Four species of Tychius have been introduced into North America from Europe: Tychius picirostris (Fabricius) (host plants: Trifolium spp.), widespread in North America; T. cuprifer (Panzer) (host plants: Trifolium spp., Teline monspessulana L.), known only from Maryland, USA; T. meliloti Stephens, new North American record (host plants: Melilotus spp.), known from scattered localities in Saskatchewan, Manitoba, Ontario, and Quebec, Canada; and T. stephensi Schoenherr (host plants: Trifolium spp.), widespread in North America. Keys to separate the species are presented.