>NZ has been supplying bees to Canada since the late 1960s/early 1970s.  >i.e. for over 30 years.

I had to withdraw from beekeeping at the beginning of 1970 because of a
location change.  I'm now interested in returning to the fold.  QUESTION:
Mites appeared while I was out of beekeeping (1970-2000).  Did the
intoduction of mites into the U.S. come via Canada from importation from
overseas?