Stenus hechiensis Liu and Tang

Liu, Sheng-Nan & Tang, Liang, 2017, Seven new species of the Stenus cirrus group (Coleoptera, Staphylinidae) from Guangxi, South China, Zootaxa 4268 (2), pp. 238-254 : 248-249

Stenus hechiensis Liu and Tang , new species

( Figs 13, 14 , 59–66 )

Type material. CHINA: Guangxi: Holotype: ♂, Hechi City, Mulun N. R., 25°3'12''N 107°57'59''E, mixed leaf litter, sifted, 450–600m, 26.VII.2015, Chen, He & Hu leg. ( SHNU) . Paratupes : 2♀♀, same data as for the holotype. ( SHNU) .

Description. Brachypterous; body dark brown with head and last four abdominal segments blackish. Antennae, maxillary palpi and legs yellowish brown except antennal club infuscate. Labrum reddish brown.

BL: 4.3–4.5 mm, FL: 1.7–2.0 mm.

HW: 0.78–0.85 mm, PL: 0.62–0.67 mm, PW: 0.59–0.64 mm, EL: 0.67–0.70 mm, EW: 0.70–0.79 mm, SL: 0.50–0.57 mm.

Head 1.07–1.11 times as wide as elytra; interocular area with two deep longitudinal furrows, median portion slightly convex, slightly extending beyond the level of inner eye margins, with a narrow impunctate line along midline; punctures round, more or less confluent especially those on the bottom of furrows, slightly larger and sparser in median portion than near inner margins of eyes, diameter of large punctures about as wide as apical cross section of antennal segment II; interstices smooth, narrower than half the diameter of punctures except those along the midline of the convex median portion, which may be slightly wider than diameter of punctures. Paraglossae oval.

Pronotum 0.99–1.05 times as long as wide; disk uneven, with distinct median longitudinal furrow, which is about 4/5 the length of pronotum; punctures round and confluent, of similar size to those of head; interstices smooth, much narrower than half the diameter of punctures except for those in the middle of the median longitudinal furrow, which could be 2.5 times as wide as diameter of punctures.

Elytra 0.88–0.95 times as long as wide, disk relatively uneven with dinstinct humeral impression and sutural impression; punctures longitudinally confluent, slightly larger than those of pronotum; interstices smooth, distinctly narrower than half the diameter of punctures.

Legs with tarsomeres IV strongly bilobed.

Abdomen cylindrical; paratergites very narrow and almost impunctate, present only in segment III, tergites and sternites totally fused in segments IV–VI, posterior margin of tergite VII with indistinct palisade fringe; punctation of tergites III–VIII round and sparse, gradually becoming smaller and sparser posteriad; interstices smooth, mostly smaller than diameter of punctures.

Male. Sternite VIII ( Fig. 59 ) with semi-circular emargination at middle of posterior margin; sternite IX ( Fig. 61 ) with long apicolateral projections, posterior margin serrate; tergite X ( Fig. 60 ) with posterior margin convex. Aedeagus ( Fig. 62 ) with apical sclerotized area triangular and acutely pointed at apex; expulsion clasps large; parameres long as median lobe, each with 7 setae on apico-internal margins.

Female. Sternite VIII ( Fig. 64 ) entire; tergite X ( Fig. 65 ) with posterior margin truncate; spermatheca ( Fig. 66 ) with basal porch distinct, the rest duct undetected.

Distribution. China (Guangxi).

Remarks. The new species can be easily distinguished from other species of the group be the combination of the following characters: body dark brown without elytra spot, punctation of forebody confluent, pronotal furrow very long with impunctate line at middle and different sexual characters.

Etymology. The specific name is derived from the type locality of this species.

Figures

FIGURES 13 – 14. Dorsal habitus of Stenus hechiensis sp. n. Scale bars: 1 mm.

FIGURES 59 – 66. Diagnostic features of Stenus hechiensis. 59. Male sternite VIII. 60. Male tergites IX – X. 61. Male sternite IX. 62 – 63. Aedeagus, in dorsal view. 64. Female sternite VIII. 65. Female tergites IX – X. 66. Valvifers. Scale bars: 0.25 mm.