Lathrobium caiyujiei X.-B. Lin and Peng, 2022

Lin, Xiao-Bin, Tan, Fei & Peng, Zhong, 2022, New data on the genus Lathrobium Gravenhorst (Coleoptera: Staphylinidae: Paederinae) of Guangxi, South China, Zootaxa 5099 (5), pp. 593-600 : 594-596

Lathrobium caiyujiei X.-B. Lin and Peng , new species

( Figs 1A , 2 )

Type material (4 ♂♂, 2 ♀♀). Holotype ♂: “ China: Guangxi, Huanjiang, Jiuwanshan N. R., Yangmeiao , 25°12’22.15’’N, 108°40’32.01’’E, 1250 m, 23.IV.2021, Tang, Peng, Cai & Song leg.” ( SNUC) ; Paratypes: 1 ♂, 1 ♀: same data as holotype ( SNUC) ; 1 ♂, 1 ♀: same data, except “ 08. V .2021” ( SNUC); 1 ♂: same data, except “ 25. IV.2021 ” ( SNUC) .

Description. Measurements (in mm) and ratios: BL 8.34–9.45, FL 3.61–3.83, HL 1.24–1.39, HW 1.24–1.30, AnL 2.61–2.84, PL 1.48–1.57, PW 1.35–1.42, EL 0.83–0.87, AL 1.40–1.42, HL/HW 0.96–1.07, HW/PW 0.91–0.96, HL/PL 0.79–0.88, PL/PW 1.10–1.16, EL/PL 0.53–0.59.

Habitus as in Fig. 1A . Body blackish brown, legs brown, antennae dark brown to light brown.

Head punctation moderately coarse and dense, distinctly sparser in median dorsal portion; interstices with distinct microreticulation. Eyes moderately small and composed of approximately 60 ommatidia.

Pronotum with weakly convex lateral margins in dorsal view; punctation somewhat sparser than that of head; impunctate midline broad; interstices glossy and without microsculpture.

Elytral punctation dense and defined. Hind wings completely reduced. Protarsi without appreciable sexual dimorphism, distinctly dilated.

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

Male. Sternites III–VI unmodified; sternite VII ( Fig. 2D ) with posterior margin shallowly concave in the middle, setae unmodified; posterior margin of sternite VIII ( Fig. 2E ) strongly convex and with moderately dense micropubescence, with sparse and short setae; aedeagus as in Figs 2F, G , with stout ventral process of highly distinctive shape; dorsal plate with long apical portion, and with very short basal portion; internal sac without sclerotized spines.

Female. Posterior margin of tergite VIII ( Fig. 2A ) strongly convex. Posterior margin of sternite VIII ( Fig. 2B ) strongly convex and with moderately dense micropubescence; tergite IX ( Fig. 2C ) with short antero-median portion and slender postero-lateral processes; tergite X ( Fig. 2C ) 2.5 times as long as antero-median portion of tergite IX.

Comparative notes. Based on the morphology of the aedeagus, this species may be allied to L. zhujianqingi Peng & Li, 2012 , from which it is distinguished by somewhat smaller body size, lighter coloration of the body, the chaetotaxy of the male sternite VII, and a more slender aedeagus. For illustrations of L. zhujianqingi see Peng et al. (2012: figures 1F, 7).

Etymology. The species is named after Yu-Jie Cai, who collected some of type specimens.

Distribution and natural history. The type locality is situated in the Jiuwanshan Nature Reserve to the north of Huanjiang, northern Guangxi. The specimens were sifted from leaf litter and grass roots in shrub habitats at an altitude of 1250 m.

Figures

FIGURE 1. Male habitus of Lathrobium spp., A L. caiyujiei B L. jiuwanshanense C L. zhusha. Scales: 1.0 mm.

FIGURE 2. Lathrobium caiyujiei. 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. Scales: 0.5 mm.