I’ve seen quite a few beetles in the plot, including several different species during June. Thanks to Bugguide.net, this one has been identified as Coleothorpa dominicana, in case you’re interested.
ENPO180611_D040
The Prairie Ecologist
Essays, photos, and discussion about prairie ecology, restoration, and management
The Prairie Ecologist 
Extraordinary-looking bugs! What are they feeding on?
I really enjoy your blog. It makes me want to see your prairie and helps me understand/appreciate my little patch in southeast Iowa.
Thanks, I’m glad you find the blog helpful. These beetles were photographed on lead plant (Amorpha canescens) but I’m not sure if they were actually feeding on it.