I had a hive this spring that went queenless, then laying worker.  I emptied
the hive of bees, distant from the
original site, them combined them with a queenright nuc on top, separated by
paper. Eventually the hive settled down,
but then faltered.  No laying worker this time, no brood either.  I
requeened once more.  This time the hive (which produced
nothing this spring was in two hive bodies, with a division syrup feeder in
the top box). The hive faltered again.

 I never did see evidence of dead bees at the entrance, but I suspected that
the hive may have been too close to an
apple orchard, and that pesticide spraying might be affecting them.

  I say this because after all this effort at "bringing the hive back" I
found wax moth damage in the upper hive body, where the
frames were not covered with bees. Cocoons appears within three days of an
inspection.  I cleaned out the damaged comb,
removed cocoons and worms, and replaced the bottom board with a screened
board with no entrance (keeping the bees inside).
I moved the hove farther away from the orchard, and plan to remove the
screen after a day hoping the bees with re-orient themselves.

If the hive has no eggs I plan to give them a frame with fresh eggs from
another hive so they can raise their own queen, or else
combing them with a nuc.

It seems like a small percentage of the hives sometimes end up taking a
majority of "management" time, and being fairly inexperienced
I don't know where to cut my losses (of time) by giving up on a hive.

/C.Crowell