Research Article |
Corresponding author: José L. Reyes-Hernández ( jl.reyeshdez@gmail.com ) Academic editor: Adam Brunke
© 2024 José L. Reyes-Hernández, Alexey Solodovnikov.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Reyes-Hernández JL, Solodovnikov A (2024) Two new rove beetle genera in Staphylininae that reduce “Heterothops” and “Quedius” taxonomic wastebaskets (Coleoptera, Staphylinidae). ZooKeys 1218: 81-98. https://doi.org/10.3897/zookeys.1218.135558
|
The here-provided description of the new genera Chiquiticus gen. nov. and Nitidocolpus gen. nov. was necessitated by a phylogenetic study of Staphylininae (to be published separately), which will be used for the proper characterization of their respective new suprageneric lineages in an upcoming update of the higher classification of this subfamily. Both new genera are erected for species that had been previously described but misplaced in the highly polyphyletic “taxonomic wastebasket” genera Heterothops (Amblyopinina) and Quedius (Quediina), resulting in the following new combinations: Chiquiticus arizonicus (Smetana, 1971), comb. nov. ex. Heterothops; Chiquiticus campbelli (Smetana, 1971), comb. nov. ex. Heterothops; †Chiquiticus cornelli (Chatzimanolis & Engel, 2013), comb. nov. ex. Heterothops; Chiquiticus gemellus (Smetana, 1971), comb. nov. ex. Heterothops; †Chiquiticus infernalis (Chatzimanolis & Engel, 2013), comb. nov. ex. Heterothops; Chiquiticus occidentis (Casey, 1886), comb. nov. ex. Heterothops; Chiquiticus pusio (LeConte, J. L., 1863), comb. nov. ex. Heterothops; Chiquiticus rambouseki (Blackwelder, 1943), comb. nov. ex. Heterothops; Nitidocolpus aurofasciatus (Bernhauer, 1917), comb. nov. ex. Quedius; Nitidocolpus championi (Sharp, 1884), comb. nov. ex. Quedius; Nitidocolpus columbinus (Bernhauer, 1917), comb. nov. ex. Quedius; Nitidocolpus germaini (Bernhauer, 1917), comb. nov. ex. Quedius; Nitidocolpus illatus (Sharp, 1884), comb. nov. ex. Quedius; Nitidocolpus laeticulus (Sharp, 1884), comb. nov. ex. Quedius; Nitidocolpus triangulum (Fauvel, 1891), comb. nov. ex. Quedius. Additionally, several more Neotropical Quedius species, which resemble Nitidocolpus, have been revised and transferred to the amblyopinine genus Cheilocolpus or the cyrtoquediine genus Cyrtoquedius, with the following new combinations: Cheilocolpus forsteri (Scheerpeltz, 1960), comb. nov. ex. Quedius; Cheilocolpus speciosus (Bernhauer, 1917), comb. nov. ex. Quedius; Cheilocolpus viridulus (Erichson, 1840), comb. nov. ex. Quedius; Cyrtoquedius viridipennis (Fauvel, 1891), comb. nov. ex. Quedius. The undescribed species diversity of the newly described genera is also highlighted.
Cheilocolpus, Chiquiticus gen. nov., Cyrtoquedius, Neotropical fauna, new combinations, new lineages, Nitidocolpus gen. nov., taxonomy
During a large-scale systematic study of Staphylininae rove beetles (in the broad sense of
Chiquiticus gen. nov. belongs to a newly recovered lineage that also includes the genus Ctenandropus Cameron, 1926 (now in the subtribe Amblyopinina of Staphylinini), the genus Amazonothops Jenkins Shaw, Orlov & Solodovnikov, 2020 (now Staphylinini incertae sedis), and a few extant and extinct (from Dominican amber) Nearctic and Neotropical species of the genus Heterothops Stephens, 1829 (now in the subtribe Amblyopinina). The small Australo-Asian genus Ctenandropus is morphologically and biogeographically peculiar and poorly known. Amazonothops is also a small Neotropical genus that was discovered only recently (
Nitidocolpus gen. nov. forms a monogeneric lineage comprising several Neotropical species of “Quedius” Stephens, 1829, primarily those related to Q. columbinus Bernhauer, 1917. The phylogenetic analysis of Reyes-Hernández et al. (in prep.) reveals that this lineage is distinct from true Quediina, as defined by
The studied specimens are deposited in the following collections:
Specimens were examined with a Leica M125 dissecting microscope (Leica Microsystems, Switzerland). Photographs were captured using a Canon 5D Mark III camera with a Canon MP-E 65mm f/2.8 1–5× macro lens (Canon, Japan) and a StackShot 3x (Cognisys, USA). Images were then stacked using Zerene Stacker (Zerene Systems, USA) with the PMax function. Further image processing, including cropping, lightening, drawing lines, and adding scales, was performed in Adobe Photoshop 2023.
Morphological terminology mainly follows
Abbreviations for measurements are as follows: EYL (eye length in lateral view), HL (head length from the apex of the clypeus to the nuchal ridge, or when the latter is dorsally absent, then to a hypothetical line joining the sides of the nuchal ridge or the groove marking the nuchal constriction), HW (head width at the widest point, including eyes), GL (gena length), NW (neck width at the widest point), PL (pronotum length along the median line), PW (pronotum width at the widest point), and TL (total length from the anterior margin of the clypeus to the posterior margin of segment VIII). All measurements were taken in millimeters using an ocular micrometer on a dissecting microscope.
Subfamily Staphylininae Latreille, 1802
Tribe incertae sedis
Heterothops pusio J.L. LeConte, 1863, here designated.
Chiquiticus arizonicus (Smetana, 1971), comb. nov. ex. Heterothops [holotype and 2 paratypes from
Small Staphylininae mainly around 2.5–3.5 mm long (Fig.
Some Chiquiticus species and characters A C. nr. pusio B C. rambouseki (Blackwelder, 1943) C C. pusio (LeConte, J. L., 1863), head ventral view D C. pusio, abdomen E C. pusio, prosternum F C. pusio, mesothorax. Abbreviations: ASP, antesternal plate; EXPR, external part of prepectus; FS, profurcasternum; ICC, intercoxal carina of the probasisternum; INPR, internal part of prepectus; IOR, infraorbital ridge; LBS, lower probasisternum; MMA, medial macroseta; MNPS, mesanapleural sutures; PMA, posteromarginal large macrosetae; PMR, postmandibular ridge; POR, postoccipital ridge; UBS, upper probasisternum; VBR, ventral basal ridge. Scale bars: 1 mm (A, B, D); 0.1 mm (C, E, F).
Body small (TL = 2.3–3.9 mm). Head (Fig.
Chiquiticus arizonicus (Smetana, 1971) (Holotype #CNC935711) A dorsal habitus B head C pronotum. Abbreviations: CATA, connection of the anterior tentorial arms (frontoclypeal “suture”); PPDS, paired punctures on dorsal series. Photos of # CNC935711 (J. Buffam, Canadian National Collection of Insects, Arachnids and Nematodes).
†Chiquiticus cornelli (Chatzimanolis & Engel, 2013) (paratype
Thorax (Fig.
Abdomen: tergites III–V with only anterior transverse basal carina; tergites III–VI with a large posteromarginal macroseta on each side (Fig.
Morphological details of Chiquiticus and Heterothops A–C Chiquiticus sp. aff. pusio from Panama D–F Heterothops sp. undescribed from Costa Rica A, D head B, E pronotum C, F aedeagus in lateral view, the scale to the right is equal to 1 mm. Abbreviations: ACP, anterolateral clypeal puncture; AFP, anterior frontal; AMRS, anterior marginal row of setiferous punctures; BP, basal puncture; CATA, connection of the anterior tentorial arms (frontoclypeal “suture”); FCP, frontoclypeal puncture; IASP, internalmost setiferous puncture of the anterior margin; IOR, infraorbital ridge; LLSP, large lateral setiferous puncture; LPSP, large posterior setiferous puncture; NR, nuchal ridge; PFP, posterior frontal puncture; POP, parocular punctures; PPDS, paired punctures on dorsal series; SAR, supra-antennal ridge; SLSP, sublateral setiferous puncture; TP, temporal puncture.
Nearctic region, Central America, the Caribbean. Introduced into Central Europe: C. pusio in Germany (
The North American species occur in various types of debris like leaf litter and similar substrates, with some species also occurring facultatively in mammal burrows or nests (Neotoma Say & Ord, 1825), especially in drier regions (
Chiquiticus gen. nov. can be distinguished from all other genera of Staphylininae in broad sense (
The name is derived from the Latinization of the word “Chiquitico”, which is a term used in some Hispanophone countries to refer to very small things. The gender is masculine.
The extinct species †C. infernalis from Dominican Amber is here restudied based on the original descriptions only. Many details important for the taxonomic placement of this species (e.g. pronotum and mesanapleural sutures) are not visible in the photos of this fossil there and probably they would be available only with the mCT examination. However, such visible features as habitus including small body size, as well as antennal bases located close to each other, very elongated last antennomere that is almost as long as the two preceding ones, oval and setose preapical maxillary palpomere that is clearly wider than the apical one, and wide neck allowed us to conclude that †C. infernalis is an extinct member of the new genus Chiquiticus. For †C. cornelli, in addition to the original description, we were able to examine better photos of the holotype and paratype kindly made available at our request (Fig.
As far as currently known, the Nearctic is the region with the greatest species diversity of Chiquiticus. However, the Chiquiticus fossils found in mid-Miocene Dominican amber (
Quedius columbinus Bernhauer, 1917, here designated.
Nitidocolpus aurofasciatus (Bernhauer, 1917), comb. nov. ex. Quedius [1 syntype from
Supra-antennal punctures and paraocular punctures absent (Fig.
Some Nitidocolpus species and characters A N. illatus (Sharp, 1884) B N. laeticulus (Sharp, 1884) C N. germaini (Bernhauer, 1917) D N. aurofasciatus (Bernhauer, 1917) E N. illatus, pterothoraces F N. columbinus (Bernhauer, 1917), metacoxa and metatrochanter, dissected right leg in dorsal view (side faced to the abdomen). Abbreviations: EXPR, external part of prepectus; INPR, internal part of prepectus; MIV, mesobasisternal intercoxal process with V-shaped projection medially; MNPS, mesanapleural sutures; MTMS, metacoxa with dorsomedial spine; MTTAS, metatrochanter with dorsoapical spine. Photo B by J. Jenkins Shaw. Scale bars: 1 mm.
Small to medium-sized Staphylininae (TL = 4.5–10 mm) (Fig.
Morphological details of Nitidocolpus and other relevant genera of Staphylininae A–C Nitidocolpus columbinus D–F Cheilocolpus viridulus G–I Cyrtoquedius sp. J–L Quedionuchus nr. impunctus M–O Quedius nr. advena. A, D, G, J, M head B, E, H, K, N pronotum C, F, I, L, O aedeagus in lateral view, the black arrow pointing down indicates the basal projection of the paramere. Abbreviations: ACP, anterolateral clypeal puncture; AFP, anterior frontal; AMRSP, anterior marginal row of setiferous punctures; APP, additional paired punctures adjacent to AMRSP; BP, basal puncture; FCP, frontoclypeal puncture; IASP, internalmost setiferous puncture of the anterior margin; IOP, interocular punctures; IOR, infraorbital ridge; LLSP, large lateral setiferous puncture; LPSP, large posterior setiferous puncture; NR, nuchal ridge; PFP, posterior frontal puncture; POP, parocular punctures; PPDS, paired punctures on dorsal series; SAP, supra-antennal puncture; SAR, supra-antennal ridge; SLSP, sublateral setiferous puncture; TP, temporal puncture. Scale bars: 1 mm.
Thorax: Prothorax with slightly transverse pronotum (PW/PL ≥ 1.1), without dorsal or sublateral series of setiferous punctures; prosternum without longitudinal keel; antesternal membrane without distinct semisclerotized patch or patches; probasisternum triangular, with narrowed lateral arms and disc protruding medially, with pair of macrosetae on the upper probasiternum; with rounded postcoxal hypomeral process, interrupted by inferior line. Mesothorax: mesoscutellum without posterior scutellar carina, without sub-basal ridge; elytra with humeral spines or spine-like setae, with even setiferous punctation on disc and epipleuron (sometimes with various setose color patterns); with setiferous punctures at apical margin of elytral suture (underside); mesanapleural sutures transverse or nearly transverse but reaching and fusing with external part of prepectus; mesobasisternum with intercoxal process narrowly pointed into sharp angle, without V-shaped projection medially; mesocoxal cavities contiguous; pericoxal ridge present and complete. Metathorax: wings present, with veins CuA and MP4 fused; metakatepisternal processes divided; metascutellar mid-longitudinal internal suture well developed (only visible in chemically cleared specimens). Legs: apical tarsomere of all legs without dorsal setae, with one empodial seta distinctly shorter than tarsal claws; protarsomeres 1–3 distinctly wider than long in both sexes, with pale adhesive setae ventrally; procoxa with internal ridge running parallel along external ridge; mesotarsi in both sexes without black comb, sometimes in males ventral side of first mesotarsomere with pale adhesive setae; mesotibiae straight; metatarsomere 1 shorter than metatarsomere 5; metatarsi shorter than metatibiae; metatrochanter apically rounded, with strong straight dorsoapical spine; metacoxae with four or fewer spines on ventral posterolateral lobe, spines on dorsomedial disc also present; basal part of metacoxae distinctly wider and more convex than apical part.
Abdomen: protergal glands well manifested as rounded cuticular acetabula; tergites III–V in some species with posterior basal transverse carinae, in some species they are only with anterior carinae; on tergite VII anterior transverse basal carina not continuing to paratergites; tergites III–VI with different patterns of posteromarginal large macroseta (PMM) on each side, IV–VI with more than one PMM per side; punctation of tergites in form of fine to moderate impressions, some species with wide glabrous areas; lateral tergal sclerites IX short and slightly laterally flattened; male sternite VIII with medial apical emargination. Aedeagus with paramere fused to median lobe only at base and very closely appressed to median lobe along entire length; base of the paramere flat medially, not projecting upwards in the middle; paramere strongly produced over apex of median lobe. Ovipositor with each second gonocoxite with one medial macroseta, without spine-like setae on outer lateral margin.
Neotropical Realm: Mexican Transition Zone, Central America, and northern South America.
This genus has been collected from a variety of microhabitats, including mushrooms (e.g., Pleurotus spp.), under decomposing logs, beneath bark, and in leaf litter found in cloud, oak, and pine forests. They are also frequently captured using flight-intercept and Malaise traps. Additionally, some species are associated with the inflorescences of plants from the families Arecaceae, Betulaceae, and Heliconiaceae.
Nitidocolpus gen. nov. can be distinguished from all other genera of Staphylininae by the combination of characters mentioned in the diagnosis. Nitidocolpus is further distinguished from the superficially similar Quediina and Cytoquediina (Fig.
The name is derived from the Latin words “nitidus” and “colpus”, which mean “shiny” and “hit”, respectively. The name refers to the great clarity with which the head and pronotum punctures are seen. The gender is masculine.
As shown above, describing the genus Nitidocolpus required careful examination of a number of the poorly known species of Quedius, some of which, as we should stress, do not belong to Nitidocolpus. They belong to neither Quedius nor Quediina. Our examination revealed that most of them belong to the amblyopinine genus Cheilocolpus, as it is defined in
Furthermore, we propose the following new combination for the species Cyrtoquedius viridipennis (Fauvel, 1891), comb. nov. ex. Quedius. Although the type material was not examined, the original description and distribution data provided by
The description of Chiquiticus gen. nov. and Nitidocolpus gen. nov. was necessitated due to the upcoming formal taxonomic embedding of the newly discovered lineages in Staphylininae in Reyes-Hernández et al. (in prep.). Also, it is a step towards badly needed taxonomic clean-up of the polyphyletic large wastebasket genera Heterothops (Amblyopinina) and Quedius (Quediina), especially for the New World fauna, because here we based our genus descriptions solely on the species earlier described in those genera. These are eight species of Heterothops (of which two are extinct) for Chiquiticus and eight species of Quedius for Nitidocolpus. Globally, many more non-related convergently similar species remain misplaced in both Heterothops and Quedius. In the American fauna, following the establishment of Chiquiticus and Nitidocolpus, the number of misclassified Heterothops species has significantly decreased. Moreover, in the course of this study we reclassified a number of the Neotropical Quedius species which superficially resemble Nitidocolpus but in fact, belong to the amblyopinine genus Cheilocolpus or the cyrtoquediine genus Cyrtoquedius. It should be noted that in both Chiquiticus and Nitidocolpus there are also several new species to be described; as well as in the genus Cheilocolpus and other genera of the former “southern quediines”. Due to the above-mentioned pragmatic taxonomic purposes of the current generic descriptions, here we considered solely the described species based on the type material or their original descriptions if they displayed enough data to adequately identify them as either new genus. Descriptions of all new species as well as the update of the taxonomy including lectotype designations, redescriptions, summary of the distribution, and bionomics information on the earlier described species in both new and other involved genera will be provided in future revisionary work.
We thank Adam Brunke, Aslak Kappel Hansen, Josh Jenkins Shaw, Alfred Newton and Qinghao Zhao, who contributed in one way or another to the completion of this work. We would like to thank all the curators listed in the Material and methods section, particularly Agnieszka Pierwola of the American Museum of Natural History, New York, who photographed type material of †Chiquiticus cornelli. Images of C. arizonicus are provided by the Canadian National Collection of Insects, Arachnids, and Nematodes (
The authors have declared that no competing interests exist.
No ethical statement was reported.
We thank Copenhagen University DATA+ program funded the PHYLORAMA project and the doctoral scholarship for the first author.
Both authors have contributed equally.
José L. Reyes-Hernández https://orcid.org/0000-0002-4726-4439
Alexey Solodovnikov https://orcid.org/0000-0003-2031-849X
All of the data that support the findings of this study are available in the main text.