In reading over the Food Grade Mineral Oil (FGMO) archives, and now the
screen bottom board treads I have a bit of a question that may apply to any
treatment study of the Varroa mites.

Since the sticky boards result in dropping mites not being able to make
their way back to a host, could some of the positive results found in some
studies be the result of the presense of the sticky boards, and have nothing
to do with the treatment being studied? Add to the question the fact that
some (if not all) smoker fuels cause some degree of mite drop. The colonies
being used for a test may be coming under more frequent manipulations, which
require smoke, to add and remove the sticky boards.