Stenothemus flavus Y. Yang & X. Yang, 2021

Yang, Yuxia, Ge, Shujuan, Yang, Xingke & Liu, Haoyu, 2021, Review of the species of Stenothemus from Southeast China (Coleoptera, Cantharidae), European Journal of Taxonomy 744, pp. 119-144 : 135-136

Stenothemus flavus Y. Yang & X. Yang sp. nov.

urn:lsid:zoobank.org:act:0F33A6EA-1C0A-4528-8A44-CF59FC42EF73

Figs 2B , 4D‒F , 7A , 8E

Differential diagnosis

The new species is related to S. melleus Švihla, 2005 (located in Sichuan, China), but can be distinguished by its larger body (no more than 9.0 mm length in the latter); femur orange, darkened only at base (in the latter, darkened at least at apical third part); aedeagus: middle emargination between dorsal plates deep, nearly as long as half its length (shallow in the latter, much shorter than half length).

Etymology

The specific name is derived from the Latin ‘ flavus ‘, meaning ‘golden-yellow’ and referring to its body coloration.

Material examined

Holotype CHINA • ♂; Zhejiang, Xitianmushan, Xianrending ; 1500 m a.s.l.; 30 May 1998; H. Wu leg.; IZAS IOZ(E)1123159 .

Paratypes CHINA – Zhejiang • 1 ♂; Anji, Longwangshan ; 490 m a.s.l.; 17 Jul. 1995; H. Wu leg.; IZAS IOZ(E)1659904 • 1 ♀; same locality and collector as for preceding; 770 m a.s.l.; 19 Oct. 1995; IZAS IOZ(E)1659887 • 1 ♂; same locality and collector as for preceding; 21 Oct. 1995; IZAS IOZ(E)1659896 • 1 ♂; Xitianmushan ; 500 m a.s.l.; 21 Jul. 1998; M.S. Zhao leg.; IZAS IOZ(E)225767 • 1 ♂; Xitianmushan, Chanyuansi ; 380 m a.s.l.; 13 Nov. 1998; H. Wu leg.; IZAS IOZ(E)215768 • 1 ♀; same collection data as for preceding; IZAS IOZ(E)215769 • 1 ♂; Tianmushan ; 12 Nov. 1998; M.S. Zhao leg.; IZAS IOZ(E)215770 • 1 ♂; Tianmushan ; 24 Nov. 1998; C.L. Ma leg.; IZAS IOZ(E)215771 • 1 ♂; Qingyuan, Baishanzu ; 1500 m a.s.l.; 23 Oct. 1993; H. Wu leg.; IZAS IOZ(E)215772 .

Description

MEASUREMENTS. Body length (both sexes): 9.0‒14.0 mm (12.0 mm in holotype); width: 2.5‒3.0 mm (2.8 mm in holotype).

Male ( Fig. 2B )

COLORATION. Body yellow, head and prothorax testaceous, pronotum orange at anterior angles, mouthparts, antennae, tarsi, tibiae and bases of femora black brown. Body densely mixed with short recumbent and slightly longer semi-erect light yellow pubescence.

HEAD. Subquadrate, surface sparsely and finely punctate, each side with smooth and rectangular impression behind antennal socket; eyes strongly protruding, head width across eyes 1.2 times as wide as pronotum; terminal maxillary palpomeres long-triangular, widest at basal third; antennae filiform, extending to two-thirds length of elytra, antennomere II about 2.3 times as long as wide at apices, III about 1.7 times as long as II, IV longest, XI slightly longer than X, pointed at apex.

PRONOTUM. Subquadrate, about 1.1 times as long as wide, anterior margin nearly straight, anterior angles roundly truncate, lateral margins slightly sinuate, posterior margin slightly sinuate, posterior angles moderately sharp and protruding, disc strongly convex on posterolateral parts, surface finely and densely punctate.

ELYTRA. Moderately dilated posteriorly, about 3.6 times as long as humeral width, 5.1 times as long as pronotum, surface densely and finely punctate, with hardly indicated longitudinal costae.

AEDEAGUS ( Fig. 4D‒F ). Strongly swollen dorsally at basal part, nearly parallel-sided in apical part; basal piece nearly as long as dorsal plate of each paramere, with a large, bifurcate conjoint middle nodule at base of ventral side; ventral processes of parameres nearly parallel to each other, short and slightly narrowed apically, bent dorsally in lateral view; dorsal plate slightly longer than ventral process, abruptly narrowed in middle, near to each other at basal part, acute at apex and folded ventrally; apical part of laterophyses depressed and separate from one another, apex acute and not reaching middle emargination between dorsal plates.

Female

Similar to male, but stouter, eyes less protruding; antennae shorter, reaching elytral mid-length, pronotum wider, nearly as wide as long.

ABDOMINAL STERNITE VIII ( Fig. 8E ). Moderately narrowed posteriorly, latero-apical angles widely rounded, posterior margin widely and rectangularly emarginate in middle and truncate on both sides, behind notch with membrane which sclerotised and triangularly bilobed at apex and present with traverse-triangular sclerite at center and small rounded sclerite on each side.

INTERNAL ORGAN OF REPRODUCTIVE SYSTEM ( Fig. 7A ). Vagina stout, with median oviduct situated at ventroapical part, diverticulum and spermathecal duct arising from apex; diverticulum moderately long, about 0.16 times body length, evenly thinned apically, slender tube-shaped and spiral; spermathecal duct longer than diverticulum; spermatheca slender tube-shaped and spiral, obviously thinner than spermathecal duct and much longer than diverticulum, with basal part extended into short tube, where accessory gland opening. Accessory gland thin and much shorter than spermatheca.

Distribution

China (Zhejiang).

Figures

Fig. 2. Male habitus, dorsal view. A. Stenothemus biimpressiceps (Pic, 1930) comb. nov., nontype specimen from Zhejiang (IZAS). B. S. flavus Y. Yang & X. Yang sp. nov., holotype, ♂ (IZAS, IOZ(E)1123159). C. S. limbatipennis (Pic, 1926) stat. rev. et comb. nov., non-type specimen from Zhejiang (MHBU). D. S. longicornis Y. Yang & H. Liu sp. nov., holotype, ♂ (MHBU, HBU(E)410001). Scale bars: 1.0 mm.

Fig. 4. Aedeagus (A, D, G = ventral view; B, E, H = dorsal view; C, F, I = lateral view). A‒C. Stenothemus nigriceps (Wittmer, 1955) comb. nov. (MHBU). D‒F. S. flavus Y. Yang & X. Yang sp. nov. (IZAS, IOZ(E)1123159). G‒I. S. longicornis Y. Yang & H. Liu sp. nov. (MHBU, HBU(E)410001). Scale bars: 1.0 mm.

Fig. 7. Female internal reproductive system, lateral view. A. Stenothemus flavus Y. Yang & X. Yang sp. nov. (IZAS, IOZ(E)1659887). B. S. fukienensis Wittmer, 1974 (IZAS). C. S. chinensis (Wittmer, 1982) comb. nov. (MHBU). Scale bars: 0.5 mm.

Fig. 8. Female abdominal sternite VIII, ventral view. A. Stenothemus biimpressiceps (Pic, 1930) comb. nov. (IZAS, IOZ(E)1435863). B. S. pallicolor (Wittmer, 1951) comb. nov. (SYSU, En-076948). C. S. limbatipennis (Pic, 1926) stat. rev. et comb. nov. (MHBU). D. S. nigriceps (Wittmer, 1955) comb. nov. (MHBU). E. S. flavus Y. Yang & X. Yang sp. nov. (IZAS, IOZ(E)1659887). F. S. fukienensis Wittmer, 1974 (IZAS). G. S. chinensis (Wittmer, 1982) comb. nov. (MHBU). Scale bars: 1.0 mm.