Othius burmensis, Assing, 2018

Assing, Volker, 2018, A revision of Othiini. XX. Two new species of Othius, the first record of the genus from Myanmar, and additional records (Coleoptera: Staphylinidae: Staphylininae), Linzer biologische Beiträge 50 (1), pp. 25-40 : 37-38

Othius burmensis nov.sp. ( Figs 15-23 , 27-29 )

T y p e m a t e r i a l: Holotype ♂: " MYANMAR (Burma), Provinz Kachin State, ca. 30 km N von Pangwa, 29.-30.IX. + 6.X.2010, N 25°43'52.4'' E 098°24'06.0'' (H = 2.255 m; TF - under wood, stones), leg. Michael Langer, S. Naumann & S. Löffler / Holotypus ♂ Othius burmensis sp. n. det. V. Assing 2015 " ( NHMW).

E t y m o l o g y: The specific epithet is an adjective derived from Burma, where this species is currently the sole representative of the genus.

D e s c r i p t i o n: Measurements (mm) and ratios: HL: 1.59; HW: 1.53; PW: 1.65; PL: 1.95; EL: 1.37; TiL: 1.40; TaL: 1.16; TL: 11.4; HL/HW: 1.04; HW/PW: 0.93; PL/PW: 1.19; EL/PL: 0.70; TaL/TiL: 0.83.

Moderately large species (see measurements). Coloration: head, pronotum, and abdomen black; elytra blackish-brown with a dark-reddish hue; legs dark-brown with reddish tarsi; antennae dark-reddish, with antennomeres I, III, and the apical portion of II blackish.

Head ( Figs 15-16 ) weakly oblong, weakly widened posteriorly, and somewhat narrower than pronotum (see ratios HL/HW and HW/PW); anterior pair of frontal punctures distinct, with additional smaller punctures; posterior pair of frontal punctures absent; median dorsal portion impunctate; lateral and posterior dorsal portions with rather sparse and coarse punctures of somewhat variable size; integument with distinct and fine transverse microsculpture ( Fig. 17 ). Eyes of moderate size, approximately half as long as postocular region in dorsal view. Antenna 2.9 mm long; antennomeres V-X weakly transverse.

Pronotum ( Fig. 15 ) moderately oblong (see ratio PL/PW) and with subparallel lateral margins in dorsal view; discal punctation pattern similar to that of most other East Palaearctic congeners; posterior discal puncture (i. e., puncture near posterior angle) separated from posterior angle by a distance less than its diameter; microsculpture finely transverse.

Elytra ( Fig. 18 ) shorter than pronotum (see ratio EL/PL); macropunctation rather sparse and shallow; interstices on average several times as broad as diameter of punctures, with very dense micropunctation rendering the surface nearly matt. Hind wings present.

Abdomen slightly narrower than elytra; punctation fine and moderately dense; interstices with fine transverse microsculpture; posterior margin of tergite VII with palisade fringe.

♂: protarsomeres I-IV strongly dilated; sternites V-VII unmodified; sternite VIII posteriorly triangularly depressed, posterior margin weakly concave; posterior processes of hemitergites IX short, apically without tooth-like processes, not reaching posterior margin of tergite X; sternite IX ( Fig. 19 ) broad, anteriorly deeply bifid, posterior margin strongly concave, postero-lateral angles without spine-like processes; aedeagus ( Figs 20 , 27-28 ) 1.4 mm long; parameres apically not distinctly dilated, each with 4 apical setae; internal sac (extruded in holotype) with six sclerotized internal structures: a short and apically weakly curved median basal structure ( Figs 22-23 ), a distinctly longer median apical structure with a hook-shaped apex (pointing ventrad) ( Fig. 29 ), and two pairs of long and slender lateral structures ( Fig. 21 ).

C o m p a r a t i v e n o t e s: The similarly modified sculpture of the elytra (dense micropunctation) and the shared absence of a pair of posterior frontal punctures on the head suggests that O. burmensis is closely related to O. opacipennis CAMERON, 1939 and allied species ( O. sericipennis ASSING, 2003; O. spoliatus ASSING, 2008), all of which are distributed in southwestern China (Yunnan, Sichuan). Othius burmensis is distinguished from all of them by a less derived morphology of the aedeagus (less elongate and with the full set of internal structures). In addition, it differs from them as follows:

from O. opacipennis (Yunnan, Sichuan) by distinctly bicoloured antennae ( O. opacipennis : antennae blackish-brown to black), a posteriorly dilated and less oblong head, subparallel lateral margins of the pronotum ( O. opacipennis : pronotum tapering posteriorly), and the shape of the male sternite IX ( O. opacipennis : sternite IX much longer and more slender, anteriorly less deeply bifid, and posteriorly bisinuate);

from O. sericipennis (Yunnan, Sichuan) by a posteriorly dilated, much broader, and less oblong head, subparallel lateral margins of the pronotum ( O. sericipennis : pronotum tapering posteriorly), and the shape of the male sternite IX ( O. sericipennis : sternite IX much longer, more slender, anteriorly not bifid, and posteriorly weakly concave);

from O. spoliatus (Yunnan) by distinctly bicoloured antennae (O. spoliatus: antennomeres IV-X dark-brown), less transverse preapical antennomeres, a less broad and posteriorly less strongly dilated head, much longer elytra, the presence of hind wings (reduced in O. spoliatus), the presence of a palisade fringe at the posterior margin of tergite VII (absent in O. spoliatus), and the shape of the male sternite IX (O. spoliatus: sternite IX much longer, more slender, and posteriorly nearly truncate with median excision).

For illustrations of O. opacipennis , O. sericipennis , and O. spoliatus see ASSING (1999b, 2003b, 2008).

D i s t r i b u t i o n a n d n a t u r a l h i s t o r y: Othius burmensis is the first representative of the genus to be recorded from Myanmar. The type locality is situated in the northeast of the country, not far from the border with the Chinese province Yunnan, at an altitude of 2255 m.

Figures

Figs 15-23: Othius burmensis: (15) head and pronotum; (16) head; (17) median portion of head; (18) sutural portion of right elytron; (19) male sternite IX; (20) aedeagus in ventral view (internal sac fully extruded); (21) lateral internal structures of aedeagus; (22-23) basal internal structure. Scale bars: 15-16: 1.0 mm; 19-20: 0.5 mm; 17-18, 21: 0.2 mm; 22-23: 0.1 mm.

Figs 24-29: Othius arater (24-26) and O. burmensis (27-29): (24-26) internal structures of aedeagus in ventral view; (27-28) aedeagus in lateral and in ventral view (without extruded internal sac); (29) apical median internal structure of the aedeagus. Scale bars: 27-28: 0.5 mm; 24-26, 29: 0.2 mm.