Four new species and a key to Australian species of the genus Diochus Erichson (Coleoptera: Staphylinidae, Staphylininae, Diochini)

The Australian species of the genus Diochus Erichson, 1839 (Coleoptera: Staphylinidae, Staphylininae, Diochini) are reviewed and four new species are described: Diochus basseti sp. nov. and D. weiri sp. nov. from Queensland, D. lawrencei sp. nov. from Northern and Western Australia, and D. slipinskii sp. nov. from Western Australia. Four previously described species from Australia are revised here based on the examination of type material: Diochus divisus Fauvel, 1877, D. octavii Fauvel, 1877, D. longus Lea, 1929, and D. pubiventris Lea, 1929. A key to all eight species is included, along with photographs and line drawing plates for each species. A lectotype for Diochus divisus Fauvel, 1877 is designated.