Bob Harrison wondered:
>Am I the only person in the world up in the middle of the night thinking
about the vinegar fogger?

        No, old man  -  it's approaching midnight here  -  and I now cop
the least plausible biochemistry in a while.  Someone is supposed to have
said:
>Acetic acid readily breaks down the hard covering (Chitin) which is made
up of  calcium which is the hard shell of the varroa mite.

        The exoskeleton of many wonderful animals is composed mainly of
this hard polymer chitin.  It is a polymer of a modified sugar.  It has
little in common with eggshell.  The calcium, if any (I haven't looked it
up  -  my browser is on the blink, how will I manage?  :-}) in chitin is at
most a small part and hardly dominates its chemical properties including
any vulnerability to solvents such as acetic acid.
         Chitin is notoriously hard to dissolve.  Dilute aqueous acetic
acid  -  which is mostly what vinegar is  -  does not look promising for
this purpose, but I stand to be corrected, could be wrong, and mustn't
pretend that all that hi-falutin' larnin' counts for much.

        I'm not sure what can be done about the wild biochemistry that
meanders around the beekeeping scene.

R