Orphnebius (Deroleptus) baccillatus, Assing, 2016

Assing, Volker, 2016, On some Lomechusini of the Palaearctic and Oriental regions (Coleoptera: Staphylinidae: Aleocharinae), Beiträge Zur Entomologie = Contributions to Entomology 66 (1), pp. 13-111 : 72

Orphnebius (Deroleptus) baccillatus spec. nov.

( Figs 63 , 90, 101 , 109 , 348–350 )

Type material: Holotype ♀: “ Lao, Phongsaly prov ., 21°41–2'N 102°06–8'E, 28.v.–20.vi.2003, Phongsaly env. , ~ 1500 m, Vít Kubáň leg. / Holotypus ♀ Orphnebius baccillatus sp. n., det. V. Assing 2015” ( NHMB).

Etymology: The specific epithet is an adjective derived from the Latin noun baccillum (walking stick, cane) and alludes to the conspicuous shape of the spermatheca.

Description: Body length 6.2 mm; length of forebody 2.5 mm. Coloration: head blackish-brown; pronotum brown with broadly pale-brown margins; elytra brown; abdomen pale reddish-brown with the posterior twothirds of tergite VII dark-brown; legs pale-reddish; antennae reddish; maxillary palpi pale-reddish, with the terminal palpomere yellowish.

Head ( Fig. 90 ) dorso-ventrally flattened, strongly transverse, 1.5 times as broad as long, and with marked posterior angles; dorsal surface with fine and sparse punctation, median dorsal portion impunctate; interstices without microsculpture. Eyes extremely large, extending along almost all of lateral margins of head nearly to posterior margin. Antenna ( Fig. 63 ) 1.7 mm long, not incrassate; antennomeres IV–V approximately as long as broad, VI–X very weakly transverse and of subequal width; XI slightly longer than the combined length of IX and X.

Pronotum ( Fig. 90 ) small and strongly transverse, broadest across anterior angles, 1.42 times as broad as long, and 0.90 times as broad as head, moderately convex in cross-section; lateral margins straight, weakly converging posteriad in dorsal view; punctation very fine and moderately sparse; pubescence depressed, short, and pale; near anterior angles with a stout, erect, black seta on either side.

Elytra ( Fig. 90 ) 1.37 times as long as pronotum; punctation moderately dense and fine; pubescence pale, short, and depressed. Hind wings present. Legs long and slender; metatibia 1.2 mm long; metatarsus approximately 0.9 times as long as metatibia; metatarsomere I approximately as long as the combined length of II and III.

Abdomen ( Figs 101 , 109 ): sternite III with a large, but not very long lateral extension of triangular shape; sternite IV with long, slender but somewhat massive, weakly erect, and apically acute postero-lateral extension; paratergite IV with a smaller spine-shaped posterior extension; posterior extensions of paratergites and sternite IV contiguous; tergites III–VI each with a lateral puncture bearing a dark seta on either side, tergite VI additionally with four setiferous punctures at posterior margin; tergite VII in posterior two-thirds with very dense and coarse non-setiferous punctation, near posterior margin with a transverse row of eight setiferous granules, posterior margin with palisade fringe; tergite VIII ( Fig. 348 ) with numerous setiferous granules in posterior portion, with dense short pubescence anteriorly, with a transverse series of non-setiferous teeth near posterior margin, with numerous small gland openings near anterior margin, and with a pair of clusters of gland openings anteriorly, posterior margin weakly concave; sternite VIII ( Fig. 349 ) transverse and with smoothly convex posterior margin.

♀: spermatheca ( Fig. 350 ) of distinctive shape, very long (0.6 mm), distal portion shaped like a walking stick, in transitional portion between distal and proximal portion somewhat coiled.

Comparative notes and comment: Orphnebius baccillatus differs from its consubgeners by distinctive external and sexual characters (large eyes, shape of pronotum, shapes of postero-lateral extensions of abdominal sternites III–IV and paratergite IV, the conspicuous shape and sculpture of tergite VIII, shape of the spermatheca). The species is additionally distinguished from O. vates , the only other large-eyed Deroleptus species known from Laos, by much larger size.

Distribution and natural history: The type locality is situated near Phongsaly in North Laos and nearly identical to that of O. vates . The holotype was collected at an altitude of approximately 1500 m.

Figures

Figs 54–83. Antenna (54–69), forebody (70–73), abdomen (74–76), abdominal segments III–V (77, 81), lateral portion of abdominal segments III–V (78, 82), tergites VI–VII (79, 83), and hind leg (80) of Orphnebius spp. of the subgenus Deroleptus: discrepans (54, 73, 75), triapicalis (55, 71, 76), gracilior (56, 72, 77–80), sexcarinatus (57, 81–83), spoliatus (58), cultellatus (59), septemcuspis (60), vates (61), tortus (62), baccillatus (63), carinatus (64), dispar (65), laticeps (66), biimpressus (67), ulcerosus (68), falagrioides (69), siamensis (70, 74). Scale bars: 70–83: 1.0 mm; 54–69: 0.5 mm.

Figs 84–101. Forebody (84–90), abdomen (91–94, 97–98), lateral portion of abdominal segments III–V/VI (95, 99, 101), and tergite VII (96, 100) of Orphnebius spp. of the subgenus Deroleptus: sexcarinatus (84), spoliatus (85, 91), cultellatus (86, 92–94), septemcuspis (87, 95–96), tortus (88, 98–100), vates (89, 97), baccillatus (90, 101). Scale bars: 84–95, 97–99, 101: 1.0 mm; 96, 100: 0.5 mm.

Figs 102–118. Forebody (102–108), abdomen (109–110, 112–113, 115), lateral portion of abdominal segments III–V/ VII (111, 117–118), and tergites VII(–VIII) (114, 116) of Orphnebius spp. of the subgenus Deroleptus: carinatus (102, 117), laticeps (103, 112), biimpressus (104, 108, 113–114), ulcerosus (105, 115–116), dispar (106, 110–111), falagrioides (107, 118), baccillatus (109). Scale bars: 102–110, 112–113, 115, 117–118: 1.0 mm; 111, 114, 116: 0.5 mm

Figs 340–358. Orphnebius vates (340–344), O. tortus (345–347), O. baccillatus (348–350), O. carinatus (351–353), and O. dispar (354–358): median lobe of aedeagus in lateral and in ventral view (340–341, 354–355); paramere (342, 356); tergite VIII (343, 345, 348, 351, 357); male sternite VIII (344); female sternite VIII (346, 349, 352); spermatheca (347, 350, 353, 358). Scale bars: 0.2 mm.