Siphlonurus zhelochovtsevi Tshernova, 1952 (first record from China)

Figures 27–28

Siphlonurus zhelochovtsevi Tshernova, 1952: 263 (male imago, from Russia).

Siphlonurus zhelochovtsevi: Kluge 1985: 15 (all stages); Soldán et al. 2009: 655 (checklist).

Material examined: 10 nymphs, 60 ♀ imagos, 5♂ imagos, 1♀ subimago, 1♂ subimago, Erdao Baihe Town, Fusong County, Jilin Province, 23–25.VII.2008, Shilei Wang and Guo Zhao; 2♀ imagos, Hunhe River, Fushun City, Liaoning Province, 41.28444348°N, 124.99140257°E, ca. 490 m, 29.VII.2023, Xinhe Qiang; 2 nymphs, 1♂ subimago, Laocaohe, Mohe City, Daxinganling District, Heilongjiang Province, 52.833392°N, 122.591656°E, ca. 480 m, 16–19.VII.2024, Xinhe Qiang, Ningning Wang, and Yuxian Sun; 1♀ imago, Dalin River, Mohe City, Daxinganling District, Heilongjiang Province, 52.968586°N, 122.269555°E, ca. 470 m, 16–19.VII.2024, Xinhe Qiang, Ningning Wang, and Yuxian Sun; 3♀ imagos, Genhe, Hexi Street, Genhe City, Hulunbuir City, Inner Mongolia, 50.796106°N, 121.578682°E, ca. 720 m, 19.VII.2024, Xinhe Qiang, Ningning Wang, and Yuxian Sun; 15 ♀ imagos, 2♂ imagos, Liujiazi, Gaoleng Town, Fangzheng County, Harbin City, Heilongjiang Province, 45.731443°N, 129.290088°E, ca. 330 m, 21–22.VII.2024, Dewen Gong and Xuhongyi Zheng.

Description: see Kluge (1985).

Distribution: China (Jilin Province); Russia, Mongolia.

Diagnosis

Mature nymph: Body length 14.0–15.0 mm, wingpads without spots (Figs 27A, B). Length ratio of first segment of maxillary palp to galea-lacinia about 1.0: 1.0, inner margin of maxillary palp segment II convex apically (Fig. 27C). Posterolateral spines on terga I–IX gradually larger from anterior to posterior, length ratio of posterolateral spine on tergum IX to its tergum = 1.0: 4.0 (Figs 27D, E). Each abdominal sternum with inverted U-shaped marking (Fig. 27B). Posterior margin of abdominal sternum IX slightly convex (Fig. 27E). Dorsal surface of tergum X with stout spine-like setae, lateral margins lack (Fig. 27F). Outer margins of dorsal and ventral lamellae of both gills I and II concave, costal rib of dorsal lamella in gill II shorter than half of anterior margin (Figs 27G, H). Outer and posterior margins of gill III concave, proximal plate of gill VII well developed (Figs 27I, J).

Male imago: Body length 14.0–17.0 mm, wings transparent. Forelegs entirely brown, midlegs and hindlegs entirely light brown (Figs 28A–C). Each abdominal sternum with inverted U-shaped marking, posterolateral spines of abdominal segments VIII and IX small (Figs 28D–G). Inner margin of basal segment of forceps with projection, length of penis subequal to styliger (Figs 28D, E). Dorsal elongation of penis arched and distinctly enlarged apically, outer margin with about 8 small spines, dorsal sclerotized transverse band of penis without expansion, two penis lobes distinctly sclerotized and separated, each tip distinctly bifurcated, ventral side with a translucent membranous projection, inner margin of each penis lobe with 6–9 small spines, outer margin concave in the middle (Figs 28H, I).

Female imago: Body length 14.0–16.0 mm, wings transparent. Color pattern similar to male (Fig. 28J). Sternum VII extended posteriorly into a triangular lobe. Sternum VIII dark laterally (Fig. 28K).

Remarks: S. zhelochovtsevi and S. chankae are very similar, but their male adults can be easily distinguished. In S. zhelochovtsevi, the apical portion of penis lobe elongation is expanded (Figs 28H, I), whereas in S. chankae, the basal portion is expanded (Figs 2H–J). However, nymphs of these two species are nearly identical and can only be differentiated by a subtle characteristic: inner margin of second segment of maxillary palp in S. zhelochovtsevi is convex apically (Fig. 27C), while in S. chankae, it is straight (Fig. 1C).