Quedius (Raphirus) cohaesus Eppelsheim 1888
Creators: name: Assing, Volker
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Quedius
Quedius cohaesus

description: Quedius (Raphirus) cohaesus EPPELSHEIM, 1888
Quedius cohaesus EPPELSHEIM, 1888: 60 f.
Quedius pseudonigriceps REITTER, 1909: 113; nov.syn.
C o m m e n t: The original description of Q. cohaesus is based on three syntypes from ̎Turcmenien̎ (EPPELSHEIM 1888), of which SOLODOVNIKOV (2004) designated the lectotype, that of Q. pseudonigriceps on an unspecified number of syntypes from ̎ Herzegowina, Türkei, Kleinasien̎ (REITTER 1909). Quedius cohaesus has three junior synonyms, Q. pseudonigriceps five (SCHÜLKE & SMETANA 2015, SALNITSKA & SOLODOVNIKOV 2018). According to the latest edition of the Palaearctic catalogue, the distribution of Q. cohaesus ranges from Bulgaria across Turkey and the Caucasus region to Iran and Turkmenistan, whereas SALNITSKA & SOLODOVNIKOV (2018) state that the distribution of this species includes Iran, Turkmenistan, Tajikistan, and Afghanistan. There is no reference to the records from other regions in the latter study, probably because it focuses on Middle Asia. The distributions given for Q. pseudonigriceps are Southeast Europe northwards to Austria, Turkey, and the Caucasus region (Georgia) (SCHÜLKE & SMETANA 2015), and South Europe, West Asia eastwards to Middle Asia (Kyrgyzstan, Kazakhstan) (SALNITSKA & SOLODOVNIKOV 2018). SALNITSKA & SOLODOVNIKOV (2018) regard Q. cohaesus and Q. pseudonigriceps as distinct species, provide redescriptions and illustrations of the aedeagi based on material from Middle Asia, and state that Q. cohaesus is most similar to Q. pseudonigriceps, but ̎easily
distinguished by the presence of an apical seam of palisade fringe VII and normally developed elytra, as well as by the characters of the aedeagus̎ (p. 143).
Although I have not studied material from Middle Asia personally, the argumentation and conclusions laid out by SALNITSKA & SOLODOVNIKOV (2018) are difficult to follow and Q. pseudonigriceps is considered a junior synonym of Q. cohaesus for two main reasons:
1. Based on personal observations and abundant material, the species previously identified as Quedius pseudonigriceps is one of the most widespread and most common representatives of the genus in the Balkans, Turkey, and the Caucasus region (Georgia, Armenia). In this region, the species always has normally developed elytra and a palisade fringe at the posterior margin of tergite VII. This would mean that, according to SALNITSKA & SOLODOVNIKOV (2018), there is an abrupt character displacement in the range of the species somewhere in North Iran. True, there are several examples of wing di- or polymorphic Quedius species, sometimes even with clinal variation. It does not seem plausible, however, that there should be another, highly similar macropterous species (Q. cohaesus) replacing the macropterous morph of Q. pseudonigriceps in this region.
2. The aedeagus of Quedius species is subject to - sometimes considerable - interspecific variation. This particularly applies to widespread species (ASSING 2018). SALNITSKA & SOLODOVNIKOV (2018) may state that there are differences between Q. cohaesus and Q. pseudonigriceps in aedeagal characters, but no such discrete differences are visible in the illustrations they provide. Instead, they illustrate a continuum of aedeagal variation.
In consequence, the available evidence suggests that a) Q. cohaesus is distributed on both sides of the Caspian Sea and that b) this species is wing-dimorphic in Middle Asia and monomorphic elsewhere.
Quedius (Microsaurus) invreae GRIDELLI, 1924 and Q. (M.) puncticollis (THOMSON, 1867)
C o m m e n t: According to the latest edition of the Palaearctic catalogue (SCHÜLKE & SMETANA 2015), the distribution of Q. invreae ranges from France, Great Britain and Scandinavia across Central Europe southeastwards to the Russian South European territory and that of Q. puncticollis from France, the British Isles (including Ireland), and Scandinavia across Central Europe southwards to Italy and eastwards to the Caucasus region and West Siberia. Recently, Q. puncticollis was recorded also from Greece and Middle Asia (ASSING 2017, SALNITSKA & SOLODOVNIKOV 2018). In his key to the Central European Quediina, SOLODOVNIKOV (2012) doubted the taxonomic status of Q. invreae and suspected synonymy of these names.
Inspired by records of specimens preliminarily identified as Q. invreae from Armenia, material of Q. puncticollis and Q. invreae in the authoŕs collection was revised. This study revealed that both names undoubtedly represent distinct taxa and that both species are easily distinguished. The aedeagi of both species may be rather similar, but the paramere of Q. invreae is broader and usually weakly concave apically, more rarely truncate or weakly convex, whereas in Q. puncticollis it is more slender and apically distinctly convex. The best characters for the separation of both species, however, are the colour, shape, and especially the chaetotaxy of sternite VIII, especially in the male, as already stated by LOHSE (1964). In Q. invreae, sternite VIII is darker, often completely black or at least black in anterior three-fourths with the posterior fourth sometimes slightly paler, whereas in Q. puncticollis tergite VIII is paler with at least the anterior and posterior portions pale-brownish and the median portion usually blackish-brown. More importantly, however, the posterior margin of the male sternite VIII is broadly concave and furnished with extremely long black setae (especially laterally), the longest of them longer than antennomere I in Q. invreae. In Q. puncticollis, on the other hand, the posterior margin is shallowly concave only in the middle and furnished with short brown setae, the longest of them barely half as long as antennomere I. The posterior margin of the female sternite VIII is furnished with relatively short setae in both species, but these setae are black in Q. invreae and brown in Q. puncticollis. The illustrations of the aedeagus of Q. puncticollis provided by SOLODOVNIKOV (2012: figures 191t-v) clearly refer to Q. invreae.
According to LOHSE (1964), Q. puncticollis is the most common representative of the genus in mole nests. This may be true of the environs of Hamburg, G.A. Lohsés hometown, but certainly not of regions farther south. Based on personal observations (studies of mole nests, extensive pitfall trap studies), Q. puncticollis is rare, much more so than Q. invreae, and the southernmost record examined is from South Germany (München). While most of the few specimens of Q. puncticollis in cAss were extracted from mole nests (some also collected with pitfall traps), material of Quedius invreae was exclusively collected with pitfall and flight interception traps (especially in warmer habitats; never from mole nests). A re-examination of a specimen from Greece, which the record of Q. puncticollis in ASSING (2017) is based on, revealed that it was misidentified and in fact belongs to Q. invreae (first record from Greece). The same most likely applies to records of Q. puncticollis from Middle Asia (SALNITSKA & SOLODOVNIKOV 2018).
description: Published as part of Assing, Volker, 2019, On the taxonomy oI some West Palaearctic Quedius species, with descriptions oI new species and new synonymies (Coleoptera, Staphylinidae, Staphylininae), pp. 189-201 in Linzer biologische Beiträge 51 (1) on pages 193-195, DOI: 10.5281/zenodo.3762449