Lathrobium desectum, 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 : 116-118

4.7 The L. desectum species group

4.7.1 Lathrobium desectum sp. n.

( Figs 308-315 , Map 8 )

Type material:

Holotype ♂: “ CHINA: Yunnan [CH07-26], Nujiang Lisu Aut. Pref., Gaoligong Shan , pass 21 km NW Liuku, 3150 m, 25°58'22"N, 98°41'00"E, bamboo with shrubs, litter sifted, 9.VI.2007, M. Schülke / Holotypus ♂ Lathrobium desectum sp. n. det. V. Assing 2013” (cSch) . Paratypes: 5 ♂♂, 5 ♀♀: same data as holotype (cSch, cAss) ; 1 ♂, 2 ♀♀: same data, but leg. Pütz (cPüt, cAss) ; 4 ♂♂, 2 ♀♀ [1 teneral]: “ CHINA: Yunnan, Nujiang Lisu Pref., Gaoligong Shan, “ Cloud Pass ”, 21 km NW Liuku, 3150 m, 25°58'21"N, 98°41'01"E, shrubs & bamboo, litter sifted, 2.IX.2009, leg. M. Schülke [CH09-22]” (cSch, cAss) .

Etymology:

The specific epithet (past participle of the Latin verb desecare: to cut off) alludes to the truncate posterior margin of the male sternite VIII.

Description:

Species of moderate size and stout habitus; body length 7.3-8.5 mm; length of forebody 3.1-3.6 mm. Coloration: body blackish; legs reddish to brown; antennae reddish.

Head ( Fig. 308 ) weakly transverse, approximately 1.05 times as broad as long, somewhat wedge-shaped (i.e., dilated posteriad); punctation moderately coarse and relatively sparse; interstices with fine and shallow microsculpture. Eyes relatively large, approximately half as long as postocular region in dorsal view or nearly so, and composed of> 50 ommatidia. Antenna 1.8-2.0 mm long.

Pronotum ( Fig. 308 ) short and broad, 1.10-1.15 times as long as broad and 1.10-1.15 times as broad as head; punctation similar to that of head; impunctate midline of variable, often somewhat irregular width; interstices without microsculpture.

Elytra ( Fig. 308 ) 0.51-0.56 times as long as pronotum; punctation fine, shallow, moderately dense, and somewhat ill-defined. Hind wings completely reduced. Protarsomeres I-IV with pronounced sexual dimorphism.

Abdomen approximately 1.15 times as broad as elytra; punctation fine and dense; interstices with distinct microsculpture; posterior margin of tergite VII without palisade fringe. Tergite VIII without sexual dimorphism,

posterior margin weakly convex or indistinctly pointed in the middle.

♂: sternites III-VI unmodified; sternite VII ( Fig. 309 ) strongly transverse, symmetric, pubescence not distinctly modified, posterior margin broadly and weakly concave, median projection of posterior margin very short and broad; sternite VIII ( Fig. 310 ) symmetric and strongly transverse, approximately 1.3 times as broad as long, somewhat depressed in the middle, but with- out impression, pubescence short, dense, and unmodified, posterior margin truncate; aedeagus ( Fig. 311 ) 1.2-1.3 mm long and symmetric; ventral process slen- der, distinctly curved in lateral view, and apically acute; apical portion of dorsal plate lamellate, distinctly sclerotized, nearly straight in lateral view, and with needleshaped apex in dorsal view ( Fig. 312 ), basal portion rather long, but thin, smoothly curved, and moderately sclerotized; internal sac with pair of large spines ( Fig. 313 ) and with additional series of numerous small sclerotized spines.

♀: sternite VIII ( Fig. 314 ) approximately 1.1 mm long and weakly transverse, posterior margin distinctly convex; tergite IX ( Fig. 315 ) with moderately long anteromedian portion without suture, and with moderately long postero-lateral processes; tergite X ( Fig. 315 ) somewhat convex (cross-section) in anterior half and flat in posterior half, slightly more than twice as long as anteromedian portion of tergite IX.

Comparative notes:

Lathrobium desectum is reliably distinguished from the following species of the L. desectum group only based on the morphology of the aedeagus, particularly the shape of the aedeagus.

Distribution and natural history:

The type locality is situated in the Gaoligong Shan in western Yunnan province, close to the border with Myanmar ( Map 8 ). The specimens were sifted from leaf litter in bamboo vegetation with shrubs at an altitude of 3150 m. One of the paratypes collected in the beginning of September is teneral .

Figures

Map 8: Distribution of the species of the L. bihamulatum (filled star) and the L. desectum (open symbols) groups: L. bihamulatum (black star); L. abscisum (white circles); L. desectum, L. sectum, L. amputatum, and L. resectum (all white triangles).

Figs 308-319: Lathrobium desectum (308-315) and L. sectum (316-319): forebody (308, 316); male sternite VII (309, 317); male sternite VIII (310, 318); aedeagus in lateral view (311, 319); apical portion of dorsal plate of aedeagus in dorsal view (312); internal structures of aedeagus in ventral view (313); female sternite VIII (314); female tergites IX-X (315). Scale bars: 308, 316: 1.0 mm; 309-311, 314-315, 317-319: 0.5 mm; 312-313: 0.1 mm.