Hi Mats you ask
>
> Does anyone here have experience and/or knowledge about treatment with
> formic acid in the spring?
I do, using a pad made of homasote in a ziploc bag as perforated for storing
vegetables in the refridgerator.


> -Is it any good?
Doing it for a quite a few years and still have bees so guess it is good.  I
alternate with Apistan in the Fall to prevent mite tolerance for either to
develop in my bees.

> -When should it be done?
When weather is expected to reach 10 degrees Centigrade for the next week or
so.  Night temperatures should not be much below freezing for the bees do not
cluster as efficiently during treatment.


> -Acid concentration?
120ml of 65% formic acid in the pad in the vegetable storage bag made by
Ziploc produces the required vapour concentration for the hive if all holes
but bottom entrance are closed.  The bottom entrance should be wide open.

> -Application methods?
As developed by Dr Medhat Nasr and now available (here) with pre made Mite
Wipe pads.

> -Required temperature?
As above

> -Drawbacks?
time consuming but not as bad as the six treatments required using acid in
paper towels

I have posted information on several lists.  You can search the archives or
You can e-mail me directly for more information.

Sorry I did not read your request sooner.  We had a few days of lovely warm
weather so was in apiaries for several days building defences from the
several skunks that love eating my bees.  But I love honey more so they must
be stopped or caught and moved elsewhere.
.... george

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