The German entomologist Jacob Hubner, 1761-1826, named this species. See John Himmelman's article
. Himmelman quotes a friend, Eric Metzler, on the origin: Latin "horridus" (adjectival horrida) means "standing on end, sticking out, rough shaggy, bristly, prickly". Aha! So Hubner did not think this was a horrifying moth at all!
means "bristly" and refers to the bristles on the thorax"(1)