If I were to guess, based upon this photo, it looks like a screen tube with a removable end.  I doubt the solid end has anything to do with shade for the cluster.
   
  My hunch is that this is not a swarm "catcher" but rather a swarm "retarder," that is, it allows the swarm to leave the colony but it won't allow them to get away, retarding their progress.  (Is it still politically correct to use that word?)
   
  I gather the screen will allow forages to exit but not the queen (or drones).
   
  That's my best guess based on the picture.  I've never seen anything like it.
   
  Grant
  Jackson, MO

       
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