Sialis kouwenkaii Tu & Zheng & Liu 2023, sp. nov.
Creators: name: Tu, Yuezheng
name: Zheng, Yuchen
name: Liu, Xingyue
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Megaloptera
Sialidae
Sialis
Sialis kouwenkaii

description: Sialis kouwenkaii sp. nov.
(Figs. 1, 2, 6)
Diagnosis. Head entirely black; male compound eyes prominent; forewing with RP 4-branched; male sternum 9 broadly lingulate, slightly longer than wide, almost as long as tergum 9 plus ectoprocts, distinctly elevated laterally, forming a V-shaped incision posteriorly in ventral view; gonocoxite 9 with ventral portion medially produced; fused gonocoxites 11 proximally with a pair of narrow pterygoid lobes, distally with a pair of digitiform processes (= gonostyli 11), each of which bears a broad semicircular ventral lobe and is hook-like at tip.
Description. Male. Body length 10.0 mm; forewing length 12.0 mm, hindwing length 10.0 mm.
Head entirely black, immaculate. Vertex medially with a pair of longitudinal raised scars. Compound eyes black, moderately prominent. Antennae black, with black setae. Mouthparts black.
Thorax black. Legs black, with dense blackish setae. Wings dark blackish brown. Forewing nearly three times as long as wide; costal area with 11 crossveins; sc-r present; 3 or 4 crossveins between RA and RP; RP 4-branched; MA bifurcate; MP proximally fused with CuA, distally separated into a simple anterior branch and a bifurcate posterior branch; CuA bifurcate; CuP simple; 1A and 3A simple; 2A bifurcate. Hind wing slightly shorter than forewing; costal area with 9 crossveins; 3 crossveins between RA and RP; RP 3 or 4-branched; MA bifurcate; both MP1 and MP2 bifurcate; CuA bifurcate; CuP simple; 1A, 2A and 3A simple (Fig. 1).
Abdomen black. Tergum 9 subtrapezoid with slightly arcuate lateral margins, anterior and posterior margins with shallow trapezoid incision (Fig. 2A). Sternum 9 broadly lingulate, nearly as long as wide, almost as long as tergum 9 plus ectoprocts, distinctly elevated laterally, forming a V-shaped incision posteriorly in ventral view (Figs. 2B, C). Gonocoxites 9 broad, in lateral view subtrapezoid, slightly prominent posteroventrad, in caudal view distinctly produced medially on ventral portion (Figs. 2D, E). Ectoprocts short, fused as a ring around anus. Fused gonocoxites 11 proximally with a pair of narrow pterygoid lobes, distally with a pair of digitiform processes (= gonostyli 11), each of which bears a broad semicircular ventral lobe and is hook-like at tip (Fig. 2E).
Female. Body length 11.0 mm; forewing length 13.0 mm, hindwing length 12.0 mm. Similar to male in general appearance. Sternum 7 subquadrate in ventral view, slightly longer than wide. Fused gonocoxites 8 broad in ventral view, nearly twice as wide as long. Gonapophyses 8 present as a subtrapezoid membranous lobe with anterior corners produced as a pair of tongue-shaped lobes (Fig. 2F).
Type material. Holotype J, China, Zhejiang, Hangzhou, Lin-an, Mt. Western Tianmu [Wƙϐψ], Xianrending [ŇKffl], [30°20’N, 119°25’E], 1480 m, 11.vi.2022, Wenkai Kou (CAU). Paratype 1♀, China, Zhejiang, Hangzhou, Lin-an, Mt. Western Tianmu, [30°20’N, 119°26’E], 1100 m, 12–16.vi.2011, Meicai Wei & Gengyun Niu (CAU).
Etymology. The new species is dedicated to Mr. Wenkai Kou [ĖẊffi], who collected the male specimen of this new species.
Distribution. China (Zhejiang).
Remarks. The new species appears to be similar to S. australis Liu, Hayashi & Yang, 2015, S. jiyuni Liu, Hayashi & Yang, 2015, S. jezoensis Okamoto, 1910, S. kumejimae Okamoto, 1910, and S. kuwayamai (Hayashi & Suda, 1995) by having the diagnostic characters of the formerly recognized Nipponosialis, now considered a junior synonym of Sialis (Liu et al. 2015a). The new species is similar to other related species by external appearance, however it may be distinguished from others by the broadly lingulate male sternum 9 with elevated lateral edges, the male gonocoxites 9 with ventral portion produced medially, and the shape of the male gonoxoxites and gonostyli 11 (Figs. 2B, C, D). In S. australis, S. jiyuni, S. jezoensis, S. kumejimae, and S. kuwayamai, the male sternums 9 are short, nearly semicircular (in S. jezoensis and S. jiyuni, Figs. 3B, C), or subquadrilateral with shallow to deep incisions on the posterior margins (in S. australis, S. kumejimae and S. kuwayamai, Figs. 3A, D, E); the male gonocoxites 9 have ventral portion not produced medially (Figs. 3, 5); the male gonocoxites and gonostyli 11 are also different from the new species (Figs. 3–5).
description: Published as part of Tu, Yuezheng, Zheng, Yuchen & Liu, Xingyue, 2023, A new species of the alderfly genus Sialis Latreille, 1802 (Megaloptera: Sialidae) from southeastern China, pp. 83-90 in Zootaxa 5343 (1) on pages 84-87, DOI: 10.11646/zootaxa.5343.1.5, http://zenodo.org/record/8324403