Lathrobium ayui 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 : 7-9

Lathrobium ayui Peng and Li , new species

( Figs 5 A, 6)

Type material. (1 ♂, 2 ♀♀). HOLOTYPE: ♂, labelled ‘ CHINA: Anhui Prov., Yuexi County, Yaoluoping N. R., 30°58'N, 116°07'E, 19.vi.2013 alt. 1,600 m, Dai & Peng leg.’ ( SNUC). PARATYPES: 1 ♀, same label data as holotype; 1 ♀, same data, but ‘ 31°00'N, 116°07'E, 18.vi.2013 alt. 1,400 m’ ( SNUC).

Description. Measurements (in mm) and ratios: BL 9.34–10.12, FL 4.34–4.56, HL 1.24–1.30, HW 1.31–1.39, AnL 2.81–2.85, PL 1.57–1.61, PW 1.31–1.35, EL 0.78–0.81, AL 1.50, HL/HW 0.94–0.95, HW/PW 1.00–1.02, HL/PL 0.79–0.81, PL/PW 1.19–1.20, EL/PL 0.50.

Habitus as in Fig. 5 A. Body brown with paler apex, legs and antennae brown to light brown.

Head approximately as long as broad; punctation coarse and dense, sparser in median dorsal portion; interstices with noticeable microreticulation. Eyes 0.32–0.35 times as long as postocular region in dorsal view and composed of approximately 60 ommatidia.

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

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

Abdomen with fine and dense punctation, that of tergite VII sparser 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. Posterior margin of tergite VIII weakly convex; sternites III–VI unmodified; sternite VII ( Fig. 6 D) strongly transverse, median impression extensive, asymmetric, of semi-elliptical shape, and with numerous strongly modified, very short black setae, posterior margin asymmetrically concave in the middle; sternite VIII ( Fig. 6 E) distinctly transverse, asymmetric, with extensive, pronounced, and weakly asymmetric median impression, this impression with numerous modified, very short black setae, posterior excision rather shallow, slightly asymmetric, and bisinuate; aedeagus as in Figs 6 F, G, strongly asymmetric and of highly distinctive morphology; ventral process asymmetric and apically divided into two lobes of different shapes; apical portion of dorsal plate long, basal portion lamellate and much shorter than apical portion; internal sac with two series of numerous moderately sclerotized small spines and additional series of tooth-like sclerotized spines ( Fig. 6 H).

Female. Posterior margin of tergite VIII ( Fig. 6 A) broadly convex; posterior margin of sternite VIII ( Fig. 6 B) obtusely angled in the middle; tergite IX ( Fig. 6 C) short, with undivided median portion and with short posterolateral processes; tergite X 1.7 times as long as antero-median portion of tergite IX ( Fig. 6 C).

Comparative notes. The new species resembles Lathrobium cooteri Watanabe, 1999 from Zhejiang in having the posterior margin of the male sternite VIII weakly asymmetric and an aedeagus with a similarly derived ventral process (apically divided into two lobes of different shapes). Lathrobium ayui is distinguished from L. cooteri by the more asymmetric male sternite VII and the shorter dorsal plate of the aedeagus. For illustrations of L. cooteri see Watanabe (1999). Lathrobium ayui is readily distinguished from the sympatric L. yaoluopingense sp. n. by greater body size, denser punctation of the forebody, the distinctly asymmetric male sternites VII and VIII, as well as by the shape of the aedeagus.

Distribution and biological notes. The type locality is situated in the Yaoluoping Natural Reserve to the northwest of Yuexi, western Anhui. The specimens were sifted from leaf litter and humus from the floor of a beech forest at altitudes of 1400 and 1600 m.

Etymology. The species is named after Cong-Chao Dai (nickname “Ayu”), who collected the holotype.

Figures

FIGURE 5. Habitus of Lathrobium spp., A — L. ayui; B — L. yaoluopingense; C — L. chenae. Scale bars: 1.0 mm.

FIGURE 6. Lathrobium ayui. 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; H — sclerotized internal structure of aedeagus in lateral view. Scale bars: A – G: 0.5 mm; H: 0.3 mm.