Since I have a program of collecting ferals from over a several county 
area to evaluate for preferred characteristics, I find that a small number 
of swarms collected can develop into extremely aggressive colonies as the 
colony reaches stages of maturity.  A casual observation is that these 
ultra aggressive colonies tend to originate in location from areas near to 
domestic beekeeping, and tend to, but not always, appear to be a somewhat 
darker strain of bee.  It’s no big deal, but the problem is that they tend 
not to exhibit much aggressiveness until the colony grows near to 
maturity, so time and resources are wasted, and the colony after maturity 
reaches problem status very quickly.

What prompted me to respond is,,,
I’m not concerned much about ‘hives that boil out when shaken a little’,  
every colony can have a bad day, and these occasions can warrant a second 
chance.

I am much more concerned about (and cull immediately) colonies that:
1. boil out from visual stimulus such as a passing shadow,  
2. boil out from sound stimulus.
3. spontaneous eruption with no apparent stimulus
4. colonies that smell of alarm pheromone when alarmed, sometimes detected 
at 3 feet away of more. 
5. follow a distance of more than about 20 meters 

As my continuing monitoring tool, colonies are watched closely concerning 
their response to any stimulus.  If a colony exhibits elevated 
aggressiveness while working them, I will come back at a later date and 
simply smoke and remove the lid while I work the yard.  I have found that 
leaving the roof off and nest exposed to sound and visual stimulus for a 
short time will often reveal the demeanor of ultra aggressive colonies.  
While doing my yard work, I will frequently walk by to observe the 
suspected aggressive colony which is left opened with the roof and 
innercover removed for several minutes. 
If the colony smells of alarm pheromone, spontaneously erupts, or erupts 
from visual or sound stimulus, it will be slated for immediate culling.    
  
Best Wishes,
Joe
 http://pets.groups.yahoo.com/group/HistoricalHoneybeeArticles

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