queen soon. If it will be accepted I will have 2 hives as before, if not I will have only one strong colony.
The queen from that hive probably had some kind of problem since the colony was more exposed to robbing, somehow more vulnerable so I'm not very sad about loosing it.
All in all I'm pleased with the activity this summer. I still lack the Winter and Spring experience.

Cristian


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## cristianNiculae (Jul 2, 2013)

After the 3rd treatment I got ~60 mites/48h on the more numerous colony(I used the coffee heater with limited AC input). Before applying the treatment there were only 3 mites/24h on the sticky. I couldn't sample bees because of the low temps and bad weather.
So it seems that OAV worked for me.
Now I need to find an alternate treatment for the next year, probably formic.

Thanks for all input,
Cristian


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