This is a species of special conservation concern in Pennsylvania and adjacent states.
Research: Head and mouthparts in anteroventral view of last larval instar (caterpillar) of the grizzled skipper, Pyrgus centaureae wyandot (Lepidoptera: Hesperiidae). Pen and ink over pencil sketch taken through stereomicroscope of preserved larva, securely positioned with pins while submerged in ethanol. Pencil work reviewed by specialist (Dr. John E. Rawlins), and modified or enhanced by artist according to his critique. Depiction requires strict attention to precise shape, location, and placement of setae and other surface structures.