Lathrobium (Lathrobium) nenkaoicum, Assing, 2010

Assing, Volker, 2010, On the Lathrobiina of Taiwan (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 60 (2), pp. 301-361 : 317-318

Lathrobium (Lathrobium) nenkaoicum sp. n. ( Figs 58-66 )

Type material:

Holotype ♂: " Taiwan, Nantou Hsien, Nenkaoshan, Tenchi Hut , 2900 m, 5.V.1992, A. Smetana [ T114 ] / Holotypus ♂ Lathrobium nenkaoicum sp. n., det. V. Assing 2010" (cAss).

Paratype ♀: same data as holotype (cSme) .

Description:

Body length 5.0- 5.5 mm; habitus as in Fig. 58 . Externally highly similar to L. involutum , except for the on average more pronounced microsculpture on the head and the slightly smaller eyes ( Fig. 59 ); reliably distinguished only by the sexual characters:

♂: posterior margin of sternite VII weakly concave in the middle, pubescence in postero-median portion weakly modified, i.e., with few blackish and longer setae on either side ( Fig. 60 ); sternite VIII approximately as long as wide, posterior excision relatively deep and in asymmetric position (i.e., not in the middle), its depth approximately 1/6 the length of sternite ( Fig. 61 ); aedeagus approximately 1.05 mm long, with slender and apically acute ventral process, and with internal structures of distinctive shape ( Fig. 62 ).

♀: tergite VIII with posterior margin broadly concave ( Fig. 63 ), latero-ventral extensions pronounced, completely enveloping abdomen and overlapping ventrally ( Fig. 64 ); sternite VIII approximately 1.3 times as long as broad and much longer than tergite VIII, distinctly produced posteriorly and apically truncate ( Fig. 65 ); tergite X approximately 2.5 times as long as tergite IX in the middle ( Fig. 66 ).

Comparative notes:

The similar male primary and secondary sexual characters suggest that L. nenkaoicum is most closely allied to L. houhuanicum , a hypothesis also supported by the vicinity of the localities where the two species were found. The Nenkaoshan is separated from the Houhuanshan only by some 20-30 km. Lathrobium nenkaoicum is distinguished from L. houhuanicum by the different shape of the ventral process of the larger aedeagus (longer, more slender, less abruptly narrowed apically), the differently shaped internal structures (particularly the short internal structure), the almost straight dorsal plate (lateral view) ( L. houhuanicum : basal portion angled), the completely different shape of the female tergite VIII, and the differently shaped female sternite VIII.

Etymology:

The specific epithet (adjective) is derived from the name of the mountain where the type specimens were discovered.

Distribution and natural history:

The type locality is situated in the Nenkaoshan, Nantou Hsien, central Taiwan, where the two specimens were sifted from leaf litter, moss, and other debris in a fir forest with bamboo and shrub undergrowth at an altitude of 2900 m .

Figures

Figs 58-66: Lathrobium nenkaoicum sp. n.: habitus (58); forebody (59); male sternite VII (60); male sternite VIII (61); aedeagus in lateral view (62); female tergite VIII (63); female tergite VIII in ventral view (64); female sternite VIII (65); female tergites IX-X (66). Scale bars: 58-59: 1.0 mm; 60-61, 63-66: 0.5 mm; 62: 0.2 mm.