Best way to kill yellow jackets deep in a wall?

We have a Versilok wall, and one stone has a gap inhabited way back in with yellow jackets, I've been stung once already! I have some foaming yellow jacket/carpenter bee spray and I've blasted them no less than 8 times with zero help! The spray has a 6" straw and I've spared no product in attempt to kill those bast**ds. Does anyone have a better suggestion? The nest is in the wall right near my automatic garage door keypad so I just can't completely avoid them.

 

I had to look up versilok wall as I'm not familiar with it. Seems like it is landscaping blocks? Did I look it up correctly? If so, then the jackets are not in the garage wall, but a very close-by exterior block structure? In any case, when the aerosols fail, it is usually because the jackets are going in and then up to their nest. The aerosol and any liquid spray go in and then down. If it's a retaining wall type of structure, can you look behind it or on top of it to see if they have another entry/exit? If so, that could be the most direct shot. Sometimes that doesn't even work, and I'd dress up well and dig it up, having aerosols at hand. Evenings near dark would be best. I may have more ideas when I get a better picture in my mind as to the situation.

 

The Versalok wall is an outside retaining wall. Apparently they are way back in possibly in the dirt or gravel behind the wall. There’s no way I’d dig down from the top, it’s too deep and there’s a bunch of fill for drainage back there.

 

I have barn type siding on my front and back porch. Several times on the front porch we've had yellow jackets find a home behind the siding. We keep spraying into the crack and eventually they are gone.

 

I'd start spraying above the hole you've seen them using and I think insecticide is pretty cheap compared to the pain of the seven yellow jacket stings I took last fall when I mowed over a nest so I might use a few cans all over the wall, but that's just me.

 

OK, got a better picture, now, thanks. I would still inspect on the soil at the top of the retaining wall to see if there is another entry/exit point, as that would be another direction to treat from. If by chance this exists, a water based insecticide poured into the opening would go down, hopefully to the nest. Insecticide concentrate mixed with water.

Otherwise, have you tried the non-foaming aerosol sprays that are more of a jet spray? They may spray with more force and penetrate deeper. Eye/splash protection advised. Insecticide powder, such as the Sevin brand, work well on nests. The difficulty is applying them. The pros use dusters of various styles, but sometimes it can be applied with a teaspoon or similar, by throwing it into the gap if there's enough room. Probably have to do that repeatedly if you can't get a large volume in.

 

I just had the same problem again. Once last year and again this week.
After chasing my tail last year... I hired a local exterminator. He used a smoke machine and powder.
There were hundreds of bees in the area.
They were gone in two days.


DIY only goes so far.