Lathrobium bitaleatum, Assing, 2018

Assing, Volker, 2018, Five new species of Lathrobium from Nepal and China (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology (Beitr. Entomol.) 68 (2), pp. 361-369 : 366-368

Lathrobium bitaleatum spec. nov.

urn:lsid:zoobank.org:act:89FDDE54-09AA-476F-BF70-36ADA0183713

( Figs 28–37 )

Type material: Holotype : “ China S-Sichuan 2017, pass btw. Yanyuan/Muli, 27.68638°N, 101.22335°E, 11.–18. VI., 3244 m, leg. C. Reuter / Petr Baňař Private Collec- tion / Holotypus  Lathrobium bitaleatum sp. n., det. V. Assing 2018” (MMB).

Etymology: The specific epithet is composed of the prefix bi- (two) and an adjective derived from the Latin noun talea (stick, pole, rod). It alludes to the pair of long and straight spines in the internal sac.

Description: Rather large species; body length 10.5 mm; length of forebody 5.0 mm. Habitus as in Fig. 28 . Coloration: body blackish-brown; legs and antennae brown. Head ( Fig. 29 ) 1.5 times as long as broad; punctation moderately coarse and moderately dense, sparser in anterior and median portions; interstices with distinct microreticulation. Eyes ( Fig. 35 ) small, composed of> 50 ommatidia, approximately one fourth as long as postocu- lar region in dorsal view. Antenna approximately 2.7 mm long. Pronotum ( Fig. 29 ) approximately 1.3 times as long as broad and 1.02 times as broad as head; punctation similar to that of head; midline broadly impunctate; interstices without microsculpture.

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CONTRIBUTIONS TO ENTOMOLOGY: BEITRÄGE ZUR ENTOMOLOGIE — 68 (2) 361–369

ASSING, V.: Five new species of Lathrobium from Nepal and China ( Coleoptera : Staphylinidae : Paederinae )

Elytra ( Fig. 29 ) 0.54 times as long as pronotum; punc- tation similar to that of pronotum; interstices without microsculpture. Hind wings completely reduced. Abdomen slightly broader than elytra; punctation dense and rather fine, slightly less dense on posterior than on anterior tergites; interstices with fine transverse micro- sculpture visible only at high magnification; posterior margin of tergite VII without palisade fringe. : protarsomeres I–IV strongly dilated; sternite VII ( Fig. 36 ) moderately transverse, shallowly impressed along middle and in postero-median portion with more distinct impression of semicircular shape, these impressions with rather sparse and weakly modified black setae, posterior margin concave in the middle; sternite VIII ( Fig. 37 ) moderately transverse, with two clusters of dense and weakly modified black setae, posterior margin somewhat asymmetric and with very small concavity in the middle; aedeagus ( Figs 30–34 ) 2.0 mm long, practically symmetric in ventral view; aedeagus smoothly curved and slender in lateral view, basally broad and apically abruptly narrowed in ventral view; dorsal plate dark, but thin, with broad, long, and apically acute apical portion and with short and weakly sclerotized basal portion; internal sac with two very long, slender, basally dilated, and distinctly sclerotized spines. : unknown. Comparative notes: As can be inferred from the morphology of the aedeagus (symmetric, ventral process slender, dorsal plate lamellate, internal sac with

two long sclerotized structures) and from the modifi- cations of the male sternite VII and VIII, L. bitaleatum belongs to the L. bibaculatum group, which was previ- ously represented in Sichuan by nine species (ASSING 2013a, c, 2016). The new species is distinguished from other species of this group particularly by the distinctive shapes of the ventral process and of the internal struc- tures of the aedeagus. In addition, it is characterized by rather large size and by the shapes and chaetotaxy of the male sternites VII and VIII.

Distribution: The type locality and other data are identi- cal to that of L. egens .

Figures

Figs 21–34: Lathrobium egens (21–27) and L. bitaleatum (28–34): forebody (21, 29); male sternite VII (22); male sternite VIII (23); aedeagus in lateral (24, 30, 33), ventral (25, 31), and dorsal view (32, 34); female sternite VIII (26); female tergites IX–X (27); habitus (28). Scale bars: 28: 5.0 mm; 21, 29: 1.0 mm; 22–27, 30–34: 0.5 mm.

Figs 35–37: Lathrobium bitaleatum: head in lateral view (35); male sternite VII (36); male sternite VIII (37). Scale bars: 0.5 mm.