# oxcilic acid



## swarm_trapper (Jun 19, 2003)

hey guys with the oxcilic acid vaporizor how many times do you have to treat you hives say this fall and how often thanks


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## Michael Bush (Aug 2, 2002)

When I used it I treated twice, a week apart in the fall after brood rearing shut down. I treated once in the spring before brood rearing started. There were NO detectable mites in the spring. But then there weren't many to start with. Only about 200 mites per hive average, probably due to the FGMO fogging I had been doing and the regression that I was almost done doing by then, not to mention the feral bees.


[This message has been edited by Michael Bush (edited August 18, 2004).]


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## swarm_trapper (Jun 19, 2003)

ok we have used FGMO but we will use the OA for this fall we might treat our small cell hives this fall to beacause they are not on small cell yet that will change next spring hopfully thanks guys oh yea which vaporizor would be better to use in the fall the top or bottom one ( we are goint to use top bar guys plans) thanks


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## Michael Bush (Aug 2, 2002)

My preference is for the top one, just because I don't have to bend over to hold the torch.







Also I can move faster if the wind shifts standing up than I can squatting down. But from the point of view that hot vapor moves up it would seem like the bottom would be better. It worked fine on the top for me.


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## swarm_trapper (Jun 19, 2003)

can it be used with a SBB?


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## Michael Bush (Aug 2, 2002)

My SBBs have a tray. I closed the tray when I did it. I don't think it will work well with it open. If yours don't have a tray, just cut a piece of cardboard the size of the bottom board to slide in the entrance to block the SBB while you treat them.


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## magnet-man (Jul 10, 2004)

Does oxalic acid work on tracheal mites like formic acid does? I have only seen references to varroa.


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## Michael Bush (Aug 2, 2002)

I have heard that it does work on tracheal mites. I don't know of any hard reference on that.


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## magnet-man (Jul 10, 2004)

Finally found something definitive on ocilic acid and tracheal mites. No or little effect the study said. Here is the link:
http://www.apis.admin.ch/host/doc/pdfvarroa/York/nasr.pdf 


[This message has been edited by magnet-man (edited August 27, 2004).]


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## Randy Bagrowski (Jan 29, 2002)

The "problem" with the study cited uses liquid oxalic. The vaporized form would be inhaled by the bees. The question still remains: Does vaporized oxalic acid effect tracheal mites?


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## WineMan (May 16, 2003)

i thought it broke down into part formic and water when vaporized? maybe im going crazy too and just made that up. if its so, it should do in tracheal mites


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## Ricko (May 18, 2004)

Okay, it sounds as though the effects of Oxcilic Acid on Tracheal mites is still up in the air. So far this is what I gather works for what.

OA - Varroa only,used at any temp.

Thymol crystals - Varroa only,used at any temp.

FGMO - Varroa only, used at any temp.

Menthol towels - Tracheal only,used at less than 80 degrees F.

Hey, I've got three methods covered.
If I could get some verification on the above,that'd be great! Thank you


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## Alex Cantacuzene (May 29, 2003)

Hi, I need a bit of advice. The colony that produced the best this year also has the most mites. I gave them an empty honey super with foundation only and they drew it out well but no nectar. The golden rod is just about over here and so I decided to pull the honey super off and use the oxalic today. I used the system as shown by Dennis, filled the lower cap and put it into the hole on the upper brood box. It evaporated well but I did not see much vapor. The hive has lost some population due to robbing etc recently. Questions: 1. Should I give them the drawn honey super back or should I start feeding right now as the temps are falling into the 40s in the night? 2. Should I do another treatment with oxalic in the lower brood super? 3.Should I continue with FGMO alongside the Oxalic? 4. Should I treat the other hive right next to the first with oxalic although they have very few varroa and are also being treated weekly with FGMO?
We are in central Kentucky. Thanks for the help.


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## Michael Bush (Aug 2, 2002)

Whats the mite drop on the hive next door? It's your choice, but if there is a lot of mites and capped brood, then you probably should treat again in five days to catch the emerging mites or wait until there is not brood and treat again before winter sets in.


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## Axtmann (Dec 29, 2002)

Alex when using the pipe vaporizer makes sure youre not burning the oxalic acid. Dont go for copper, use aluminum or brass, copper has a high reaction to the acid and the residues are not healthy.
Heat it slow so the acid can melt, boil and than evaporate. When heating to fast all you have left is ash and a poor result.
OA needs approx 180ºC / 360ºF to evaporate and the propane torch goes up to 1800º in no time.
The electric one goes up to 200ºC/400ºF in a little bit more than a minutes, just the right temperature.
With the honey super on put a newspaper between brood and honey super to make the room smaller, otherwise you need more acid to reach the same result.
Forget the FGMO and save your money, its not worth even to talk about.

Mites starts falling approx 48 hours after the OA evaporates in the hive. Treat all your hives the same time.


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## Alex Cantacuzene (May 29, 2003)

Hi guys, well the oxalic acid vaporization worked quite good. I made sure that I did not have the burner too close to heat up slowly and heated the vaporizer from the top down to make sure that the acid could not crystallize. On inspection of the vaporizer it was nice and clean inside with a faint white dusting and no residue in the magazine. One hive got up to about a hundred varroa in 24 hrs, the other about 5 to 6 in that time and they are only two feet apart. By the way MB, the cell size is 5.2 mm on the frames that they did not touch and chimneyed right through to the upper honey super. In any case, I will use oxalic on the one with the low count as well and see what happens. After the first treatment through the upper deep in the high count hive I have a heavy drop of varroa, both dark colored and light colored ones. Thanks to all for the advice.


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## Michael Bush (Aug 2, 2002)

>By the way MB, the cell size is 5.2 mm on the frames that they did not touch and chimneyed right through to the upper honey super.

What's the cell size on the ones she DID lay in?


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## wishthecuttlefish (Jun 24, 2003)

Ricko - 
I think this is incorrect:
"Menthol towels - Tracheal only,used at less than 80 degrees F."

Menthol crystals only start to vaporize at about 84 degrees F. Not less than that, which is why it is recommended that it be put in while temperatures will still reach that for at least 15 days. In Maryland, that's about August 15th. 

Kai


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## Walt McBride (Apr 4, 2004)

Axtman: Would you elaborate on your comment about not using copper in constructing an OA pipe vaporizer? What are the residues you speak of? Thanking you for your input in advance.
Walt


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## Axtmann (Dec 29, 2002)

Walt when using a pipe vaporizer the end where you head the acid should be at least from brass, better stainless steal or aluminum.
Copper has a very high reaction with boiling OA and parts of verdigris ending up in the hive.


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## Alex Cantacuzene (May 29, 2003)

Hi MB and Axtmann, all of the foundation that we have is 5.2mm and it did not present any problems in the deep brood supers. The problem was in the honey super that had this foundation that I inherited from a friend and it was older and I cut it down from deep to medium to just use it up. I had tow honey supers on and the bees totally ignored this one for a whole month, I pulled it off and am letting them work the one that they did draw out. Axtmann, the vaporizer that I use I made from brass tubing and fittings and then brazed the joints with the exception of the vertical part with the magazine. I think the main trick is to make sure that the tubing going into the hive box is hot before you put the high heat to the magazine. In any case it works for us and today I will treat the other hive after I pull the honey super off. I also only do it on non windy days.Thanks guys for the input.


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## Ricko (May 18, 2004)

wishthecuttlefish,this is what I found on the Ohio State University web site:
(2) Menthol: 

Menthol is available in bulk quantities or in 1.8-ounce (50 grams) packets from most major bee suppliers. Treat only over-wintered colonies having no surplus honey intended for human consumption. Colonies should be treated in the fall or early spring when daytime temperatures are expect to be above 60°F but not over 95°F. Treatment must end one month before the first nectar flow to avoid contaminating marketable honey. Use one menthol pact per hive, on top bars in temperatures up to 80°F. Above 80°F, place the packet on the bottom board. Treat for 14 to 28 days with an entrance-reducer on the hive. Replace the menthol as needed during the treatment period.


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