Larvae of Sthenopis auratus (Grote) were found tunneling in the artichoke-like leaf bases and stems of several ferns: Ostrich Fern (Matteuccia struthiopteris (Linnaeus) Todaro), Marginal Shield Fern (Dryopteris marginalis (Linnaeus) Gray), Mountain Wood Fern (Dryopteris campyloptera (Kunze) Clarkson), and Lady Fern (Athyrium filix-femina (Linnaeus) Roth), all Polypodiaceae. An ichneumonid parasite, Pterocormus devinctor Say, was associated with a cocoon of S. auratus. The early evening calling behavior by males is described. The male has prominent androconia on the hind tibia presumably for dissemination of a pheromone. Males did not seek out females, but rather adopted sessile calling displays on emergent understory vegetation. Additional locality records are given for this rare northeastern moth. The larva and pupa are described and illustrated in detail.