Adony Melathopolous assumed a bee flight muscle temperature lower
   threshold of 25 C, and predicted a sustained flight temperature
   threshold of 12 C, with flights below that temperature, dependant on
   heat retained from a visit to the cluster.
 
   The reasoning is fine, but since in this area we have a lot of days when
   the temperature never gets to 12 (most of our spring build up), yet
   there is a lot of sustained bee flight, some of the thresholds must be
   different from those Adony used.
 
   Perhaps we'll get some actual measurements from someone, but I could add
   a few impressions or observations:
   - at -10 C bees that fly out from an exposed cluster will shut down and
   drop out of the sky after 5 or 10 seconds (my impression, not timed)
 
   - when hives are opened to feed bees in the fall at 0 C, bees will fly
   from the cluster quite actively and keep it up for minutes (perhaps
   they're creating heat as fast as they're loosing it). If they land on a
   bee suit they will cluster, and when brushed off they might fly.
 
   I've seen bumblebees foraging at less than 5 C (though they might
   experience warmer temperatures in the sun, especially in those blossoms
   that track the sun and provide a parabolic solar heated platform)
 
   - hives put out in "spring" (2 weeks ago here) at 5 C can have lots of
   flight, apparently sustained although a lot of bees end up on the snow.
   However, a bright sun on a still day might add quite a bit of heat to a
   dark bee.
 
   SEASONAL CONDITIONS: Dawson Creek 55 deg N Lat  April 24
 
   Well, I've bit my tongue and held back any response to the reports of
   honeyflows and swarms from S Carolina, but I guess it's time to report
   that winter is over here. We had an impressive blizzard April 2, lots of
   drifting snow, but the daylight hours are too long to allow it to stay.
   About April 15, the temperature stayed above freezing through the night,
   for the first time since about October 20 (nearly 6 months). Flat open
   ground became snow free over the past 10 days, south facing slopes have
   a few blades of green poking through the dusty beige dried grass. Shaded
   spots still have piles of icey snow. Pussy willows are out and I've
   heard of some pollen being spotted, I guess from a particularly sunny
   spot. At the base of a southern wall, I even saw a dandelion blossom
   open!
 
   This isn't a complaint (well maybe it is, but I know that won't help).
   The remarkable thing is that the honey bee colonies that look so pitiful
   now, will recover and build up to the point that 150 lb of honey can be
   harvested from them.
 
   Busy days ahead
 
   Kerry Clark, Apiculture Specialist
   B.C. Ministry of Agriculture, Fisheries and Food
   1201 103 Ave
   Dawson Creek B.C.
        V1G 4J2  CANADA          Tel (250) 784-2231     fax (250) 784-2299
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