You could try luring the wasps away with those toss away traps, or just skewer some bacon on a stick & lay it across a can or margarine tub w water in it. The wasps will try to take chunks of the meat & fall into the water. Looks pretty gross though after a couple of days & possums/raccoons will get it at night if you don't pick it up...

I'm jealous you still have hummers. Ours leave around the 4th of July with only stragglers from up north till sept. Jody