Orphnebius (Deroleptus) protuberatus, 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 : 77-84

Orphnebius (Deroleptus) protuberatus spec. nov.

urn:lsid:zoobank.org:act:06A78E32-C968-43A9-97E1-7682FE870CB6

( Figs 3, 26–28 , 75–78 )

Type material: Holotype ♀: “ INDIA No. 47 Kerala, Anaimalai Hills , 48 km. N.E. de Munnar, 700 m. 25-XI-72. Besuchet Löbl Mussard / Holotypus ♂ Orphnebius protuberatus sp. n., det. V. Assing 2016” ( MHNG).

Etymology: The specific epithet is the past participle of the Latin verb protuberare (to swell, to stand out) and alludes to the pronounced postero-median process of the abdominal tergite VIII.

Description: Body length 4.7 mm; length of forebody 1.7 mm. Coloration ( Figs 3, 26–27 ): head blackish; pronotum blackish-brown; elytra pale-brown with the postero-lateral portions extensively darker; abdomen dark-brown with tergite II and the posterior margins of tergites III–VII broadly paler; forelegs yellowish; mid-and hindlegs with dark-brown femora and pale-brown tibiae and tarsi; legs with antennomeres I–V palereddish, VI brown, and VII–XI dark-brown; maxillary palpi reddish-yellow with the terminal palpomere yellowish.

female tergite VIII (176); female sternite VIII (177). Scale bars: 173, 175–177: 0.5 mm; 174: 0.1 mm.

Head ( Fig. 26 ) 1.25 times as broad as long, posterior angles convex, moderately marked; dorsal surface anterolaterally with moderately fine and moderately dense punctation, otherwise impunctate or with very sparse and fine punctation; interstices without microsculpture. Eyes large, occupying anterior two-thirds of lateral margins of head. Antenna ( Fig. 3 ) short and distinctly incrassate, approximately 1.0 mm long; antennomeres IV weakly transverse, V distinctly transverse, VI–X approximately twice as broad as long and slightly asymmetric, and XI of oval shape and slightly longer than the combined length of IX and X.

Pronotum ( Fig. 26 ) approximately 1.25 times as broad as long and 1.09 times as broad as head, moderately strongly convex in cross-section; lateral margins weakly convex in dorsal view; disc with a median pair of coarser punctures slightly behind middle; lateral margins each with four moderately long, thin, and erect setae; otherwise with few scattered short setae.

Elytra ( Fig. 26 ) approximately 0.85 times as long as, and distinctly broader than pronotum; punctation very fine and sparse; pubescence long, depressed to sub-erect; interstices with oblique microsculpture best visible in postero-lateral portions. Hind wings present. Legs moderately long and not particularly slender; metatibia 0.75 mm long; metatarsomere I nearly as long as the combined length of II–IV.

ASSING, V.: On the LOMeChuSini Fauna OF the EaSt PalaearCtiC and Oriental regiOnS, With a FOCuS On the genera Orphnebius and Amaurodera

Abdomen ( Figs 27–28 ) broader than elytra; sternites III– VIII each with a series of stout setae postero-laterally; tergites III–VII each with a lateral setiferous puncture on either side, otherwise impunctate; tergite IV anterolaterally with microsculpture; sternites III and IV each with distinct postero-lateral process on either side, those of sternite IV much more pronounced than those of sternite III; tergite VII with dense non-setiferous punctation except near anterior margin, posterior margin with palisade fringe; tergite VIII ( Fig. 75 ) of highly distinctive shape, distinctly oblong, strongly tapering posteriad, posteriorly with pronounced process, lateral apices nearly completely reduced, across middle with moderately dense gland openings.

♂: unknown.

♀: posterior margin of sternite VIII ( Figs 76–77 ) strongly convex, in the middle indistinctly concave, laterally with three stout setae inserting in distinct protuberances; spermatheca approximately 0.2 mm long and shaped as in Fig. 78 .

Comparative notes: Based on the external and sexual characters, O. protuberatus belongs to the O. niger group (see ASSING 2016b). Regarding the shape of the head and the forebody, this species somewhat resembles O. siamensis CAMERON, 1946 ( Thailand) , from which it is readily distinguished by smaller body size, much shorter and more strongly incrassate antennae, and the pronounced postero-lateral processes of sternites III and IV alone. Orphnebius protuberatus differs from all its congeners particularly by the presence of stout spines on the lateral margins of sternites III–VIII, the distinctive shape of tergite VIII, and by the shape of the spermatheca. For illustrations of O. siamensis see ASSING (2016b).

Distribution and natural history: The type locality is situated in Kerala province in Southwest India. The holotype was collected at an altitude of 700 m.

Figures

Figs 1–30: Antenna (1–19), forebody (20, 23, 26), abdomen (21, 24, 27, 29), antero-lateral portion of abdomen in lateral-dorsal view (22, 25, 28), and abdominal segment VII (30) of Orphnebius triacuminatus (1, 20–22), O. gracilis (2, 23–25), O. protuberatus (3, 26–28), O. pertortus (4, 29–30), O. reticulipennis (5), Zyrastilbus almorensis (6), Pheidologitonetes bursata (7), Rabdotodrusilla vara (8), Amaurodera bicarinata (9), A. gilvicornis (10), A. latisulcata (11), A. brevipes (12), A. migritheca (13), A. longisetosa (14), A. calicitheca (15), Drusilla smetanai (16), D. nepalensis (17), D. lativentris (18), and Witteia tensa (19). Scale bars: 1–29: 1.0 mm; 30: 0.5 mm.

Figs 62–81: Orphnebius triacuminatus (62–65), O. niger (66–70), O. gracilis (71–74), O. protuberatus (75–78), and O. pertortus (79–81): female tergite VIII (62, 71, 75, 79); posterior margin of female tergite VIII (63); female sternite VIII (64, 72, 76, 80); spermatheca (65, 74, 78, 81); male tergite VIII (66); male sternite VIII (67); median lobe of aedeagus in lateral and in ventral view (68–69); paramere (70); medio-lateral portion of female sternite VIII (73, 77). Scale bars: 62, 64, 66–67:0.5 mm; 68–72, 75–76, 79–80: 0.2 mm; 63, 65, 73–74, 77–78, 81: 0.1 mm.