I spotted this round black bug yesterday on the leaf of a Mullein plant (Verbascum thapsus) yesterday (August 17, 2019). At first glance, you might think it a beetle, but upon closer examination, I recognized the yellowish outer margin from a larger, very similar specimen someone had asked me to identify earlier. This isn’t a beetle, but a BUG. True Bug, that is. It’s classified in the insect order Hemiptera. Hemiptera means “Half-wing” in Greek. This is a large order of insects with over 10,000 species in North America. It includes “bugs” like aphids, scale insects, cicadas, giant toe biters, stink and shield bugs (like this one!) and more.
This specimen isn’t a full-grown Conchuela Bug, but a nymph. True bugs have what is called Hemimetabolous or incomplete metamorphosis. This means there are 3 stages of development that go from egg, to nymph, to adult. The nymph basically looks like a miniature version of the adult. To contrast, the Lepidoptera (moths and butterflies) and Coleoptera (beetles) have Holometabolous development with 4 stages that include egg, larva, pupa, and adult.
Conchuela is derived from Spanish and means the diminutive of concha shell. These bugs do indeed look like a little black shell with their hardened pronotum, scutellum and rounded body.
In case bugs don’t interest you, perhaps the Hairy Woodpecker on a Mullein plant will. I’ve been enjoying watching these birds rock the Mullein back and forth like a clock pendulum, pecking away at the thousands of seeds held in a single flower head. https://youtu.be/U6lTDcHefz8