(Figs 1, 4, 7, 8F, 13B, 15, 20)
Quedius sundukovi Smetana 2003: 189-193 [Type locality: Badshalskyi Khrebet mountains]
References. Sආൾඍൺඇൺ & SHൺඏඋංඇ (2018): 834 (distribution); Sൺඅඇංඍඌĸൺ & Sඈඅඈൽඈඏඇංĸඈඏ (2018a):130–131 (distribution); (2019):50 (characters and distribution).
Material examined. KAZAKHSTAN: SW Altai, East of Narymskij Mt. Ridge, upper course of Ozernaja River, 49.0478, 85.1614, 1900-2300 m, supalpine zone, 18.VII.1997, leg.R.Yu.Dudko & V.K. Zinchenko (ZIN). RUSSIA: JൾඐංඌH Aඎඍඈඇඈආඈඎඌ RൾG.: Kuldur vill., 49.1854, 131.6171, pitfall trap, stream, 480m, 14.-15.VII.2017, leg.A.Bergmann (1 J cSch). Eൺඌඍ YൺKඎඍංൺ: Suntar-Khayata Mts, Valley of Tyry river valley, Kidyrki river near Khalya, [62.35, 138.46], 800-950 m, 14.-19.VIII.1991, leg. Alexeev (NHMD). KHൺൻൺඋඈඏඌK Tൾඋඋ.: Badshalskyi chr., Omot lake, [50.54, 134.26], tundra, 1850-2050 m, 7.-19.VII.1997, leg A.Plutenko (2 JJ 2♀♀ cSch); Levaja Bureya riv., estuary Don riv., [51.68, 134.51], 24.- 25.VII.2006, leg. U. Valainis (ZIN); Levaja Bureya riv., the left bank of the Imganakh river near the mouth, 51.7355, 134.572, 650-670 m, sloppy rocky hills with burrow pits, litter and mosses of Picea ajanensis, Abies nephrolepis, Larix gmelinii, Rhododendron dauricum, Betula platyphylla, Hylocomium splendens, Pleurozium schreberi, Ptilium crista-castrensis, Dircranum sp., Polytrichum sp., Sphagnum girgensohnii, Sph. sp., 26.VI.2011, leg.A.B. Ryvkin (ZIN);Verkhnebureinsky natural park, Ust--Urgal project gauging station Ust-Niman Topolevnik, 51.3995, 132.733, 1.IX.2009, leg. L.A. Trilikauskas (NHMD); Verkhnebureinsky natural park, Ust-Urgal project gauging station Ust-Niman Topolevnik, 51.3995, 132.733, 315 m, Padus, Alnus, Salix, Picea, Plagiomium, 4.VIII.2009, leg. A.B. Ryvkin (ZIN). SൺKHൺඅංඇ Iඌඅൺඇൽ: 13 km N from Korsakov, 2km N from Solovyovka, [46.74, 142.73], Acer, Betula, 5.VIII.1992, leg. V. Gusarov, (CNC); 13 km N from Korsakov, 2 km N from Solovyovka, [46.74, 142.73], Abies, Larix, Ledum, Betula, 6.VIII.1992, leg.V.Gusarov (CNC). ZൺൻൺඒKൺඅඌKඒ Kඋൺං: Stanovoy Highlands, W part of Kodar, top Chara River, 50 km WSW River Novaya Chara, [56.65, 117.54], 1700- 2000 m, 27.VII.1995, leg.A. & R. Dudko, D. Lomakin (ZIN); Stanovoy Highlands, top Chara River, Lake Leprindo, 56.636, 117.537, 1000 m, 23.VII.1995, leg. A. & R. Dudko, D. Lomakin (ZIN).
Redescription. Measurements JJ (n = 5): HW = 1.40– 1.69 (1.53); HL = 1.22–1.40 (1.29); HL/HW 0.79–0.89 (0.85); PW = 1.82–2.22 (2.00); PL = 1.71–2.07 (1.81); PL/PW 0.80–0.96 (0.91); EW = 1.80–2.09 (1.88); EL = 1.44–1.71 (1.60); EL/EW 0.80–0.89 (0.85); EL/PL 0.83–0.95 (0.89); PW/HW 1.46–1.67 (1.55); forebody length 4.38–5.18 (4.70). ♀♀ (n = 5): HW = 1.58–1.73 (1.67); HL = 1.33–1.42 (1.38); HL/HW 0.78–0.87 (0.83); PW = 1.93–2.24 (2.04); PL = 1.80–2.11 (1.88); PL/PW 0.90–0.94 (0.92); EW = 1.89–2.09 (1.96); EL = 1.69–1.78 (1.72); EL/EW 0.83–0.91 (0.88); EL/PL 0.82–0.96 (0.92); PW/HW 1.39–1.58 (1.48); forebody length 4.82–5.27 (4.99).
Small sized species; body dark brown to black (Fig. 8F).
Head black, distinctly transverse, with eyes medium sized (EyL/TL = 1.73–2.00 (1.83)); microsculpture of fine transverse waves; no additional punctures between anterior frontal punctures (cf. Fig. 6F); antennae dark internally becoming continuously lighter, all antennomeres slightly elongate; palpi pale with apical palpomere slightly darkened.
Thorax: pronotum black, wider than long, wider than head, with microsculpture of transverse waves; three punctures in dorsal row and one to two in sublateral row with its posteriormost puncture reaching just beyond level of first puncture of dorsal row; scutellum sparsely punctured and pubescent; elytra most often fully darkened but occasional dark reddish brown, short uniformly pubescent, clearly shortened wider than long, clearly shorter than pronotum; legs dark with tarsi lighter.
Abdomen black, tergites sparsely and uniformly punctured, without palisade fringe of tergite 7, without clear iridescence.
Male. Aedeagus (Fig. 13B): paramere lanceolate with slight medial attenuation and extending into a slight expansion broadest below apex, apex slightly asymmetric, reaching just beyond apex of median lobe, with sensory peg setae forming two long rows fusing together towards apex (Fig. 15); median lobe broad with gentle constriction to a point at apex, on parameral side with two small teeth pointing slightly basad, positioned at level near basal level of peg setae band of paramere; internal sac without a continuation of C-sclerite.
Differential diagnosis. Quedius sundukovi is most similar to Q. unicolor, Q. subunicolor, and Q. molochinus. It can easily be distinguished from all these species by its smaller size and brachypterous habitus with shortened elytra and absent palisade fringe on tergite VII. If in doubt, the aedeagus can be checked for characters listed in the diagnosis. It is also similar to Siberian species Q. (Raphirus) jenisseensis Sahlberg, 1880, from which it is easily distinguished by the entire labrum (medially incisioned in Q. jenisseensis).
Comments. Quedius sundukovi was described by Sආൾඍൺ-ඇൺ (2003) based on 13 specimens from the Badshalskyi Khrebet mountains in Khabarovsk Krai in the Far East of Russia. Sආൾඍൺඇൺ & SHൺඏඋංඇ (2018) reported additional specimens from Vitimskiy Nature Reserve and the Udokan Plateau extending the species range significantly westwards in Russia to Transbaikalia. Sൺඅඇංඍඌĸൺ & Sඈඅඈൽඈඏඇංĸඈඏ (2018a) reported a number of records of this species from the Altai Mountains in Kazakhstan. Sൺඅඇංඍඌĸൺ & Sඈඅඈ-ൽඈඏඇංĸඈඏ (2019) reported the occurence of this species in Buryat Republic in Transbaikalia and in the Russian Far East regions of Amur Oblast and Sakhalin Island (Fig. 20). Here we add detailed information on many of these records along with COI barcodes from specimens across the range (Fig. 4). The barcodes showed high variation as we recovered five OTUs (four BINs) with as high as 7.7% divergence between the OTUs (Table 2). Morphological studies of the specimens also revealed some variation in size – but not in the shape – of the paramere (Fig. 15). We found no differences to correspond to any of the molecular clusters, which also did not cluster geographically. Lack of a clear congruence between the molecular and morphological variation, as well as no hiatus between different morphological variants, suggests that they all represent a single species. The species is known across a large area with complex montane orography and it is flightless, with the palisade fringe of abdominal segment VII absent and clearly shortened elytra.Apparently, the high degree of the intraspecific variation can be related to the flightlessness of the species leading to low dispersal abilities of members of different populations and accelerated rates of divergence in the barcode region (Mංඍඍൾඋൻඈൾർĸ & Aൽൺආඈඐංർඓ 2013).
Bionomics. Little is known about the specific habitat requirement of Q. sundukovi. Based on the examined material, the species appear to occur in various leaf litter, both coniferous and deciduous, and is commonly associated with talus debris and moss, often near streams or rivers. Specimens are found within a wide range of elevations from 315 to 2300 m, at higher elevation at lower latitudes.
Distribution. Quedius sundukovi is currently known from relatively few specimens scattered across a large range comprising the Altai Mountains, Transbaikalia, Bureya and the Suntar-Khayata Range (Fig. 20). It is also found on Sakhalin Island.Although currently known from only a few localities, the species distribution is most likely continuous. The range maybe poorly known because it spans through an area with very little recent and historical entomological activity, especially for leaf-litter dwelling organisms.