Stenothemus parameratus Y. Yang et S. Ge, 2021

Ge, Shujuan, Yang, Xingke, Liu, Haoyu & Yang, Yuxia, 2021, Definitions of two species groups of Stenothemus Bourgeois (Coleoptera, Cantharidae), with descriptions of three new species from China, Zootaxa 5047 (2), pp. 139-152 : 143-148

publication ID	https://doi.org/ 10.11646/zootaxa.5047.2.3
publication LSID	lsid:zoobank.org:pub:0C398339-EF37-45C2-AA8C-3BDAF601E2AB
DOI	https://doi.org/10.5281/zenodo.5540666
persistent identifier	https://treatment.plazi.org/id/03F9A67D-FF99-FFE2-FF0C-59E9FDF7499A
treatment provided by	Plazi
scientific name	Stenothemus parameratus Y. Yang et S. Ge
status	sp. nov.

Treatment

Stenothemus parameratus Y. Yang et S. Ge , sp. nov.

Figs 2B View FIGURE 2 , 3D‒F View FIGURE 3 , 4C‒D View FIGURE 4

Type material. Holotype ♂ ( MHBU, HBU (E) 410054), China, Yunnan, Dehong, the Dai and Jingpo nationality Autonomous Prefecture , Yingjiang , Tongbiguan Natural Reserve , 10.VIII.2016, D.X. Zhang & J.J. Ye leg. Paratype: 1♀ ( MHBU, HBU (E) 410055), China, Yunnan, Gongshan, Dulongjiang , 14.VIII.2018; K. Sun & Z.P. Li leg.

Description. Body length (both sexes): 10.8‒12.0 mm (12.0 mm in holotype); width: 2.9‒3.0 mm (3.0 mm in holotype).

Male ( Fig. 2B View FIGURE 2 ). Coloration. Body yellow, head pitch black on dorsum, antennae black, yellow at apex of each antennomere, pronotum mostly pitch black, yellowish brown at margins and anterior angles, elytra pitch black, legs mostly black, yellow at coxae, trochanters and basal two-thirds parts of femora. Body densely covered with short, semi-recumbent pale-yellow pubescence, sparsely on pronotum.

Head. Surface densely punctate, each side with a smooth and rectangular impression behind antennal socket; eyes large, strongly protruding, head width across eyes 0.9 × as wide as anterior margin of pronotum; terminal maxillary palpomeres long-triangular, widest at basal one-third; antennae filiform, extending to two-thirds length of elytra, antennomeres II 1.7 × as long as wide at apices, III 1.8 × longer than II, V‒XI each with a small and smooth oval impression in the middle of inner edge, IV longest, XI longer than X, pointed at apex.

Pronotum 1.25 × as wide as long, anterior margin rounded, lateral margins sinuate and converging posteriorly, posterior margin bisinuate and narrowly bordered, anterior angles widely rounded, posterior angles sharp and protruding, disc strongly convex on postero-lateral parts, surface sparsely punctate.

Elytra 3.0 × as long as humeral width, 4.5 × as long as pronotum, lateral margins moderately diverging posteriorly, surface densely punctate, longitudinal costae weakly visible.

Male genitalia ( Figs 3D‒F View FIGURE 3 ). Moderately swollen laterally at basal part in ventral view; basal piece 0.8 × as long as dorsal plates, with a large, bifurcate conjoined middle nodule at the base of ventral side; ventral processes of parameres obliquely diverging apically in ventral view, thickened apically, bent dorsally in lateral view; dorsal plates nearly as long as ventral processes, evenly narrowed apically, subrounded at outer apical angles, shallowly and roundly emarginate at inner margins in dorsal view, each present with a longitudinal ridge in lateral view, which extending from apical outer angle; laterophyses parallel to dorsal plates, conjoined and expanded apically, divided and obtusely hooked at apices, obviously exceeding over middle emarginate area between dorsal plates in dorsal view.

Female. Similar to male, but eyes smaller and less protruding, antennae shorter and roughly extending to elytral mid-length, V‒XI without impressions; the lateral margins of pronotum feebly converging posteriorly, elytra 2.8 × as long as humeral width.

Internal organ of reproductive system ( Fig. 4C View FIGURE 4 ). Vagina stout and abruptly narrowed apically and extended into a thick tube where diverticulum and spermathecal duct arising from; diverticulum moderately long, 0.4 × adult body length, evenly thinned apically, slender tube-shaped and spiral; spermathecal duct short and stout, 0.2 × as long as diverticulum; spermatheca slender tube-shaped and spiral, much thinner than spermathecal duct and 1.2 × longer than diverticulum, with basal part extended into a short and stout tube, at opening of accessory gland; accessory gland thin, 0.8 × as long as spermatheca.

Abdominal sternite VIII ( Fig. 4D View FIGURE 4 ). Obliquely narrowed posteriorly, latero-apical angles widely rounded, posterior margin shallowly and triangularly emarginate in the middle, behind the notch with a small and round weakly sclerotized lobe.

Diagnosis. Although the new species resembles those of S. laterophysus species-group in the appearance, but the male genitalia is in different shape as described in the above definition part. Within S. notaticollis species-group, S. parameratus sp. nov. seems more similar to S. bourgeoisi in the male genitalia, but it can be easily distinguished from the latter by the following characters: body is yellow, pronotum and elytra are mostly pitch black, elytral costae are hardly visible; in male genitalia, ventral processes are thick and feebly widened at apices, dorsal plates are evenly narrowed apically. By contrast, in S. bourgeoisi ( Fig. 1B View FIGURE 1 ), body is brown, pronotum is pale-yellow, with dark brown markings on the disc, elytra are black brown, elytral costae are weakly visible; in male genitalia ( Wittmer, 1974: fig. 3; Švihla, 2011: figs 108‒109), ventral processes flattened and obviously widened at apices, dorsal plates are abruptly narrowed in the middle.

Etymology. The specific name is derived from the Latin paramere (lateral lobe), referring to its characteristic parameres of male genitalia.

Distribution. China (Yunnan).