Herpetogramma sphingealissp. n., a new species of Crambidae (Lepidoptera), is described from Québec, Canada. The species is included in the genus Herpetogramma Led., 1863, a genus in the subfamily Spilomelinae. Adults and genitalia of this species are described and illustrated, as well as those of Herpetogramma aeglealis (Walker, 1859) and Herpetogramma thestealis (Walker, 1859), and adults of the semi-melanic form of Herpetogramma aeglealis are illustrated.
Keywords: Christmas fern; Crambidae; Dryopteridaceae; Herpetogramma; Polystichum; Taxonomy; eastern North America.