Oodinotrechus (Pingleotrechus) yinae, Sun, Feifei & Tian, Mingyi, 2015

Sun, Feifei & Tian, Mingyi, 2015, First cavernicolous trechine beetle discovered in Guilin karst, northeastern Guangxi (Coleoptera, Carabidae, Trechinae), ZooKeys 545, pp. 119-129 : 121-124

Taxon classification Animalia Coleoptera Carabidae

Oodinotrechus (Pingleotrechus) yinae sp. n. Figs 1, 2, 3, 5-6

Diagnosis.

A small, short and stout beetle, anophthalmic and depigmented, with short appendages, fore body distinctly shorter than elytra, head short and narrow, with two pairs of supraorbital setae, mentum and submentum separated by clear labial suture, pronotum broad and campanulate, both lateromarginal setae present, elytra serrate and ciliate, shoulders distinct, 5th and 6th pores of the marginal umblicate series widely separated, a crescent-form structure present on apical part of each elytron.

Description.

Length: 4.0-4.8 mm; width: 1.3-1.7 mm. Habitus as in Fig. 2.

Depigmented; yellowish to reddish dark brown, very shiny, palps and tarsi light yellow.

Genae with several sparse and short setae, frons and vertex glabrous; a pair of suborbital setae present between mentum and prosternum; disc of pronotum with four erect setae each side of median line; propleura and mesosternum glabrous, pro- and metasterna with a few setae medially; elytra, prosternum and abdominal ventrites sparsely pubescent, entire legs pubescent. Microsculpture formed by faintly engraved transverse meshes on head and elytra, moderately transverse on pronotum.

Head anophthalmic, subquadrate, distinctly longer than wide, HLm/HW=1.74-1.79, HLl/HW=1.22-1.29; frons depressed and almost flat, vertex slightly convex, frontal furrows long and deep. Genae slightly expanded laterally, distance between anterior and posterior supraorbital pores almost as great as minimum distance between frontal furrows. Mentum bisetose, with medial tooth simple and blunt. Submentum with a row of 6 setae. Palps slender, 3rd maxillary palpomere as long as 4th while 2nd labial palpomere longer than 3rd. Antennae short and subfiliform, extended to about basal 1/3 of elytra and pubescent from 2nd antennomere; 1st antennomere with several additional setae near apex, slightly longer than 2nd, 3rd longest; antennomeres 4-10 decreasing gradually in length, 11th as long as 4th.

Pronotum transversely campanulate, PW/PL=1.40-1.47, as long as head, widest just before hind angles, which are widely obtuse and not denticulate; sides gently and gradually converging apicad in a smooth arc; fore angles are rounded off; anterior margin nearly straight. Base nearly straight, markedly wider than apex, PWb/PWf=1.67-1.71, with sides in advance of median part and oblique towards hind angles; lateral margins widely expanded and reflexed; anterolateral seta a third from apex, posterolateral seta just in front of hind angle. Disc moderately convex. Median line fine and deep. Both frontal and basal transverse impressions well-marked, basal foveae indistinct.

Scutellum large, visible from above. Elytra longer than forebody, EL/(HLm+PL)=1.32-1.39, longer than wide, EL/EW=1.54-1.79, with unbordered base, rounded shoulders and narrowed apex; widest about 1/3 from base; lateral margin serrate and ciliate throughout. Disc moderately convex, distinctly depressed at base and along suture. Parascutellar striole absent. 1st stria distinct, 2nd and 3rd faint but traceable; apical striole long and well-marked. Intervals flat, 2nd wider than any other. Basal setigerous pore present, anterior dorsal pore on 3rd stria about 1/6 from base, second pore on 4th stria a little behind middle; preapical pore distinct, inserted at anterior end of apical striole about 1/4 from apex, where 3rd and 4th striae anastomosed. Umbilicate setigerous pores subdivided into subhumeral group (setae 1-4, closely spaced), middle group (setae 5 and 6, widely separated) and preapical group; seta 5 much closer to 4th than to 6th, 6th closer to 7th than to 5th; distance between 5th and 6th about three times greater than between 5th and 4th, preapical pore equidistant from suture and from apex of elytra. Apical stria (Fig. 3a) and an additional, inner, striole (Fig. 3b) rising from preapical pore and forming a crescent combined; this additional striole gently curved inwards behind and not quite reaching stria 1.

Protibia straight, without longitudinal external sulcus. Protarsomeres 2-4 nearly moniliform. 1st tarsomere slightly shorter than or as long as, or longer than 2-4th combined in protarsi, mesotarsi, and metatarsi, respectively.

Male genitalia (Figs 5-6): Aedeagus moderately sclerotized; median lobe small, short and stout, moderately arcuated in lateral view; ventral margin deeply concave in median portion, then gently and almost straight towards apex, which is rather broad, not tube-like. Basal portion very large, with a large basal orifice, sagittal aileron absent. Dorsal orifice wide and long. Inner sac armed with an indistinct copulatory piece, about 1/3 as long as aedeagus. Apical lamella in dorsal view rather long and thin, not parallel-sided, gently narrowed towards apex which is rounded at tip. Parameres short and narrow, right slightly longer than left, both are broadly rounded at apex and bearing three and four long setae, respectively.

Etymology.

This new species is named in honor of Ms. Haomin Yin, an active member in our cave biological study team.

Distribution.

Northeastern Guangxi (Fig. 1). Known only from cave Chaotianyan, the type locality. The cave Chaotianyan is located in Letang village (Fig. 7), Ertang, Pingle County, at the southern part of Guilin karst. It opens in a subway of a hill, at about 60 m above foot, with a big entrance (Fig. 8). There is a large hall after the entrance, decorated by different deposits (Figs 9-11). It is a long cave according to the villagers, but detailed information is still not available. The beetles were collected in a dark and wet area under stone, not far from the entrance.

It is an interesting discovery to find an Oodinotrechus species in Guilin karst, northeastern Guangxi, because cave Chaotianyan, the type locality of Oodinotrechus yinae sp. n. is approximately 300 km away from the Maolan-Mulun karsts in the bordering areas between southernmost Guizhou and northernmost Guangxi where other two species of Oodinotrechus are found. However, in the Letang area there is a Fengchong landscape (Fig. 7), rather than Fenglin landscape which is dominant in other parts of the Guilin karst ( Zhu 1988).

Materials examined.

Holotype: male, Guangxi: Guilin: Pingle: Ertang: Letang: cave Chaotianyan, 110°45'501"E / 24°37'075"N, 5-XII-2011, Mingyi Tian, Weixin Liu & Haomin Yin leg, in SCAU. Paratypes: 3 males and 4 females, same data as holotype; 6 males and 4 females, same cave, 29-IV-2013, Mingyi Tian, Weixin Liu, Haomin Yin & Feifei Sun leg. All are deposited in SCAU, except one male paratype in each of IOZ, MNHN and ZUBM, respectively.