Mike asked-
" Why did the bees attack and pursue him? Why
 did they keep attacking after he was down"

If the bees were the result of a swarm, with all of the travel, the bees
could have been an AHB swarm that hitched a ride that far north.  In
general, I find it difficult to believe that the AHB will not eventually
adapt to our northern climates eventually.

Coleene