How to make a wasp, hornet or yellow jacket trap from a 2 liter bottle. To keep the bees from getting in here (and keep them doing their good job!) just add apple cider vinegar. Bees don't like the sour, but wasps do.
Prevention of wasps and yellow jackets. Slice a fresh cucumber into thin slices and arrange them in a single layer on an aluminum pie plate. The cucumber must be fresh – the pan must be aluminum. The cucumber reacts with the aluminum and gives off a chemical reaction/scent that is undetectable to humans but drives wasps and yellow-jackets away and makes them flee the area.
I saw this tip in "Country" magazine years ago and use it every year to trap yellow jackets and hornets. I have this one hanging in the grapevine. The yellow jackets like the apple juice better than the grapes. Lures them right in and they can't get out.
The best wasp/yellowjacket repellant for summer picnics: 2 ounces of mint extract. 2 ounces peppermint extract. 10 ounces rubbing alcohol. Pour ingredients into spray bottle and label. Spray down picnic area and play area. The mint is neurotoxic to bees and wasps. Somehow they know to stay away, but if you spray it on them directly it can also kill them.