... introduced it to a new 6 frame nuc box on Friday (around 5pm) evening using the bedsheet and ramp method. I watched to confirm some of the bees were entering the potential new home and left them too it. When I checked later (around 10PM) I found that most of the bees had settled (bearding?) outside the nuc.
It's now Sunday and no change ...
It's a fair size swarm, the guy that helped me catch it said probably around 15-20,000 bees.
... there are a few bees clustered just inside the entrance and the rest is empty.
They haven't gone in.
It isn't that the space is too small and they are overflowing.
They never went in.
So ... why?
1/ Is the entrance disc
pinned fully open?
The central screw is simply
not enough to prevent the disc rotating under the weight of a beard of bees.
2/ "Walking the bees in" is for spectators benefit. Do it differently, to benefit you and the bees.
Set the entrance to the Queen Excluder setting. And pin it securely - map pin or nail, not a drawing pin.
Dump the bees inside.
Add frames gently and allow them to sink gently between the bees - don't push them down!
Fit cover and roof.
And I'd leave them like that until dark and all the scouts and stragglers have joined and gone inside.
Close and pin the entrance for the journey home.
Once home, repin it at the QX position.
Leave for a couple of days before feeding and opening the entrance properly. Again pin it so it stays where you set it.
3/ Give them an old frame, not all foundation. Bees love "second hand" not new. And your nuc is new.
I have 6 frames with foundation in the nuc but none are drawn.
4/ I'd bet that it was from one of your own hives
I do have two other hives in my garden (one of which produced this swarm) but I am reluctant to open these as they have new queens (I hope) in them.
The rest of that story might well help to explain the origin of the swarm.
5/ Swarms don't start out Queenless.
If Q ain't there, they just return to their hive. (As we know, this is the justification for Q clipping.)
They may get Q- as a result of beekeeper misadventure, but it sounds like this swarm was in or around your own apiary.
If you didn't catch Q, they'd have leapt straight back up into the tree where Q was last seen/smelled.
6/ I reckon they either cannot get in or Q is under the nuc.
I'd probably try and shake/brush them off the outside of the nuc into a cardboard box, and then tip them into the nuc (as above, then add frames).
The one thing you need to ensure is that Q is NOT left on the outside of the nuc. Check the ground beneath the nuc ...
It ain't about finding her, it is about ensuring that she ISN'T in the wrong place.
Depending on your weather, I might water mist the cluster to prevent too many flying off.
The cardboard box needs to be taped internally so that there are no 'flaps' that bees can hide under and resist being dumped into the nuc.
And I'd feed them this afternoon as it is a few days since they swarmed.
With Q inside, and the entrance pinned at QX, there would be no risk of absconding.
I'd move the nuc just far enough so it isn't covering the same patch of ground.
Then watch to see whether the flyers Nasonov at the nuc entrance or at the patch of ground next door.
They'll tell you where THEY think Q is. If she's outside, repeat the exercise until successful.
