Gavin Ramsay wrote:
I think that we would both agree that scented flowers will be pollinated
more effectively than unscented flowers, so it wouldn't be surprising if
truly scent-free bee flowers are rare.

You seem to be forgetting that scent is only one way that flowers have of
attracting pollinators. A strongly scented flower may be passed over in
favor of one that produces more OR sweeter nectar. Pollinators are
economists: they don't go where they don't get what they are after. 

By the same reasoning you can see why bees are attracted to patches of
flowers. There may be individual flowers that produce much nectar or pollen,
but the pollinators may find they can get more food from a dense patch of
lower quality flowers. Size, color, these are all important. 

But there are two aspects to the whole process: the scouting and the actual
foraging. A flower may get the scout's attention but if it doesn't contain
the right stuff, it won't be foraged en masse. Of course, the information
from the scout is passed on to the foragers via the "dance symbolic
communication system".

pb

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