Lobrathium quadrum, Solodovinikov, Xiao-Yan Li Alexey & Zhou, Hong-Zhang, 2013

Solodovinikov, Xiao-Yan Li Alexey & Zhou, Hong-Zhang, 2013, Four new species of the genus Lobrathium Mulsant & Rey (Coleoptera: Staphylinidae: Paederinae) from China, Zootaxa 3635 (5), pp. 569-578 : 570-573

1. Lobrathium quadrum sp. n.

( Figs. 1 A–I, 5A)

Type material. Holotype, 3, CHINA: Sichuan Province, Mountain Qingcheng, 24. VIII. 2005, leg. Xiaoyan Li; Paratypes, 2ƤƤ, same data as holotype (IZCAS).

Description. Length: 6.7–7.7 mm; width: 1.09–1.14 mm. Body parts (all in mm): HL 0.98; AL 2.05; PL 1.16; ELL 1.29; HW 0.98; PW 0.87; ELW 1.07; ABW 1.12.

Body blackish-brown to brown with luster. Elytra blackish–blue with slight metallic luster, with pair of pale yellowish spots close to posterior margin. Antennae, legs and abdomen more or less brown.

Head with broadly rounded posterior margins, as long as wide. Eyes relatively large, protruded laterally; HL/ EL = 3.3, eye length slightly longer than gena but shorter than temple (gena eye temple = 0.24: 0.30: 0.44 mm). Punctation on head irregular, coarse and dense, punctures of different size, denser and coarser laterally, especially around eyes. All punctures bearing setae of different length and pale brown color. Vertex and middle front smooth and glossy with very sparse and coarse punctures.

Pronotum only slightly longer than wide (PL/PW = 1.2), lateral sides with slight and s–shaped line borders; surface with yellowish brown hairs. Scutellum v–shaped and slightly longer than wide; surface without luster, with reticulate microsculpture and very weak punctation.

Elytra with ELL\ELW = 1.2, ESL/ELL = 0.8, epipleural ridge absent in the basal fifth of elytral length. Punctures on elytra 1.5 times as large as those on pronotum, each puncture with brownish yellow seta, intervals between punctures slightly shorter than diameter of puncture. Brownish yellow spots on elytra large, taking ca. 1/3 of elytral length.

Abdomen widest at segment VI (4th visible), where it is slightly wider than head, pronotum or elytra. Setiferous punctures on tergites fine and dense, denser laterally, base of tergites unevenly punctured with same sized punctures, posterior and lateral areas with sparse black hairs.

Aedeagus ( Figs. 1 G–I) robust and symmetrical, length/width = 2.3. Median lobe (except dorsal plate) short and thick, slightly curved ventrally, with short, robust ventral process. Dorsal plate of median lobe with basal part thin and broadened posteriad, widest at apical 1/3 and sharply constricted forming acute apex. Ventral plate strongly chitinized and rather projected ventrally, posterior part with a rhombic structure in ventral view.

Secondary sexual dimorphism.

Both sexes differ from each other in the structure of terminalia. In male sternite VI with shallow midlongitudinal depression; posterior margin of sternites VII–VIII with narrow notch and longitudinal depression basally to the notch, the notch and depression of sternite VIII ( Fig. 1 A) distinctly longer than those on sternite VII; sternite IX ( Fig. 1 C) distinctly asymmetrical. Tergite IX ( Fig. 1 B) broad with semicircular notch; tergite X semicircular.

In female sternite VIII ( Fig. 1 D) with shallow emargination on posterior margin; lateroventral parts of tergite IX ( Fig. 1 E) with rather acutely pointed apex; anterior and posterior gonocoxites separated; sternite IX ( Fig. 1 F) with small protrusion and four setae.

Etymology. The specific epithet is the Latin noun in apposition, meaning quadrate and referring to somewhat angular shape of elytral spots.

Remarks. Externally the new species L. quadrum sp. n. is similar to L. tortile Zheng and L. hongkongense Bernhauer , but it differs from both of them in the length of the color spots on elytra. In L. quadrum sp. n., color spot is about 1/3 of elytral length, whereas in the latter two species they are about 1/2 of elytral length. Also, the ventral process of the aedeagus in the new species is much broader and shorter ( Figs. 1 G, I) than in L. tortile Zheng. In contrast to L. hongkongense with the deep and short depression, the new species has shallow and very elongate median depression on sternite VIII that is about the entire length of the sternite. In L. quadrum sp. n. that depression in its middle area is covered by setiferous punctures that are much sparser than in L. hongkongense ( Fig. 1 A).

Distribution. Lobrathium quadrum sp. n. is known only from the type locality at the foothills of the Mountain Qingcheng located ca. 2 km of town Qingcheng in the south of Sichuan Province. The type specimens were collected under dense and wet grass at the moist edge of a creek. All specimens were collected in August at the altitude of about 1100 m.

Figures

FIGURE 1. Lobrathium quadrum sp. n. from Sichuan. A. sternite VIII, male; B. tergites IX – X, male; C. sternite IX, male; D. sternite VIII, female; E. sternites IX – X, female; F. tergite IX, female; G. aedeagus, ventral view; H. apex of aedeagus, dorsal view; I. aedeagus, lateral view. Scale = 0.5 mm.