Boston Bees
Bumblebee
So how would you establish the ‘strain’....
DNA test? To be honest, best to just keep life simple and just forget about trying to identify bee species. You certainly can't just by looking at them. What you have is almost certainly a hybrid/mongrel, just like all of mine are (I would imagine) and most other people's.
I’ve been told by a few people that ‘local bees’ are usually dark coloured.
What, though, do you or they mean by a "local bee"? That's the question.