Taxonomic review of the Dichotomius (Luederwaldtinia) agenor species group (Coleoptera: Scarabaeidae: Scarabaeinae)

Abstract

The Neotropical D. agenor species group of the subgenus Luederwaldtinia Martínez, 1951 is taxonomically reviewed. After examination of specimens in collections, the D. agenor species group will consist of seventeen species, a leap from the former nine species: D. agenor (Harold, 1869), D. amplicollis (Harold, 1869), D. belus (Harold, 1880), D. centralis (Harold, 1869), D. deyrollei (Harold, 1869), D. sagittarius (Harold, 1869) stat. rev., D. tristis (Luederwaldt, 1923), D. triquetrus (Luederwaldt, 1923), D. validipilosus (Luederwaldt, 1931), D. fornicatus (Luederwaldt, 1931) [transferred to D. lucasi species group and to which D. bosqi (Pereira, 1941) is considered to be a new synonym], D. inachoides (Felsche, 1901) [transferred from the group fisus (Selenocopris)], D. simplicicornis (Luederwaldt, 1935) [transferred from the group fisus (Selenocopris)], D. subaeneus (Castelnau, 1840) [transferred from the D. carbonarius species group], D. rafanunezi sp. nov. from Mato Grosso, D. henripittieri sp. nov. from Venezuela and D. enioi sp. nov. from Guatemala and Costa Rica. This review was based on external morphology and characters of the male genitalia (aedeagus and internal sac). Descriptions of new species and redescriptions were made after examining the type-specimens of the already described species. Lectotype designations, species revalidations, redescriptions and new species descriptions are provided.

Dung beetle tribal classification (Coleoptera: Scarabaeidae: Scarabaeinae): progress, problems, and prospects

“…However, having been published by Pereira (1954), Dichotomiini has been cited as valid on several subsequent occasions (Halffter and Matthews 1966, Halffter and Edmonds 1982, Zunino 1983, Montreuil 1998), which renders this tribal name available as corrected by Bouchard et al (2011) and Tarasov and Dimitrov (2016). The last cited authors reerected the tribe Dichotomiini with a new concept for just 4 Nearctic and Neotropical genera comprising 215 valid species (Smith and Génier 2001, Rossini and Vaz-de-Mello 2015, 2017, Nunes and Vaz-de-Mello 2016, 2019, Montoya-Molina and Vaz-de-Mello 2021, Solís and Kohlmann 2022, Cupello et al 2023). These dichotomiine genera are distantly related to members of the Coprini but sister to Ateuchus (Tarasov and Dimitrov 2016), which is the type genus of the Ateuchini as currently defined (Table 1).…”

Taxonomic revision of the batesi species group of Dichotomius Hope, 1838, with the description of three new Amazonian species (Coleoptera, Scarabaeidae, Scarabaeinae)

“…The scarcity of taxonomic information has resulted in difficulties for modern biologists who seek to identify species accurately. Many recent papers dealing with taxonomic revisions on Dichotomius species groups have provided redescriptions and diagnoses after careful comparison of types and additional material deposited in collections (Nunes and Vazde-Mello 2013;Maldaner et al 2015;Nunes et al 2016;Valois et al 2017;Arias-Boriticá & Vaz-de-Mello 2019;Nunes & Vaz-de-Mello 2019;Rossini & Vaz-de-Mello et al 2020;Cassenote et al 2020;Montoya-Molina & Vaz-de-Mello 2021). However, in Dichotomius (Selenocopris) such efforts have been concentrated in groups that have practical characteristics for identification, such as: 1) low diversity, with less than ten species; and (2) easy definition based on a distinctive character, such as the presence of metallic coloration (Maldaner et al, 2015), a pair of deep foveae on pronotum (Valois et al 2017), or hairy depression on hypomera (Nunes et al 2016).…”