What would cause dozens of yellow jackets to swarm over my patio table, grill, and hot tub for weeks now? I understand they look for sources of protein in the fall but I've never seen this before and there is no meat. Does this mean there is a nest near by? My son is deathly allergic to them. I have tried to watch them return to their nest after dusk, but as you can imagine, that is impossible.
We would guess that they are there primarily because there have been food sources there in the past.
Yellow jackets feed on sweets and protein, and likely they can still smell that, especially from the grill.
If there are any overhanging trees that have insects dripping honeydew, that could also draw them.
It's not likely that there is a nest nearby. They also aren't likely to bother anyone if you stay calm and gently shoo them away, avoiding any rapid flailing.
They will die off with the first good freeze.
thank you so much. Your response caused us to look up at our 120 year old oak and 60 feet away at another dying oak.
It appears to be an aphid problem as it shades a good portion of the deck. But also, we have noticed honeydew on our cars. (under the other oak). A tree expert has come out and said there is no saving the one oak, but will treat the deck oak now systemically as it still has leaves. This should diminish the dew and yellowjackets for next year at least. Could aphids kill a tree?
Are you noting a sticky residue on the deck? Or perhaps a black sooty film/mold which sometimes grows on honeydew?
Aphids feed on almost any woody tree or shrub. They don't usually kill them. Some are native and they have evolved together and can easily take the damage. It's all the circle of life.
Scale insects can also drop honeydew.... but if you are not seeing it, it probably is just the grill.