Zaitzevia triangularis, Peng & Bian & Wang, 2024

Peng, Yun-Fei, Bian, Dong-Ju & Wang, Ju-Ping, 2024, Heterlimnius luyashanensis sp. n. and Zaitzevia triangularis sp. n. from Shanxi Province, China (Coleoptera: Elmidae), Zootaxa 5403 (4), pp. 488-494 : 491-493

Zaitzevia triangularis sp. n.

( Figs. 3 A–D ; 4 A–C )

Type material: holotype, male ( IAECAS): “ CHINA: Shanxi / Xinzhou City / Luya Mountains | 112.178611°E 38.735556°N / ca. 1550 m, VIII. 14. 2021 / Leg. Peng.” Paratypes: 1 female ( IAECAS), the same data as holotype. 1 male, 1 female ( IAECAS): “ CHINA: Shanxi / Xinzhou City / Luya Mountains | 111.875278°E 38.693611°N, 1920 m / VIII. 13. 2021 / Leg. Peng”; 5 males, 3 females ( SIH): same label data as last one, but VI. 15. 2020; 3 males, 2 females ( IAECAS): “ CHINA: Shanxi / Xinzhou City / Luya Mountains | 111.885272°E 38.729431°N / VIII. 13.2021 / Leg. Peng” .

Diagnosis. In the genus Zaitzevia , the new species has the similar size with the five known species: Zaitzevia chenzhitengi Jiang & Wang, 2020 , Z. muchenae Bian & Zhang, 2022 , Z. rufa Nomura & Baba, 1961 , Z. xiongzichuni Jiang & Wang, 2020 and Z. sichuanensis Jiang & Chen, 2023 ; it is distinctly smaller than Z. fengtongzhaiensis Jiang & Chen, 2023 and larger than other species in Zaitzevia . This species can be easily distinguished from Z. chengzhitengi by its median longitudinal sulcus wide, apex of penis sub-triangular, not like an arrow as in Z. chenzhitengi ; from Z. muchenae by distal third of elytra distinctly attenuated, not gradually attenuated as in Z. muchenae and also by distal 0.4 of penis distinctly narrowed, not distal 0.1 of penis distinctly narrowed as in Z. muchenae ; from Z. rufa by its body colour dark brown, median longitudinal sulcus of pronotum wide and distinctly impressed, distal 0.4 of penis distinctly narrowed, but in Z. rufa , body colour reddish brown, middle sulcus shallowly impressed, and distal 0.4 of penis gradually narrowed; from Z. xiongzichuni by its median longitudinal sulcus of pronotum broad in middle, apices of elytra distinctly separated rounded, apex of penis sub-triangular, but in Z. xiongzhichuni , median longitudinal sulcus narrow, not broad in middle, apices of elytra almost connected, and apex of penis is cuspidal; from Z. sichuanensis by basal 1/3 disc of pronotum and elytral intervals coarse, distal 0.4 of penis distinctly narrowed, while in Z. sichuanensis , surface of pronotum and elytral intervals smooth and shiny, subapical part of penis distinctly inflated and apex of penis arrowhead-like.

Description. BL 3.0 mm, EW 1.2 mm (holotype). Habitus see fig. 3A–B. Head and pronotum black, elytra, femora, tibiae and ventral surface brown. Tarsi light brown. Antennae yellowish brown. Labrum wider than long; surface smooth and shiny, densely pubescent; lateral margin with long yellowish fringe. Clypeus and frons densely granulate and pubescent.

Pronotum (fig. 3C) broadest at basal 0.4, distinctly attenuated anteriorly and slightly attenuated posteriorly. PL 0.8 mm, PW 0.9 mm. Disc of basal third coarse, and base with some granules medially. Disc of distal 2/3 smooth and shiny, punctures moderately dense. Lateral areas coarse, densely granulate. Median longitudinal sulcus is present from basal 0.2 to 0.7, or even shorter, broadest at middle, then gradually narrowed anteriorly and posteriorly. Sublateral carinae present in basal 0.4, subparallel in 0.3, then bend outwards. Anterior angles sharp, slightly produced, and posterior angles almost right-angled. Anterior half of lateral margin serrate.

Elytra broadest at basal 2/3, slightly attenuated anteriorly and distinctly attenuated posteriorly. Strial punctures small and deeply impressed. Intervals slightly convex, rugose. Intervals 1, 3, 5 with a row of longitudinal pubescence. Intervals 5, 7, 8 carinate.

Prosternal process (fig. 3D) elongated and slim, gradually narrowed from base to apex; lateral margin distinctly rimmed; apex broadly rounded; surface coarsely granulated. Disc of metaventrite (fig. 3D) broadly impressed, smooth and shiny, with some sparse punctures; median groove present in posterior 0.8; lateral area densely pubescent and sparsely granulate.

Disc of ventrite I coarse, sparsely granulate, and disc of ventrite II densely punctate and sparsely granulate. Disc of ventrites III to IV, and basal 1/3 of ventrite V sparsely punctate and granulate. Lateral areas of ventrites I to IV densely pubescent and sparsely granulate. Distal 2/3 of ventrite V densely granulate and sparsely pubescent.

Aedeagus (figs. 4A–C). 1.4 mm long. Penis about 2.4 times as long as phallobase, subparallel in basal 0.6, distinctly narrowed in distal 0.4, with a pair of developed teeth at distal 0.25. Endophallus simple. Parameres completely fused to penis; apices of parameres reach basal 0.6 of penis.

Males: BL 2.9–3.2 mm, EW 1.2–1.3 mm (n=13). Apices of elytra separately rounded.

Females: BL 3.0– 3.2 mm, EW 1.2–1.3 mm (n=4). Apices of elytra separately sharpened.

Distribution. China: Shanxi.

Etymology. The epithet is derived from the Latin adjective “triangularis ” = triangular, refers to the apex’s shape of penis.

Figures

FIGURE 3. Zaitzevia triangularis sp. n. A. Habitus, holotype, male, in dorsal view. B. Habitus, in ventral view C. Pronotum D. Prosternal process and metaventrite.

FIGURE 4. Aedeagus, holotype, male, Zaitzevia triangularis sp. n. A. in ventral view B. in dorsal view C in lateral view.