Subject: Mason Was planning – I think!
Geographic location of the bug: SE Louisiana
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!
How you want your letter signed: Margie from Louisiana
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.
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.
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.