Ken Hoare asked, "But if screens are used in the States (are they?),"...
 
They are not used much at all.  Until very recently we were encouraged to
use the ether roll.  However, during the past year one researcher has
determined that we are missing a good thing in not using screens, so maybe
that will change.
 
Last year I visited some beekeepers in France.  I was surprised to see that
not only did they have Varroa screens permanently on the hives, but they
also took off the bottom boards!  The bees landed directly on the screens
and went up into the hive, as you might expect.  When the sticky boards were
not below the screens, the Varroa (and other junk) fell through to the
ground.  I was told they were left on, without bottom boards, all winter and
there was no wintering difficulty that could be measured.
 
The latest I have heard is that the ether roll will only pick up about 50%
of the mites on the bees being shaken.  I have stopped using ether roll and
am now relying on drone brood inspection.  Dr. Calderone recently said that
2 mites per 100 drone brood inspected are not a problem and do not require
treatment.  Twelve mites per 100 drone brood in the spring or fall means a
beekeeper should treat in the normal course.  In late summer, six mites per
12 drone brood inspected means take off the supers and treat immediately, as
the hive is in danger of collapse!  (These were the notes I took.  As I type
them, I realize I don't know the meaning of three or four mites per 12 drone
brood in late summer..., sorry.)
 
Lloyd
Email [log in to unmask]
Owner, Ross Rounds(tm), the finest in comb honey production.
http://www.rossrounds.com