Yesterday I grilled a 28 pound king salmon and fed a couple of dozen people dinner. Although we have a significant home orchard (7 trees) and large organic garden, all of which attract a large number of yellowjacket wasps, we had no significant number of wasps at the barbecue, a sharp difference from previous occasions. I'm posting what we did to avoid having the unwelcome visitors to our dinner party.
There are a lot of wasps who live in nests under the eaves of my house. I could kill them, but the last time I did that in a week my plum trees were covered with aphids and the light dawned: there is a link between wasps and aphids. More wasps = fewer aphids. I did a little research and found that yellowjacket wasps are carnivorous. They eat bugs voraciously. Now I encourage them in my yard and garden, and although the aphids and other pests multiply furiously the wasps (and ladybugs, and green lacewings) eat enough of them so they don't interfere with the fruit production. This means I have to spray much less and can use much milder chemicals (I use soap) when I do spray. I have little fear of yellowjackets, because I live and work around them and if I don't bother them, they don't bother me.
But I didn't want my guests to freak out, either. I was fortunate to have a friend who is a commercial salmon fisherman in Alaska fly me down a beautiful big whole king salmon. I filleted it, which left me with two nice fillets and a salmon carcass. About 1PM on a hot day, I put the salmon carcass, tail, fins, everything on a board and put it out in the sun just outside my yard where I knew the wasps would find it. They swarmed over the carcass all day, gorging on the rich food, and by dinnertime they were stuffed and sleepy and left the dinner party almost entirely alone.
I was delighted that my idea worked so well. Most of my guests, like most Americans, are very fearful of yellowjackets and they spent a comfortable 4 hours in my yard without knowing they were within a few feet of many hundreds of them. I believe this method would work at nearly any yard barbecue or dinner party. What a freedom, not having guests swatting at wasps!
Grant Erwin Kirkland, Washington