>Which means that over time the angry nature could be bred out with enough diluting of the gene pool.
The problems with that are:
1) We have a program to kill any feral colonies, regardless of their aggressiveness, assuring that it will never happen.
2) AHB have a well developed reproductivity. They make more drones, the smaller drones can fly further and longer than our large cell oversized European drones, drifting of drones means that the AHB drones will drift to EHB hives. The presence of those AHB drones will suppress the EHB desire to raise drones. etc. etc. etc.
3) We have bred for reproductive disadvantage with our EHB. For a century or more we have bred for LESS drones and BIGGER bees which means BIGGER drones who are slower and fly for a shorter period of time. We have even enhanced that by putting them on large cell comb to make the bees even larger resulting in even larger drones.
So far we have been very careful to make sure that diluting AHB does not work.