A couple of weeks ago I predicted that suppliers of beekeeping equipment
would come out with screened bottom boards that could be used instead of
normal bottom boards, rather than as an accessory to such boards.  With
catalogs starting to come out, I see that Dadant and Kelley have such
screens, and I understand that Rossman will also be offering them.

For reasons that are not clear to me, both Kelley and Dadant show the
screens on top of normal bottom boards, implying that they are designed to
be used in that manner.  Because wax moths find the area between the screen
and the bottom board to be a lunch table, I feel pretty strongly that this
is not an appropriate use.  In addition, bottom boards cost money!

I have previously reported that my bees over winter well here in upstate NY
with only a screen on the bottom of the hive.  However, the first winter I
only had 3 hives so set up.  This year I have 23, but the winter is not
over.

I had long heard that a local commercial beekeeper, Ed Lord in Hannacroix,
had been using nothing but screens for bottom boards for more than 40 years.
However, beekeeping legends being as they are I did not provide this
information to the list or adopt it myself as evidence that solid bottom
boards are not necessary.  Last week I got to see for myself!

Beekeeping has been Ed's sole source of income since 1942.  Such beekeepers
tend to know what they are doing.  Ed is now 80 years old, and keeps 100
hives for pollination.  When they come back from pollination, Ed makes
splits and the next spring sells 50-100 full hives, keeping 100 hives for
pollination.

This winter has been a little strange.  We had unseasonably warm weather
until just before Christmas, when it turned bitter cold and that lasted for
a month.  Roughly four weeks with nights often -20 degrees F, and no snow
for insulation.  Daytime high temperatures ran from 5 degrees to 35 degrees.
Then three weeks ago it started to snow, and we now have 2-3 feet on the
ground.  So, with very cold temperatures and no snow the bees would be
pretty stressed if using screens as bottom boards was a bad idea.

Last week we got a day in the 40's, and Ed and I inspected several of his
yards to determine if he had unusual winter kill, so should cut back on his
pollination commitments.

We struggled through 2-3 foot deep snow to get to the hives.  All hives are
on pallets, and are not wrapped.  I don't think we saw a single hive that
was in less than 12" of snow, and most had snow entirely covering the bottom
hive body.  Ed and I dug out a few, so I could see that they had nothing but
screens on the bottom.  The screens are 1/8" hardware cloth and, at this
time of year, had mouse guards in place.  During the course of 4 or so hours
of work we popped the covers on perhaps 50 hives and never found one dead.

His story of how he came to use these bottoms is of interest.  During the
50's, Ed over wintered in Florida and used tarps (rather than netting) to
cover his hives in transit.  After one experience with over heating the
hives in transit, he decided he would use screened bottoms and covers while
in transit.  For the first few years he left the screened bottoms on all
summer, but replaced them with solid boards for the winter.  Then came the
year when he couldn't get free from extracting and got an early snowfall
that lasted the winter.  He was convinced that come spring he would have
massive losses.

To his surprise, in the spring the losses were entirely normal.  Since, for
some 40 years, Ed has used nothing but screens and he has left them on all
year.

As Bee-L readers know, I have personally used a combination of old queen
excluders and 1/4" to 1/2" hardware cloth as screens.  After talking to Ed,
I will exclusively use 1/8" hardware cloth.  (I do not know what Kelley,
Dadant and Rossman are using.)  While 1/8" is the most expensive, Ed points
out that bees can easily get through 1/4".  When he moves the hives for
pollination, he can't have that.  When I pointed out that I don't have to
worry about that as I don't do pollination he replied "but someday you will
want to move that hive, and you will be sorry if you can't close off the
bottom board".  Of course, he is right!

Today Medhat Nasr reported on using a variety of Varroa control methods to
reduce Apistan use to once a year, and avoid resistance.  Avoiding
resistance to Apistan (fluvalinate) means that Coumaphos does not have to be
used and, as we all know, Coumaphos may be our unique industry time bomb!
At least two research studies have shown that the use of screens as hive
bottoms will reduce early Varroa build up by as much as 30%.  I urge
beekeepers to add screens to their arsenal of Varroa weapons.

Lloyd
Lloyd Spear, Owner, Ross Rounds, Inc.  The finest in comb honey production.
www.rossrounds.com