At 08:21 PM 9/9/2005, Dick Allen wrote:
>  It seems there may be two sides to the story; I've heard both of them
> from the university bee folks.


We don't have to propose a 'disagreement among university folks'.  We
simply have to consider climate.

Ok, I've kept bees over a winter in Dewey Caron's apiary -- and what works
for that climate is not what works for the plains of eastern Montana, or
the high elevation mountains of the western part of the state.  Similarly,
Winston has a coastal climate - even if he is farther north.  Marion has
yet another climate in Oklahoma.

If your winter weather hits -20 to -40 degree F, and you get high winds --
you are NOT going to want to have the bottoms open with screens, unless you
get a deep snow pack.

You will want to reduce the front entrance.  If you wrap, you do so for two
reasons:  1) CUT THE WIND that pulls or flushes heat from the hive --  the
wrap reduces the air flow through cracks, knotholes, entrances, tops
(remember, most commercial folks don't use telescoping tops - so their
hives get a lot of air movement around the tops), and 2) -- WARM THE BEES
up during a break in the severe cold as a result of the dead air space and
solar absorbance on sunny days.

We need that boost in some areas -- its just too cold for the cluster to
break and move over to frames with food.  Unwrapped hives in our coldest
area sometimes starve with food stores still present -- the cluster moves
from bottom to top, empties the core area, but never moves sideways.  So
they starve.

Not all of our folks wrap, but they at least close down the entrances and
often add some insulation on top, plus pull the hives together so that they
shield each other from the wind.

What we have learned -- don't pack a bunch of straw, insulation between the
wrap and the hive -- we get a thaw in January, then a return of very cold
in February (most years).  Old time beekeepers used to throw in a lot of
straw -- that worked until the thaw - then the water soaked the straw,
which then froze into a block of ice, which melted later in the spring,
soaking everything.

When in Dewey's region, I don't wrap and may even crack the lid -- his
climate has an excess moisture problem.

In Seattle - no reason to wrap, but they used to use slatted bottom boards
to keep the moisture away from the cluster.  I've seen water sheeting down
the inside of the boxes.  I'd guess that bottom screens would work much the
same.

Haven't tried Oklahoma, but I'll bet they get some cold winter.

If the wrap keeps the bees too warm, they'll stay more active and eat more
food.  But if it gets too cold, a wrap may help reduce thermal loss.  E.E.
Southwick did the classic studies on this topic, bee colonies that have
clustered are very efficient in terms of energy consumption at cold
temperatures typical of many climates -- BUT they consume more food when
conditions are either warmer OR colder than that optimal range.

Cheers

Jerry

-- Visit www.honeybeeworld.com/bee-l for rules, FAQ and  other info ---