Oxyporus delgadoi Márquez, Asiain & Fierros-López, sp. nov. is described based on seven specimens collected on mushrooms of the genus Pholiota near Zacualtipán, Hidalgo, Mexico. The new species is similar to O. flohri Sharp known from Veracruz, Mexico and Guatemala, and represents the seventh Mexican species of Oxyporus. New locality records and taxonomical comments are provided for O. lawrencei Campbell and O. flohri.

A systematic revision of Plochionocerus Dejean, 1833 and Agrodes Nordmann, 1837 (Staphylinidae: Xantholinini) is conducted. Based on a phylogenetic analysis, the genus Agrodes, which includes A. conicicollis and A. elegans, and appears as the sister taxon to Plochionocerus, is revalidated. The genus Renda was found to be the sister taxon of Agrodes plus Plochionocerus. Plochionocerus leprieuri is transferred to Renda (comb. nov.). Plochionocerus (sensu stricto) is a monophyletic genus supported by six synapomorphies, but relationships of its species are not resolved because of the high proportion of homoplastic characters. Keys to the genera Renda, Plochionocerus and Agrodes, and to the species of the two latter genera are provided. Plochionocerus and Agrodes stat. rev. are redescribed, and diagnoses for their species are given. Eight new species of Plochionocerus are described: P. ashei, P. gracilis, P. hermani, P. modestus, P. newtonorum, P. pronotalis, P. reticularis and P. transversalis. Based on the study of type specimens, 17 new synonymies are proposed for species of Plochionocerus and Agrodes: Plochionocerus fulgens (Fabricius, 1793) = P. violaceus (Olivier, 1795) syn. n., = P. amazonicus (Sharp, 1876) syn. n., = P. carinatus (Bernhauer, 1916) syn. n., = P. auripennis (Bernhauer, 1927) syn. n.; P. janthinus (Erichson, 1847) = P. peruvianus (Bernhauer, 1907) syn. n.; P. simplicicollis (Waterhouse, 1879) = P. basalis (Sharp, 1885) syn. n., = P. mandibularis (Sharp, 1885) syn. n., = P. pollens (Sharp, 1885) syn. n., = P. nordmanni (Fauvel, 1901) syn. n.; P. discedens (Sharp, 1885) = P. nevermanni (Bernhauer, 1942) syn. n.; P. humeralis (Sharp, 1885) = P. kayseri (Bernhauer, 1927) syn. n.; P. puncticeps (Sharp, 1885) = P. lautus (Casey, 1906) syn. n.; P. impressipennis (Sharp, 1891) = P. punctipennis (Bernhauer, 1916) syn. n.; P. igneus (Fauvel, 1901) = P. magnificus (Bernhauer, 1911) syn. n.; Agrodes elegans Nordmann, 1837 = P. longicornis (Sharp, 1885) syn. n., = P. melancholicus (Schubert, 1911) syn. n.; A. conicicollis Sharp, 1876 = P. longiceps (Sharp, 1876) syn. n. Lectotypes are designated for P. humeralis, P. impressipennis and P. simplicicollis. Biological and distributional information is given, and 24 first country records are reported.

Se presentan 14 primeros registros estatales de 13 especies de Staphylinidae para los estados de Hidalgo (siete especies), San Luis Potosí (cinco especies) y Guanajuato (dos especies). Se incluyenlos datos de distribución geográfica hasta ahora conocidos para cada especie, los cuales se ubicaron en las provincias biogeográficas mexicanas. Al analizar la distribución geográfica de cada especie, seapreció que corresponden con cuatro patrones de distribución, tres de ellos previamente reconocidos en distintos grupos de coleópteros y uno más que se reconoció en este análisis: Componente Mexicano de Montaña (una especie), Componente Mesoamericano (siete especies), Componente Mexicano de Montaña-Componente Neártico Continental (tres especies) y patrón biogeográfico Sureste de México (dos especies). Además de ubicar a las 13 especies en cada uno de estos patrones, se incluyen otras especies de Staphylinidae y de varias familias de coleópteros que sustentan estos patrones.

The geographical distributions of 2 species of Agrodes and 13 species of Plochionocerus were analyzed using a panbiogeographic approach to identify their biogeographic patterns. Nine species have been recorded as being exclusively from South America, 2 exclusively from Central America, and 4 are shared between both areas. Two species of Agrodes and 3 of Plochionocerus are widely distributed in 2 or more subregions of the Neotropical region, and 6 species of Plochionocerus have more restricted distributions, basically ranging in a single subregion, and 4 species are restricted to a small number of localities. Three generalized tracks were identifi ed in the Mesoamerican dominion of the Caribbean subregion, in the northwestern South American dominion of the Caribbean subregion, and in the Amazonian subregion. Species of other staphylinid genera provide additional support to these tracks.