Stenothemus distortirudis Y. Yang et X. Yang

Yang, Yuxia, Su, Junyan & Yang, Xingke, 2014, Review of the Stenothemus harmandi species-group (Coleoptera, Cantharidae), with description of six new species from China, Zootaxa 3847 (2), pp. 203-220 : 212-213

Stenothemus distortirudis Y. Yang et X. Yang , sp. nov.

Figs. 4 , 16, 27‒29, 44

Type material. Holotype ♂ ( MHBU): CHINA: Xizang, Nyingchi , Pêlong , 23.‒28.IX.2007, leg. F.M. Shi. Paratypes: 1 ♂, 3 ♀♀ ( IZAS): CHINA: Xizang, Bomi, Tangmai, 2100m, 30.VIII.2005, leg. X.L. Chen . [all transliterated from Chinese labels].

Distribution. China (Xizang).

Description. Male ( Fig. 4 ). Head black, reddish brown on middle line of vertex, mouthparts light yellow, more or less darkened at maxillary and labial palpi, apices of mandibles dark brown, antennae black, light yellow at apex of each antennomere, pronotum light yellow, with a dark brown marking on disc, scutellum light yellow, elytra light yellow and mottled with irregular dark brown markings, legs light yellow, black at bases of coxae and tibiae, apices of femora and tarsomeres, more or less darkened at outer sides of femora and outer and dorsal sides of tibiae, prosternum light yellow, meso- and metasterna dark brown, abdominal ventrites black, light yellow at posterior margins of abdominal ventrites. Body densely covered with light brown pubescence, mixed with slightly long and semirecumbent light brown pubescence and erect black brown setae on elytra.

Head subquadrate, temples straight and slightly converging posteriorly, dorsum slightly convex in central part, surface semilustrous, densely and finely punctate, each side with a smooth and rectangular impression behind antennal socket; eyes strongly protruding, head width across eyes slightly narrower than pronotum; terminal maxillary palpomeres long-triangular, widest at basal one-third, with apical parts of inner margins arcuate and sharp, acute at apices; antennae extending to basal two-thirds length of elytra, antennomeres II about twice longer than wide at apices, III about one-third longer than II, IV longest, from V to XI gradually shortened, XI pointed at apex.

Pronotum about 1.15 times as wide as long, widest nearly at posterior one-third, anterior margin arcuate, lateral margins sinuate, posterior margin arcuate and narrowly bordered, anterior angles rounded, posterior angles sharp and protruding, disc distinctly convex on posterolateral parts, surface matt, finely and sparsely punctate.

Elytral length about 4 times length of pronotum, 3 times as long as humeral width, with lateral margins slightly diverging posteriorly, surface semilustrous, rugulose-lacunose and finely punctate.

Aedeagus ( Figs. 27‒29 ): ventral process of each paramere thickened and widened at basal part, in a curved stick-shape, bent ventrally about 90 degrees, with the bent portion at apical part distinctly shorter than the basal portion, distinctly thickened terminally and circular at apex in lateral view, dorsal plate distinctly shorter than ventral process, abruptly narrowed apically, acute and folded ventrolaterally at apex; laterophyse rounded at apex.

Female. Similar to male, but head slightly convex on dorsum, head width across eyes distinctly narrower than pronotum, antennae shorter and extending to elytral midlength, pronotum wider, about 1.24 times as wide as long, moderately convex on posterolateral parts of disc, elytra with lateral margins distinctly diverging posteriorly, abdominal sternite VIII (Fig. 16) abruptly narrowed posteriorly, nearly parallel-sided on posterior part, longitudinally and narrowly convex on middle sclerotized part, the convex narrowed posteriorly and acute at apex, with lateral margins nearly membranous, posterior margin roundly emarginated in middle, lateroapical angles subrounded, the lobe moderately sclerotized, triangular and acute at apex.

Body length: 7.0‒10.0 mm; width: 1.5‒2.5 mm.

Diagnosis. This species can be easily distinguished from others by the aedeagus: ventral process of each paramere thickened, distinctly widened at basal part, in a bent stick-shape, dorsal plate abruptly narrowed apically, acute and folded ventrolaterally at apex.

Etymology. This specific name is derived from the Latin distortus (curved) + rudis (stick), referring to its aedeagus with ventral process of each paramere in a curved stick-shape.

Remarks. The left fore leg of the holotype is broken but adhered, and the right pro- and mesotarsi are missing.

Figures

FIGURES 1 ‒ 4. Male habitus, dorsal view: 1, 2. Stenothemus harmandi (Bourgeois, 1902) (1. Lecotype, 2. non-type from Nepal); 3. S. fugongensis sp. nov.; 4. S. distortirudis sp. nov. Scale bars: 2.0 mm.

FIGURES 24 ‒ 32. Aedeagus (24, 27, 30. ventral view; 25, 28, 31. dorsal view; 26, 29, 32. lateral view; 26 a. laterophyse, lateral view; 31 a. apex of paramere, dorsoapical view): 24 ‒ 26. Stenothemus fugongensis sp. nov.; 27 ‒ 29. S. distortirudis sp. nov.; 30 ‒ 32. S. parallelus sp. nov. Scale bars: 1.0 mm.