Wulongius Tian & Huang, 2021

Tian, Mingyi, Huang, Sunbin, Jia, Xinyang & Zhao, Yi, 2021, Two new genera and three new species of cavernicolous trechines from the western Wuling Mountains, China (Coleoptera, Carabidae, Trechinae), ZooKeys 1059, pp. 57-78 : 57

Wulongius Tian & Huang gen. nov.

Type species.

Wulongius qilinger Tian & Huang, sp. nov. (cave Qiankou Dong, Wulong, Chongqing).

Generic characteristics.

Medium-sized for cavernicolous trechine beetles, aphaenopsian and depigmented; body thin and elongate, with thin and slender appendages. Head glabrous, pronotum covered with dense and long erected setae; apical portions of elytra covered with very sparse and short hairs; head strongly elongate, much longer than wide (excluding mandibles); widest at about middle, gently narrowed posteriad, neck constriction short; 2 pairs of supra-orbital setiferous pores present; frontal furrows short and incomplete, ending at the level of the head widest portion; vertex strongly convex; mandibles thin, sharply hooked at apices, right mandibular tooth completely reduced; labial suture clear; mentum with 2 setae on each side of median tooth, base of mentum with small basal pits on each side; submentum with a row of 10 setae; palps thin and very elongate, all glabrous but bisetose on inner margin of 2nd labial palpomere; antennae very thin and long, extending over apices of elytra. Propleura visible from above; pronotum cylindrical, distinctly elongated, much longer than wide, lateral margins nearly parallel-sided though slightly divergent medially, presence of only anterior latero-marginal setae (posterior ones lacking), both fore and hind angles widely obtuse. Scutellum present. Elytra elongated ovate, dorsum strongly convex and expanded laterally, partly concealing lateral margin of elytra in middle portion; humeral angle indistinct, lateral margin well bordered and ciliate throughout; striae almost obsolete though traceable; 2 pairs of dorsal setiferous pores present on the 3rd stria, preapical pores present; basal pores located behind scutellum; the humeral group of the marginal umbilicate pores not aggregated, 1st pore inwardly and backwardly shifted to the site of 6th stria and located at level between 2nd and 3rd pores, 5th and 6th pores widely spaced each other.

Remarks.

The position of Wulongius gen. nov. within Trechini is undetermined. It might be related to the genus Xiangxius Tian & X. Huang, 2021, which has been recently described from Tangle Dong cave in western Hunan, in the eastern Wuling Mountains. Both genera are aphaenopsian, with highly specialized morphological characters. They are somewhat similar in thoracic configuration and, in particular, in the elytral chaetotaxy, in which the 1st pore of the marginal umbilicate series is backwardly and inwardly shifted and both 5th and 6th pores are widely spaced. However, there are many different important characters between them including the body shape: (1) elytra are much more convex and expanded laterally in Wulongius , concealing median part of the lateral margins, and without aprotruding humeral angle on each elytron, versus elytra less expanded laterally in Xiangxius , whole lateral margin visible from above, and with a distinct protruding humeral angle on each elytron; (2) pronotum covered with long setae, without posterior latero-marginal setae in Wulongius , versus pronotum glabrous, with posterior latero-marginal setae in Xiangxius ; (3) mentum glabrous in Wulongius , but pubescent in Xiangxius ; (4) labial suture clear in Wulongius , whereas mentum fused with submentum in Xiangxius ; (5) right mandibular tooth edentate in Wulongius , while bidentate in Xiangxius ; (6) submentum with a row of 10 setae in Wulongius , instead of 15 or 16 setae in Xiangxius ; (7) head slender in Wulongius , not thickened, with longer antennae extending beyond the apices of elytra, versus head stout, widely convex laterally, and with shorter antennae extending only to apical 2/3 of elytra in Xiangxius .

Etymology.

" Wulong "+ "- ius ", indicating the homeland of this new genus. Gender masculine.

Generic range.

China (Chongqing). Known only from limestone cave Qiankou Dong (Fig. 1 ).

Figures

Figure 1. A distribution map showing the localities of the three surveyed caves (stars) and the known species and subspecies of the genus Qianotrechus Ueno, 2000 (dots) A Shigao Dong B Qiankou Dong C Qianlong Dong.