There are still a few occupied bee trees in this area (western West
Virginia) and one of the largest swarms I captured this year came from a
house in town that is said to have been there for many years. AFB is not a
problem here so this may help.
Speaking of small cell size, I noticed my older hives without queen
excluders move up into new honey supers as I add them through the summer.  I
know this could be from many reasons but wonder if bees do prefer newer
comb.
 
Steve Davis
 
>I doubt the small cell or the infrequent handling theory mentioned in
>another post. Just a few years after the onset of varroa there are
>practically no feral colonies here in Western New York. Farmers and long
>time residents have told me of bee trees that have been around for many
>years, were always populated and are now dead. Gardeners and vegetable
>farmers tell us there are no bees visiting their crops. It seems likely
>that  many of these colonies had small cells as you mentioned and bee
>trees are seldom disturbed by beekeepers.