Reorganization of New World Helopini (Coleoptera: Tenebrionidae: Tenebrioninae)

The New World Helopini are reorganized following the examination of the holotype from the neglected taxon Dinomus Brme, 1842 (type species Dinomus perforatus Brme, 1842, by monotypy). It has been known for some time that the New World taxa, mostly treated under the genus Helops Fabricius, 1775, are unrelated to the Palearctic type species of the genus. Our investigations lead us to recognize two genera: Dinomus which contains most of the known Nearctic and Neotropical helopine fauna and Nalassus Mulsant, 1854, a primarily Palearctic genus with several Nearctic species. The following genera are synonymized under the genus Dinomus Brme, 1842: Doyenellus, Nabozhenko & Steiner, 2021 syn. nov.; Neohelops, Dajoz, 2001 syn. nov.; Nautes Pascoe, 1866 syn. nov.; and Tarpela Bates, 1870 syn. nov. Other North American genera previously synonymized under Helops Fabricius, 1775 are here moved into synonymy with Dinomus: Stenotrichus LeConte, 1862 syn. nov.; Biomorphus Motschulsky, 1872 syn. nov.; Coscinoptilix Allard, 1876 syn. nov.; and Lamperos Allard, 1876, previously synonymized under Tarpela Bates, 1870, syn. nov. All species in the previous synonymized genera are transferred to Dinomus Brme. All other current New World species identified as belonging to the genus Helops are transferred to the genus Dinomus Brme. Helops perforatus Horn, 1880 from Texas is renamed Dinomus horni Aalbu & Johnston nom. nov. A table is presented for all specific name changes in the New World Helopini.