cover it up, I would make one suggestion. You have two vent screens on top the bucket. I would remove one and replace it with a piece of queen excluder. Cover it with cardboard and tape over it. Once you have the swarm on the ground and the lid on, remove the tape and cardboard. You will know with in 2 minutes if you have the queen.
If she is there, the flying bees will gather there and go in. If she's not there, they will empty the bucket in 2 or 3 minutes. Then you will see them go to her and you can try again.