Stenus maoershanus Pan, Tang & Li

Pan, Yu-Hong, Tang, Liang & Li, Li-Zhen, 2012, Notes on the Stenus cirrus group, with description of two new species from China (Coleoptera, Staphylinidae), ZooKeys 169, pp. 61-77 : 66-68

Stenus maoershanus Pan, Tang & Li sp. n. Figs 7 –841– 49

Type material.

Holotype:CHINA: Guangxi Prov.: ♂, Xing’an County, Mt. Mao’ershan, alt. 2100 m, 10.VII.2011, TANG Liang & HE Wen-Jia leg. (SHNU). Paratype:CHINA: Guangxi Prov.: 1♀, same data as holotype. (SHNU).

Description.

BL: 4.3 mm; FL: 2.0 mm.

HW: 0.81-0.82 mm, PW: 0.60-0.61 mm, PL: 0.63-0.64 mm, EW: 0.76 mm, EL:0.71-0.72 mm, SL: 0.54-0.55 mm.

Brachypterous; body brownish black, head darker, anterior margin of labrum, antennae, maxillary palpi and legs yellowish brown, each elytron with a large elongate orange mark near lateral margin, this mark 4/5 as long as and about 3/5 as broad as the respective elytron.

Head 1.07-1.08 times as wide as elytra; interocular area with two broad longitudinal furrows, median portion convex, almost reaching the level of inner eye margins; punctures round, slightly larger and sparser in median area than those near inner margins of eyes, diameter of large punctures as wide as apical cross section of antennal segment II, interstices between punctures smooth, mostly narrower than half the diameter of punctures, those along midline a little wider. Relative length of antennal segments from base to apex 15: 9: 24: 14: 12: 9.5: 9.5: 6.5: 7: 8: 10. Paraglossae oval.

Pronotum 1.04-1.05 times as long as wide, 0.80-0.81 times as wide as elytra; disk with distinct median longitudinal furrow, this furrow about half the length of pronotum; punctation round and confluent, similar to that of head, interstices smooth, much narrower than half the diameter of punctures except for those in median furrow, which may be wider.

Elytra 0.94-0.95 times as long as wide, distinctly constricted at base, lateral margins gently divergent posteriad; punctation similar to that of pronotum, but slightly coarser, interstices similar to those of pronotum.

Legs with hind tarsi 0.74-0.75 times as long as hind tibiae, tarsomere IV strongly bilobed.

Abdomen cylindrical; paratergites very narrow and smooth, present only in abdominal segment III, posterior margin of tergite VII with indistinct palisade fringe; punctation of tergite III–VIII sparse and shallow, gradually becoming finer posteriad, interstices smooth, varying from narrower to much wider than diameter of punctures.

Male. Sternite VII with inconspicuous emargination at middle of posterior margin, anterior to this emargination flattened; sternite VIII (Fig. 41) with semi-circular emargination at middle of posterior margin; sternite IX (Fig. 42) with long apicolateral projections, posterior margin serrate; tergite X (Fig. 43) with posterior margin truncate and slightly emarginated at middle. Aedeagus (Fig. 44) with apical sclerotized portion of median lobe triangular; expulsion hooks absent (probably lost in this specimen); parameres longer than median lobe, each with 8-9 setae on apico-internal margins.

Female. Sternite VIII (Fig. 46) inconspicuously prominent at middle of posterior margin; tergite X (Fig. 47) with posterior margin truncate and slightly emarginated at middle. Valvifers (Fig. 48) each with big apicolateral tooth; spermatheca strongly sclerotized (Fig. 49).

Distribution.

China (Guangxi Province: Mao’ershan).

Diagnosis.

The new species resembles Stenus nanlingmotis Tang & Li, 2008 from Guangdong, but may be distinguished by the broader and deeper pronotal furrow with wider interstices, which may be as wide as diameter of punctures (in Stenus nanlingmotis smaller than half the diameter of punctures); the elytral marks are broader, about 3/5 as broad as the respective elytron (in Stenus nanlingmotis about 2/5 as broad as the respective elytron).

Etymology.

The specific name is derived from “Mao’ershan”, the type locality of this species.

Biological notes.

The female specimen was collected by sifting the leaves of bamboo and broad-leaved shrubs near the mountain summit, the male specimen was collected by beating grass along a drain exposed in sunshine.