Sialis kouwenkaii, Tu & Zheng & Liu, 2023

Tu, Yuezheng, Zheng, Yuchen & Liu, Xingyue, 2023, A new species of the alderfly genus Sialis Latreille, 1802 (Megaloptera: Sialidae) from southeastern China, Zootaxa 5343 (1), pp. 83-90 : 84-87

publication ID	https://doi.org/ 10.11646/zootaxa.5343.1.5
publication LSID	lsid:zoobank.org:pub:8379B120-3178-4321-963F-EC50AE1BA283
DOI	https://doi.org/10.5281/zenodo.8324651
persistent identifier	https://treatment.plazi.org/id/2D3C87B2-C438-642C-FF1C-FCF0FD4CF92A
treatment provided by	Plazi
scientific name	Sialis kouwenkaii
status	sp. nov.

Treatment

Sialis kouwenkaii sp. nov.

( Figs. 1 View FIGURE 1 , 2 View FIGURE 2 , 6 View FIGURE 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 View FIGURE 1 ).

Abdomen black. Tergum 9 subtrapezoid with slightly arcuate lateral margins, anterior and posterior margins with shallow trapezoid incision ( Fig. 2A View FIGURE 2 ). 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 View FIGURE 2 ). Gonocoxites 9 broad, in lateral view subtrapezoid, slightly prominent posteroventrad, in caudal view distinctly produced medially on ventral portion ( Figs. 2D, E View FIGURE 2 ). 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 View FIGURE 2 ).

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 View FIGURE 2 ).

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) GoogleMaps . 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) GoogleMaps .

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 View FIGURE 2 ). 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 View FIGURE 3 ), or subquadrilateral with shallow to deep incisions on the posterior margins (in S. australis , S. kumejimae and S. kuwayamai , Figs. 3A, D, E View FIGURE 3 ); the male gonocoxites 9 have ventral portion not produced medially ( Figs. 3 View FIGURE 3 , 5 View FIGURE 5 ); the male gonocoxites and gonostyli 11 are also different from the new species ( Figs. 3–5 View FIGURE 3 View FIGURE 4 View FIGURE 5 ).