Shenoblemus minusculus Tian & Fang, 2020

Fang, Jie, Li, Wenbo, Wang, Xinhui & Tian, Mingyi, 2020, New cavernicolous ground beetles from Anhui Province, China (Coleoptera, Carabidae, Trechini, Platynini), ZooKeys 923, pp. 33-50 : 33

Shenoblemus minusculus Tian & Fang sp. nov. Figs 1 , 2 , 3A , 4A, B

Material.

Holotype male, cave Shenxian Dong, Qiaoshan, Xinming, Huangshan, Anhui, 30°23'9.55"N, 118°14'7.66"E, 366 m in altitude, 2016-IV-22, leg. Wenbo Li, deposited in the insect collections of South China Agricultural University, Guangzhou, China (SCAU).

Diagnosis.

Small-sized, eyeless and yellowish-brown beetle, with stout body and short appendages; covered with pubescence which are sparser on head, prothorax and elytra, and denser on abdominal ventrites.

Description.

Length: 2.45 mm; width: 0.84 mm. Habitus as in Fig. 1 . Fore body (head plus pronotum including mandibles) much shorter than elytra. Microsculpture made of isodiametric meshes irregularly distributed on head, pronotum and elytra.

Head large and widened, a little narrower than head including mandibles, HW/HLm = 0.90, or wider excluding mandibles, HW/HLl = 1.17; widest at about 1/4 of head from base excluding mandibles; front and vertex convex; frontal furrows well-defined and complete, strongly divergent at both anteriorly and posteriorly; genae markedly expanded laterally; anterior and posterior supra-orbital pores close, both at widest area of genae; clypeus quadrisetose, labrum transverse, almost straight in the front margin, 6-setose; mandibles widened and moderately curved at apices; ligula thin and short, adnated with paraglossae; palps short, penultimate joints much stouter than apical ones; the 2nd labial palpomere slightly longer than the 3rd, bisetose on inner margin, with two or three additional setae at subapex on outer margin; the 3rd maxillary palpomere as long as the 4th; the 1st-6th antennomeres filiform, while the 7th-11th semi-moniliform; relative length of each antennomere as: the 1st (1.13), 2nd (1.00), 3rd (1.08), 4th (1.04), 5th (1.13), 6th (1.00), 7th (1.04), 8th (1.04), 9th (1.04), 10th (1.00) and 11th (1.42).

Pronotum moderately transverse, PnW/PnL = 1.21, as long as head (including mandibles), much wider than head, PnW/HW = 1.32; lateral margins finely bordered, anterior lateromarginal pores located at about apical sixth, posterior ones at a little before hind angles; base slightly narrower than front, PbW/PfW = 0.97, both nearly straight and unbordered; hind angles denticulate at tips; both frontal and basal impression faint, basal foveae large and deep; disc moderately convex. Scutellum small and almost rounded.

Elytra much longer than wide, EL/EW = 1.56, wider than pronotum, EW/PnW =1.24; unbordered at base; strial punctures large and widely isolated; basal pores distant from scutellum, anterior and posterior dorsal pores on the 3rd striae at about 1/4 and 4/7 of the elytra from the base respectively; preapical pores at about apical 1/7 of elytra, subequal to suture and apical margin; humeral group of marginal umbilicate series regular though the 2nd closer to marginal gutter than other; the 5th widely separated from the 6th, apical pores close to elytral margin (Fig. 3A ).

Legs short and stout, densely pubescent; protarsi short, the 1st tarsomere much shorter than the 2nd-4th combined in fore and middle legs, whereas slightly shorter in hind legs; abdominal ventrites IV - VI each with a pair of paramedical setae in male.

Male genitalia (Fig. 4A, B ): The median lobe of aedeagus moderately sclerotized, rather long and thin, weakly arcuate at median portion, rounded at apex; dorsal margin suddenly folded at about basal quarter; base small, sagittal aileron quite large and hyaline, inner sac provided with a triangular and small copulatory piece, which is about 1/5 as long as aedeagus; in dorsal view, apical lobe widened at subapex, nearly triangular form, longer than wide, with a broadly rounded apex; parameres moderately elongated, right one as long as the left, each armed with two long setae at apex.

Female: Unknown.

Etymology.

To refer to the small body size.

Distribution.

China (Anhui). Known only from a limestone cave called Shenxian Dong in Huangshan Shi.

The Shenxian Dong limestone cave is more than 3000 m long. It is divided in three parts (front, middle, and back) for touristic purpose. There is an underground stream along the main passage. The single beetle specimen was collected in a dark area approximately 50 m from the entrance.

Figures

Figure 1. Habitus of Shenoblemus minusculus, sp. et gen. nov., male, holotype.

Figure 2. Head of Shenoblemus minusculus, sp. et gen. nov., male, holotype.

Figure 3. Left elytra of two cave trechines to show chaetotaxy A Shenoblemus minusculus, sp. et gen. nov., male, holotype B Wanoblemus huangshanicus, sp. nov., male, holotype.

Figure 4. Male genitalia of Shenoblemus minusculus, sp. et gen. nov. (A, B) and Wanoblemus huangshanicus, sp. nov. (C, D) A, C median lobe and parameres, lateral view B, D apical lobe, dorsal view.