Hi Jim,  This is a case of wood worm infestation if I ever heard of
one.  Better hope it stays put until you kill it.  You can take it to
an exterminator and he'll gas it with pesticides.  Or you can soak it
in alcohol or lacquer thinner, but that will probably destroy the finish
(although naphtha might be OK).

A much better and simpler way is to put it into the microwave oven
for a couple of minutes.  That kills the worm AND any eggs that might
be laying around.  A couple of minutes ought to fry the little buggers
real good.  I do this to small organ pipes and it works just fine.
Doesn't take very long, just long enough to detect a slight odor of
damp wood, _not_ anywhere enough to get the wood hot.  The bugs are
mostly water and you just have to boil them a bit.

Hope it fits in the oven.  By the way, we won't be able to come over
to your house for dinner this week !

Regards,
Craig Smith