I collected the beetle on 12/1. In the light of the parking lot that I found it in, I couldn't tell for sure what the cluster was. When touched with a plastic card, it felt hard. Yesterday I decided to remove the egg cluster. As I was pulling on it, there was a gummy substance that almost seemed like old chewing gum, that held the eggs to/in the beetle's abdomen. When looked at under a strong hand lens, the surface of a couple of them appeared to have a pattern like lizard skin (albeit tiny), like a very light net- or scale-like pattern, and they had a darker gray patterned area with the same look. Unfortunately, they have started to dry up in the container I put them in. (The brown strands are just pieces of substrate.)

These are the beetle images: