I have screen bottom, 1/4 hardware wire, queen extruder, open bottom,
and solid bottoms on nucs.  The screen bottom has the highest success rate.
This is setting 100 nucs with queen cell in the citrus bloom and also the
gallberry and palmetto bloom (still in bloom).
       Also the bees must have a good time on the screens as one will hear
them using the screen as a trampoline.  The tension of the aluminum screen is
where you hear the bongs.  Plastic window screen I didn't try.  I wonder if
the bounce has an effect in the mite reduction.
       The best results was with the screen tilted from 1 inch in the back to
the bottom of the 2by4 screen frame in the front.  Top bars was used to frame
the screen to get the best angles.  It also left the bees to clean the screen
which will keep debree if flat while the 1/4 hardware wire dropped most of
the debree thur to the ground.
       No chemicals used.
       Two outside frames were plastic and wood without being drawn.  Sprayed
with sugar water if nuc was low on bees.  This was done to help keep beetles
out.  Lost two frames in 1/4 inch hardware wire but no nucs lost to beetles.

       The queen extruder had died bees, Drones and workers, stuck in it.
Was unable to be sure of any benefit in keeping the drones out of the hives.
Removed drone frames to a separate medicated drone hive in hope to trap and
remove mites.  Unable to establish a useable result.  Will run it again this
fall when I need extra drones from best hives for mating.
       Michael Housel      Orlandobee