Rhagonycha (s.str.) falcata Y. Yang, Liu & X. Yang, 2024

Xiao, Yun-Feng, Liu, Hao-Yu, Yang, Xing-Ke & Yang, Yu-Xia, 2024, Taxonomic review of the Rhagonycha flava species group (Coleoptera, Cantharidae), with descriptions of fourteen new species from China, Zootaxa 5534 (1), pp. 1-69 : 28-32

publication ID	https://doi.org/ 10.11646/zootaxa.5534.1.1
publication LSID	lsid:zoobank.org:pub:C36ED8DA-FCF2-44FE-A38E-41112A1C0D6D
DOI	https://doi.org/10.5281/zenodo.14023626
persistent identifier	https://treatment.plazi.org/id/F9023D04-FFE1-FFDD-FF69-E58D3BEBE99F
treatment provided by	Plazi
scientific name	Rhagonycha (s.str.) falcata Y. Yang, Liu & X. Yang
status	sp. nov.

Treatment

Rhagonycha (s.str.) falcata Y. Yang, Liu & X. Yang , sp. nov.

( Figs 15C‒D View FIGURE 15 , 16D‒F View FIGURE 16 , 17B View FIGURE 17 , 18B View FIGURE 18 , 39 View FIGURE 39 )

Type material. HOLOTYPE: ♂ ( CAS), CHINA, Yunnan: Tengchong, Jietou, Datang , 25.74556° N, 98.69630° E, 2030 m, 15.Ⅴ.2006, leg. H.B. Liang. GoogleMaps PARATYPES: CHINA, Yunnan: 1♂, 2♀♀ ( CAS), Tengchong, Houqiao, Danzha, Zhaobitang, 25.55627° N, 98.20941° E, 29.Ⅴ.2006, leg. H.B. Liang GoogleMaps ; 1♂ ( MHBU), Malipo, Ganbazi, 7.VI.2015, leg. L.M. Li.

Differential diagnosis. It looks similar to Rh. spinosa in the appearance, but can be easily distinguished from the latter by the characteristic aedeagus: ventral process of each paramere processively thinned near apex, while expanded in Rh. spinosa ( Fig. 5D View FIGURE 5 ); conjoint dorsal plate of parameres with lateral margins each with a falcate prominence, and apical margin deeply emarginate in middle, while lateral margins without any prominence, apical margin hardly emarginate in Rh. spinosa ( Fig. 5E View FIGURE 5 ).

Description. Body length: 7.0‒ 8.5 mm (7.0 mm in holotype); width: 1.8‒2.2 mm (1.8 mm in holotype).

Male ( Fig. 15C View FIGURE 15 ). Coloration. Body black except for the following parts: head and pronotum uniformly yellowish orange, elytra pale yellow, almost transparent and feebly darkened at apices. 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 elytral apices when reclined, antennomeres II shortest, about 2.8 times as long as wide at apices, III about 1.9 times longer than II, VII 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 nearly parallel-sided, about 3.3 times as long as humeral width, 4.6 times longer than pronotum, surface finely rugulose-lacunose, almost lustrous at basal parts.

Aedeagus strongly swollen laterally near middle ( Fig. 16D, E View FIGURE 16 ); ventral processes of parameres abrutly thinned apically near bases, with apices narrowly rounded and strongly bent to each other in ventral view ( Fig. 16D View FIGURE 16 ), progressively narrowed apically and almost straight in lateral view ( Fig. 16D View FIGURE 16 ); conjoint dorsal plate of parameres obviously longer than ventral processes ( Fig. 16D, F View FIGURE 16 ), with apical margin roundly and deeply emarginate in middle, lateral margins distinctly diverging apically in dorsal view ( Fig. 16E View FIGURE 16 ), latero-apical angles acute, inclined ventrally in lateral view, each side with a falcate prominence in middle of lateral margin ( Fig. 16E, F View FIGURE 16 ); emargination between conjoint dorsal plate and ventral process about 2/5 length of aedeagus ( Fig. 16F View FIGURE 16 ).

Female ( Fig. 15D View FIGURE 15 ). Similar to male, but with larger and stouter body, eyes less protruding, head width across eyes about as wide as anterior margin of pronotum, antennae thinner and shorter, extending to apical third length of elytra when reclined, pronotum wider and about 1.2 times as wide as long, disc feebly convex on posterolateral parts, elytra about 3.1 times as long as humeral width.

Internal organ of reproductive system ( Fig. 17B View FIGURE 17 ): vagina stout and abruptly thinned at ventroapical portion into a long and thin tube, where diverticulum and spermathecal duct arising separately; diverticulum long and spiral, almost evenly thin along the whole length; spermathecal duct very short and about 1/8 length of apical tube of vagina; spermatheca provided with a spiral tube, progressively thinned apically and nearly as long as diverticulum; accessory gland extremely long, almost three times as long as spermatheca.

Abdominal sternite VIII ( Fig. 18B View FIGURE 18 ) moderately narrowed posteriorly, widely triangular at latero-apical angles, and widely and trapezodinally protuberant in middle of posterior margin.

Etymology. The specific name is derived from the Latin falcatus (hooked), referring to its conjoint dorsal plate each side with a falcate prominence.

Distribution ( Fig. 39 View FIGURE 39 ). China (Yunnan).