Re: Mystery Egg or Intercaste Queen.
I do a lot of cutouts. This is pretty typical. I have seen them continue to build emergency cells even after they get a laying queen only for them to be subsequently torn down. I have heard differing explanations on why they are later torn down. Some folks say that a new queen herself is supposed to damage them when she comes across them, others say the workers do it when they decide the queen is acceptable.
I also have a number of hives that keep a lot of empty queen cups around just to be prepared. I don't know if the queen will lay in them and the workers clean out the eggs or if they just escort her away from them until they are needed. Eventually they tear them down or fill them in with wax if they are never used. All my hives headed by Russian queens do this.
"The UNKNOWN, huh? That would be SNORBERT ZANGOX over in Waycross."