Tom asks >moved it to an out apiary - a distance of 15km (9 miles) - to
prevent bees
returning to their old hive.
 
How soon could I move it back to my home apiary without losing bees?.>
 
Tom, three weeks is surely enough time.  I do not know how little time is
possible, but I suspect it might be as little as a week.  Think about what
is going on...a beekeeper wants the field bees to "forget" the location of
the old hive, which they do by orienting to the location of the new hive.
This will happen within a day or two at the new site.
 
In the September issue of Bee Culture, one of our national magazines, Roger
Morse (one of the most respected researchers) cites two studies of how long
a field bee lives.  Both studies found it is only 3-7 days.  If this is
true, all the bees that were oriented to the old site will be dead in 8
days...meaning a week is probably enough.
 
Lloyd