Rhagonycha nigricolor Y. Yang, Liu & X. Yang 2024, sp. nov.

Rhagonycha (s.str.) nigricolor Y. Yang, Liu & X. Yang, sp. nov. (Figs 15A‒B, 16A‒C, 17A, 18A, 41) Type material. HOLOTYPE: ♂ (IZAS), CHINA, Sichuan: Emeishan, 18.VI.1955, leg. K.R. Huang & Y.T. Jin. PARATYPES: CHINA, Sichuan: 1♂, 4♀♀ (IZAS), Emeishan, 20.VI.1955, leg. K.R. Huang & Y.T. Jin; 1♀ (IZAS); same data as the preceding, 17.VI.1955; 3♂♂ (IZAS), same data as the preceding, 18.VI.1955; 1♂ (IZAS), same data as the preceding, 23.VI.1955; 1♀ (IZAS); same locality as the preceding, 1600‒2100 m, 24.VI.1955, leg. X.K. Bu; 1♀ (IZAS), Emeishan, Xixiangchi, 1800‒2000 m, 25.Ⅴ.1957, leg. K.R. Huang; 1♀ (IZAS), Emeishan, Jiulaodong, 1800‒1900 m, 6.VII.1957, leg. F.X. Zhu. Guizhou: 4♀♀ (MHBU), Leigongshan, Xiaodanjiang, 860‒ 1300 m, 31.V–1.VI.2005, leg. Q.R. Liao; 4♀♀ (MHBU), Leigongshan, Lianhuaping, 1300‒2178 m, 2‒3.VI.2005, leg. Y.H. Song; 1♀ (MHBU), same data as the preceding, leg. Z.H. Zhou. Chongqing: 1♂ (MHBU), Wuxi, Lanying, Lanying, 31°24′24.54″ N, 109°53′7.92″ E, 1764 m, 24.VI.2022, leg. L.Y. Wang; 1♂ (MHBU), Wuxi, Lanying, Yintiaoling Nature Reserve, Huangcaoping, 31°24′50.13″ N, 109°55′40.2″ E, 2039 m, 24.VI.2022, leg. L.Y. Wang; 1♀ (MHBU), Wuxi, Yintiaoling Nature Reserve, Zhuanping Management and Protection Station, 31°29′56.9889′′ N, 109°56′59.2115′′ E, 1973.24 m, 18.VIII.2022, leg. L.Y. Wang, T.Y. Ren et al. Differential diagnosis. This species can be easily distinguished from all others by its uniformly black head and pronotum, as well as its aedeagus shape, which is strongly swollen laterally and ventrally at basal part (while at most moderately swollen in other species). Description. Body length: 7.8‒8.7 mm (8.6 mm in holotype); width: 1.9‒3.5 mm (2.1 mm in holotype). Male (Fig. 15A). Coloration. Body black except for elytra pale yellow, each elytron with a wide longitudinal median black band that extending from humerus to apex and narrower in the anterior part than the posterior part. Surface sparsely and finely yellow pubescent, anterior margin of clypeus fringed with pale bristles. Head rounded, surface densely and finely punctate; eyes moderately protruding, head width across eyes about as wide as anterior margin of pronotum; terminal maxillary palpomeres subtriangular, widest at apical third; antennae extending to basal 3/4 length of elytra when reclined, antennomeres II shortest, about 2.5 times as long as wide at apices, III about 1.8 times longer than II, V longest, XI feebly longer than X and pointed at apices. Pronotum subquadrate, about 0.9 times as long as wide, anterior margin rounded, anterior angles subrounded, lateral margins feebly diverging posteriorly, posterior margin nearly straight, posterior angles sub-rectangular, disc strongly convex on posterolateral parts, surface finely and sparsely punctate. Elytra with lateral margins feebly diverging posteriorly, about 3.7 times as long as humeral width, 5.6 times longer than pronotum, surface finely rugulose-lacunose, almost lustrous at basal parts. Aedeagus feebly swollen laterally near middle (Fig. 16A, B) and strongly swollen ventrally in lateral view (Fig. 16C); ventral processes of parameres abruptly and strongly thinned apically near bases, with apices rounded and bent to each other in ventral view (Fig. 16A), narrow and almost straight in lateral view (Fig. 16C); conjoint dorsal plate of parameres feebly longer than ventral processes (Fig. 16C), with apical margin roundly and shallowly emarginate in middle, lateral margins nearly parallel, latero-apical angles truncate in dorsal view (Fig. 16B), feebly inclined ventrally in lateral view (Fig. 16C); emargination between conjoint dorsal plate and ventral process about 1/3 length of aedeagus (Fig. 16C). Female (Fig. 15B). Similar to male, but with larger and stouter body, eyes less protruding, head width across eyes 0.9 times as wide as anterior margin of pronotum, antennae shorter and extending to apical third length of elytra when reclined, pronotum wider and about 1.3 times as wide as long, anterior margin more arcuate, disc feebly convex on posterolateral parts, elytra about 3.5 times as long as humeral width, with lateral margins moderately diverging posteriorly. Internal organ of reproductive system (Fig. 17A): vagina stout and abruptly thinned at ventroapical portion into a very short and stout tube, where diverticulum and spermathecal duct arising separately; diverticulum very short and spiral, evenly thin along the whole length; spermathecal duct very short; spermatheca provided with a spiral tube, progressively thinned apically and about twice longer than diverticulum; accessory gland extremely long, about five times longer than spermatheca. Abdominal sternite VIII (Fig. 18A) moderately narrowed posteriorly, widely triangular at latero-apical angles, and small-triangularly emarginate in middle of posterior margin. Etymology. The specific name is derived from the Latin niger (black) and color (colour), referring to its black body colouration. Distribution (Fig. 41). China (Sichuan, Chongqing, Guizhou).