They have been a menace here last season - more than I can remember for many years - said to be because of global warming and/or less chemicals being sprayed on farm crops.
Easy and cheap traps can be made by putting some beer and/or Coke (Found a good use for the stuff at last!) in a wine bottle and laying it at an angle (so rain doesn't get in and flood it). Wasps love it, bees don't., so you won't drown any of our friends. A weakness is that some wasps just use it as a drinking fountain, so I will be experimenting with some kind of one-way type reversed funnel in the neck of the bottle this year.