To: [log in to unmask]
From: [log in to unmask] (P-O Gustafsson)
Subject: Re: Suffocate?
 
Hi Allen,
 
Here are some thoughts on the subject. I'm located in Sweden not far
from Tony.
 
>> It all started with the suggestion that some winter loss could be
>> explained by suffocation -- I would suggest that nobody has actually
>> claimed to have had such a loss, if they had it would be worth
>> discussing why and how to avoid it.
>> We use fairly well sealed hives  here to overwinter (mid-Norway)
>> with a ventilation opening at the bottom.
 
>* Do you use any insulation?
Hives made from high density styrofoam, 25 mm sides and 30 mm lid.
>* Do winter the hives singly or in groups?
Singly.
>* What type of hives do you use?
Langstroth full depth.
>* What is miminum acceptable hive weight going into winter?
20 kg net of sugar, often 5 kg honey left.
>* What are you minimum and average winter temperatures?
Minimum -20, average just below 0.
>* How long at the lowest temperature?  When?
One or two weeks, january-february.
>* When is your first frost?  Last flow?
October-november, august.
>* When is your first pollen?  Snow melt?
Beginning of may, april
>* Typical survival maeasured at May 10th
95%
 
I use hives made only from styrofoam, bottom board as well. The bottom
have an 8 mm entrance and a 200 mm square hole in the center with a
mesh to keep mice out. My opinion is that a hive that is sealed upwards
and have good ventilation under is the best here. Preferably there should
be two entrances during winter so the  wind can move through under the
bees and take CO2 and moisture away. I don't se any difference when
the hives get covered with snow, on the contrary they get a better insulation
and will not be disturbed by birds or other things.
 
I have experienced suffocation problem earlier when I had hives without the
bottom vent hole. After a mild day there can be a build up of ice in the
entrance
that cause the bees to get stressed by the lack of oxygen. They will get
restless, start moving around, raise temp and oxygen consumption and soon
be in a circle that cause them to either deficate inside or fly out to die
in the
snow.
 
Cheers  P-O