These 4 mud chambers were found on the main stem of the erect skeleton of an herbaceous plant (too withered for me to speculate what it may have been) on a sunny, grassy, north-facing slope surrounded by nearby oak woodland. The chambers were positioned about a foot and a half above the ground. The Calochortus luteus flower in the photo was included to remind me of where I found this (and add some zest to the image)...though it was growing next to the stem, that stem was not from a Calochortus plant.

I gently pulled the top chamber off at its attachment to the stem, leaving the others undistubed. I found 3 pupae and detritus (frass?) inside the chamber. I brought them home and am observing them, though I wonder if the indoor light at night and constantly warm indoor temps may adversely effect their pupal development and/or emergence phenology. If anything emerges, I'll photograph and post it.

Using Photoshop to measure pixel lengths, the uppermost chamber is approximately 10 mm long, based on comparison to my 15mm thumbnail.