A new species of Ormocerus Walker (Hymenoptera: Pteromalidae) from North America and a range expansion for Ormocerus latus Walker.
Ormocerus dirigoius Morin & Gates, n. sp. is described and compared to the North American O. americanus Dzhanokmen and Grissell and European species O. latus Walker and O. vernalis Walker. A range expansion into the Nearctic is reported for O. latus, previously only known from the Palearctic. Specimens were collected in Harpswell, Maine during a study of the parasitic Hymenoptera community associated with Operophtera brumata Linnaeus (Lepidoptera: Geometridae), an invasive species. The species are keyed and illustrated using macrophotography and scanning electron microphotography.