In a message dated 5/31/01 1:08:01 PM Eastern Daylight Time,
[log in to unmask] writes:

<< The chemical formula for vinegar is CH3-COOH very similar to formic acid
 which is HCOOH. Do we know the way formic acid kills varroa and tracheal
 mites? I stopped at this point in the post and reread the complete writings
 on formic acid from the new book *Mites of the Honey Bee* (Webster &
 Delaplane 2001)and there is no explanation of exactly what process kills the
 mites. >>

One very big difference is concentration. Normal household vinegar is about
4-5% by volume-the rest being water. The formic I have seen advertized was
higher in concentration. To a certian extent this is why I suspect that
methol works well, but cough drops don't  :O)--Concentration is important.
This is another reason to be careful when using homemade versions of
commercial products. Too much can kill more than you wish and not enough can
make things resistant.  I now wish I had gone into bee work instead of
environmental chemistry--would have been interesting to use my chemistry
knowledge working on solving bee problems.

Tim Morris