Nitidula obenbergeri, Lasoń & Hájek & Jelínek, 2021

Lasoń, Andrzej, Hájek, Jiří & Jelínek, Josef, 2021, The Nitidula carnaria complex, with description of a new species from Central Asia, and a key to world species of the genus (Coleoptera: Nitidulidae), Acta Entomologica Musei Nationalis Pragae 61 (2), pp. 503-516 : 507-509

Nitidula obenbergeri sp. nov.

( Figs 3 , 6, 9, 12 )

Nitidula carnaria : JൾඅටඇൾK (1965):144 (new records, Mongolia); JൾඅටඇൾK (1974): 184 (new records, Mongolia).

Type material. Hඈඅඈඍඒඉൾ: J ( NMPC), labelled: ʻCHINA: Qinghai province / HAIBU env., 3100-3270 m / 36°48.4-49.8′N 100°45.5- / 49.7′E ( GPS), 13.-15.VII. / 2005, J. Hájek, D. Král & / J. Růžička leg. (Ch18) [p] // individually on carrion / (several remnants of Ovis / and Capra ); loamy soil / not far from the bank of / the Qinghai Hu lake [p] // HOLOTYPUS J / NITIDULA / obenbergeri sp. nov. / Lasoń, Hájek & Jelínek det. 2021 [red label, p]ʼ. Pൺඋൺඍඒඉൾඌ: CHINA: QංඇGHൺං: 7 JJ 26 ♀♀, same label data as holotype ( ALCB, NMPC); 3 spec., ‘CHINA: Qinghai province, HAIBU env., 3190-3270 m,36°48.4-49.8′N, 100°45.4-49.7′E, 13.-15.VII.2005, J. Hájek, D. Král & J. Růžička leg.’, ‘individually under stones, in excrements and on vegetation, loamy soil not far from the bank of the Qinghai Hu lake ( NMPC, ALCB). KAZAKHSTAN: 4 spec., ‘Kasakhstan, Tsharyn valley, 25 km NE Zhalanash, 43°15′N, 78°48′E, 1200 m, 21.v.1993, lgt.?’ ( ALCB, NMPC). MONGOLIA: 2 spec., ‘Nordl. Mongolei, Changai, Leder’ ( HNHM); 1 spec., ‘MONGOLIA: Central aimak, Bajan-Zurch sum, 1300 m, 30 km O v.Ulan Baator, Exp.Dr.Z.KASZAB,1963’, ‘Nr.1., 16.VI.63’ ( HNHM); 1 spec., ‘MONGOLIA: Ostgobi aimak 13 km SSO v. Chara- Eireg, 1100 m, Exp.Dr.Z.KASZAB,1963’, ‘Nr.56., 29.VI.63’( HNHM); 5 spec., ‘MONGOLIA: Suchebaator aimak, Ongon elis, 10 km S von Somon Chongor, 900 m, Exp.Dr.Z.KASZAB,1965’, ‘Nr.355, 3.-5.VIII.1965 ’ ( HNHM); 3 spec., ‘MONGOLIA: Suchebaator aimak, Somon Dariganga, 1150 m, Exp.Dr.Z.KASZAB,1965’, ‘Nr.364, 5.VIII.1965 ’ ( HNHM); 8 spec., ‘MONGOLIA: Suchebaator aimak, Molzog elis, 2km S von Somon Dariganga, 1150 m, Exp.Dr.Z.KASZAB,1965’, ‘Nr.366, 6.-7. VIII.1965 ’ ( HNHM); 4 spec., ‘MONGOLIA: Baajanchongor aimak,

Changaj Gebirge, Ulaan čolon, 18 km S vom Pass Egijn davaa, 2300 m, Exp.Dr.Z.KASZAB,1966’, ‘Nr.711, 18.-19.VII.1966 ’ ( HNHM); 1 spec., ‘MONGOLIA: Central aimak, Cagan Dirschin chodag, im Tal des Tola, 24 km von Somon Tariat, 1180 m, Exp.Dr.Z.KASZAB,1966’, ‘Nr.741, 24.VII.1966 ’ ( HNHM); 17 spec., ‘MONGOLIA:Central aimak, Chentej Gbg., 15 km von. Ulaan Baator, Waldgrenze, 16.v.1971, leg.Zs.Peregi’ ( HNHM); 1 spec.,‘MONGOLIA: Central aimak, Chentej Gbg., 15 km N von Ulaan Baator, 12.VI.1971, leg.Zs.Peregi’ ( HNHM); 6 spec., ‘MONGOLIA: Uvs aimak, Senke des Sees Ačit nuur, Flusstal Altan gadasin chev gol, 20-25 km NO von Somon Böchmörön, 1600 m, Exp. Dr.Z.KASZAB,1968’, ‘Nr.1040, 29.VI.1968 ’ ( HNHM); 6 spec., ‘MON- GOLIA: Bajan-Olgij aimak am Pass Schine davaa, 27 km S von Somon Cagannuur, 2690 m, Exp.Dr.Z.KASZAB,1968’, ‘Nr. 1045, 30.VI.1968 ’ ( HNHM); 1 spec., ‘MONGOLIA: Uvs aimak, am Fluss Baruunturuun gol neben Somon Baruunturuun, 1280 m, Exp.Dr.Z.KASZAB,1968’, ‘Nr. 1012, 25.VI.1968 ’ ( HNHM); 2 spec., ‘MONGOLIA: Bulgan aimak, 11 km W von Somon Bajannuur am See Bajan nuur, 1000 m, Exp. Dr.Z.KASZAB,1968’,‘Nr.958, 14.VI.-24.VII.1968 ’ ( HNHM). RUSSIA: 4 spec., ‘Tschita, Transbaikalien, Hermann Frieb’ ( HNHM, NMPC); 1 spec., ‘Ostsibirien, Werchne-Udinsk, leg. F. Ziegler, 1914-18’ ( PACR); 1 spec., ‘RUSSIA: S Tuva, 36°31′N, 95°35′E, Khorumung - Tayga Mt. Range, Ular-Khem Riv., 23.V.2000, leg. Vashchenko S.’ ( ALCB); 6 spec., ‘RUSSIA: SW Tuva, S slopes of W Tanu-Ola Mts. near Soglyi vill., 2000-2800 m, 13.V.-1.VI. 2003, leg. Vashchenko S.’ ( ALCB); 4 spec., ‘RUSSIA: SW Tuva, 2000 m, SW Tannu-Ola Mt., Sogly vill., 1-5. VII.2003, leg. Vashchenko S.’ ( ALCB, USMB).

Description. Male (holotype). Body oblong oval, moderately convex. Head and pronotum densely punctate, dull, elytra moderately shining. Black, each elytron with two orange spots: very large basal one, occupying most of the area between scutellum and lateral margin, embracing humeral bulge; and smaller round spot situated posterior to midlength of each elytron; lateral and apical margins with orange border. Legs and antennae yellow-brown, antennal club black. Pubescence long, dense, recumbent, yellow, lateral margins of both pronotum and elytra fringed with dense long yellow setae ( Fig. 3 ). Body length 3.8 mm, width 1.5 mm.

Head little narrower than anterior pronotal margin. Frons flatly convex with pair of shallow impressions between antennal insertions. Punctures of somewhat variable size, almost equal in size to eye-facets, almost contiguous, separated by very narrow, at places somewhat raised interspaces. Punctures on clypeus somewhat granular, anterior margin of clypeus subtruncate, not bordered. Eyes setose. Submentum concave, punctures equal in size to eye-facets, separated by less than one diameter.Antennal furrows deep, well-defined, converging posteriad, not exceeding posterior margin of eye. Antennae almost as long as width of head across eyes; antennomere III as long as IV + V, each of IV and V longer than wide, VI and VII as long as wide, VIII transverse; antennal club occupying less than third of antenna length (ratio ANLE/ANCL = 3.58), broadly oval (ratio ANCL/ANCW = 1.15).

Pronotum transverse (ratio WPR2/LEPR = 1.69), widest posterior to midlength, more strongly rounded anteriad than posteriad (ratio WPR1/WPR3 = 1.20). Anterior margin of pronotum truncate, anterior angles obtuse, not prominent. Lateral margins not explanate, flatly arcuate in anterior half, strongly curved posterior to midlength, feebly concave besides posterior angles. Basal margin distinctly bordered, very shallowly concave besides posterior angles, those obtuse to subrectangular. Pronotal disc moderately convex, obliquely shallowly impressed besides posterior angles, densely punctate like frons; size of individual punctures variable, larger punctures sometimes rasp-like.

Scutellar shield small, subtriangular, densely punctate with narrow impunctate border.

Elytra widest at apical fourth, separately rounded apically reaching their maximum length between longitudinal axis and suture. Ratio LELY/WELY = 1.18. Lateral margins not explanate, in basal half almost rectilinear, in posterior half regularly arcuate. Surface of elytra flatly convex along suture, strongly convex laterally, lateral margins hardly visible simultaneously from above in their entirety. Punctures somewhat smaller than eye-facets, separated by one diameter or less, interspaces with traces of reticulation, moderately shining. Sutural lines distinct in apical fourth.

Pygidium subtriangular with rounded apex, densely rugosely punctate, punctures of variable size.

Legs. Ratio distances between pro-, meso- and metacoxae as 1.0: 2.0: 3.6. Pro-, meso- and metafemora simple, oval, ratio length/width = 2.64, 2.66 and 2.81, respectively. Anterior tibia 3.3 × longer than wide, outer subapical angle sharp, prominent. Protarsomeres I–III bilobed, ca. half the width of protibia, tarsal claws simple. Mesotibia 4.3 × longer than wide, outer subapical angle prominent, outer margin bearing long dense setae. Metatibia 5.8 × longer than wide, outer subapical angle blunt, feebly prominent.

Ventral side. Prosternum moderately convex in middle, shallowly concave laterally, punctate like submentum; anterior margin markedly bordered. Notosternal sutures distinct. Hypomera flat, densely shallowly punctate, punctures somewhat larger than eye-facets, separated by less than one diameter, sometimes almost contiguous. Prosternal process dilated posterior to procoxae, flatly arcuate apically with long acute lateral angles. Mesoventrite moderately convex, densely rugosely punctate. Metaventrite somewhat flattened posterior to midlength, discrimen developed as impunctate medio-longitudinal strip in posterior half of metaventrite. Punctures almost equal in size to eye-facets or smaller, shallow, separated by one diameter or less, becoming closer and larger laterally; interspaces moderately shining in middle, reticulate and dull laterally. Punctation of abdominal ventrite I as on metaventrite, but somewhat closer, punctation of following ventrites similar, but somewhat finer. Posterior intercoxal margin arcuately emarginate.

Male genitalia. Median lobe of aedeagus almost twice as long as wide, widest in distal half, lateral margins broadly arcuate ( Fig. 6 ). Tegmen ca. 1.4 × longer than wide, subparallel-sided in basal half, in distal half gradually narrowed towards flatly rounded apex ( Fig. 9 ). Tergite VIII broadly rounded apically ( Fig. 12 ).

Female similar to male, but elytra nearly simultaneously rounded apically, reaching their maximum length at suture, sutural angles accentuated by longer yellow setae. Punctation of pronotum as a rule more heterogeneous, intermixed with large rasp-like punctures. Protarsomeres I–III not bilobed, ca. one third of tibia width.

Variation. Background colour of dorsal surface varying from brown to black, elytra often lighter than head and pronotum. Shape and size of elytral spots somewhat variable, sometimes both spots on one elytron confluent.

Measurements. Body length 2.7–4.2 mm, width 1.0– 1.8 mm. Ratio ANLE/ANCL = 3.27–3.40, ANCL/ANCW = 1.12–1.22, WPR2/LEPR = 1.51–1.70; WPR1/WPR3 = 1.22–1.44, LELY/WELY = 1.18–1.23.

Differential diagnosis. Nitidula obenbergeri sp. nov. resembles closely related Palaearctic N. carnaria , from which it differs in more transverse pronotum (ratio WPR2/ LEPR = 1.51–1.70, in N. carnaria 1.41–1.57), antennomeres IV and V as a rule longer than wide (as long as wide in N. carnaria ) and different male genitalia (cf. Figs 4, 7, 10 and 6, 9, 12 respectively). Nitidula obenbergeri sp. nov. differs from N. maculosa in subtruncate anterior margin of pronotum and flatly rounded apex of prosternal process (anterior margin of pronotum shallowly concave anteriorly and prosternal process truncate apically in N. maculosa ). Collection circumstances. In China, the new species was collected on Capra , Lepus and Ovis carcasses, in the steppe/pasture surrounded with sand dunes at one side, and the bank of the Qinghai Hu lake at the other side ( Figs 13–16 ).

Etymology. The new species is dedicated to the late Czech entomologist, Professor Jan Obenberger, who was the first to establish it as a distinct taxon, having labelled the specimens from Tschita in NMPC as aberrations of Nitidula carnaria . The specific epithet is a noun in the genitive case.

Distribution. Northern China (Qinghai Province), southeastern Kazakhstan, Mongolia and Russian East Siberia (Tuva and Zabaykalsky Krai).

Figures

Figs 1–3. Habitus of Nitidula carnaria species complex. 1 – Nitidula carnaria (Schaller, 1783) (Czech Republic, body length: 3.3 mm); 2 – N. maculosa Fairmaire, 1866 (Algeria; 2.8 mm); 3 – N. obenbergeri sp. nov. (paratype; China: Qinghai; 3.8 mm).

Figs 4–12. Male genitalia of Nitidula species. 4, 7, 10 – Nitidula carnaria (Schaller, 1783) (Czech Republic); 5, 8, 11 – N. maculosa Fairmaire, 1866 (Algeria); 6, 9, 12 – N. obenbergeri sp. nov. (holotype; China: Qinghai). 4–6 – median lobe of aedeagus; 7–9 – tegmen; 10–12 – tergite VIII. Scale bar = 0.25 mm.

Figs 13–16. Habitat of Nitidula obenbergeri sp. nov. in China (Qinghai): 13–14 – general view of the habitat; 15 – pasture with sheep (Ovis sp.); 16 – Jan Růžička collecting on hare (Lepus sp.) carcass at the locality. Photos David Král.