Sinaphaenops (Sinaphaenops) chengguangyuani Ma & Huang & Tian 2020, n. sp.
Creators: name: Ma, Zijun
name: Huang, Sunbin
name: Tian, Mingyi
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Sinaphaenops
Sinaphaenops chengguangyuani

description: Sinaphaenops (Sinaphaenops) chengguangyuani n. sp.
(Figs. 1–6)
Material. Holotype: male, cave Shuijing Dong, Baihuashu, Shibantan Cun, Xima Zhen, Longli Xian, Qiannan Miao & Buyi Zizhizhou, Guizhou Province, China, 26°36'45.57"N, 107°01'17.80"E, 1546 m in altitude, 30-I-2020, leg. Guangyuan Cheng & Jingyi Lai, deposited in SCAU. Paratypes: 2 males, Guangyuan Cheng, 26-VI-2020, deposited in SCAU; 2 males & 2 females, same locality, 26-VI-2020, leg. Mingyi Tian, Yi Zhao, Guangyuan Cheng, Xiaohong Jin & Chenggang Wang, deposited in SCAU.
Description. Length: 6.5–7.1 mm from apex of right mandible to elytral apex, 6.1–6.4 mm from labrum to apex of elytra; width: 1.60–1.79 mm. Habitus as in Fig. 1. Fore body (including mandibles) longer than elytra, (HLm+PrL)/EL=1.02–1.03. Overall yellowish brown, with paler tarsi and palps; body moderately shiny, impunctate and glabrous; microsculpture meshes transversely striate on vertex of head and pronotum, moderately transverse on clypeus and frons of head and elytra.
Head elongate subtriangular, much longer than wide (HLm/HW=2.84–2.90, HLl/HW=2.24–2.26), widest at about 3/7 from base (including mandibles); neck constriction wide, about 0.48–0.49 times as wide as head; frons depressed, frontal furrows well-marked, not parallel-sided, strongly divergent posteriorly; clypeus transverse, 4-setose; labrum transverse, 6-setose; mandibles stout and long, with obvious bidentate; two pairs of frontal setiferous pores present, the posterior more narrowly spaced than the anterior, at about the 1/3 level between neck constriction and anterior frontal pores; labial suture clearly visible, submentum 10-setose; mentum with two setae near base of median tooth which is thin and bifid; basal foveae concave and separated each other; ligula adnate to paraglossae, 10-setose; palps long, slender and glabrous except for the 2 nd labial palpomere which possesses two setae on inner margin and another seta on outer margin; the 2 nd labial palpomere 1.2 times longer than the 3 rd; the 3 rd maxillary palpomere 1.3 times longer than the 4 th. Ventral head with sparse and long setae; suborbital setae present, closer to neck of head than to submentum. Antennae slender, both the 10 th and 11 th antennomeres extending beyond elytral apices; the 1 st antennomere stouter and shorter than others, the 4 th longest, the comparative length ratio of antennomere as follows: 1 st (1.00), 2 nd (1.33), 3 rd (1.40), 4 th (2.07), 5 th (1.87), 6 th (1.80), 7 th (1.50), 8 th (1.37), 9 th (1.33), 10 th (1.10) and 11 th (1.20).
Prothorax stouter than in S. banshanicus Tian et al., 2017 and S. lipoi Chen, Huang & Tian, 2020 (Fig. 2), much shorter than head (PrL/HLm=0.47–0.61, PrL/HLl=0.75–0.80); distinctly wider than head (PrW/HW=1.24–1.33); widest at about 2/5 from base; anterior lateral-marginal setae present at about 1/3 distance from front; propleura distinctly expanded and visible from above (PrW/PnW=1.11–1.14); pronotum faintly wider than head (PnW/ HW=1.09–1.20), widest at about 1/2 from base; base distinctly wider than front (PbW/PfW=1.24–1.27); front not stoutly emarginate; lateral margins feebly sinuate, posterior angles acuminate, front angles obtuse and rounded; median line obvious.
Elytra oval-like, much longer than pronotum (EL/PnL=2.55–2.68), moderately elongate for Sinaphaenops species, about twice as long as wide (EL/EW=1.94–2.02), widest at about 3/5 from base, basally narrow and depressed, middle strongly convex; shoulders distinctly oblique, not serrulate, humeral angles broad; lateral margins finely margined and visible throughout, not parallel-sided; elytral striae generally invisible except punctures of the 1 st stria more or less clear at basal part. Chaetotaxy similar in S. (s. str.) banshanicus and S. (s. str.) lipoi (Fig. 3): presence of two dorsal pores on approximate position of 3 rd stria, at about 3/10 and 1/2 from elytral base, respectively; presence of preapical pore, which is well-marked, closer to suture than to apical margin of elytra; 1 st umbilicate pore of the humeral group roughly shifted to the position of 5 th interval and away from marginal gutter; 2 nd and 3 rd pores close to each other, the former near the marginal gutter; 4 th pore more or less located on the site of 5 th stria, closer to 5 th pore than to 3 rd; 5 th and 6 th pores of the middle group close to each other, both also widely distant from marginal gutter (Fig. 3A).
Legs slender, the 1 st tarsomere shorter than 2 nd– 4 th tarsomeres together in fore legs, while slightly longer in middle and as long as in hind legs, respectively. The 1 st and 2 nd protarsomeres modified in male, each denticulate on inner side of apex, with spongy setae ventrally.
Prosternum with several setae near base and apex, propleura smooth and glabrous; fore, middle and hind coxae with several setae. All ventrites sparsely setose; ventrite IV–VI each with 4 paramedial setae, and a few additional setae which are much shorter, ventrite VII with two pairs of setae in male, but three pairs in female.
Male genitalia (Fig. 4) moderately sclerotized, distinctly arcuate at middle in lateral view, widely membranous on its dorsal part; base large, sagittal aileron large and almost rounded; apex almost straight, and blunt at tip; inner sac armed with a wide copulatory piece, which is about 1/5 as long as median lobe; apical lobe wide, although longer than wide, slightly sinuate on the right side, broadly rounded at apex (Fig. 4B); parameres elongate and welldeveloped, each armed with two long setae at apex (Fig. 4A); genital ring triangular (Fig. 4C).
Remarks. This new species belongs to the same lineage as Sinaphaenops (s. str.) banshanicus and S. (s. str.) lipoi, in possessing anterior lateral-marginal setae on pronotum and preapical dorsal pores on elytra. It differs from the above two species by the shorter pronotum and presence of a distinct sagittal aileron on the male genitalia.
Etymology. Dedicated to Mr. Guangyuan Cheng, who discovered this interesting species.
Distribution. Guizhou (Guiyang). Known only from a limestone cave called Shuijing Dong (Fig. 5). The single beetle was collected on wet floor inside the cave, a place about 250 meters from the entrance (Fig. 6).
description: Published as part of Ma, Zijun, Huang, Sunbin & Tian, Mingyi, 2020, Two new species of cavernicolous trechines from central Guizhou and northwestern Guangxi, China (Coleoptera: Carabidae: Trechinae), pp. 581-593 in Zootaxa 4861 (4) on pages 582-587, DOI: 10.11646/zootaxa.4861.4.6, http://zenodo.org/record/4416789