Lathrobium glandulosum, Assing, 2013

Assing, Volker, 2013, On the Lathrobium fauna of China V. New species and additional records from Yunnan (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 63 (1), pp. 53-128 : 103-105

4.3 The L. celere species group

4.3.1 Lathrobium glandulosum sp. n.

( Figs 236-245 , Map 7 )

Type material:

Holotype ♂: “ CHINA: Yunnan [CH07-24], Nujiang Lisu Aut. Pref., Gaoligong Shan , valley 18 km W Gongshan, 3020 m, 27°47'54"N, 98°30'13"E, mixed forest, litter, moss, wood sifted, 7.VI.2007, M. Schülke / Holotypus ♂ Lathrobium glandulosum sp. n. det. V. Assing 2013” (cSch) . Paratypes: 1 ♂, 8 ♀♀: same data as holotype (cSch, cAss) ; 4 ♀♀: same data, but leg. Pütz (cPüt, cAss) ; 1 ♀: “ CHINA: Yunnan [CH07-21], Nujiang Lisu Aut. Pref., Gaoligong Shan , pass 22 km W Gongshan, N slope, 3350-3400 m, 27°46'27"N, 98°26'50"E, fern, moss, litter, sifted, 6. VI.2007, M. Schülke ” (cSch) ; 1 ♀: same data, but leg. Pütz (cAss) ; 2♂♂, 9♀♀: “ CHINA: N-Yunnan [2005- 16], Nujiang Lisu Aut. Pref., Gongshan Co., Gaoligong Shan, sidevalley, 3000-3050 m, 27°47.90'N, 98°30.19'E, conif. forest with Rhododendron, broad leaved bushes, litter, moss, dead wood sifted along creek and snowfields, 21.VI.2005, M. Schülke [2005-16]” (cSch, cAss); 1 ♂, 2 ♀♀: “ CHINA: N-Yunnan Nujiang Lisu Aut. Pr., Gongshan Co. , Gaoligong Shan, valley at 3000-3050 m, 27°47.90'N 98°30.19'E, 21.VI.2005 A. Smetana [C169]” (cSme, cAss); 1 ♂, 2 ♀♀: “P. R. CHINA, Yunnan, E slope N Gaoligongshan, N 27°46.782' E 98°33.087', 14.vi.2009, 2956 m, sifting04, V. Grebennikov” ( CAS, cSme, cAss) ; 1 ♂, 1 ♀: “P. R. CHINA, Yunnan, E slope N Gaoligongshan, N 27°47'22.1" E 98°32'17.7", 24.v.2010, 3027 m, sifting20, V. Grebennikov ” (cSme, cAss); 3 ♂♂, 2 ♀♀: “P. R. CHINA, Yunnan, E slope N Gaoligongshan, N 27°46.8' E 98°33.1', 12-15.vi.2009, 200- 3000 m [sic], sifting1-7, V. Grebennikov” ( CAS, cSme, cAss); 1♂: “P. R. CHINA, Yunnan, E slope N Gaoligongshan, N 27°53.626' E 98°24.168', 08.vi.2009, 2500 m, sifting01, V. Grebennikov” (cAss) .

Etymology:

The specific epithet (Latin, adjective: with numerous glands) refers to the presence of numerous hypothesized gland openings on the male sternites VII and VIII, one of the synapomorphies of the L. celere group.

Description:

Species of moderately large, rather variable size and slen- der habitus ( Fig. 236 ); body length 8.0- 10.5 mm; length of forebody 3.8-4.6 mm. Coloration: body dark-brown, usually with dark reddish elytra; legs and antennae reddish-brown to brown.

Head ( Fig. 237 ) distinctly oblong, usually approximately 1.1 times as long as broad, lateral margins subparallel; punctation rather coarse and rather dense; interstices with distinct microreticulation and nearly matt. Eyes rel- atively small, 0.25-0.35 times as long as postocular region in dorsal view and composed of approximately 50 ommatidia. Antenna 2.2-2.5 mm long.

Pronotum ( Fig. 237 ) slender, approximately 1.3 times as long as broad and approximately as broad as head; punc-

tation rather sparse and fine, distinctly finer than that of head; interstices without microsculpture and glossy; impunctate midline moderately broad.

Elytra ( Fig. 237 ) approximately 0.55 times as long as pronotum; punctation shallow and ill-defined. Hind wings

completely reduced. Protarsi without appreciable sexual dimorphism.

Abdomen slightly broader than elytra; punctation fine and moderately dense; microsculpture very shallow, on anterior tergites usually almost obsolete; posterior margin of tergite VII without palisade fringe; tergite VIII without sexual dimorphism, posterior margin obtusely angular in the middle.

♂: sternites III-VI unmodified; sternite VII ( Fig. 238 ) distinctly transverse and symmetric, with numerous minute gland openings ( Fig. 239 ), pubescence not distinctly modified, posterior margin broadly concave; sternite VIII ( Fig. 240 ) symmetric and moderately transverse, with numerous minute gland openings in antero-median portion ( Fig. 241 ), along the middle with rather dense, weakly modified short black setae, posterior excision almost semicircular; aedeagus ( Figs 242-243 ) approximately 1.2 mm long, symmetric, and of highly distinctive shape; ventral process short, stout, and apically hooked; apical portion of dorsal plate short, broad (dorsal view), strongly sclerotized, bisinuate in lateral view, and apically pointed, basal portion lamellate, nearly straight, and much longer than apical portion; internal sac with long and dark membranous structures.

♀: sternite VIII ( Fig. 244 ) approximately 1.1 mm long and approximately as broad as long, posterior margin convexly produced in the middle; tergite IX ( Fig. 245 ) with very short antero-median portion with median suture, and with moderately long postero-lateral processes extending slightly beyond apex of tergite X; tergite X ( Fig. 245 ) weakly convex in cross-section, approximately ten times as long as antero-median portion of tergite IX.

Comparative notes:

As can be inferred particularly from the shared and evidently synapomorphic presence of gland openings on the male sternites VII and VIII, L. glandulosum is allied to L. celere ASSING, 2013 from the Gongga Shan in Sichuan. Both species additionally share a similar external morphology (slender habitus, oblong head, relatively long legs, coarse puncation and distinct microsculpture of the head) and similar sexual characters (absence of a sexual dimorphism of the protarsi; similar shapes and chaetotaxy of the male sternite VII and VIII, compact symmetric aedeagus with a short dorsal plate, similar shapes of the female sternite VIII and tergites IX and X). Both species differ by the absence of a distinct sexual size dimorphism in L. glandulosum (pronounced in L. celere ), the morphology of the aedeagus, the shape of the female sternite VIII ( L. celere : distinctly oblong and more broadly convex posteriorly), and the length of the antero-median portion of the female tergite IX (longer in L. celere ). For illustrations of L. celere see ASSING (2013).

Distribution and natural history:

The species is known from several geographically close localities in the Gaoligong Shan, to the west of Gongshan ( Map 7 ). The specimens were sifted from leaf litter, some of them in a mixed and a coniferous forest at altitudes of 2500-3400 m, partly together with L. abscisum , as well as the closely related L. secans or L. bidigitulatum . The sex ratio is biased in favour of females (11 ♂♂: 29 ♀♀).

Figures

Map 7: Distribution of the species of the L. lijiangense (filled star), the L. celere (other filled symbols), the L. squamosum (open star), and the L. curvatissimum (other open symbols) (sub-)groups: L. seriespinosum and L. sexspinosum (black star); L. squamosum (white star); L. glandulosum (black circles); L. acre (black triangle); L. incurvatum (white diamond); L. stipiferum (white circles); L. yinae (white triangles); L. curvatissimum (white square).

Figs 236-252: Lathrobium glandulosum (236-245) and L. secans (246-252): habitus (236); forebody (237, 246); male sternite VII (238, 247); anterior median portion of sternite VII (239); malesternite VIII (240, 248); anterior median portion of male sternite VIII (241, 249); aedeagus in lateral and in ventral view (242-243, 250); female sternite VIII (244, 251); female tergites IX-X (245, 252). Scale bars: 236-237, 246: 1.0 mm; 238, 240, 242-245, 247-248, 250-252: 0.5 mm; 239, 241, 249: 0.1 mm.