Stenothemus shaanxiensis Švihla, 2004 (Yang & Yang & Liu, 2004)

Yang, Yuxia, Ge, Shujuan, Yang, Xingke & Liu, Haoyu, 2021, Taxonomic revision of the species of Stenothemus from Southwest China (Coleoptera, Cantharidae), with the descriptions of five new species, European Journal of Taxonomy 757 (1), pp. 1-36 : 3-6

Stenothemus shaanxiensis Švihla, 2004 stat. nov.

Figs 1B , 2A‒C , 3A , 4A

Stenothemus benesi shaanxiensis Švihla, 2004: 202 , fig. 164.

Material examined

Holotype

CHINA • ♂; [p] “China: Shaanxi 21.‒23.6. // Quing Ling Shan Mts. 1998 // rd. Baoji-Taibai , 35 km S Baoji // O. Šafránek & M. Trýzna lgt.”, “HOLOTYPUS // Stenothemus // benesi shaanxiensis ssp. n. // V. Švihla det. 2003”; NMPC.

Additional material

CHINA – Chongqing • 1 ♂; Chengkou, Dong’an, Shengjiaping ; 31.791º N, 109.241º E; 1819 m a.s.l.; 16 Jun. 2017; B. Chen leg.; CQNU • 1 ♂; Chengkou, Dong’an, Huang’anba Grassland ; 31.846º N, 109.199º E; 2249 m a.s.l.; 15 Jun. 2017; B. Chen leg.; CQNU . – Shaanxi • 1 ♀; Zhouzhi, Houzhenzi ; 1550‒3000 m a.s.l.; 22 Jun. 1999; J. Hu leg.; IZAS • 1 ♀; Zhouzhi, Houzhenzi ; 2500‒3000 m a.s.l.; 22 Jun. 1999; C.M. Liu leg.; IZAS .

Descriptive notes

Body length (both sexes): 5.5‒8.3 mm; width: 1.5‒2.6 mm.

Male ( Fig. 1B )

AEDEAGUS ( Fig. 2A‒C ). Moderately swollen dorsally at basal part, moderately reduced basally in diameter; basal piece nearly as long as dorsal plate of each paramere, with a large, bifurcate conjoined middle nodule at base of ventral side; ventral processes of parameres nearly parallel to each other, long and slightly widened apically, nearly straight in lateral view; dorsal plate nearly as long as ventral process, evenly narrowed apically and next to each other, apex rounded and folded ventrally; apical parts of laterophyses depressed and approaching each other, apex acute and directed dorsally, slightly exceeding middle emargination between dorsal plates.

Female

ABDOMINAL STERNITE VIII ( Fig. 3A ). Obliquely narrowed posteriorly, lateroapical angles obtusely rectangular, posterior margin deeply and triangularly emarginate in middle and feebly sinuate on both sides, behind the notch with a membrane which is moderately sclerotized and triangularly bilobed at apex.

INTERNAL ORGAN OF REPRODUCTIVE SYSTEM ( Fig. 4A ). Vagina stout, with median oviduct situated at ventroapical part, vagina abruptly narrowed in apical part and extended into a long duct which diverticulum and spermathecal duct are arising from; diverticulum relatively short, about 0.33 times adult body length, evenly thinned apically, slender tube-shaped and spiral; spermathecal duct much shorter than diverticulum; spermatheca slender, tube-shaped and spiral, clearly thinner than spermathecal duct and slightly shorter than diverticulum, with basal part extended into a short tube, at opening of accessory gland. Accessory gland thin in basal part and the remainder moderately thin, nearly as long as spermatheca.

Distribution

China (Shaanxi, Chongqing). New record for Chongqing.

Remarks

In the original publication ( Švihla 2004), this species was treated as a subspecies of S. benesi . However, differences between the two taxa are found not only in the external appearance, but also in the structures of the aedeagus. In S. shaanxiensis , the body is smaller and yellow ( Fig. 1B ), aedeagus ( Fig. 2A‒C ) with the dorsal plate of each paramere approaching that of the other, and the ventral process of each paramere distinctly thickened apically. In contrast, in S. benesi , the body is larger and brown ( Fig. 1A ), aedeagus ( Švihla 2004: figs 161‒163) with dorsal plates of parameres separated from each other and ventral process of each paramere slightly thickened apically. These differences are sufficient to support their independent status, so it is proposed that S. shaanxiensis is separated from S. benesi and upgraded to the specific level. The dorsal and ventral view of the aedeagus and the female reproductive system for this species are described and illustrated for the first time.

Figures

Fig. 1. Habitus, dorsal view.A. Stenothemus benesiŠvihla, 2004, holotype, ♂ (NMPC). B. S. shaanxiensis Švihla, 2004 stat. nov., holotype, ♂ (NMPC). C. S. davidi (Pic, 1926) comb. nov., holotype, ♀ (MNHN). D. S. diffusus Wittmer, 1974, paratype, ♂ (NHMB CANTH00003518). E. S. dundai Švihla, 2004. holotype, ♂ (NMPC). F. S. grahami Wittmer, 1974, paratype, ♂ (NHMB CANTH00003898). Scale bars = 1.0 mm.

Fig. 2. Aedeagus(A, D, G = ventral view; B, E, H = dorsal view; C, F, I = lateral view). A‒C. Stenothemus shaanxiensis Švihla, 2004 stat. nov. (CQNU, Chongqing). D‒F. S. davidi (Pic, 1926) comb. nov. (IZAS, Sichuan). G‒I. S. diffusus Wittmer, 1974 (MHBU, Sichuan). Scale bars = 0.5 mm.

Fig. 3. Abdominal sternite VIII of female, ventral view. A. Stenothemus shaanxiensis Švihla, 2004 stat. nov. (IZAS, Shaanxi). B. S. davidi (Pic, 1926) comb. nov. (IZAS, Shaanxi). C. S. diffusus Wittmer, 1974 (MHBU, Sichuan). D. S. dundai Švihla, 2004 (MHBU, Sichuan). E. S. grahami Wittmer, 1974 (IZAS, Gansu). F. S. jindrai Švihla, 2004 (IZAS, Sichuan). Scale bars = 1.0 mm.

Fig. 4. Female reproductive system, ventral view. A. Stenothemus shaanxiensis Švihla, 2004 stat. nov. (IZAS, Shaanxi). B. S. davidi (Pic, 1926) comb. nov. (IZAS, Shaanxi). C. S. diffusus Wittmer, 1974 (MHBU, Sichuan). D. S. dundai Švihla, 2004 (MHBU, Sichuan). Abbreviations: see Material and methods. Scale bars = 0.5 mm.