I study local feral hives.  The hives that are surveying are the open outside
the tree (Orlando's weather permits) ones.  The ones inside walls, fire
chimney, and dressers are hives that have open area under them.  All the
hives have mites but the ones with an area underneath them of open space are
survival hives.  The small hive beetle ate the center brood and pollin from
the hives but they survived.  Weaken but not gone they have went thur another
year.  Open Bottom is the only common item.  The bees that are weaken fall
from the hive and or can't reach the 25 to 40 feet height where the hive is
located.  If propolis, pollin, or honey nectar had been the answer the hives
would have a common plant/flower in the area.  Ants have cleaned up weaken
hives but they can be chemically controlled away from the honey and products.
 I use a queen extruder inplace of a floor and these have are starting to
produce excess.   Michael Housel  Orlandobee