Discovery of New Genera Challenges the Subtribal Classification of Tok-Tok Beetles (Coleoptera: Tenebrionidae: Sepidiini)

Abstract

Sepidiini is a speciose tribe of desert-inhabiting darkling beetles, which contains a number of poorly defined taxonomic groups and is in need of revision at all taxonomic levels. In this study, two previously unrecognized lineages were discovered, based on morphological traits, among the extremely speciose genera Psammodes Kirby, 1819 (164 species and subspecies) and Ocnodes Fåhraeus, 1870 (144 species and subspecies), namely the Psammodes spinosus species-group and Ocnodes humeralis species-group. In order to test their phylogenetic placement, a phylogeny of the tribe was reconstructed based on analyses of DNA sequences from six nonoverlapping genetic loci (CAD, wg, COI JP, COI BC, COII, and 28S) using Bayesian and maximum likelihood inference methods. The aforementioned, morphologically defined, species-groups were recovered as distinct and well-supported lineages within Molurina + Phanerotomeina and are interpreted as independent genera, respectively, Tibiocnodes Gearner & Kamiński gen. nov. and Tuberocnodes Gearner & Kamiński gen. nov. A new species, Tuberocnodes synhimboides Gearner & Kamiński sp. nov., is also described. Furthermore, as the recovered phylogenetic placement of Tibiocnodes and Tuberocnodes undermines the monophyly of Molurina and Phanerotomeina, an analysis of the available diagnostic characters for those subtribes is also performed. As a consequence, Phanerotomeina is considered as a synonym of the newly redefined Molurina sens. nov. Finally, spectrograms of vibrations produced by substrate tapping of two Molurina species, Toktokkus vialis (Burchell, 1822) and T. synhimboides, are presented.

Female terminalia morphology and cladistic relations among Tok‐Tok beetles (Tenebrionidae: Sepidiini)

“…With about 150 species, Psammodes is the most diverse genus of tok-tok beetles (Kami nski et al, 2019). Although the monophyly of this genus already has been questioned by previous authors (Gearner et al, 2021;Kami nski et al, 2021), this study is the first to revise the morphology of the type species. When taking into consideration the results of the combined (morphology + DNA) analyses, representatives of Psammodes were recovered in three separate clades (Fig.…”

“…Combined analysis of female terminalia traits and molecular data. The majority of the molecular dataset was assembled from previous studies (Gearner et al, 2021;Kami nski et al, 2021). Seven additional species were sequenced to increase (Bouchard et al, 2011), were used as outgroups.…”

“…Furthermore, Molurina is the only lineage among the tribe whose representatives possess well-developed 3rd lobes of the coxites (5:1). An alternative definition of Molurina, based solely on external features, was recently provided by Gearner et al (2021).…”

“…Tok-tok beetles are a morphologically diverse tribe of darkling beetles, composed of >1000 species distributed throughout the African continent and Southern Palaearctic (Kami nski et al, 2019). As a consequence of their unique tapping behaviour, which is assumed to be a form of sexual communication (Gearner et al, 2021;Lighton, 1987Lighton, , 2019, they are one of the most conspicuous beetle groups in the region (Matthews et al, 2010). To date, 59 genera of Sepidiini have been described (Gearner et al, 2021).…”

Review of genus-group names in the family Tenebrionidae (Insecta, Coleoptera)

“…The classification presented in Table 2 is a synthesis starting from works on Tenebrionidae family-group names (e.g., Bouchard and Bousquet 2020a) with additional data published in recent regional catalogues (e.g., Bousquet et al 2018;, on fossils (Nabozhenko 2019), as well as on the diversity, taxonomy and phylogenetics of various clades (e.g., Bremer and Lillig 2014;Aalbu et al 2017Aalbu et al , 2018Kamiński et al 2019aKamiński et al , b, c, 2021bLumen et al 2020;Lillig and Bremer 2021;Gearner et al 2021). Only nomenclaturally available names are included in Table 2 wherein the valid genus-group names are listed in alphabetical order under each valid family-group name and the synonyms (preceded by "=") are given in chronological order.…”