Lathrobium piraticum, Assing, 2017

Assing, Volker, 2017, Four new species and additional records of Lathrobium from Nepal and China (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 49 (1), pp. 285-297 : 293-294

Lathrobium piraticum nov.sp. ( Figs 25-36 )

T y p e m a t e r i a l: Holotype 3: " CHINA: Sichuan Prov., Wolong National Nature Reserve, Namasi vill., 2145 m, 23.VI.2014, 31°01'28''N, 103°09'40''E, / sift #25, shrubs in close stream valley, above small water dam, side valley, J. Hájek & J. Růžička leg. / Holotypus 3 Lathrobium piraticum sp. n., det. V. Assing 2016 " (NMP). Paratype ♀: " CHINA: Sichuan Prov., Wolong National Nature Res., Wolong vill. env., 24.VI.2014, track to Wuyipeng Mt., 2170 m, 31°00'03''N, 103°09'05''E, / sift #28, wet broadleaved forest with bamboo undergrowth, steep slope, light brown soil, J. Hájek & J. Růžička leg. (cAss).

E t y m o l o g y: The specific epithet (Latin, adjective: of pirates) alludes to the conspicuous and distinctive shape of the sclerotized internal structure of the aedeagus, which somewhat resembles a grapnel (grappling hook).

D e s c r i p t i o n: Rather large species without evident sexual size dimorphism; body length 9.0- 9.5 mm; length of forebody 4.6-4.8 mm. Coloration: body blackish; legs blackish with reddish tarsi; antennae with blackish base, apically becoming gradually paler, antennomere XI reddish.

Head ( Fig. 25 ) distinctly transverse, 1.11-1.12 times as broad as long; punctation coarse and dense, somewhat sparser in median dorsal portion; interstices with fine microreticulation. Eyes ( Fig. 34 ) moderately small, approximately one-third as long as postocular region in dorsal view, composed of numerous ommatidia. Antenna 2.5- 2.6 mm long.

Pronotum ( Fig. 25 ) approximately 1.2 times as long as broad and 1.03 times as broad as head; punctation similar to that of head; interstices without microsculpture; midline narrowly impunctate.

Elytra ( Fig. 25 ) 0.56-0.57 times as long as pronotum; humeral angles weakly marked; punctation dense and distinct; interstices without microsculpture. Hind wings completely reduced.

Abdomen slightly broader than elytra; punctation distinct and dense, nearly as dense on tergite VII as on anterior tergites; interstices with shallow transverse microsculpture;

posterior margin of tergite VII without palisade fringe; posterior margin of tergite VIII obtusely produced in the middle, without sexual dimorphism.

3: protarsomeres I-IV ( Fig. 25 ) strongly dilated; sternite VII ( Fig. 26 ) strongly transverse, approximately twice as broad as long, with postero-median impression of triangular shape, this impression with numerous dense modified short and stout black setae, posterior margin broadly concave, in the middle more distinctly concave; sternite VIII ( Fig. 27 ) 1.18 times as broad as long, slightly asymmetric, with extensive posteromedian impression with numerous modified, short and stout black setae, postero-laterally with very dense stout and long black setae, posterior excision broad and deep, of nearly semi-circular shape; aedeagus ( Figs 28-33 ) 1.85 mm long, of highly derived shape, strongly asymmetric, dorso-ventrally compressed, apically divided into two distinct lobes of different lengths and shapes; dorsal plate not noticeable (either reduced or fused with ventral process); internal sac with very long and apically strongly curved sclerotized spine.

♀: protarsomeres I-IV distinctly dilated, but less so than in male; sternite VIII ( Fig. 35 ) oblong and with broadly convex posterior margin, with micropubescence in apical portion; tergite IX ( Fig. 36 ) undivided and without median suture, very short in anteromedian portion, postero-lateral processes moderately long; tergite X ( Fig. 36 ) moderately convex in cross-section and rather long, approximately ten times as long as anteromedian portion of tergite IX.

C o m p a r a t i v e n o t e s: Lathrobium piraticum is assigned to the speciose L. fissispinosum group (see ASSING 2013a), which includes numerous species from Sichuan, Shaanxi, Hubei, Chongqing, and Guizhou, primarily based on the following, partly synapomorphic character conditions: aedeagus dorso-ventrally depressed and strongly asymmetric, with a long sclerotized spine in the internal sac, with an apically bilobed ventral process, and without a separate dorsal plate; chaetotaxy of the male sternites VII and VIII distinctly modified; male sternite VIII slightly asymmetric and with a rather large posterior excision; antero-median portion of the female tergite IX very short; relatively large body size. Lathrobium piraticum differs from all the previously described representatives of the L. fissispinosum group particularly by the shape of the aedeagus and by the shapes and chaetotaxy of the male sternites VII and VIII.

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: Thespecimenswerecollected in two close localities in the Wolong National Nature Reserve, Sichuan, by sifting litter in a shrub habitat in a stream valley and in a wet broad-leaved forest with bamboo undergrowth at altitudes of 2145 and 2170 m. The female had mature eggs in the ovaries.

Figures

Figs 25-33: Lathrobium piraticum nov.sp.: (25) male forebody; (26) male sternite VII; (27) male sternite VIII; (28-30) aedeagus in lateral, ventral, and dorsal view in dry preparation; (31-33) aedeagus in lateral, ventral, and dorsal view in transparent preparation. Scale bars: 1.0 mm.

Figs 34-36: Lathrobium piraticum nov.sp.: (34) head in lateral view; (35) female sternite VIII; (36) female segments IX-X. Scale bars: 34: 1.0 mm; 35-36: 0.5 mm.