Stenothemus diffusus Wittmer 1974

Abstract

Stenothemus diffusus Wittmer, 1974 Figs 1D, 2G‒I, 3C, 4C Stenothemus diffusus Wittmer, 1974: 58, fig. 17. Material examined Paratype CHINA • 1 ♂; [h-p] “Yao Gi nr Mu- // pin 15 Jul // ‘29 7400‒8000 ft ”, [p] “Szechuen // CHINA // D.C. Graham ”, [h] “119”, [p] “PARATYPUS”, [h-p] “ Stenothemus // diffusus // Wittm. // det. W. Wittmer ”, [p] “Naturhistorisches // Museum Basel // Coll. W. Wittmer ”, “ CANTHARIDAE // CANTH00003518”; NHMB. Additional material CHINA ‒ Sichuan • 1 ♀; Wolong, Wolonggou; 2150 m a.s.l.; 21 Jul. 2004; X. Wan leg.; IZAS • 3 ♂♂, 7 ♀♀; Anzihe; 9 Aug. 2016; W.Y. Zhou leg.; MHBU • 1 ♂, 6 ♀♀; Anzihe, Shaoyaogou; 1450 m a.s.l.; 9‒11 Aug. 2016; W.Y. Zhou leg.; MHBU • 1 ♀; Liziping; 25 Jul. 2016; L.M. Li leg.; MHBU • 1 ♂, 3 ♀♀; Baoxing, Kyaʼgyu Shan; 30 Jul. 2016; L.M. Li leg.; MHBU. Descriptive notes Body length (both sexes): 10.0‒ 12.8 mm; width: 2.1‒3.0 mm. Male (Fig. 1D) AEDEAGUS (Fig. 2G‒I). Strongly swollen dorsally in basal part, diameter decreased apically; basal piece slightly shorter than 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 thickened apically; dorsal plate slightly shorter than ventral process, evenly narrowed apically, layering in middle, external layer roundly emarginate in middle, internal layer deeply and triangularly emarginate, rounded at apex; apical parts of laterophyses compressed and next to each other, apex rounded and bent dorsally, slightly exceeding middle emargination between dorsal plates. Female ABDOMINAL STERNITE VIII (Fig. 3C). Obliquely narrowed posteriorly, lateroapical angles widely triangular, posterior margin shallowly and triangularly emarginate in the middle, and weakly sinuate on both sides. INTERNAL ORGAN OF REPRODUCTIVE SYSTEM (Fig. 4C). Vagina elongate, with median oviduct situated at ventroapical part, vagina abruptly narrowed in apical part and extended into a short duct which diverticulum and spermathecal duct are arising from; diverticulum moderately long, about 0.35 times adult body length, evenly thinned apically, slender tube-shaped and spiral; spermathecal duct slightly longer than diverticulum; spermatheca slender tube-shaped and spiral, thinner than spermathecal duct and nearly as long as diverticulum, with basal part extended into a short tube, at opening of accessory gland. Accessory gland thin and nearly as long as spermatheca. Distribution China (Sichuan); Myanmar. Remarks The dorsal and lateral views of aedeagus and the female reproductive system are described and illustrated for the first time.Published as part of 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, pp. 1-36 in European Journal of Taxonomy 757 (1) on page 10, DOI: 10.5852/ejt.2021.757.1409, http://zenodo.org/record/503310