If robbing is caught early on can it be stopped?
The frenzy can dispersed but the bees may remain in the mood to rob for awhile afterwards.
heavily smoke the source
remove or limit outside access to any sugar syrup
Reduce the entrance to all hives in apiary to the size of a single bee
continue to smoke the source
a beek can close off an entrance completely with #8 hardware cloth so air can pass through
you can also leave an active smoker near the entrance of a source hive to dissuade robbers. though the bees of that hive will hate it too
the bees will calm down but will start up again if they can access the source again
Yes.
Install a robbing screen.
Yes.
http://www.bushfarms.com/beesrobbing.htm (http://www.bushfarms.com/beesrobbing.htm)