Hi Everyone,
Lloyd wrote in part:

"But I patiently explain to them that a by-product of the bees
maintaining  a 90 degree temperature in the center of the cluster is
that
air is heated.  Warm air will gain moisture as it rises upward in the
hive.
If it hits the top of the hive, where it is cold, that moisture will
precipitate (as cold air will not hold as much moisture as warm air),
literally causing 'cold rain' to fall onto the bees below.  Dry and cold
the
bees can handle, wet and cold they cannot handle."

Lloyd there is another way to prevent the condensation that drips down
on cluster namely insulating the top of the hive.  I know a beekeeper
here in MN who wraps his bees but makes sure that the top of the hive in
insulated and there is an upper entrance between the two broodboxes.  He
wrapped hives one year in many different ways and opened them up every
week all winter long.  When it got cold he observed hoarfrost forming
around the upper entrances at the top and spreading across the top and
down the sides of the hive.  The longer the cold went on the worse it
got.  Hives with the upper entrance between the broodboxes and with the
top insulated did not have any frost form inside the top of the hive.  I
have wintered colonies here unwrapped with an upper entrance at the top
of the hive and they usually do fine but have switched to an entrance
between the boxes and insulation on top of the inner cover.  This might
actually be better for early spring than for the coldest part of winter
as the insulation helps the cluster remain looser and larger so more
honey stores are covered.  So provide an upper entrance like Lloyd and
most beekeepers advise but I suggest it should be between the boxes
instead of at the top of the hive.  My observation is the main benefit
of the upper entrance is to allow cleansing flights when there is a
shorter break in the cold weather than a colony without an upper
entrance can take advantage of.

FWIW

blane

******************************************
Blane White
MN Dept of Agriculture
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