Dear bee liners,
 
At 11:24 PM 12/31/96 -0400, Stan Sandler wrote:
 
>I know of two methods that are often used when experiments are done on the
>biological clocks of other organisms.  One method is sometimes to transport
>the animals to a place where the biological clock would be out of sync.> snip
 
>Another method is to put the animals in an artificial environment with
>controlled environment and see how their behaviour changes.  Maybe Jerry's
>flight control rooms are something like that, I'm not sure.  I think that in
>many of the environmentally controlled indoor wintering setups that the bees
>still have an outside entrance and can get light clues.  I would love to
>know whether the bees which wintered under sods as someone described
>recently had built up in anticipation of spring.  I'm not sure, but I think
>it probable that bees overwintered here in cellars in the past would have
>started brood rearing in the dark.  If not I would not think they would be
>much good here where spring arrives so suddenly.
 
We winter our colonies indoors with zero lighting. When we remove our
colonies from the building in late February to early March we see sealed
brood in some of the colonies. The number of colonies with brood from year
to year is highly variable. Around 25 - 50% from one year to another.
 
The bees are not fed in the building and no changes in temperature or
lighting are made during the wintering period. The temperature fluctuates
from 43-47 F and the air exchange rate (3/hr) is held constant.
 
I have no means of regulating the humidity, however, I have noticed that
humidity levels go up toward late winter. This may be because some of
colonies are feeding more because they have brood to feed or possibly
humidity levels go up when outside temperatures rise during late winter
which may prompt brood rearing. Probably not though, we have had one year
when the outside temperature was very cold up until the week we removed the
hives from the building but the inside humidity levels were still greater
than earlier in the year.
 
I believe there is an internal biological clock that can tell the hive
(queen or workers or both) when the queen should begin laying but the
biological clock is only one of many factors that can regulate the onset of
egg laying. This is just an opinion I've formed since wintering bees
indoors, I've never done anything close to a controlled experiment on this.
 
Craig Abel (Entomologist)
USDA-ARS Plant Introduction Station
Iowa State University
Ames, Iowa, USA 50011
Please visit our homepage at:  http://www.ars-grin.gov/ars/MidWest/Ames