Keyhole Wasp Nesting

Subject:  Mason Was planning – I think!
Geographic location of the bug:  SE Louisiana
Date: 07/29/2018
Time: 09:47 AM EDT
Your letter to the bugman:  Found two of these tiny wasp-looking creatures leaving their baby creatures in tiny perfectly round holes in my shed wall. Got a photo of one but the other flew off before I could get her. I say ‘her’ because she was a bit thicker in the abdomen and I thought that maybe she was carrying eggs. After an Internet search I figured that they are probably Mason Wasps, but I’m wondering if you can tell me more. I’m an avid outdoors person and am astounded that I’ve never seen these before! I’m quite familiar with Carpenter Bees, they like my shed as well. An ID would be appreciated!
Thanks,
How you want your letter signed:  Margie from Louisiana

Keyhole Wasp Nesting

Dear Margie,
We feel pretty confident that this is NOT a Mason Wasp in the subfamily Eumeninae, as those tend to be bulkier, based on images posted to BugGuide.  We believe this is a Thread-Waisted Wasp in the family Sphecidae, but we would gladly accept any identification assistance our readership can provide.

Keyhole Wasp Nest
Thanks, Daniel! I also posted to the Insect ID page on Facebook. One of the readers there thinks that it is a Crabronid Trypoxglon? He said “Not a potter, mason, mud dauber, or thread waisted.”
What do you think about this ID?
Margie
Hi Margie,
The large head was one of the features we observed, and according to a comment by Eric Eaton on BugGuide:  “All other our species (the ‘keyhole wasps’) nest in pre-existing tunnels like beetle borings, sealing the finished nest with mud. Paralyzed spiders are used as provisions in each cell.”  That seems like a very good identification to us and we like the name Keyhole Wasp.
Hi,
I’m looking at your site and searching under the Trypoxylon group I found this guy – I think it is the same:
Is this one called a keyhole wasp, too?
Margie
Hi again Margie,
That link was from BugGuide, not our site.  The name Keyhole Wasp was used in a comment by Eric Eaton.  When we researched the common name Keyhole Wasp, we found it in reference to the Mason Wasp
Pachodynerus nasidens on BugGuide.

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