> That said, and having worked with Formic acid in the lab, with Fume Hoods
and full protective equipment at my disposal, It's not something I'd want to
play around with at home.  It's stinky, smelly stuff, and while it is
miscible in water, it does not dissolve readily in water.  Thus we use
acetone to rinse and clean the Formic acid off of our samples, and to make
sure that our glasswear is clean.  Residue left behind concentrates as it
dries and becomes even more corrosive than the diluted solution.

In Canada we have been using Formic Acid treatments for HBTM and varroa for
some years.  We purchase it from the beekeeping supplier in the recommended
65% formulation so no mixing.

It is recommended that we work with it after chilling it in a refrigerator
or keep it in a very cool place, and always working outdoors or in a
well-ventilated place.  We wear acid-proof rubber gloves and apron, with
protective footwear to prevent burns.  A respirator is also recommended.
After a couple of treatments, this doesn't seem onerous at all, just
routine.

We can purchase "Mite Wipes", a little absorbent pad similar to the pads in
meat trays from the grocery store.  They have a solid plastic side, and a
perforated side, which is placed face down onto the top bars at the back of
the super after absorbing the prescribed amount of formic acid.  These pads
can be "charged" with acid in a plastic pail or container with an air-tight
lid.  Placing the required number of pads in the pail, then adding the
appropriate amount of acid (chilled so it won't evaporate quickly into your
face) close it up and keep it cold until you place it on the hives.  An old
styrofoam cooler with a freezer pack works well while you drive to your bee
yard.

There are many absorbent materials used such as paper towel, napkins,
newspaper in ziplock bags with "windows" cut in the plastic for evaporation.
Some meat departments in supermarkets will sell the absorbent meat pads, and
they may be cheaper, but work as well.

After about 5 years of dealing with HBTM at levels of between 20% down to a
low level of about 4% for two years, I dissected the usual sample this
spring and found none.  There is an economic threshold of 10 mites per
sample approx. where studies have shown that the bees will still build up in
spring, will still produce a crop.  I will not treat with FA this spring,
but will test again after the honey is harvested to determine the need to
treat for anything but varroa in the fall.

One advantage of the use of FA is that if alternated with Apistan to treat
for varroa it will ensure several generations of varroa not exposed to
fluvalinate and prolong the period of efficacy of Apistan against varroa.
It is not quite as effective against varroa as Apistan, but there is still
that economic threshold of infestation that the bees can likely live with.
Sampling for varroa levels in the colonies will determine your need to
treat.

Cheers
Jaquie