Orphnebius (Deroleptus) migrus, Assing, 2017

Assing, Volker, 2017, On the Lomechusini fauna of the East Palaearctic and Oriental regions, with a focus on the genera Orphnebius and Amaurodera (Coleoptera: Staphylinidae: Aleocharinae), Beiträge Zur Entomologie = Contributions to Entomology 67 (1), pp. 63-106 : 86

Orphnebius (Deroleptus) migrus spec. nov.

urn:lsid:zoobank.org:act:550FAFD7-3EA5-40E2-9E95-9203CB6C7505

( Figs 32–33 , 82–89)

Type material: Holotype ♂: “ INDIA: Meghalaya #2a, West Garo Hills dist., Trail Tura – Tura Peak , summit 650 m, 14.X.2004, 25°30'28"N, 90°13'54"E / Leg. G. Cuccodoro, C. Carlton, R. Leschen & D. Erne / Holotypus ♀ Orphnebius migrus sp. n., det. V. Assing 2016” ( MHNG) . Paratype ♀: same data as holotype (cAss).

Etymology: The specific epithet (Latin, adjective: minute) alludes to the conspicuously small body size of this species.

Description: Body length 1.7–2.4 mm; length of forebody 0.9–1.1 mm (female larger than male). Coloration ( Figs 32–33 ): head dark-brown with the anterior portion paler; pronotum dark-yellowish to yellowish-brown; elytra yellowish with the postero-lateral portions darker; abdomen yellowish to yellowish-red; legs yellowish; antennae dark-yellowish; maxillary palpi yellow.

Head ( Fig. 32 ) flattened, strongly transverse, nearly 1.5 times as broad as long, and with marked posterior angles (in postero-dorsal view); posterior margin concave in the middle; dorsal surface with fine, shallow, and sparse punctation, median dorsal portion impunctate; interstices without microsculpture. Eyes extremely large, strongly bulging, and with coarse ommatidia, occupying almost all of lateral margins of head nearly to posterior margin. Antenna ( Fig. 32 ) 0.7–0.9 mm long, weakly incrassate; antennomeres IV–X transverse and of gradually increasing width, X approximately 1.5 times as broad as long, and XI approximately as long as the combined length of IX and X.

Pronotum ( Fig. 32 ) of trapezoid shape and strongly transverse, broadest near anterior angles, approximately 1.6 times as broad as long, and 0.9 times as broad as head, moderately convex in cross-section; lateral margins straight, distinctly converging posteriad in dorsal view; punctation fine, but distinct, moderately sparse, and somewhat granulose; pubescence depressed, short, and pale; lateral margins with two long and erect setae on either side.

Elytra ( Fig. 32 ) approximately 1.25 times as long as pronotum; punctation moderately sparse and granulose; pubescence pale, depressed, and short. Hind wings present. Legs relatively short; metatibia 0.4–0.5 mm long; metatarsus nearly as long as metatibia; metatarsomere I short, slightly longer than II, but distinctly shorter than the combined length of II and III.

Abdomen ( Fig. 33 ) slightly narrower than elytra; sternite III weakly produced postero-laterally, other sternites unmodified; all sternites with long, stout, and erect setae laterally; tergites V and VI postero-laterally with a long and stout erect seta on either side; tergite VII with dense non-setiferous punctation except near anterior margin, middle of posterior margin with a pair of more or less distinct smooth tubercles, posterior margin with palisade fringe; tergite VIII ( Figs 82, 87 ) strongly transverse and with several long black setae in posterior portion, posterior margin weakly concave and weakly serrate.

♂: sternite VIII ( Fig. 83 ) transverse and with convex posterior margin; median lobe of aedeagus 0.24 mm long and shaped as in Figs 84–85 ; paramere ( Fig. 86 ) 0.27 mm long, condylite much shorter than paramerite, apical lobe of paramerite obliquely truncate apically.

♀: sternite VIII ( Fig. 88 ) transverse, middle of posterior margin concave; spermatheca ( Fig. 89 ) with long and slender proximal portion.

Comparative notes: This species is readily distinguished from its consubgeners by its small size alone. In addition, it is characterized by the chaetotaxy of the abdominal sternites, the granulose punctation of the pronotum and elytra, the strongly transverse pronotum, the shape and chaetotaxy of the abdominal tergite VIII, and particularly by the primary sexual characters.

Distribution and natural history: The type locality is situated in Meghalaya, Northeast India. The specimens were collected at an altitude of 650 m.

Figures

Figs 31–42:Orphnebius pertortus(31),O. migrus(32–33),O. reticulipennis(34–36),Zyrastilbusalmorensis(37–38),Pheidologitonetes bursata (39–40), and Rabdotodrusilla vara (41–42): forebody (31–32, 34, 37, 39, 41); elytra and abdomen (33); abdomen (35, 38, 40, 42); antero-lateral portion of abdomen in dorso-lateral view (36). Scale bars: 37–38: 1.0 mm; 31–36, 39–42: 0.5 mm.

Figs 82–100: Orphnebius migrus (82–89), O. reticulipennis (90–94), Tetrabothrus semiapterus (95–96), Zyrastilbus almorensis (97), and Pheidologitonetessetifer (98–100): maletergite VIII (82);male sternite VIII (83); medianlobeof aedeagus inlateral and inventral view (84–85, 95–96, 98–99); paramere (86); female tergite VIII (87, 90); female sternite VIII (88, 93); spermatheca (89, 94, 100); posterior portion of female tergite VIII (91); postero-lateral portion of female tergite VIII (92); median dorsal portion of head (97). Scale bars: 82–83, 87–88, 90, 93, 95–96, 98–99: 0.2 mm; 84–86, 89, 91–92, 94, 97, 100: 0.1 mm.