Microedus schilenkovi ( Zerche, 1992 ) Shavrin, 2024

Shavrin, Alexey V., 2024, Microedus LeConte, 1874 (Coleoptera: Staphylindae: Omaliinae: Anthophagini), a new genus for the Palaearctic Region, Zootaxa 5443 (2), pp. 205-223 : 215-217

Microedus schilenkovi ( Zerche, 1992) comb. n.

( Figs 4 , 7, 9, 11, 13 , 18–21 , 24–30 )

Altaiodromicus schilenkovi Zerche, 1992: 108

Type material examined. Holotype ♂: ‘Алтай, хр. Коргон | верх.руч. Мохнатый | прит. Кумира. 1750- | 2000 м, 10-24.У[V]II. | В. Шиленков 1984 [Altai, Korgon Mts., upper flow of Mokhnatyi Stream , tributary of Kumir River […] V.G. Shilenkov leg.]’ <photo label>, ‘Коргон | 1950 м | берег оЗера [Korgon, 1950 m a.s.l., bank of the lake]’ <handwritten by blue pen>, ‘Holotypus | Altaiodromicus [handwritten] | schilenkovi [handwritten] | Zerche’ <red, printed> ( ZIN) .

Paratypes 2 ♀♀: same data as that of holotype, except red printed label :‘ Paratypus | Altaiodromicus [handwritten] | schilenkovi [handwritten] | Zerche’ <red, printed> ( ISU, ZIN) .

Material examined. RUSSIA: ALTAI: 1 ♂, 2 ♀♀: same data as the type material ( ISU) ; 1 ♀: Altaiskiy Nature Reserve, Akitchu River . 10.07.2002. A.V. Matalin & S.S. Demidov leg. ( MSPU) ; 2 ♂♂, 2 ♀♀: same Nature Reserve and collectors, Teletskoye Lake , kordon Kokchin. 05.07.2002 (cSh, ZMM) ; 1 ♂, 1 ♀: SE slope of Aygulakskiy Mts., lower flow of Bel`gabash River. 1250 m a.s.l., under stones. 29.06.2000. S.S. Demidov leg. (cSh, MSPU) ; 1 ♂, 1 ♀: same data, middle flow of Bel`gabash River. 1700 m a.s.l., stones near river. 02- 03.07.2000. K.V. Makarov leg. (cSh, ZMM) ; KAZAKHSTAN: EAST KAZAKHSTAN: 6 ♂♂, 5 ♀♀: Altai, connections of Kara-Koba and Tauchilik rivers . 15.08.1988. V.A. Kastcheev leg. (cSh, NME, ZIN) ; 14 ♂♂, 16 ♀♀: same data. 06.08.1989 (cSh, ZIN) ; 7 ♂♂, 4 ♀♀: same data. 16.08.1988 (cSh, ZIN) ; 1 ♂, 1 ♀: Karakoba River , 2 nd bridge. 16.08.1988. V.A. Kastcheev leg. ( ZIN) ; 3 ♂♂, 2 ♀♀: Sorvenok River near Aksubas Mt. 12- 14.08.1989. V.A. Kastcheev leg. ( ZIN) ; 6 ♂♂, 2 ♀♀: Prokhodnoy Belok, Marchikha River . 12.07.1989. V.A. Kastcheev leg. ( ZIN) ; 4 ♂♂, 5 ♀♀: same data. 06.07.1991 (cSh, ZIN) ; 27 ♂, 13 ♀♀: same data. 11.08.1989 (cSh, ZIN) ; 16 ♂♂, 20 ♀♀: Marchikha River . 12.07.1989. V. Kastcheev leg. (cSh, ZIN) ; 1 ♀: Markakol`, Sorvenok River . 14.08.1989. V. Kastcheev leg. ( ZIN) ; 1 ♂: same data, 18.06.1988 (cSh) ; 3 ♂♂, 3 ♀♀: same data, 12.08.1989 (cSh) ; 1 ♀: Sarymsakty River, Katon-Karagai. 28.08.2010. V. Kastcheev leg. ( NMW) ; 5 ♂♂, 5 ♀♀: Burkhat Pass. 06.08.1989. V. Kastcheev leg. (cSh, ZIN) .

Redescription. Measurements (n=180): HW: 0.60–0.83; HL: 0.37–0.50; OL: 0.17–0.19; LT: 0.10–0.11; AL (averaged): 1.99; PL: 0.55–0.75; PWmax: 0.80–1.02; PWmin: 0.63–0.80; ESL: 0.92–1.28; EW: 1.22–1.41; MTbL (averaged): 0.87; MTrL (averaged): 0.32 (MTrL 1–4: 0.17; MTrL 5: 0.15); AW: 1.30–1.72; AedL: 0.45–0.77; BL: 3.15–4.60.

Habitus as in Fig. 4 . Body reddish-brown, sometimes with darker head and abdomen; mouthparts, antennae and legs yellow-brown; apical segment of maxillary palpi and tarsi yellowish. Head with dense and coarse isodiametric microreticulation, usually finer in middle and slightly coarser on infraorbital portions; neck with dense and coarse mesh-like sculpture; pronotum with very dense and coarse isodiametric microsculpture, somewhat similar to that on head, sometimes finer in medioapical portion; scutellum with fine isodiametric meshes; abdominal tergites with very dense isodiametric microreticulation, usually coarser on abdominal tergites III–IV.

Head 1.6 times as broad as long; medioapical depression slightly or strongly narrowing posteriad; temples about 1.7 times as long as longitudinal length of eyes. Ocelli located slightly below level of posterior margins of eyes, distance between ocelli 1.2–1.4 times as long as distance between ocellus and posterior margin of eyes. Punctation of head very sparse and fine, indistinct in middle portion, usually larger and denser on infraorbital portions. Labrum as in Fig. 7 . Mandibles as in Fig. 9 . Maxilla as in Fig. 11 ; apical segment of maxillary palpi about 1.3 times as long as preapical segment. Labium as in Fig. 13 . Antennomeres 4–10 slightly elongate; basal antennomere about three times as long as broad, 2 slightly narrower and distinctly shorter than basal antennomere, 3 slightly broader than 2, 4 moderately small, distinctly shorter than 3, 5–6 distinctly longer than 4, 7–8 slightly shorter than 6, 9–10 slightly broader than 8, apical antennomere about as long as two preceding antennomeres, from about middle gradually narrowed toward rounded or subacute apex.

Pronotum 1.3–1.4 times as broad as long, 1.2–1.3 times as broad as head, gradually or strongly narrowed posteriad toward obtuse posterior angles; anterior margin rounded, about as long as straight posterior margin or slightly shorter. Punctation indistinct; longitudinal band of pronotal disc usually without punctation.

Elytra distinctly broader than long, 1.6–1.7 times as long as pronotum, with widely rounded apical margins. Punctation distinctly finer around scutellum and along suture.

Abdomen distinctly broader than elytra, with two transverse tomentose spots in the middle of abdominal tergite IV.

Male. Apical margin of abdominal tergite VIII somewhat straight ( Fig. 24 ). Apical margin of abdominal sternite VIII concave ( Fig. 25 ). Genital segment as in Fig. 26 . Aedeagus with wide basal portion, strongly narrowed toward narrow and moderately short median lobe with small rounded apex; parameres narrow, distinctly exceeding apex of median lobe, with two short apical setae and two additional short setae on inner margin of apical half of each paramere; internal sac narrow and moderately long, without additional sclerotized structures ( Figs 18, 20, 21 ; Fig. 1 in Zerche (1992)). Lateral aspect of the aedeagus as in Fig. 19 .

Female. Apical margins of abdominal tergite VIII ( Fig. 27 ) and sternite VIII ( Fig. 28 ) straight. Genital segment as in Fig. 29 .

Comparative notes. Altaiodromicus schilenkovi can be distinguished from A. kastcheevi sp. n. by the slightly broader head with slightly longer temples, somewhat coarser punctation of the middle portion of the head, and less distinct punctation of the pronotum. It can be reliably distinguished from A. kastcheevi sp. n. by the external and the internal structure of the aedeagus, with narrower median lobe, the presence of short setae on inner margin of each paramere and the lack of large sclerotized structures of the internal sac. Based on the slightly elongate antennomeres 4–10, it is somewhat similar to the Himalayan M. brevitarsis , from which it can be distinguished by the shallow interocellar foveae, broader pronotum, and the morphology of the aedeagus.

Distribution. Altaiodromicus schilenkovi is known from several localities in Altai mountain range, Altai Republic ( Russia) and north-eastern part of Kazakhstan ( Fig. 30 )

Bionomics. Specimens from Russia were collected under stones near rivers and lakes at elevations from 1250 to 1950 m a.s.l. Detailed bionomical data for the specimens collected in Kazakhstan are unknown.

Figures

FIGURE 30. Distribution of Microedus in the Middle Asia: M. schilenkovi (circles), M. kastcheevi (squares).

FIGURES 1–5. Habitus of Microedus: 1—M. austinianus (USA: New Hampshire), 2—M. brevitarsis (holotype), 3—M. kastcheevi (paratype, Kazakhstan: Dzhungar Mts.), 4—A. schilenkovi (Russia: Altai, Korgon Mts.), 5—M. sp. (Kashmir). Scale bar: 1.0 mm.

FIGURES 6–13. Mouthparts (dorsal view) of M. austinianus (Figs. 6, 8, 10, 12) and M. schilenkovi (Figs. 7, 9, 11, 13): 6–7— labrum, 8–9—mandibles (left and right), 10–11—maxilla (right), 12–13—labium. Scale bars 0.1 mm.

FIGURES 18–23. Aedeagus of Microedus schilenkovi (Figs 18–19: Russia, Altai, Aygulakskiy Mts.; Fig. 20: Russia, Altai, Teletskoye Lake; Fig. 21: Kazakhstan, Tauchilik River) and A. kastcheevi (Figs. 22–23: paratype, Dzhungar Mts.): 18, 20–22— parameral view, 19, 23—lateral view. Scale bar: 0.1 mm.

FIGURES 24–29. Abdominal segments of Microedus schilenkovi: 24—male tergite VIII, 25—male sternite VIII, 26—male genital segment, 27—female tergite VIII, 28—female sternite VIII, 29—female genital segment. Scale bars 0.1 m