Taxonomic review of the genus Tetraechma Blanchard, 1842 (Coleoptera: Scarabaeidae: Scarabaeinae: Deltochilini)

Abstract

The genus Tetraechma Blanchard, 1842 is revised for the first time, and species distribution data updated. Three species previously placed in Canthon are transferred to Tetraechma; T. balteata (Boheman, 1858), comb.n., T. chlorophana (Mannerheim, 1829), comb.n., T. liturata (Germar, 1822), comb.n.. Canthon balteatus lojanus Balthasar, 1939 is considered a syn.n. of T. balteata, Canthon apicalis Lucas, 1859 is considered a syn.n. of T. chlorophana, and Ateuchus pictus Mannerheim, 1929 as syn.n. of T. liturata. Lectotypes are designated for Tetraechma sanguineomaculata Blanchard, 1845; Canthon balteatus Boheman, 1858, C. balteatus lojanus Balthasar, 1939, Canthon apicalis Lucas, 1859, Ateuchus chlorophanus Mannerheim, 1829, Ateuchus lituratus Germar, 1822, Canthon lituratus solutus Schmidt, 1920, Canthon lituratus solutus Schmidt, 1920, Canthon lituratus bifasciatus Schmidt, 1920 and Ateuchus pictus Mannerheim, 1929. Tetraechma, which was known only from two endemic species from Argentina, now has five species distributed from northern Colombia and Venezuela to the northern coast of Argentina.

The Taxonomic Revolution of New World dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae)

“…However, as inevitably happens to any publication in an active field of scientific inquiry, the work is, at some points, already outdated. Four new genera have since been described (Geńier, 2010;Roggero et al, 2016;Gonzaĺez-Alvarado et al, 2019;Pacheco and Vaz-de-Mello 2019a) (one of them, Lobidion Geńier, 2010, not included in the key, has since been lowered to a subgenus of Ateuchus; Geńier and Cupello, 2018), a subgenus has been reelevated to genus, Boreocanthon (Edmonds, 2022), a new subgenus has been described, Canthon (Bajacanthon) (Halffter et al, 2022a), the subgeneric classification of Dendropaemon has been completely modified, including the recognition of 12 subgenera in contrast to the previous three (Geńier and Arnaud, 2016;Cupello and Geńier, 2017), some names used as valid in the key have now been invalidated (viz., Eucanthidium Martıńez and Halffter, 1986, Luederwaldtinia Martıńez, 1951, Telhyboma Kolbe, 1893, Tetramereia Klages, 1907, and Vulcanocanthon Pereira and Martıńez, 1960 (Geńier, 2012;Geńier and Arnaud, 2016;Cupello, 2018;Nunes and Vaz-de-Mello, 2019;Vieira et al, 2019), some genera have been re-delimited and the key is no longer adequate to identify them completely (e.g., Sylvicanthon and Tetraechma) (Cupello and Vaz-de-Mello, 2018;Nunes and Vaz-de-Mello, 2022), and some names, due to nomenclatural problems discovered since 2011, have changed their allocation and denote different taxa in the key than they now do (e.g., Selenocopris and Canthidium s. str.)…”

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

“…However, both molecular and morphological systematics analyses have shown it to be highly polyphyletic and composed of numerous lineages (Philips et al 2004b, Monaghan et al 2007, Tarasov and Génier 2015, Tarasov and Dimitrov 2016). Tarasov and Dimitrov (2016) reduced the tribe, Deltochilini, to just 20 genera comprising 457 valid species that are endemic to the Neotropical and Nearctic regions where they are, essentially, sister to other prominent tribes and lineages of these 2 regions (Halffter and Martínez 1977, Vaz-de-Mello et al 2011, González-Alvarado and Vaz-de-Mello 2014, 2021a, 2021b, Valois et al 2015, Cupello and Vaz-de-Mello 2018, Nunes et al 2018, 2020, Vaz-de-Mello and Cupello 2018, González-Alvarado et al 2019, Sawaris et al 2019, Silva and Valois 2019, Edmonds 2022, Halffter et al 2022, Nunes and Vaz-de-Mello 2022, Cupello et al 2023). To maintain monophyly within the Deltochilini this decision leaves many former Afrotropical, Madagascar, Oriental, Australian, and further Neotropical deltochiline genera without a certain tribal placement.…”