Having been stung by bees and wasps and bumblebees (sometimes to
extremely unconfortable extremes) I can't resist putting in my two cents
worth here.  I agree completely that light-dark color contrasts (like a
wristwatch band on a white wrist) are inviting targets for disturbed bees.
As for rough textures my guess is that entanglement (as in the hair) provokes
defensive stinging.
        One additional important factor surely is the release of alarm or
excitatory pheromones by a stinging bee or wasp.  Subsequent stings will
usually be directed at the site of an initial sting.  A number of years ago
I disturbed (by choice) a nest of white-faced hornets and watched as they
directed their communal ire
(mistakenly) on the decorative finial of a porch railing post.  Within a
short time the poor finial was soaking wet with alarm pheromone, and I could
feel the stuff splashing through my protective veil.  Chemosensory cues are
important.
        Despite the bickering among beekeepers about the virtues of one
source of smoker fuel over another, I've wondered if the most important
"calming" component of smoke isn't carbon dioxide--which is a wonderful
anesthetic for insects.  Has anyone out there tried working honeybees with
a reasonably dilute CO2 gas mixture?
        Several years back I was interesting in sound frequencies to which
honey bees are sensitive--particularly the "quacking" sounds emitted by
newly emerged queens.  When I played appropriate frequencies (1000 - 1500 hz
as I remembered) to small groups of confined workers, they often reflexly
"froze" for brief periods.  This gave me the cockeyed idea that a sound gener-
ator might make a wonderful tool to handle bees with.  So I rigged up a
loudspeaker to play a pure 1500 hz tone, strapped it to a hive, turned it
on and opened the hive.  The bees did not seem to mind, kept moving, but were
not aggressive either.  The problems were with the neighbors--who complained
bitterly about the noise.
        A final thought has to do with stinging in honeybees, and the
seemingly extraordinary altruism it involves.
I would like to ask if honeybees, which often sting other bees or insects while
defending their colonies, fatally lose their stings in that sort of defense.
If anyone knows, I'd appreciate the information.
        Sanford Moss