Zaitzevia coronifer, Bian & Jäch, 2025

Bian, Dong-Ju & Jäch, Manfred A., 2025, The species of the genus Zaitzevia Champion, 1923 (Coleoptera, Elmidae) from Shaanxi Province, China, ZooKeys 1264, pp. 129-157 : 129-157

Zaitzevia coronifer sp. nov.

Figs 2 C, D , 7 A – C , 11 D – F

Material examined.

(117 exs) Holotype: China • ♂ ( IAECAS): “ China – Shaanxi \ Zhouzhi County l. w [leg. Wang] | Houzhenzi Ca 1200 m \ 2. VI 1998 ” [ CWBS 308 ] . Paratypes: China, Shaanxi • 5 ♀♀ ( IAECAS), the same data as holotype • 35 exs ( NMW): “ China: Shaanxi, 2. 6. 1998 \ Zhouzhi County, ca. 1200 m \ 2 km W Houzhenzi Nat. Res. \ leg. M. Wang ( CWBS 308 ) ” • 2 ♂♂, 3 ♀♀ ( IAECAS): “ China: Shaanxi, Ankang City, \ Ningshan County, Xunyang Dam | 33°33.473′N, 108°32.808′E, \ 1355 m, 2019.8. 20 \ Leg. Tong Y. F ” • 1 ♂, 1 ex. ( IAECAS): “ China-Shaanxi \ Mei County L [leg.]. W [ Wang] | Tangyu ca. 1100 m \ 1. VI. 1998 ” [ CWBS 307 ] • 1 ♂ ( NMW): “ China: Shaanxi, 4. 6. 1998 \ Foping County, ca. 1 300 m \ 5 km S Longcaoping \ leg. Wang ( CWBS 312 ) ” • 2 ♂♂, 8 ♀♀ ( IAECAS): “ China-Shaanxi \ Ningshan L. [leg.] W [ Wang] | Xunyangba ca. 1500 m \ 6. VI. 1998 ” [ CWBS 315 ] • 40 exs ( NMW): “ China: Shaanxi, 6. 6. 1998 \ Ningshan Co., ca. 1 500 m \ 10 km NE Xunyangba \ leg. M. Wang ( CWBS 315 ) ” • 1 ♂, 1 ♀ ( NMW): “ China: Shaanxi, 8. 6. 1998 \ 2 km SE Liuba, 1 400 m \ ( Zhangliangmiao ) \ leg. M. Wang ( CWBS 317 ) ” • 22 exs ( CBC, NMW): “ China, 17. – 22. VI. \ Shaanxi prov. 1991 \ Hua Shan peak env. \ 100 km E of Xi’an \ Z. Kejval lgt. ” ; Hubei • 3 exs ( NMW): “ China: Hubei, 13. 10. 2004 \ Shennongjia Forest Distr. \ 5 km E Muyu , Tong Mu \ 1 250 m, leg. Schönmann \ & Wang ( CWBS 531 ) ” • 2 ♂♂, 4 ♀♀ ( IAECAS): “ China: Hubei \ Shennongjia For. Dist. | 1600 m, 2004.10. 15 \ Leg. Wang ( CWBS 536 ) ” .

Differential diagnosis.

In Shaanxi, this species is similar to Z. pilosa sp. nov. in body size ( BL 2.3–2.7 mm) and habitus, but it can be easily distinguished from the latter by the less pronounced dorsal pilosity, the granules on the elytral interval 5 not reaching the elytral base and by the glabrous shoulders; the aedeagus differs mainly in the more strongly produced apex and the absence of endophallic teeth.

Zaitzevia coronifer also resembles Z. tangliangi , but it can be easily distinguished from the latter, e. g., by the stronger pronotal punctation, more distinct sublateral pronotal carinae, stronger tibiae (especially foretibiae), and by the clearly different aedeagus, being less elongate, apically more acuminate, with characteristic endophallic sclerotizations.

The new species is externally also somewhat similar to Z. tsushimana , which is, however, markedly smaller ( BL 1.8–2.2 mm), with its median pronotal groove more or less reaching the pronotal base, and its elytral carinae being located on intervals 5–7 (see Jung et al. 2015; Iwata et al. 2022: fig. 3 G).

Description.

Male ( holotype). Body broadly obovate. BL 2.6 mm, BW 1.2 mm. Antennae yellowish brown, dorsum black, ventral side brown to black, legs reddish brown to dark brown except tarsi light brown.

Labrum microreticulate in basal 0.1, distal 0.9 smooth and shiny, sparsely punctate and pubescent. Anterior margin broadly rounded, not emarginate, densely pubescent laterally. Clypeus coarse, densely pubescent, sparsely granulate. Frons densely pubescent, with a few small granules near inner sides of eyes.

Pronotum ( PL 0.7 mm, PW 0.9 mm) broadest at base, gradually narrowing anteriad. Lateral margin slightly rimmed. Anterior corners acute, slightly produced, posterior corners right-angled. Disc smooth and shiny, densely punctate, and sparsely pubescent. Area near anterior and posterior corners and in front of scutellum coarse, finely granulate. Median sulcus reaching from basal 0.2–0.5, narrow, not broadened medially. Sublateral carinae extending from base to basal 0.4, slightly raised.

Elytra ( EL 1.9 mm, EW 1.2 mm) broadest at distal 0.33, slightly narrowed anteriorly and distinctly attenuate posteriorly. Strial punctures moderately large, especially in the middle area, separated by ~ 0.5–1.0 × their diameters, becoming smaller and shallower towards declivity, separated by 2–3 × their diameters. Intervals flat, more or less smooth and glabrous, hardly punctate, and hardly pubescent. Intervals 5, 7 and 8 carinate; carinae on interval 5 extending from basal 0.2 to apex; carinae on intervals 7 and 8 extending from basal 0.1 to apex. Elytral apices densely granulate, separately rounded (in posterior view).

Prosternum laterally densely pubescent; prosternal process gradually narrowed from base to distal 0.2, distinctly narrowed in distal 0.2, apex narrowly rounded, lateral margin distinctly rimmed; disc coarse with some large granules, sparsely punctate. Disc of metaventrite broadly and distinctly impressed, smooth and shiny, with a few very small punctures and large granules; with a row of large punctures behind of mesocoxa and another row of small punctures in front of metacoxa; median sulcus complete, gradually narrowing anteriad; lateral margin of disc in the median part (between meso- and metacoxae) with a large hump covered with a few distinct granules; lateral areas densely pubescent and sparsely granulate.

Ventrite I moderately densely punctate, with a pair of admedian carinae; disc more or less impressed, anterior margin raised. Middle of ventrites II – IV smooth and shiny, sparsely and finely punctate. Lateral areas of ventrites I – V densely pubescent. Ventrite V densely pubescent and sparsely granulate; lateral margins V fringed with short spines; apical margin weakly emarginate medially; lateral corners not forming distinct teeth.

Protibiae slightly enlarged.

Aedeagus. 1.2 mm long, elongate, cylindrical. Penis ~ 1.9 × as long as phallobase, gradually broadened in basal 0.33, then almost subparallel to basal 0.67, distinctly acuminate in distal 0.33, apex acute. Endophallus with characteristic sclerotizations resembling a crown. Parameres very slim, reaching apical 0.2 of penis.

Females. Metaventrite not distinctly impressed; pair of humps between meso- and metacoxae smaller, without granules. Disc of ventrite I glabrous, very sparsely punctate, partly and faintly microreticulate, concave in posterior 0.5. Apex of ventrite V straight or weakly rounded, not emarginate. Protibiae not enlarged.

Measurements.

Males: BL 2.50–2.65 mm ( n = 10), BW 1.1–1.2 mm ( n = 6); females: BL 2.3–2.7 mm ( n = 10), BW 1.1–1.2 mm ( n = 5).

Distribution.

Hubei, Shaanxi.

Etymology.

The epithet is derived from the Latin noun coronifer (carrier of a crown) and refers to the crown-like sclerotizations of the endophallus.

Figures

Figure 2. Habitus. A, B. Zaitzevia pilosa sp. nov.; holotype, male; C, D. Z. coronifer sp. nov., holotype, male; A, C. Dorsal view; B, D. Ventral view.

Figure 7. Zaitzevia coronifer sp. nov., holotype, male; A. Pronotum; B. Prosternum; C. Metaventrite and abdominal ventrites.

Figure 11. Aedeagus. A – C. Zaitzevia pilosa sp. nov., holotype, male; D – F. Z. coronifer sp. nov., holotype, male; A, D. Ventral view; B, E. Dorsal view; C, F. Lateral view.