Lathrobium nannani Peng and Li

Peng, Zhong, Li, Li-Zhen & Zhao, Mei-Jun, 2014, Seventeen new species and additional records of Lathrobium (Coleoptera, Staphylinidae) from mainland China, Zootaxa 3780 (1), pp. 1-35 : 17-19

Lathrobium nannani Peng and Li , new species

( Figs 9 C, 12)

Type material. (36 ♂♂, 52 ♀♀). HOLOTYPE: ♂, labelled ‘ CHINA: Zhejiang Prov., Kaihua County, Gutian Shan, 29°15'N, 118°08'E, 21.vi.2013 alt. 500–800 m, Xie, Lv & Yu leg.’ ( SNUC). PARATYPES: 16 ♂♂, 21 ♀♀ [3♂♂ teneral], same label data as holotype; 3 ♂♂, 8 ♀♀ [1♂, 1♀ teneral]: same data, but ‘Jia-Yao Hu leg.’; 7 ♂♂, 11 ♀♀ [2♀♀ teneral]: same data, but ‘ 29°14'N, 118°08'E, 19.vi.2013 alt. 400–500 m, Jia-Yao Hu leg.’; 1 ♂, 2 ♀♀: same data, but ‘ 5–7.v.2005, Zhu & Li leg.’; 1 ♂, 3 ♀♀: same data, but ‘ 29°14'N, 118°08'E, 19.vi.2013 alt. 400–500 m, Yi-Ming Yu leg.’; 3 ♀♀ [2 teneral]: same data, but ‘ 29°16'N, 118°07'E, 18.vi.2013 alt. 1,200–1,250 m, Xiao-Bin Song leg.’; 1 ♂, 1 ♀: same data, but ‘ 29°14'N, 118°08'E, 19.vi.2013 alt. 400–500 m, Zheng & Li leg.’; 1 ♂, 1 ♀: same data, but ‘ 29°16'N, 118°07'E, 18.vi.2013 alt. 1,200–1,250 m, Jia-Yao Hu leg.’; 5 ♂♂, 2 ♀♀: same data, but ‘ 29°14'N, 118°08'E, 19.vi.2013 alt. 400–500 m, Lv & Xie leg.’ ( SNUC).

Description. Measurements (in mm) and ratios: ♂: BL 7.78–9.06, FL 3.45–4.00, HL 0.96–1.02, HW 0.98– 1.10, AnL 1.85–1.97, PL 1.22–1.42, PW 1.10–1.20, EL 0.65–0.74, AL 1.14–1.18, HL/HW 0.93–0.98, HW/PW 0.89–0.92, HL/PL 0.72–0.79, PL/PW 1.11–1.18, EL/PL 0.51–0.54. ♀: BL 6.95–7.95, FL 3.39–3.56, HL 0.87–0.93, HW 0.93–1.02, AnL 1.81–1.90, PL 1.20–1.31, PW 1.05–1.13, EL 0.60–0.65, HL/HW 0.91–0.94, HW/PW 0.88– 0.92, HL/PL 0.71–0.75, PL/PW 1.14–1.16, EL/PL 0.50–0.53.

Habitus as in Fig. 9 C. Size subject to weakly pronounced sexual dimorphism, males on average slightly larger; body brown with paler apex, legs and antennae light brown to yellowish brown.

Head as long as broad or weakly transverse; punctation moderately sparse and coarse, sparser in median dorsal portion; interstices with shallow microreticulation. Eyes 0.33–0.38 times as long as postocular region in dorsal view and composed of approximately 50–60 ommatidia.

Pronotum with weakly convex lateral margins in dorsal view; punctation sparser than that of head; impunctate midline moderately broad; interstices without microreticulation.

Elytra short; punctation dense, shallow, and weakly defined. Hind wings completely reduced. Protarsi with pronounced sexual dimorphism.

Abdomen with fine and dense punctation, that of tergite VII slightly sparser than that of anterior tergites; interstices with shallow microsculpture; posterior margin of tergite VII without palisade fringe; tergite VIII with pronounced sexual dimorphism.

Male. Posterior margin of tergite VIII weakly convex; sternites III–VI unmodified; sternite VII ( Fig. 12 D) strongly transverse, with shallow median impression posteriorly, this impression laterally with short black setae directed obliquely postero-mediad and without setae in the middle, posterior margin broadly concave, in the middle nearly truncate; sternite VIII ( Fig. 12 E) strongly modified and of distinctive shape and chaetotaxy, with deep, asymmetric, and extensive median impression, middle of this impression without pubescence, laterally with dense short and very stout black setae, posterior margin asymmetric, shallow, and broad; aedeagus as in Figs 12 F, G, ventral process apically strongly curved and acute in lateral view; dorsal plate with distinctly sclerotized apical portion, and with moderately long lamellate basal portion; internal sac with a very long slender and a shorter large sclerotized spine, and with a ring-shaped membranous structure.

Female. Tergite VIII ( Fig. 12 A) oblong, posteriorly strongly produced and acutely pointed; posterior margin of sternite VIII ( Fig. 12 B) distinctly convexly produced in the middle; tergite IX ( Fig. 12 C) relatively short, anteriorly undivided and with short stout postero-lateral processes; tergite X 3.7 times as long as antero-median portion of tergite IX ( Fig. 12 C).

Comparative notes. Lathrobium nannani resembles L. ayui sp. n. from Anhui in having a similarly short female tergite IX. It is distinguished from L. ayui by smaller body size, the shape and chaetotaxy of the male sternites VII and VIII, the morphology of the aedeagus (shape of ventral process and dorsal plate; internal sac with two sclerotized spines), and the shape of the female tergite VIII. Lathrobium nannani is distinguished from the sympatric L. gutianense sp. n. by somewhat smaller body size, the shape and chaetotaxy of the male sternites VII and VIII, as well as by the morphology of the aedeagus (shape of ventral process and dorsal plate, internal sac with two large sclerotized spines).

Distribution and biological notes. The type locality is situated in the Gutian Shan to the northwest of Kaihua, western Zhejiang. The specimens were sifted from leaf litter, grass and humus from the floor of a hardwood forest with beech, Moraceae and Rosaceae at altitudes of 400–1250 m (Hu, pers. comm.).

Etymology. The species is named after Nan-Nan Xie, who collected some of type specimens.

Figures

FIGURE 9. Habitus of Lathrobium spp., A — L. fengae; B — L. gutianense; C — L. nannani. Scale bars: 1.0 mm.

FIGURE 12. Lathrobium nannani. A — female tergite VIII; B — female sternite VIII; C — female tergites IX – X. D — male sternite VII; E — male sternite VIII; F — aedeagus in ventral view; G — aedeagus in lateral view. Scale bars: 0.5 mm.