> On the introduction side, I have introduced emerging queens into a nuc from
> which the queen bee has just been caught many times with success.  Maybe it is
> the disruption of catching the queen that increases the acceptance.
 
I don't claim to be an expert on this: maybe I'm just lucky.
 
My understanding was that virgins lose acceptibility to the bees rapidly
after emergence, so have never presumed to try to introduce an older
virgin (more than a few hours old), except at swarming time when I have
found them emerging or running around in a hive and grabbed a few to use
later in the day elsewhere in my travels.  At such times I can't recall
ever having trouble with acceptance, but then again, I did not check back
*too* carefully.  I think I would have noticed though if there had been
problems.
 
In our queen rearing, on the other hand, we have been presented with
emerging virgins a number of times when schedules get loused up for
whatever reason, and again, we have not had much trouble having them
accepted in either baby or 2 and three frame nucs.
 
Again, though I did not presume to hold them more than a few hours, and
after all these years, I guess the things that David was saying come
naturally and I may have met the conditions without thinking consciously.
 
At any rate, I cannot recall having had problems with rejection of virgins
to the extend I have occasionally had problems with rejection of mated
queeens - even after long and careful introductions, sometimes.
 
To my taste there is nothing easier to introduce than a cell. David hit
the nail on the head when he mentioned cell protectors.  We use the JayZee
BeeZee ones - the larger two tang ones are better if the cells are a
decent size - and even put them on the cells *as soon as they are capped*
in the cell holding colonies if there is any chance of a stray queen  or
early emergence. (Note: Jean-Marie sent me some European cell protectors,
and I think we decided that the JayZee BeeZee are superior.  I believe he
purchased some subsequently).
 
We stick cells into anything.  Particularly, we like to make two
frame splits above an excluder.  We slip in a division board and
introduce a cell all in one second trip.  Acceptance and success is fairly
close to the average acceptance level (for us) of mated queens, and cost
is much less.  Any duds we use as seconds on the successful ones when we
move them out, so nothing is lost.
 
As for introduction time, we find cells result in laying queens 11
days later about 75% of the time or better.  With mated queeens on the
other hand, typical release is *at least four days* and often seven, and I
can't count on finding the queen laying until at least a week after
introduction.  I often wait the same ten or eleven days, since the
release rate is so variable.
 
Thus the difference between cells and queens is not great, and
although that can be significant sometimes, on average, it is
not important.  I do direct release queens sometimes to cut the time, but
it is time consuming, since much more attention must be paid, and weather
and time of day are huge (uncontrollable) factors.
 
> Also I have found that if the virgin queen is older i.e say 6 days as against
> 1 or 2 days, the acceptance rate is better.
 
I really can't recall having any virgins that old and can't comment.  One
reason is that I assumed that virgins that old are near the end of their
mating window and risky.
 
Allen