Chu pheggomisetoides, Tian & He, 2020

Tian, Mingyi & He, Li, 2020, A contribution to the knowledge of cavernicolous ground beetles from Sichuan Province, southwestern China (Coleoptera, Carabidae, Trechini, Platynini), ZooKeys 1008, pp. 61-91 : 61

Chu pheggomisetoides sp. nov. Chinese name: 汉王初盲步甲 Figs 2 , 4B, D , 5C, D , 7 , 8

Material.

Holotype: male, cave Hanwang Dong, Zhongbai, Zengjia, Chaotian, Guangyuan, Sichuan (四川省广元市朝天区曾家镇中柏村汉王洞), 32.577297°N, 106.106979°E, 1210 m, 2020-VI-07, leg. Li He & Yuan Li, in SCAU. Paratypes: 1 male, idem, in SCAU; 1 female, same cave as above, 2020-VI-06, leg. Li He, Yuan Li & Yimei Wen, in CLH; 1 female, same cave, 2018-IV-06, leg. Li He, in SCAU.

Diagnosis.

Medium-sized troglobitic beetles, eyeless and lacking pigmentation, somewhat similar to a Pheggomisetes species of Bulgaria and Serbia in Balkan Peninsula due to its convex head and subcordate pronotum with very sharpened hind angles.

Description.

Length: 6.0-6.5 mm; width: 1.5 mm. Habitus as in Fig. 7 .

Body yellow or brown, but antennae, palps and tarsi paler; surface glabrous and smooth though genae sparsely setose and elytra covered with a few, minute, pubescence on lateral margins. Underside of head with a few sparse setae, of thorax and abdominal ventrites glabrous. Microsculpture engraved meshes more or less polygonal on head and pronotum, and irregularly and densely striate on elytra.

Head slightly elongate, ellipsoidal, longer than wide, HLm/HW = 1.67-1.72, HLl/HW = 1.18-1.28; genae expanded laterally, widest a little behind middle of head excluding mandibles, neck constriction broad, moderately defined, frons and vertex strongly convex, anterior and posterior supraorbital setiferous pores narrowly spaced, frontal furrows deep and fairly long, strongly divergent posteriorly, ending beside posterior supraorbital pores; clypeus quadrisetose; labrum transverse, deeply and widely emarginated at frontal margin, 6-setose; mandible stout and widened, curved at apical 1/3, strongly hooked at apices, right mandibular tooth very developed; labial suture disappearing medially, making mentum and submentum partly fused; mentum bisetose, base largely concave, tooth short and bifid at apex, about half as long as lateral lobes; submentum 8-setose; ligula 6-setose at apex; palps moderately elongate and glabrous but the 2nd labial palpomere bisetose on inner margin, with an additional seta at outer margin at subapex; 2nd labial palpomere slightly longer than 3rd; 3rd maxillary palpomere as long as 4th; suborbital pores located on ventral side of head, intermedial between neck constriction and submentum (Fig. 4B ). Antennae with 10th and 11th antennomeres extending over elytral apices, 1st antennomere smooth and stout, covered several long setae, pubescent from the 2nd antennomere; relative length of each antennomere compared with the 2nd in the holotype as: the 1st (1.13), 2nd (1.00), 3rd (1.67), 4th (1.73), 5th (1.93), 6th (1.87), 7th (1.80), 8th (1.57), 9th (1.54), 10th (1.43) and 11th (1.57).

Pronotum wider than long, PnL /PnW = 0.76-0.83; much shorter than head without mandibles, PnL/HLl = 0.55-0.75; wider than head, PnW/HW = 1.07-1.11; lateral margins and front finely bordered, widest at about 1/3 from front, gently narrowed anteriorly and posteriorly, but strongly curved before base, forming a large and acute hind angle with the arcuate base; anterior latero-marginal setae at about 1/7 from front; front slightly emarginate, distinctly wider than base, Pnb/Pnf = 0.83-0.86; disc moderately convex, mid-line clear, both front and posterior transversal impressions moderately marked. Scutellum large.

Elytra much longer than fore body including mandibles, much longer than wide, EL/EW = 1.90-2.02; much wider than pronotum, EW/PrW = 1.65-1.67; base unbordered, prehumeral part widely rounded, lateral margins finely but well-bordered throughout, widest at about middle, gently and gradually contracted towards base and apices; disc moderately convex though slightly depressed on each elytron near base; striae faint but noticeable; basal pore present at side but behind of scutellum, anterior and posterior dorsal pores along the 3rd stria located at about basal 1/5 and apical 2/5 of elytra respectively, preapical pore at about apical 1/8 of elytra, much closer to suture than to apical margin; locations of the marginal umbilicate pores as in Fig. 4D .

Legs densely pubescent; the 1st tarsomere much, and slightly shorter than 2nd-4th combined in fore and middle legs, respectively, whereas as long as in hind ones; tibiae without longitudinal sulci.

Ventrites pubescent; IV-V each with two pairs, VI with three pairs of paramedian setae, and several additional setae which are much shorter; VII bisetose in male, while quadrisetose in female.

Male genitalia (Fig. 5C, D ). Median lobe and parameres long and thin, suddenly curved at basal one fourth, then nearly straight towards apex. Basal opening small, without a sagittal aileron; inner sac provided with a long copulatory piece, which is about 1/3 as long as aedeagus; in dorsal view, apical lobe suddenly narrowed before the enlarged apex which is broadly rounded; each paramere armed with four long setae at apex.

Etymology.

Refers to the similarity of this new species with a Pheggomisetes species from Balkans.

Distribution.

China (Sichuan). Known only from the cave Hanwang Dong in Guangyuan (Fig. 2 ), sympatric with Boreaphaenops liyuani sp. nov., Agonotrechus sinotroglophilus Deuve, 1999 and Pterostichus (Huaius) hanwang Tian & He, 2020.

The exemplars of Chu pheggomisetoides gen. nov. & sp. nov. were collected under a stone at the water edge in the innermost main passage in the cave (Fig. 8A-C ). In addition to the four ground beetle species mentioned above, other animals found in Hanwang Dong are a Pseudonesticus spider, a Nepalella millipede, a Gammarus amphipod, bats, crickets and diplurans (Fig. 8D-I ).

Figures

Figure 2. Map of Sichuan Province showing the locations of the related caves.

Figure 4. Cave trechine beetles A ventral head of Uenoaphaenops fani (Ueno, 2003), comb. nov., female B ventral head of Chu pheggomisetoides gen. nov. & sp. nov., female C-E elytral chaetotaxy of Uenoaphaenops fani (Ueno, 2003), comb. nov., female, Chu pheggomisetoides gen. nov. & sp. nov., female paratype, and Boreaphaenops liyuani sp. nov., female holotype. Scale bars: 1.0 mm.

Figure 5. Male genitalia of cave trechine species, lateral and dorsal views A, B Uenoaphaenops fani (Ueno, 2003), comb. nov. C, D Chu pheggomisetoides gen. nov. & sp. nov.

Figure 7. Habitus of Chu pheggomisetoides gen. nov. & sp. nov., male holotype.

Figure 8. Cave Hanwang Dong, the type locality of Chu pheggomisetoides gen. nov. & sp. nov. and Boreaphaenops liyuani sp. nov., and some sympatric cave animals A, B habitat inside the cave, arrow in A indicates the place where a Chu pheggomisetoides gen. nov. & sp. nov. was found, arrow in B indicates the place where the single female of Boreaphaenops liyuani sp. nov. was found C an individual of Chu pheggomisetoides gen. nov. & sp. nov. running in cave D a ground beetle's larva was trapped in web of spider Pseudonesticus sp. E a Nepalella millipede F a bat G a cricket H Gammarus qinling Hou & Li, 2018 I a dipluran.