Re: Combatting Aggressiveness
If overly defensive ferals (african or otherwise) are in your area - re-queen on the second generation with a new queen line, and practice drone flooding. You can also take a defensive hive and put it in a yard of calm hives, let it swarm or supercede a few times, and eventually it should calm down due to out-crossing with sheer numbers of your own good drones. I do both.
NM desert/mountain beekeeper - Black Mesa Honeybees - locally adapted Southern Rocky Mountain honeybees.