In looking for non-apistan treatment options for varroa I came across
a web page that describes an "anti-varroa bottom board"  According to
the designer of the board  the principle of the anti-varroa bottom
board came from the fact that wild colonies of honey bees can be
found, free of varroa, in highly infested areas. The assumption of the
designer is that many varroa mites fall from the colony and are
eliminated in this way, having no means to climb back. On the
contrary, in a hive, they do not  have any difficulty joining up with
their initial  environment from the classic bottom boards.  The idea
of the anti-varroa bottom board is that  the mites fall through the
tubes under the hive.  According to the designers experience on his
colonies, this bottom board eliminates any need for chemical
treatment. The varroa mites are not fully eliminated, but they remain
in such a small number that they are no longer harmful.   Additionally
he says in winter, waste as well as condensed water are automatically
eliminated, which avoids production on the board of bacteria and
fungus, potentially a source of diseases.   There are some other
claims made by the designer of the bottom board that are on his web
site: http://www.apiculture.com/plateau-anti-varroas/index_us.htm

I would appreciate any comments in regards to ones experience with
this, the perceived practicality of the idea and any other insights
that can be offered.

Thank you,

Tom