>...better yet, do not wrap at all.   COLD DOES NOT HURT BEES.  Moisture
and lack of food hurts and kills bees.  They can stand periods of 3-4
months
of severe cold without any wrapping at all...

Not to take issue too much with Lloyd's otherwise good advice, I'd like to
say that this statement -- "COLD DOES NOT HURT BEES" -- may be true
where he lives, and may be true in the Vancouver area, but it is untrue
in many regions, and believing it has caused many, many beekeepers to
come to grief.

Cold DOES kill bees.  Take a few and put them in a freezer.  They'll be
dead
when you take them out an hour later.

Granted, a strong cluster of bees on sufficient feed can 'stand 3-4 months
of severe cold', BUT, in many areas, winter can last longer.  Moreover,
cold -- particularly if accompanied by extreme dryness and wind -- is a
stressor. In many regions, by moderating that stress with appropriate
wrapping, a beekeeper can ensure better survival and much r colony
condition at the end of winter, particularly if the cluster is small and
conditions less than ideal.  Towards spring, the protection wrapping can
provide will make a huge difference in survival and buildup.

In the case of weak colonies and nucs, wrapping or indoor wintering can
mean the difference between life and death for the bees. This has been
proven enough times in enough places to be considered a fact.
Murray's latest post to sci.ag.bee reproduced here also shows how
insulation can make a difference in production.

Nonetheless, there are places and circumstances where wrapping may not be
beneficial or even counterproductive.  I agree with Lloyd that Vancouver
B.C. is likley one of those regions.

allen
http://www.internode.net/honeybee/diary/