Here's a great link about chemical control for cicada killers..it doesn't advocate the use of chemicals because if they are attracted to your yard..you may kill this years stock but they will return..he gives good suggestions about changing your area so they will not return, he also gives a break down of what chemicals will be effective..go to his home page also...he has a wealth of info about them..

I know this doesn't answer your question..and perhaps you are not interested in the article..but using sevin might only be a temporary solution..

Here is a link that might be useful: Prof. Holliday Cicada Killer control..

Why do you have to kill the cicada killer wasps? They are loading up those burrows with numbed cicadas, for their kids to eat. Cicada larva chew on your plants' roots & damage/kill them if there are enough larvae. If you have cicada killers, you must have plenty of cicadas---bugs don't go places where they can't find food.
In other words, they are your friends, just like lady bug larva---as ugly as can be but boy do they eat aphids.
The cicada killers are attracted to the sandy soil; it is easy for them to dig & it is banked a bit. That is what they need, a sandy bank. They won't hurt your plants unless there are thousands of them in a very concentrated spot. They won't sting you (unlike yellow jackets) unless you do something like grab one. All they want is to dig burrows & drag home drugged cicadas. Leave 'em alone & enjoy the show when they are dragging home the booty (Last year we had a very entertaining afternoon keeping a cat from a Mama cicada killer who was trying to drag her catch across our back lawn--too big to fly with).

Well, now it's mid-October, and I'm seeing cicada killers for the first time ever. I thought my yard had been invaded by aliens. There must have been 100 little holes with the little dirt plugs beside them (the plugs look like goose guano). I happened to find a dead wasp and was able to Google it and figure out what was going on. What I don't understand is -- why now? I haven't had any cicadas for several weeks. What is this wasp burying in the ground? And how many wasps do I have if I have so many holes? I haven't seen any but the one dead one. It's very bizarre. I actually contacted Chuck Holliday, but I'm not getting everything answered.

Cicada Killers are beneficial insects that do not threaten humans in any way, so there is no reason to try, or do, anything to control them.

They can be a problem if they decide to set up housekeeping in a well-traveled location. They are quite territorial of their 'nests', something I can personally attest to. Other than that, I've never known them to be aggressive or problematic. I'm one of the very few (I've never met anyone else) people to have been stung, so can also testify (yikes) to the severity. I stepped on one while walking barefoot in my back yard. My fault, entirely.

Kimmsr say that when you have an infestation in your yard or close to your house!