The common grass mantid, Brunneria borealis Scudder, is well known as perhaps the only completely parthenogenetic species among the more than 2,400 named mantid species. An abundant mantid within its broad geographic range, it has long been considered a native North American endemic; however, all other known species in the genus Brunneria (and in its family, Coptopterygidae) are South American. We were able, for the first time, to perform a genetic comparison between B. borealis and a congeneric South American species, B. subaptera. We sequenced a standard segment of the mitochondrial cytochrome oxidase I (COI) gene for which there is no variation among different populations among localities throughout the range of B. borealis, and compared this sequence with haplotypes from different South American populations of B. subaptera.The single B. borealis haplotype falls within the genetic variation of populations of B. subaptera, suggesting that the North American mantid is really a colonist from this South American species.