It’s amazing what you can find in a muddy ditch in a prairie.
There were quite a few insects gathering on the edge of the mud; on closer inspection, some were actually gathering the mud.
Black and yellow mud daubers are in the same family (Sphecidae) as the cicada killers (covered in earlier posts), but a different subfamily called the thread-waisted wasps — that’s the long skinny connection between thorax and abdomen, which can be yellow or black in these mud daubers.
Mud daubers are solitary wasps that build a multi-chambered cylindrical mud nest for their developing larvae. Females select an overhanging structure (often man-made) to begin construction of the first cell, add a select number of paralyzed spider prey, lay a single egg in the cell, and then seal it with a layer of mud before beginning the next cell. Then they move on, to start the process over again elsewhere. The larvae are left to develop on their own without adult attendance.
The video below shows how the female brings in the spherical globule of mud in her mandibles and then pats it into place, forming each cell. (You can skip the ad after about 3 seconds.)