Stenus liuyei Gao & Tang, 2017

Gao, Feng-Mei & Tang, Liang, 2017, A review of the Stenus viridanus group (Coleoptera, Staphylinidae) from China with descriptions of two new species, Zootaxa 4299 (3), pp. 432-440 : 435

Stenus liuyei Gao & Tang , new species

( Figs. 4 , 7–10 )

Type material. Holotype. China: Yunnan: ♂, glued on a card with labels as follows: “ China: Yunnan Prov., Lushui County, Yaojiapoing , alt . 2700 m, 22.VI.2010, Wen-Xuan Bi leg.” “ Holotype / Stenus liuyei / Gao & Tang ” [red hand written label] ( SHNU). Paratypes. China: Yunnan: 1♂, Dulong & Nu Minority County, Gongshan , Dulong Yakou to Heipu Yakou , alt . 3363 m, 11.VIII.2005, Ye Liu leg. (IOZ)

Description. Body entirely black with blue metallic tint. Antennae brownish yellow with club darker, maxillary palpi brownish with segment I slightly lighter. Legs with tibiae and tarsi reddish brown, femora yellowish except apical third dark brown.

BL: 6.3–6.5mm, FL: 3.3–3.7 mm.

HW: 1.17–1.26 mm, PL: 0.93–0.98 mm, PW: 0.85–0.89 mm, EL: 1.28–1.37 mm, EW: 1.20–1.26 mm, SL: 1.11–1.17 mm.

Head 0.98–1.00 times as wide as elytra; interocular area with two deep longitudinal furrows, median portion convex, distinctly extending beneath the level of inner eye margins; punctures round, mostly well delimited except those along the bottoms of longitudinal furrows, which is more or less confluent, the size of the punctures is almost in same, diameter of punctures distinctly smaller than median cross section of antennal segment II; interstices smooth, narrower than half to entire diameter of punctures except those along the midline of the convex median portion, which may be as wide as diameter of punctures. Paraglossa oval.

Pronotum 1.09–1.10 times as long as wide; disk distinctly uneven, with deep median longitudinal furrow which is about 2/3 as long as pronotum, two shallow impressions in anterior half, two impressions in the middle, two deep impressions in posterior half each; punctures very confluent, especially those around the median furrow; interstices smooth, ridge-like, distinctly narrower than half the diameter of punctures except those at the actual middle of longitudinal furrow, which could be 1.5 times as wide as diameter of punctures.

Elytra 1.07–1.09 times as long as wide; disk uneven, humeral impressions shallow, each with distinct inner tubercle; punctures extremely confluent; interstices smooth, ridge-like, distinctly narrower than half the diameter of punctures, forming vorticose sculpture in posterial half.

Legs with tarsomeres IV deeply bilobed.

Abdomen subcylindrical, segments III–VI with paratergites horizontal, each paratergite with one row of punctures, paratergite IV about as wide as antennal segment II, tergite VII with apical membranous fringe; punctures round, becoming slightly smaller posteriad; interstices with microsculptures, mostly narrower than diameter of punctures on tergites III–VI.

Male. Sternite VIII ( Fig. 7 ) with semi-circular emargination at middle of posterior margin; sternite IX ( Fig. 8 ) with long apicolateral projections, posterior margin serrate. Aedeagus ( Figs. 9, 10 ) robust; apical sclerotized area of median lobe subtriangular with a “U” shape impression at middle; sclerotized expulsion clasps very long, median longitudinal bands with ventral bands each long, broad, dorsal bands each short narrowed apically, copulatory tube large, fusiform, with bifurcate apex; parameres almost as long as median lobe, expanded in apical fourth, each with three groups of setae: two along the apico-internal margins and one at middle.

Female. Unknown.

Distribution. China (Yunnan).

Remarks. The new species is very similar to the rest members of S. viridanus complex, and the safest way to distinguish them is by examining aedeagus. From the habitus, it can be distinguished from others by more strongly confluent punctation on pronotum and elytra, and from S. viridanus and S.viridivestis also by narrower elytra.

Etymology. This species is named in honor of Mr. Liu Ye who collected one specimen of the new species.

Figures

FIGURE 1 – 6. Habitus. 1 Stenus viridanus 2 S. viridivestis 3 S. viridicans 4 S. liuyei sp. n. 5 S. cyanogaster 6 S. panyuhongae sp. n. Scale bars: 1 mm.

FIGURES 7 – 10. Stenus liuyei 7 Male sternite VIII 8 Male sternite IX 9, 10 aedeagus. Scale bars: 0.25 mm.