Shuangheaphaenops, Tian, Mingyi, 2017

Tian, Mingyi, 2017, A new highly cave-adapted trechine genus and species from northern Guizhou Province, China (Coleoptera, Carabidae, Trechinae), ZooKeys 643, pp. 97-108 : 99-101

Genus Shuangheaphaenops gen. n.

Type species.

Shuangheaphaenops elegans sp. n.

Diagnosis.

Large sized blind beetles, fore body evidently elongated and as long as elytra, shape intermediate between Uenotrechus and Dongodytes species, presence of three pairs of supraorbital setae on head, two dorsal and preapical pores on elytra, the first and second protarsomeres in male distinctly modified.

Generic characteristics.

Highly modified aphaenopsian trechines, fore part (head and thorax) of the body somewhat similar to Uenotrechus Deuve & Tian, 1999, while hind part (elytra) to Dongodytes Deuve, 1993; large sized, with body and appendages thin and very elongate, fore body almost as long as hind part; three pairs of supraorbital setiferous pores present on head, with the posterior two pairs very close to each other; mandibles thin and elongated, feebly curved apically, longer than width of head, right mandible edentate though two vanished teeth can be faintly traced; labial suture moderately defined, separating of mentum and submentum, with the former bisetose and the latter 6-setose; mental tooth simple and thin, basal foveae quite narrow; antennae very long, the 10th and 11th antennomeres extending over apical margin of elytra. Prothorax dolioform, propleura distinctly tumid at basal half, evidently visible from above; pronotum barrel-shaped, distinctly elongated, longer than head excluding mandibles, narrower than head; without lateromarginal setae. Elytra similar to those of Dongodytes (s. str.) Deuve, 1993, narrowed anteriorly and dilated posteriorly, side margins narrowly bordered throughout, shoulders lacking; striae lacking though easily traceable; presence of two dorsal and preapical setiferous pores; the 1st pore in the humeral group of the marginal umbilicate series not transversely and backwardly shifted, the 5th and 6th pores in the middle group widely spaced. Protibia smooth, without longitudinal sulcus; the 1st and 2nd protarsomeres in male dilated and inwardly spurred at apices. Abdominal ventrites sparsely pubescent, each of ventrites IV-VII in male bisetose apically. Male genitalia moderately sclerotized, small, strongly curved ventrally in lateral view, with a quite large sagittal aileron; apical lobe very thin in dorsal view; parameres well developed, but much shorter than median lobe.

Discussion.

Shuangheaphaenops can not be included in any lineage of the highly modified aphaenopsian genera known in southern China regarding to the peculiar morphological characteristics mentioned above, such as the peculiar facies and configuration of the body (which is more or less similar to Uenotrechus Deuve & Tian, 1999 in fore body, but to Dongodytes Deuve, 1993 in elytra), vanished bidentate right mandible, and chaetotaxal patterns in which there are three pairs of supraorbital setiferous pores on head, lack of lateromarginal setae on pronotum, and unique pattern on elytral marginal umbilicate series, in particular, the humeral and middle groups.

Apart from the similarity in elytra and antennae between Shuangheaphaenops and Dongodytes (s. str.) which occurs only in northern Guangxi where is far distant from Cave Shuanghe Dong in northern Guizhou, the following characteristics are different: (1) head subparallel-sided, with three pairs of supraorbital setiferous pores, right mandibular teeth bidentate but almost vanished in Shuangheaphaenops (versus triangular shaped in general, presence of two pairs of supraorbital pores, and well-marked tridentate teeth on right mandible in Dongodytes ); (2) the 1st and 2nd protarsomeres of male distinctly modified in Shuangheaphaenops (indistinctly or not modified in Dongodytes ); (3) pronotum much slender and lack of lateromarginal setae in Shuangheaphaenops (versus stouter and presence of lateromarginal setae in Dongodytes ); and (4) the middle group (the 5th and 6th pores) of the marginal unbilicate series on elytra widely spaced each other in Shuangheaphaenops (versus close to each other in Dongodytes ).

The fore body of this new genus is more or less similar to that of Uenotrechus Deuve & Tian, 1999, but Shuangheaphaenops has a slenderer head bearing three pairs of supraorbital setiferous pores, reduced bidentate teeth of right mandible, and much longer antennae (versus bearing two pairs of supraorbital setiferous pores, mandibular teeth well-defined and clearly tridentate, and shorter antennae in Uenotrechus ), and pronotum without lateromarginal setae (versus with pair of lateromarginal setae in Uenotrechus ). In addition, head and elytra are glabrous in Shuangheaphaenops (versus whole body densely pubescent in Uenotrechus ), the 1st pore of the marginal umbilicate series is located before the 2nd in Shuangheaphaenops (versus transversely shifted inwards and backwards, at level behind the 2nd pore in Uenotrechus ), and both the 1st and 2nd protarsomeres in male are modified in Shuangheaphaenops (versus not modified in Uenotrechus ).

Etymology.

"Shuanghe + Aphaenops". To indicate that the highly modified trechine genus occurs in Shuanghe Dong, the longest cave system in China.

Generic range.

Guizhou (Suiyang) (Fig. 1).