I have a giant ground wasp nest by my back gate, which is making mowing awkward. The nest is big and deep enough that spraying was ineffective, as was putting a bucket of ice on it, and I didn't want to go to the more extreme methods like gasoline and flame because it's right against the house, and gasoline is much more dangerous than wasps. So we decided to try some traps. If you add cat food to the juice bait, the bees aren't interested in the bait, but the wasps are even more delighted with it. So we bought a really cute wasp trap:
After three days we caught nothing but ants in it,(it's not deep enough) so I made a ghetto version out of a plastic milk jug and holes in the middle of the sides and at least 4 inches of liquid in the bottom (fruit juice and cat food mixed, tablespoon extra sugar) that I knew from experience works:
You do have to let it sit for a couple of days for the wasps to find it, even if you put it right in front of the flyway for the nest. But they did find it:
That is the view down into the milk jug after 3 days. Eww. We still had to spray again and when it gets cold we will have to add more ice and dig the nest out. If the wasps had moved in on the far side of the yard we would have left them alone, but they really can't live where I need to work. And I was happy to say there were no bees (like the one on the thistle above) in the trap.