I rarely kill wasp nests, unless they pose a danger to me and students and friends as they are such effective predators, especially of caterpillars. But this morning, seconds after I began weeding my back door veggie garden I got stung in the right cheek...I'd not noticed that small wasps had built a nest on the tomato cage just inches from my face. I am nearly immune to bee and wasps stings, probably due to my having been bit many hundreds of times over the years as a Florida landscaper by fire ants, who inject the same poison.....formic acid. So the pain and swelling will be brief. Yet I DO need to weed that garden!
So I went to my laundry room, and grabbed a giant can of WD 40 that I dumpster dived ages ago, and sprayed the nest. Death of the adults is near-immediate, plus the larvae all die soon therefter when the WD 40 penetrates the paper nest. It is best to do this at night when all the wasps have returned to the nest, but I want to weed that bed today.
Sure this is not an "organic" technique, but it is cheap and one hell of a lot less toxic than using a commercial bug spray. I realize that this approach will be outside the comfort zone of a purist, but it IS effective and meets my own comfort zone needs.