Bob,
You mentioned in your comments on the evolution of the sting of  the honey bee,
that the sting of the worker caste is barbed and the sting of the Queen's is
not.
In fact, the sting of the Queen is barbed - but at much reduced level - but
barbs are present.
So, it may be asked:
Has the queen retained a  barb structure closer to the "original" construction
pattern, with workers developing more effective barbs later in the passage of
evolution, or,
has the queen lost the barbed pattern, which has been retained in worker bees?
Possibly, a primitive stage occurred where the sting was similar for both worker
and queen, with subsequent development of barbs in workers and "suppression" in
the queen!

Peter