>    When they swarm, they are broodless for awhile, so I would guess that
they
> did not swarm. Did you notice if the population was down?   More likely
they
> were in process of supercedure. The old queen and the young queen may both
> lay for awhile, so there may be no interruption in the brood cycle.
>

Yes, I forgot to mention that the population was down quite a bit from
before.
I think there were some supercedure cells there when I squished the old
queen,
but I removed them at that time.  But there were the two empty cells at the
bottom
of the frame which I assume were swarm cells.   When I went to see if the
new
queen was accepted, it was a week after she was introduced and 2 weeks after
I made the colony queenless.   It was then that I noticed only eggs, no
larvae and
this unmarked queen.

Does this extra info help?


Thanks,

Ian Watson