That's a great idea. I'll have to dig out my old minnow traps and do that. Thanks for the tip.I have figured out a very clever way to catch flies..
I bought a collapsible (pop-up) minnow trap from Amazon.com for about $12.
I closed off one of the holes leading in with a sewed-on patch of old nylon stocking. What I do, is I put it outside with something smelly down in the bottom. the flies fly in, but they can't figure out how to fly out!
I take out the stinky food, cover up the other hole with a piece of duct tape, and pop the entire contraption into the freezer for a few moments to stun them.
Voil'a! Jumping spider and mantis dinner!
P.S. This would probably work well to catch moths, as well, if I substituted a light of some sort inside for the stinky food.