First detection of the adventive large rove beetle Ocypus nitens (Schrank) in Canada and an update of its Nearctic distribution using data generated by the public.

The adventive rove beetle Ocypus nitens (Staphylinidae: Staphylininae) is newly recorded in Canada (Ontario) and the state of Vermont, and additional range expansion is documented. The updated distribution of this large, conspicuous species is based mostly on data from digital photographs posted by users of the online community BugGuide. All available data are summarized and made available as a DarwinCore dataset, and an updated distribution map is provided. Citizen-generated distributional data continues to be a valuable ally in the detection of adventive insects and the study of their distributional dynamics.