In message <[log in to unmask]>, Nathan W.
Lawrence <[log in to unmask]> writes
>Basically, should I use them with a closed
>bottom board

Are there not 2 separate functions for screens - to let the varroa fall
through and ventilation? A permanent tray (cleaned regularly along with
counting) and screened ventilation holes, in the back of the hive under
the main screen, would provide permanent ventilation (without propolis)
to a degree that suited the location.

--
James Kilty