Hello All,
Robert wrote:
> >        V B Wigglesworth was a  -  I would suggest  the  -  the top
> >scientist in insect physiology.  When he says as Bob quotes, you can take
> >it as reliable.  If VBW said  glycogen stored in *flight muscle*
supports
> >flight for only 10-20 minutes, you can infer that this animal indeed
> >possesses the means to replenish that glycogen store several times daily
> >(because we know bees typically fly many trips of 10-20min daily).
     If in response it be postulated that a bee can die from inability
> >to fly owing to depletion of that glycogen store while far from the hive
on
> >a foray, I would then ask whether it can run on sugars from nectar
gathered on that very foray.  I would expect it to do so.  Has this been
examined?

Wigglesworth says after the stored glycogen in the flight miscles is used up
then the trehalose from the blood is the primary fuel ALONG with sugars from
the honey stomach.  With much  of his research Wigglesworth gives exact
data. Quote Wigglesworth 1984:
"When foraging bees are taken from flowers, the sugar disolved in the
hemolymph averages 2.6% (0.08molar). Blood sugar  concentrations as high as
11.5%(0.35 molar) have been recorded. Should the concentration fall below
1%(0.03 molar), the forager is no longer able to fly. When bees feed on
*rich* sugar solutions , they can fly as fast as 29km/h, while a dilute
solution results in slower flight speeds (4-7 km/h)."
I can go on and on quoting about glycogen.  Mr. Winston is simply incorrect.
The honey bee does not DIE  after the glycogen in the flight muscles is used
up. (as stated in previous post and in the quote from*The biology of the
Honey Bee*) but uses the sugars  in its blood and the sugars in its honey
stomach ( which are gathered from flowers).  The above is pretty elementary
stuff.  Maybe the original quote by Mark Winston is incorrect or taken out
of context.
According to Wigglesworth the sugar normally carried in the blood provides
for 15 min. of flight or about 5.5 km distance.
Sincerely,
Bob Harrison
Odessa,  Missouri