Zyras (Zyras) nigroaeneus CAMERON, 1939

Assing, Volker, 2017, On Zyras sensu strictu in the East Palaearctic and Oriental regions, with a focus on the faunas of the Himalaya, India, Sri Lanka, Thailand, and Sulawesi (Coleoptera: Staphylinidae: Aleocharinae: Lomechusini), Beiträge Zur Entomologie = Contributions to Entomology 67 (1), pp. 117-192 : 133

Zyras (Zyras) nigroaeneus CAMERON, 1939

( Figs 22 , 50 , 81 , 140–141 , Map 2 )

Zyras (Zyras) nigroaeneus CAMERON, 1939a: 543 f.

Type material examined: Syntype ♂ [aedeagus missing]: “Narkanda 9230', Simla Hills / Fungus / Dr. Cameron. 14-IX.1921 / Z. nigraeneus [sic] Cam Type / M. Cameron. Bequest. B.M. 1955-147 / Holotype / Syntypus Zyras nigroaeneus Cameron , rev. V. Assing 2016” ( BMNH) .

Comment: The original description is based on an unspecified number of syntypes from “Simla Hills: Narkanda, alt. 9230 feet ” ( CAMERON 1939a). Only one syntype, a male without aedeagus, was located in the Cameron collection.

Additional material examined: India: 1 ♀, Uttar Pradesh, Nainital Div., Kumaon, leg. Champion (BMNH).

Redescription: Species of slender habitus. Body length 5.1–6.0 mm; length of forebody 2.7–2.8 mm. Coloration ( Figs 22 , 50 , 81 ): whole body black, forebody with a faint blueish hue; legs bicoloured: femora blackish-brown, tibiae and tarsi pale-yellowish; antennae blackish-brown with antennomeres I–II and the base of III yellowish; maxillary palpi brown, with the terminal palpomere yellowish.

Head ( Fig. 50 ) moderately transverse, median portion extensively impunctate; punctures in lateral portions sparse and coarse. Eyes longer than postocular region in dorsal view. Antenna ( Fig. 22 ) approximately 1.8 mm long and moderately slender; antennomeres IV–V approximately as long as broad, VI–X increasingly transverse and of gradually increasing width, X approximately 1.5 times as broad as long, and XI barely as long as the combined length of IX and X.

Pronotum ( Fig. 50 ) approximately 1.1 times as broad as long and approximately 1.25 times as broad as head, not distinctly tapering posteriad, broadest approximately in the middle; lateral margins weakly convex in dorsal view; punctation coarse, sparse, and very irregularly distributed, with rather large impunctate areas on either side of midline; midline broadly impunctate.

Elytra ( Fig. 50 ) 0.86–0.93 times as long as pronotum; punctation moderately coarse, defined, rather sparse, and regularly distributed; interstices on average approximately three times as broad as diameter of punctures. Hind wings fully developed. Metatarsomere I shorter than the combined length of II–IV.

Abdomen ( Fig. 81 ) narrower than elytra, gradually tapering from base to apex, with sharp paratergites; anterior impressions on tergites III–V rather shallow; anterior impressions of tergites III–V each with a transverse row of sparse and fine non-setiferous punctures; tergites III–IV with a lateral setiferous puncture on either side and with four setiferous punctures at posterior margin; tergite V with a lateral setiferous puncture on either side and with six setiferous punctures at posterior margin; tergite VI with a transverse row of non-setiferous punctures anteriorly, with a lateral setiferous puncture on either side, with a median pair of setiferous punctures in posterior portion, and with six setiferous punctures at posterior margin; tergite VII with a transverse band of sparse and fine non-setiferous punctures anteriorly and with scattered setiferous punctures in posterior portion, posterior margin with palisade fringe; tergite VIII ( Fig. 140 ) with sparse setiferous punctures only in posterior portion, posterior margin convex and with distinct concavity in the middle.

♂: sternite VIII ( Fig. 141 ) much longer than tergite VIII, posteriorly strongly convex; aedeagus not available.

♀: posterior margin of sternite VIII shallowly concave in the middle.

Comparative notes: Among its geographically close congeners, Z. nigroaeneus is characterized particularly by its slender habitus, the conspicuous coloration of the body and the legs, and by the punctation pattern of the abdomen.

Distribution and natural history: This species is currently known only from its type locality in Himachal Pradesh and from one locality in Uttar Pradesh, North India ( Map 2 ). The syntype was collected at an altitude of approximately 2800 m.

Figures

Map 2: Revised distributions of Zyras pindarae (black circles) and Z. nigroaeneus (white circles) in the Himalaya.

Figs 1–41:Antennae of Zyrasspp.:kraatzi(1),exasperatus(2),pindarae (3–5),perforatus(6),championi(7),pallipes (8),condignus (9), nitens (10), truncatus (11), nilgiriensis (12), hirsutiventris (13), russiceps (14), brignolii (15), hastatus (16), parageminus (17–18), latilobatus (19), alternans (20), hirtus (21), nigroaeneus (22), luteipes (23), longilobatus (24), morvani (25), gratellus (Malaysia) (26), castaneus, lectotype (27),proximus (28–29),novinversus (30–31), brevilobatus(32), parvicollis(33), ambulans (34),matangensis (35), densissimus (36), densihirtus (37), nigrihirtus (38), gratellus (Sulawesi) (39), gardneri (40), titan (41). Scale bar: 1.0 mm.

Figs 42–54: Forebody of Zyras spp.: kraatzi (42), exasperatus (43), pindarae (44), perforatus (45), championi (46), pallipes (47), condignus, holotype (48), condignus, Nepal (49), nigroaeneus (50), morvani (51), truncatus (52), longilobatus (53), hastatus (54). Scale bar: 1.0 mm.

Figs 68–81: Forebody (68–77), head and pronotum (78), and abdomen (79–81) of Zyras spp.: brevilobatus (68), parvicollis (69), ambulans (70), nitens, holotype (71), gratellus (Malaysia) (72), matangensis (73), gratellus (Sulawesi) (74), densissimus (75), titan (76), densihirtus (77), nigrihirtus (78), kraatzi (79), asperatus (80), nigroaeneus (81). Scale bar: 1.0 mm.

Figs 134–155: Zyras perforatus (134–135), Z. pallipes (136–139), Z. nigroaeneus, holotype (140–141), Z. condignus (142–147), Z. morvani, holotype (148–149), and Z. truncatus (150–155): male tergite VIII (134, 138, 140, 146, 148, 152); male sternite VIII (135, 139, 141, 147, 149, 153); median lobe of aedeagus in lateral and in ventral view (136–137, 142–143, 150–151); paramere (144–145); female tergite VIII (154); female sternite VIII (155). Scale bars: 0.5 mm.