Dongodytes (s. str.) elongatus, Tian, Mingyi, Yin, Haomin & Huang, Sunbin, 2014

Tian, Mingyi, Yin, Haomin & Huang, Sunbin, 2014, Du'an Karst of Guangxi: a kingdom of the cavernicolous genus Dongodytes Deuve (Coleoptera, Carabidae, Trechinae), ZooKeys 454, pp. 69-107 : 75

Taxon classification Animalia Coleoptera Carabidae

Dongodytes (s. str.) elongatus sp. n. Figs 1k, 8, 17, 28, 33-34, 47-49, 73l

Description.

Length: 8.1-8.5 mm (mean 8.3 mm); width: 1.9-2.4 mm (mean 2.1 mm). Habitus as in Fig. 8.

Colour: Light yellowish brown to brown, dull, palps pale.

Macrosculpture: Head including underside surface and pronotum smooth and rather polish, sparsely covered with rather long and erected setae (except the tumid propleura), elytra and prosternum wholly covered with long setae; legs and abdominal ventrites pubescent.

Microsculpture: Engraved meshes clearly and strongly transverse on head and pronotum, faintly isodiametric on elytra.

Head (Fig. 17) much longer than wide, HL/HW=2.7-3.5 (mean 3.0); head excluding mandibles distinctly longer than pronotum, 1.3-2.3 times (mean 1.8), with a long and gradually narrowed neck constriction; widest at a little behind antennal articulations, two pairs of supraorbital setae present in holotype and three paratypes, setae on posterior pores shorter, asymmetrically sited, left one a little more behind than the right; right posterior pore absent in a female paratype; a pair of suborbital pores present, long, not far from the ring-shaped base, more or less asymmetrically sited; clypeus transverse, quadrisetose, sparsely covered with six additional short setae; labrum transverse, sexsetose; front shallowly emarginated; palps thin and very elongate, penultimate palpomeres longer than the apical ones; 2nd labial palp bisetose on inner margin; mentum and submentum partly fused, labial suture shortly traceable at sides; mentum bisetose basally, mental tooth simple, mental pits fine but distinct; submentum octosetose (but 12-setose in one female paratype, and 13-setose in one male paratype); antennae filiform, extending over elytral apex, all antennomeres pubescent, 1st as long as 2nd, 3rd 1.84 times longer than 2nd, each of 3 rd– 5th subequal in length, then gradually shortened towards apex, 10th as long as 11th, slightly longer than 1st.

Prothorax comparatively short (though much longer than wide) and narrow, slightly wider than head, PW/HW=0.7-1.1 (mean 0.9); front much narrower than base, PAW/PBW=0.4-0.7 (mean 0.6); propleura strongly tumid, much wider than pronotum, PW/PTW=0.8-0.9 (mean 0.8); pronotum rather short, lateral borders invisible from above at about 1/6 of apical parts (but visible in a male paratype), hind angles (Fig. 28) nearly rectangular, but obtuse, posterior lateral setae absent.

Elytra very elongate (but abnormally ovate in a male paratype), EL/EW=1.8-2.1 (mean 2.0), much wider than prothorax, EW/PTW=2.0-2.1 (mean 2.0); moderately convex; base comparatively thick (Fig. 28), humeral parts nearly straight, apex round; widest at about 2/3 from base; elytra slightly longer than head (excluding mandibles) plus prothorax; striae shallow, 2nd and 3rd traceable, others vague; 3rd elytral stria with three dorsal pores at about 1/3, 4/7 and 6/7 from base, respectively; chaetotaxal pattern of the marginal umbilicate pores similar in Dongodytes baxian , but distance from 1st to 2nd pores over twice as long as that from 2nd to 3rd (less than twice in Dongodytes baxian ); distance from 3rd to 4th pores much longer than that from 4th to 6th (almost as long as in Dongodytes baxian ).

Male genitalia (Figs 33-34): Median lobe of aedeagus stout, slightly sinuate before apex, apical part very short and broad, basal part wide and larger, basal orifice large, with margin distinctly protruding ventrally; ventral margin arcuate ventrad; sagittal aileron very small; inner sac armed with a broad and long copulatory piece which covered with scale structures on surface, as long as 1/3 of the median lobe; in dorsal, apical lobe very broad, and rounded at apex; parameres wide and rather long, right and left ones with four and three long apical setae respectively.

Remarks.

This species is a peculiar representative within Dongodytes (s. str.) because of its wholly pubescent elytra and comparatively shorter antennae in which only 10-11th segments extending over elytra. It is rather similar to Dongodytes baxian in appearance, but easily distinguished from the latter by its larger body size, slenderer and more elongate head, more expanded of propleura, without posterior latero-marginal setae, and stouter aedeagus.

Etymology.

This new species is named referring to its very slender and elongate body.

Material examined.

Holotype: male, Guangxi: Du’an: Lalie: Fuyan: Jianong: cave Lapo Dong I, 24° 11.987N, 108° 20.378E, 140 m, 2013-VI-23, leg. Mingyi Tian, Weixin Liu, Haomin Yin & Sunbin Huang; Paratypes: 2 males and 2 females, ibid. All are deposited in SCAU.

Distribution.

Guangxi ( Du’an). Known only from the type locality, cave Lapo Dong I in Lalie (Figs 1k and 73l).

The species was found close to the entrance of Lapo Dong (Figs 47-49). Deeper parts of the cave were not accessible during our visit. It was said that the cave is about 400 m long. There is no pool in the cave, but it is wet and muddy, and covered with guano. Other cave-dwelling animals living in this cave are crickets, mosquitoes, pselaphids, spiders, millipedes, snails and bats.