Re-evaluation of the genera Phloeodes, Noserus and Nosoderma (Coleoptera: Zopheridae) with description of a new species of Nosoderma from northern Mexico

We revise the Nearctic species of Nosoderma previously associated with the genera Noserus LeConte 1862 and Phloeodes LeConte 1862 (Coleoptera: Zopheridae). These genera were characterized within the subfamily Zopherinae mainly by the presence of a marked hypomeral groove that may contain totally or almost completely the antennae while in repose. Differences between Noserus and Phloeodes were considered insufficient and the two genera have been treated as a single genus. In this work, a detailed morphological re-description of the Pacific species Noserus plicatus and Phloeodes diabolicus using SEM is compared to previous descriptions of the Atlantic N. doyeni and to some species of the related genus Nosoderma. As a result we found no consistent characters supporting the recognition of either Noserus or Phloeodes as distinct from Nosoderma, and we therefore placed them in the synonymy of Nosoderma. Further examination of type specimens of the Californian Noserus collaris, N. convexulus, N. corrosus and N. torvus allowed us to place them as junior synonyms of N. plicatus. The specimens from Tamaulipas and Nuevo Leon (Mexico) previously included in Noserus emarginatus differ markedly from typical material from Texas (USA) including elytral and pronotal sculpture. We consider that these differences justify the taxonomic recognition of the Mexican taxon at the species level. A description of the new taxon Nosoderma sylvaticum sp. nov. is provided. The Nearctic species included in the genus Nosoderma are thus: N. plicatum, N. diabolicum and N. pustulosum, distributed along the Pacific versant of North America; N. emarginatum, present only in Texas; N. doyeni, known from Nuevo Leon (Mexico); and N. sylvaticum, distributed in Tamaulipas and Nuevo Leon (Mexico).