>Should we -- or do we -- have different spacings of excluder wire for
>different species/races of bees?


Allen, I can't speak to the excluder size, but we have worked with a
variety of pollen scrapers over the last decade, some commercially
available, some that we made.  We also weighed thousands of bees from
various parts of the U.S.

Honey bees do vary in size more than is commonly acknowledged.  As you
know, bees reared in old comb may be emerging from smaller cells (all of
the lining and relining sizes them down until the bees tear down and
rebuild).  With new foundation/comb different manufacturers use different
size cells.

Pollen scrappers made from thin material allows bees of more variable size
to pass through.  As a bit of thickness to the scraper material, and some
colonies won't be able to work through them.  Sort of like you or I trying
to crawl through a tight culvert (tube) versus a wire hoop of the same
size.  You can wiggle through the hoop, not the tube.

I once paid a beekeepers for a heat prostrated colony after he put an
entrance mounted pollen screen on his hive and didn't follow our
suggestions to watch the bees to be sure they could pass.

I also suspect that different races of bees produce slightly different
sized worker bees.

Now, for the oddest observation.  Four years ago we had a set of our
electronic colonies in MT for several weeks.  We were using our own
manufactured pollen scrappers made by punching holes in a thin, stiff
plastic.  We pulled the pollen screens, loaded up the bees, and drove the
colonies/hives from MT to MD.  Four days later in MD, the bees were flying
and we re-inserted the pollen scrappers.  None of the bees could get
through!!  Same bees, same screens, same hive boxes.  They worked four days
earlier and had for some weeks.

It's like the bees swelled up.  I know that people on extended air flight
sometimes get swollen feet.  Didn't know this happened to bees!

Never did figure it out.  We had to use a different scrapper.
Jerry J. Bromenshenk, Ph.D.
Director, DOE/EPSCoR & Montana Organization for Research in Energy
The University of Montana-Missoula
Missoula, MT  59812-1002
E-Mail: [log in to unmask]
Tel:  406-243-5648
Fax:  406-243-4184
http://www.umt.edu/biology/more
http://www.umt.edu/biology/bees