Hornets

[Fried Chicken]

Spectracide professional wasp and hornet spray. Takes very little and it will absolutely decimate them. It also kills them out of the air like brake parts cleaner, and it’s super cheap.

Do a first dose and wait a day or so, then do another dose in case any of them are still hanging on. Then leave it for a week. They’ll all be dead.

I believe it’s a neo nicotioid pesticide. These are so effective, it’s my humble opinion that they’re responsible for the dwindling bee population. As such, try to use it sparingly. It really wreaks havoc on nature.

 

[FXJenkins]

I've had good luck with road flares on ground bees. Usually there are two entrances, so when you install the flare in the hole, look for escaping smoke.
Pretty hard to extinguish a flare, they usually do the trick

Never thought of that...sounds a lot more efficient than DE. But for this "in tree" situation, invite a friend or neighbor over, give em a beer, simple as that.