…..rages on.
I took the advice of Dan Barnhurst about baiting tuna or a can of cat food with fipronil. Initially I used way too much of my expired Frontline and I believe it was a deterrent to them. Not long after I moved the cage trap closed with the bait onto the balcony off my kitchen after finding their nesting site in the brick underneath. Watching these monsters file in and out constantly was infuriating as well as creepy! Went out and bought pet armor plus and just used half a cc to a whole 5 Oz can and placed it on a paper plate in the cage trap and lashed it to the parapet.
They are definitely feeding and I see them more on really warm days of course, but I feel that the numbers are dropping off. Mixing up a new batch today as it tends to dry out.

Down on the ground below I used K Snows idea of a pop bottle with the top cut off and turned upside down to act as a funnel and put Mountain Dew and some tuna fish in there. Catch mostly flies in that one but there were a few Yellowjacket corpses in there!

Any other ideas would be appreciated. The cold is coming but not soon enough

Very soapy boiling water down the hole after dark

Woah!!!!!! Yikes!!!
I better put my rocket skates on for that!!

If you give to much poison at once, it kills the yellow jackets too quickly. They don't make it home with it. The dosage needs to be small, so they take the poison back and get it in the communal food supply. It will still kill them in a couple of hours or so. You won't see any more after that.

Keith

If you do anything after dark to disturb them, don't carry a light on ya. They will swarm to the light. If you need light set it up where you won't be working and attack from a different angle.

I recently had a small ground nest here at the house....I hit them with brake cleaner as they came out . About 50 jackets in total .....all dead now

Mountain dew draws 'em in. Don't need to add a drop of dish soap, they eventually tire and fall in.

Tempo 1% Dust Insecticide

https://www.domyown.com/tempo-dust-p-391.html

The best by far!!

I have ALWAYS had great success just pouring a few ounces of gasoline down the hole at night, then drop a cover over the hole so they can't get out. Whole nest will be dead by am. Not great if hole is next to a plant you want. Good luck!

get a can of spectracide pro wasp and hornet spray, it contains permethrin, wait till dark, spray a generous amount into the hole, will conntinuee to kill bees for over a week as they go in and out of the nest.

You got a vacuum don't you?

With the cool evenings we're having I don't see those bee's flying anywhere

Powder Seven at the hole.They walk in it and lick it off like a cat.Done.

Shawn Woods or mousetrapmonday on youtube has a bunch of ideas. It's a great channel to watch. He lives someplace near me but I have never met him.

wws

X 2 on Seven Dust
Works
Use a cup with your seven dust or open container so you hit the nest hole

X3 with Sevin Dust. Years ago I have them in the foundation of my house so bad I could hear a hum in the basement. I am pretty sure it was Drifter that recommended it. Took a couple days but all went quiet.

Moosetrot

Permethrin Especially if you can get full strength

Does sevin have a shelf life?

I gave some YJs a lovin spoonful
three times and still buzzin.
No big deal, we get winter.

I use shop vac for those in building.

We're creating killer wasps lol.

They’re creating one mean lady

Diesel fuel, starting fluid, gas, and you may want a lighter or not it’s your choice.