I agree with the posts which say that it depends on the flow and weather
conditions as to whether an excluder is needed. In a heavy flow the
pressure of activity in the Super will keep the Queen down below. Here
in Scotland our "interrupted"coastal weather system and therefore flows
are so variable that we need excluders.

However I don't think excluders hinder the bees at all - I have an
excluder which is made up of a 4" x 8" piece of zinc excluder tacked
over a 3" x 6" hole in a cover board - the bees produce the same amount
of honey with this excluder as they do with the full area Hertzogs.

As far as bee space is concerned I conclude that Queen Excluder design
is one of these items which is truly beyond the wit of man. If you keep
the wires flush with the bottom of the perimeter frame the bees have the
correct space under the excluder (top bee space hive) but there is now
space above the excluder (perimeter frame depth) and therefore more than
a bee space in total - the bees see the excluder as transparent because
it is full of open slots.
If you only use the wire sheet you crush bees as you replace the super-
not possible to get it right. But then they say the most difficult part
of invention is defining the problem - so come on Inventors - I've done
the most difficult part !

Alan Riach
Edinburgh, Scotland