A Taxonomic Revision of the Dichotomius depressicollis (Harold, 1867) Species Group (Coleoptera: Scarabaeidae: Scarabaeinae), with Description of Five New Species

Recently, the taxonomy of Dichotomius Hope, 1838 (Coleoptera: Scarabaeidae: Scarabaeinae) was updated, a new species group division was proposed, and the Dichotomius depressicollis (Harold, 1867) species group was created. Based on the external morphology and the male genitalia of all type material and 1443 specimens deposited in eight entomological collections, the taxonomic revision of this group is carried out. The group contains eight species, five of which are new: Dichotomius audinoae sp. nov. (Brazil), Dichotomius barberoi sp. nov. (Brazil), Dichotomius davidedmondsi sp. nov. (Bolivia), Dichotomius depressicollis (Harold, 1867) (Argentina and Brazil), Dichotomius inca sp. nov. (Peru), Dichotomius melzeri (Luederwaldt, 1922) (Bolivia, Brazil, and Peru), Dichotomius salomaoi sp. nov. (Brazil), and Dichotomius zikani (Luederwaldt, 1922) (Bolivia and Brazil). Lectotypes were designated for Pinotus depressicollis Harold, 1867, Pinotus melzeri Luederwaldt, 1922, and Pinotus zikani Luederwaldt, 1922. A complete description of the D. depressicollis species group and a species identification key are presented. For each species, the following information is provided: taxonomic history, description or redescription, list of material examined, photographs of external morphology, male genitalia and its endophallites, and distribution map.