Revision of the Genera Pseudatheta Cameron and Phymatura Sahlberg (Coleoptera, Staphylinidae, Aleocharinae) from Japan.

New taxonomic and distributional data for five species of the genera Pseudatheta Cameron, 1920 and Phymatura Sahlberg, 1876 from Japan are provided, and the following seven species are recognized: Pseudatheta crenulicauda (Bernhauer, 1907), comb. nov. (= Pseudatheta similis Pace, 2010, syn. nov.); Pseudatheta taiwanensis Pace, 2008; Pseudatheta hilaris (Sharp, 1888), comb. nov.; Pseudatheta cooteri Pace, 1998; Pseudatheta elegans Cameron, 1920; Phymatura japonica Cameron,1933, stat. rev. (= Phymatura cooteri Assing, 2005, syn. nov.); and Phymatura russa Assing, 2021. Pseudatheta cooteri, Ps. elegans, Ps. taiwanensis, and Ph. russa, are recorded from Japan for the first time. Platyola oligotinula (Sharp, 1888), comb. rev. is excluded from Pseudatheta and confirmed as a member of the genus Platyola Mulsant & Rey, 1875. Lectotypes are designated for two species, Atheta crenulicauda (= Ps. crenulicauda comb. nov.) and Homalota oligotinula (= Platyola oligotinula comb. rev.). Although the two genera were reviewed in this paper, there are some diagnostic problems in the two genera and in species classification and identification, and further studies, including DNA analysis, are required in the future. We also examined specimens from outside of Japan relevant to the taxonomic study of Japanese species.