Re: SHB - Northern Extent Question
I have never bought a package and have SHB. I am told my queens originated from Hawaii. Once you have them I think you will always have them, just my thoughts. Unless you can kill every last one in the hive (including eggs). The SHB can fly up to 5 miles away so if your neighbor within 5 miles has or had SHB you can get them too. I see the SHB in the north more of a nuisance, right now anyway, for northern beeks rather than a major threat to the hive, similar to ants.
Zone 5a, Practicing non-intervention beekeeping