Thecturota tenuissima Casey, is reported for the first time from Canada, based on records from Ontario and Quebec. It was originally described from Rhode Island, USA, and no other records of this species in North America were published since that time. The specimens from Canada were captured by car netting. We provide here a redescription of this species and never before published images of habitus, tergite, and sternite VIII of both sexes, median lobe of aedeagus and spermatheca. The features distinguishing T. tenuissima from T. capito Casey (=pusio (Casey)), the only other species reported in Canada, are provided and illustrated.
Keywords: Aleocharinae; Canada; Coleoptera; Staphylinidae; Thecturota; new record.