Sid Pullinger in his piece on bee races suggested "I would suppose
that in countries as large as the U.S. and Canada beekeepers are
widely spaced. Thus most matings would be with drones from one's own
apiary and would be pure most of the time."
I would seriously doubt that there are many (if any) places in the
U.S. (or Canada?) where the conditions described exist. The
relatively new mite problems in the "Lower 48" (This refers to that
portion of the U.S. which has the misfortion not to be Alaska or
Hawaii) may leave feral colonies scarce (temporarily) in some areas.
Even so I would guess that the density of beekeepers is still too high
to leave many matings with drones from the same colony. I'd be
interested to hear some statistics on that, both ante-mites and
post-mites.