Dianous hubeiensis Tang & Huang, 2018

Tang, Liang & Huang, Meng-Chi, 2018, Notes on the Dianous bimaculatus complex with description of a new species from China (Coleoptera, Staphylinidae), Zootaxa 4527 (4), pp. 560-568 : 561-566

Dianous hubeiensis Tang & Huang , sp. n

( Figs. 3 , 17–24 )

Type material. Holotype. China: Hubei: ♂, glued on a card with labels as follows: “ China: Hubei Prov. , Wufeng Co., Houhe N. R., 30°05′26′′N, 110°34′23′′E, alt. 1052 m, 20.VII.2018, Jiang, Hu & Zhang leg.” “ Holotype / Dianous hubeiensis / Tang & Huang” [red handwritten label] (SHNU). Paratypes. 1♂, same data as for the holotype (cPut) ; 1♂♂ 2♀♀, Wufeng Co., Houhe N. R., 30°04′53′′N, 110°32′38′′E, alt. 1200 m, 21.VII.2018, Jiang, Hu & Zhang leg. ( SHNU) ; 2♀♀, Wufeng Co., Houhe N. R., 29.IV. –1.V.2004, Li-Zhen Li leg. ( SHNU) .

Description. Body black, each elytron with an orange spot, diameter of spots as long as antennal segment IV, antennae blackish with club dark brown, legs blackish with tarsomeres dark brown, maxillary palpi dark brown with segment III slightly darker. Pubescence silvery, distinct on head and abdomen, nearly invisible on pronotum and median portion of elytra.

BL: 6.2–6.8 mm, FL: 3.5 mm.

HW: 1.26–1.32 mm, PL: 0.96–1.00 mm, PW: 0.85–0.87 mm, EL: 1.46–1.52 mm, EW: 1.31–1.35 mm, SL: 1.23–1.28 mm.

FIGURES 7–16. Sexual characters. 7, 8 Dianous bimaculatus 9–16 D. flavoculatus 7, 11 male sternite IX 8, 12, 13 aedeagus 9 male tergites IX and X 10 male sternite VIII 14 female tergites IX and X 15 female sternite VIII 16 valvifers. Scale bars: 0.25mm.

Head 0.96–0.97 times as wide as elytra; interocular area with deep longitudinal furrows, median portion as wide as the side portions and convex posteriorly, extending to the level of inner eye margins; punctures round and well delimited, diameter of punctures a little wider than medial ommatidia of eyes; interstices smooth, varying from wider than half the diameter of punctures to wider than twice the diameter of punctures except those at the bottoms of longitudinal furrows which could be narrower than half the diameter of punctures. Antennae long, when reflexed, reaching apical two-thirds of elytra.

Pronotum 1.11–1.18 times as long as wide; disk uneven with transverse impression near anterior margin, two transverse impressions at about middle and flattened area near posterior margin; punctures distinctly larger than those of head, partially confluent; interstices smooth, varying from narrower than half the diameter of punctures to as wide as diameter of punctures, except some on median portion or near impressions, which may be much wider.

Elytra 1.10–1.15 times as long as wide; disk relatively even with humeral and sutural impressions indistinct; punctures slightly larger than that of pronotum in average, mostly well delimited, though some on basal portion and near elytral spots ditinctly confluent, interstices smooth, varying from narrower than half the diameter of punctures to narrower than diameter of punctures.

Legs slender, tarsomeres with long and dense setae on ventral sides, metatarsomere I slightly shorter than the following three segments combined, metatarsomere IV deeply bilobed.

Abdomen semi-cylindrical with broad, raised and densely punctate paratergites, width of paratergites of segment IV as wide as median cross section of metatibiae; posterior margin of tergite VII with palisade fringe; punctures on abdominal tergites III–VII minute, distinctly smaller than ommatidia of eyes, those on abdominal tergite VIII a little larger than ommatidia of eyes; interstices indistinctly microsculptured on abdominal tergites III– VI, distinctly microsculptured on abdominal tergite VII, reticulated on abdominal tergites VIII–X, narrower than half the diameter of punctures on abdominal tergites III–VII.

Male. Tergite X ( Fig. 17 ) with posterior margin broadly rounded; sternite VII slightly impressed at posteromedian part, posterior margin of the impression shallowly emarginated; sternite VIII ( Fig. 18 ) with deep emargination in the middle of posterior margin; sternite IX ( Fig. 19 ) with apicolateral projections long and strong, posterior margin convex at middle. Aedeagus ( Figs. 20, 21 ) slender, apical sclerotized area of median lobe with faint mid ridge, rounded laterally, tapering apicad and forming a round point at apex; expulsion clasps large; parameres slender and straight, longer than median lobe, each with 19–24 setae on inner side.

Female. Tergite X ( Fig. 22 ) with posterior margin distinctly prominent at middle; sternite VIII ( Fig. 23 ) with posterior margin more or less prominent at middle; valvifer ( Fig. 24 ) acute apically.

Distribution. China (Hubei).

Remarks. The species is similar to D. bimaculatus in appearance, but can be distinguished from latter by larger body size, larger elytral spots, sparser and well delimited punctation of forebody. It is similar to D. flavoculatus in shape of aedeagus, but can be distinguished from latter by smaller elytral spots, shorter pronotum, stronger apicolateral projections of male sternite IX and more pointed apical sclerotized area of aedeagal median lobe.

Etymology. The specific name is derived from “ Hubei ”, the type locality of the species.

Figures

FIGURES 1–6. Habitus. 1 Dianous bimaculatus 2 D. flavoculatus 3 D. hubeiensis 4 D. hainanensis 5 D. siamensis 6 D. strabo. Scale bars: 1mm.

FIGURES 17–24. Sexual characters of Dianous hubeiensis. 17 male tergites IX and X 18, male sternite VIII 19 male sternite IX 20, 21 aedeagus 22 female tergites IX and X 23 female sternite VIII 24 valvifers. Scale bars: 0.25mm.