Hello Gerald & All,
A guess is about all you will get because as you say several possible
scenarios are possible.

>I manually released her, and I noted no evidence of balling the queen. She
casually looked around, sat on my finger actually, and then as I put my
finger between frames, she ran off down the frames.

The big drawback to the above method of release (which I use myself with
Russians) is you need to observe for at least five minutes. Less if the new
queen moves into an area  of older workers. Nurse bees normally accept even
new queens without an introduction period.

.>Now, seven days later, I find no larvae in the hive,

Assuming she started to lay right away  the only larva you might find would
be four days old (still very small). At times even mated queens take a few
days before laying however I have direct released queens which layed and egg
within the first five minutes.
I believe you should *normally* at least find eggs after 7 days *unless* the
queen was not mated. An unmated queen could be a possibility.

> an old opened queen cell, and an unmarked, large, light colored
queen on the frames (the Buckfast queen was marked).

The above is the most likely reason your Buckfast queen is missing. The hive
*honored* the lone queen cell and later dispatched the Buckfast queen or the
newly emerged queen dispatched the buckfast queen.
I still believe if you look carefully now the next time you look at the hive
you will find eggs from the new unmarked queen. If the new queen is large,
normal looking and laying a good pattern you might consider leaving her as
the time to add honey supers in Missouri is fast approaching (if not
allready on for Black Locust).

If she is punny looking and the cell she emerged from is small and dinky
then I would consider a replacement queen. Because you dispatched the old
queen the hive might have selected a correct age larva for her replacement .
Not all queens the bees raised by the bees  are poor but many raised from
failing hives are for sure.
Sincerely,
Bob Harrison

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