Will North American honeybees build colonies out in the open?
 
The answer is that such colonies are not common, but they do exist (at least
in the summer).   The way such a colony gets going is if a swarm is
unsuccesful at finding a new homesite, they will build comb where the swarm
gathered and set up shop.   I have seen one such colony in a tree; it lasted
all summer.  Regrettably, such colonies cannot overwinter successfully (at
least in Maryland).
 
Based on my observations, wild honeybees much prefer nice, sheltered trees
and house attics to roughing it out on a tree limb.
 
W. G. Miller
Gaithersburg, MD