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).]
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
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.
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.
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.
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.
Alex when using the pipe vaporizer makes sure youre not burning the oxalic acid. Dont 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, its 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.
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.
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.
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.