A new species of Ogdoconta Butler (Lepidoptera, Noctuidae, Condicinae, Condicini) is described from the Patagonia Mountains, Santa Cruz County, Arizona, USA. Ogdoconta
margareta
sp. n., is related closely to Ogdoconta
tacna (Barnes) from Texas. Modifications are proposed to a recently published key to the Ogdoconta species north of Mexico to allow identification of the new species.