Thank you for that Finman. As you know we have a problem with Asian Hornets over here and that swarm trap will be perfect for catching the Queens in the spring Mike
Agreed wbchive. I wasn't planning to put a lure in it but the hornet queens start a small nest in the spring - last year I had one in a bird nesting box - then once there are enough workers they build another nest in an place where they can expand it as the "colony" grows. Once they move into it the queen remains there and the workers forage. So the time to trap the queens is March to mid May and I think that these traps will be attractive to queens looking for a place to start their "colony"
Mike
If you can find a plastic plant pot with a single hole in the bottom, or use clay ones, they would work. You could close the top with the sort of dish or saucer often put under plant pots.
With a big enough pot they would work as bait hives near honeybees as well, although you would have to dig them out if they were there for any length of time after being discovered.