Can you lure them with something sweet?
We cut the top of a soda bottle and taped it "upside down" (think funnel), then added some sweet juice to attract them. Add a little soap to the juice to do funny stuff to the surface tension. You now have a deadly wasp spa
(It actually works very good)
[ source:
http://blog.patelive.com/2009/07/16/wasp-traps ]