Cicada Killers

I have a huge infestation of Cicada Killers. They are a fascinating creature and surprisingly unthreatening, but they are in the front and back yard of a house with a tenant whose dog uses the yard and freaks out in their presence, and I have small children that play in the area. I have tried a few spot treatments and it is hard to tell if I am making a dent in the population. I put out over 100 flags today marking the entry holes. The property has my food forest / orchard on site and they are on the edge on one side and intermingling a few trees and raspberries at the back.

These guys popped up last year at this time (as they do) when the previous tenants were moving out so it wasn't noticed but they have multiplied considerably this year, and I would like to keep them from further spreading into the orchard where treatment will more greatly impact the trees.

I would love to find a more natural treatment, and I understand these things can be beneficial, but the balance is WAY out of order and it is truly and infestation. I have read plenty of things on what treats them, but I am hoping to hear a personal success story or alternative way of dealing with them around food producing plants.

That sounds tricky, especially since you have other folks and a dog who aren't quite as tolerant of the insects to think of. Depending on the ages of the children, perhaps some simple education about the insects being harmless as long as you don't mess with them would help? The dog is trickier. Perhaps there are certain times of day that the cicada killers are less active that would be better for the dog going out until you figure out a better solution? Maybe the dog tried to eat one and got stung? I wonder if something like Rescue Remedy for pets could help calm them down so they can learn that as long as they don't mess with them, they aren't a threat?

While I totally see why you'd want to check their numbers given the circumstances, I do wonder if that's a good idea. If there are that many of them, it seems to me it would indicate a ridiculously high number of cicadas and their larvae. I guess I'm saying, if you remove the cicada killers, you might just have a cicada overpopulation issue in some years. Just something to consider.

There is some good information about the life cycle and habitat preferences of the cicada killers here:
https://entomology.ca.uky.edu/ef004
They suggest that drenching the area around their burrows with just water could sometimes cause them to abandon the site, because they don't like wet soil. Maybe worth a try in areas where interaction with people and pets is most problematic? Then if it works, you could try just keeping up with more regular deep watering to discourage them? It sounds like even if you killed all of them, as long as the site is attractive, more will show up. So changing the conditions to not favor them seems the best long term solution. Wet soil and reduced sunlight seem to be what they don't want and are easiest to address.

I would try one of two things or both:

Pour vinegar onto their nests.

Make a soap solution to spray the cicada killer wasps.  

I have a very good tolerance for insects, bugs and critters in and around my house, orchard, and garden and I often point out the predatory wasps flying around and appreciate their job eating whatever it is they eat. This is something different, and on the level of an Alfred Hitchcock movie. I thought a similar thing about cicadas, but I have not seen any evidence of those for years and have only had these wasps show up as recently as last year. If these things were eating Japanese Beetles that would be a different story, but I have yet to find a good natural solution to those either and they do great damage to my trees.

The ability to store the dog in an enclosed area is part of our agreement, and I completely understand the objection to the infestation as it stands. I absolutely hate considering more drastic solutions, but it may be what needs to be done.