first oxalic treatment: did it work?

[buford]

i've been away for a while, but now i'm back with a list of questions.

i figure i'll start where i left off.

in february i gave the bees their first oxalic treatment (using a homemade vaporizer with a copper pipe).

while treating the hives i neither saw nor smelled the vapor (so it was difficult to know how long to heat the copper).

when i opened the hive i saw a light "frost" in the corner where i had inserted the pipe.

did i do it right?

if so, would the treatment be more effective if the hole were cut in the middle of the super (so as to diliver the oxalic directly over the clustered hive)?

also, is it possible to use too much?

[Michael Bush]

>while treating the hives i neither saw nor smelled the vapor (so it was difficult to know how long to heat the copper).

You don't want to smell it. You will regret it if you do.

>when i opened the hive i saw a light "frost" in the corner where i had inserted the pipe.

Normal.

>did i do it right?

How much did you use and how large is the volume of the hive? (2 deeps? 3 mediums? etc)

>if so, would the treatment be more effective if the hole were cut in the middle of the super (so as to diliver the oxalic directly over the clustered hive)?

From my observation the issue is to have enough volume of vapor to fill the volume of the hive. If you do that it's irelevant if it's in the top, the bottom or the middle.

>also, is it possible to use too much?

Yes, it is. I purposely overdosed a small, but mean hive by about four times as much as recommended to see what would happen. It will kill the bees.

But a little bit too much doesn't seem to hurt nor does a little less.

[Lechwe]

Buford,

Do you have a picture of your evaporater you could post? How much did you use?

Thanks

D

[buford]

michael,

i use two deeps for brood, i used 1" copper pipe with a 1" cap full of oxalic per hive. some hives a gave a bit more, but since none of my hives have died, i gues i did o.k.

breathing the stuff was a concern of mine. since the vapor is invisible and (as i've been told) will come out through any crack in the super, it's hard to avoid getting a taste of it, other than trying to stay up-wind. any suggestions?

do you see a need of using this in a smoker (as some are recommending) for more mite fall?


lechwe,

[Michael Bush]

>since the vapor is invisible and (as i've been told) will come out through any crack in the super, it's hard to avoid getting a taste of it, other than trying to stay up-wind. any suggestions?

I just stay up-wind.

>do you see a need of using this in a smoker (as some are recommending) for more mite fall?

In a smoker? I've never seen that. In the pipe evaporator? If you have some mites or you want to just treat in the fall after brood rearing stops, it's a useful treatment.

[buford]

i found the OA smoker idea on the FGMO site. i haven't seen pictures or a detailed description of how it works, but "thekeeper" seems to like it.

thanks again for the help. smile.gif

[buford]

btw, how much oxalic vapor can a person breathe before he has a problem? is a little bit o.k.?

[Michael Bush]

A very little bit will throw you into a coughing fit. You WILL notice. It is much more of an irratant than anything else.

[Bob Harrison]

Would not a varroa tolerant installed queen be much easier than sniffing OA fumes, fogging each week with FGMO ( talk about breathing fumes!), or putting on chaps, face mask ,respirator & nitrile gloves to dose your hive with formic. Many commercial beekeepers are ignoring the new twitch they have developed from breathing coumaphos dust(similar to WWII mustard gas twitch).
My 2 cents worth!

[buford]

michael,

i wrote my measurements wrong. i used a 1/2" pipe with a 1/2" cap to measure the oxalic (not 1").

is a 1/2" cap full for a two deep hive enough or is ot better to use two?

[Michael Bush]

That's about what I use. One cap for three mediums or two deeps. Two would be too much.

[buford]

thanks again.

...and you say that many can get through the year on one oxalic treatment in the fall?

[Michael Bush]

>...and you say that many can get through the year on one oxalic treatment in the fall?

I can't say that for sure. I'm on small cell with feral survivors. I find about 100 mites per hive when I treat a small cell hive in the fall after a year of not treating. I can't say what you'll get with large cell bees, but it should certainly put a dent in it and I would think it would suffice. But I would monitor the mites to make sure.

[buford]

maybe it would be a good idea to have FGMO or sucrocide on hand for late summer? i've already got the sucrocide, but i havn't tried it yet.

i've heard about resistant queens (mainly the weaver's) but i don't know much about them (if they're really as good as they say).

[willyray]

Have read on another site that did testing on Oxalic , they mixed it with water 30 grams to one liter and sprayed 3-4 ml per comb side . A the end of the report they said they had more confidence in the spray than the fogging method.I guess i need to keep up with the sites so i can refer the quote.

[Michael Bush]

Axtman from Germany was the one who introduced the idea of Oxalic acid vapor here (on this forum). His opinion is that the oxalic acid drip is what they were doing 10 years ago, and now they have moved on to the vapor. Seems like you're starting 10 years behind if you want to start with what they have already left behind.

But I'm sure the drip also works. It does not look as easy to do as the vapor. I can treat a lot of hives in a day with the vapor.

[willyray]

My mistake , it was 10 years ago And it was between the drip system and the spray Not the vapor

[buford]

i ask the following question just to make sure i'm not about to make a big mistake.

can i place my homemade vaporizer box on top of the honey supers, put a double does of oxalic in the pipe, and note contaminate the consumable honey? will enough oxalic even make it down to the brood chambers?

thanks.

[Michael Bush]

Why not pull the supers first and then put them right back on?

[willyray]

Could not get the topbarguy's vaporizer to come up but found the wrangler http://bwrangler.madpage.com/bee/goxa.htm

[wishthecuttlefish]

By the way, Buford, Oxalic vapor is definately visable as a white smoke. I put a thick sheet of plexiglass on top of a deep super to watch as the acid evaporates and I can see when to stop heating. When I use it I always wear an organic vapor rated gas mask and eye protection.

This year, however, I am going to switch things up and use sucrocide. Not because I have no confidence in Oxalic, but because I think using a variety of methods is the way to go to prevent resistance.

Kai Richardson

[Michael Bush]

Since the mechanism is simply a caustic, organic acid, it seems doubtful there will be any resistance.

[wishthecuttlefish]

MB, As much as I respect your beekeeping and general knowledge, I have to humbly disagree. Biological systems are notoriously robust, and although it may take many, many generations, if one accepts the basic precepts behind natural selection there is nothing to say resistance can't develop in the species. In previous posts I have pointed out, quite logically, just a few mechanisms by which Varroa might develop resistance to caustic acids such as oxalic or formic acid.

Mucous, as we all know, is very good at protecting an organism from all sorts of nasty environments. Go to any deep sea vent, and one will find any number of complex organisms that have adapted to extreme temperatures and highly caustic chemicals. If we believe Varroa (as a species) has access to the same adaptation mechanisms, then we can't discount resistance, especially given the speed at which Varroa reproduce. In addition, there are behavioral modifications that can occur in a very short time in a species which may also have the same protective effect.

Kai Richardson

[Axtmann]

Kai there is a big problem with the resistant against oxalic acid.
As far as I know, OA works from the outside and destroyed the body of the mites. You might be right that one day the Varroa can be resistant to OA, but I think it is a long way. Like a worker on a blast furnace, melting steel for 50 years, and still not resistant against liquid metal and that’s the same with his kids and grandchildren.

After the evaporation, OA contaminate everything in the hive. Not in crystal form, but in connection with moisture as microscopic fine acid drops. OA takes connection with all moisture in the hive, even with the moisture from the Varroa body. This kills the Varroa in a short time.
The Bee bodies also have moisture but the acid concentration is too low to injure the bee or the larva.
When you evaporate 200 grams instead 2 grams OA per colony that’s a different story, I’m sure it kills everything in the hive.

I don’t know the different in size and weight between a Varroa and a Bee but I would say a bee has much more than 200 times the size of a Varroa.
OA is one of many Varroa treatments in Germany and since at least 1982 and there is no knowing resistant.

OA is one of the strongest natural acids, make a test and take a few grains with your fingers, in a short time you will feel it.

@ Buford

You can treat your colonies with a honey super on, but I would do it only if absolutely necessary. Go with any electric vaporizer through the entrance and put a sheet newspaper between brood and honey super. You will have a better result with a smaller room and less OA in your honey. The hot acid fog goes up much easier and faster than down.

[buford]

thanks.

i never saw a white smoke when i tried this, but i have my super/vaporizer covered with a piece of wood (so all i would see is what seeps between the supers.

i can't afford an electric vaporizer at this point, but if i take the supers off and blast the colony, how long do i have to wait before i put the honey supers back on the hive? i assume immediately.

[Axtmann]

Budford remove the honey super and treat your colony with your vaporizer. Don’t overheat the OA with your torch; this will burn some of the acid (destroy) before the fog left the pipe into the hive.
OA needs approx 180ºC – 360ºF to evaporate, a torch reach 900ºC – 1650ºF or more in a very short time.
After approx 1 hour put a newspaper on top of the brood and give the honey super back.
After the evaporation close the entrance for at least 10 minutes otherwise your bees blowing most of the fog out of the hive.

That’s my opinion but I would do it only in an emergency.

[buford]

thanks.

i wonder now if i may have heated it to much when i tried it in february. there eas really no way i could tell when it was done or not.

also, i neither blocked the SBB nor the entrance. but, right now the mite counts are low, so maybe i did SOMETHING right. smile.gif