Helius (Helius) pallidissimus Alexander, 1930

Helius (Helius) pallidissimus Alexander, 1930 View in CoL ( Figs 6–8 View Figure 6 View Figure 7 View Figure 8 )

Helius (Helius) pallidissimus Alexander, 1930b: 515 View in CoL . Type locality: China, Sichuan, Mt. Emei .

Diagnosis. Antenna with basal flagellomeres short and crowded. Rostrum about 1.4 times as long as remainder of head. Prescutum and presutural scutum pale yellow with anterior area paler. Pleuron pale yellow to yellow. Wing with distance between tips of R 4 and R 5 about 2.5 times as long as distance between tips of R 1 and R 4. Tip of outer gonostylus bispinous, outer spine slightly smaller. Interbase oval, tip slightly expanded; laterally producing into a narrow, apically blunt outgrowth, hook-like in lateral aspect.

Description. Male. Body length 6.5–6.9 mm (excluding rostrum), wing length 6.1–6.5 mm, rostrum length 0.6–0.7 mm, antenna length 1.4–1.5 mm.

Head ( Fig. 6B View Figure 6 ). Light gray with dark brown setae. Antenna ( Fig. 6C View Figure 6 ) with scape pale yellow, pedicel brown and flagellomeres brownish black. Scape long cylindrical, three times as long as wide. Pedicel oval, tip slightly expanded. Basal flagellomeres short and crowded with unilaterally arranged dark brown verticils; outer flagellomeres long, apically tapering and elongated, with long dark brown verticils that longer than corresponding flagellomere. Rostrum about 1.4 times as long as remainder of head, pale brownish yellow with pale brown setae. Basal segments of palpus pale brownish yellow with tips darker, terminal segment brown with tip darker. Setae on palpus dark brown.

Thorax ( Fig. 6D View Figure 6 ). Pronotum pale yellow. Prescutum and presutural scutum pale yellow with anterior area paler. Postsutural scutum pale yellow with middle area darker. Scutellum pale yellow. Mediotergite dark brown with middle area slightly daker. Pleuron ( Fig. 6A View Figure 6 ) pale yellow to yellow. Setae on thorax pale brown. Coxae and trochanters pale yellow; femora yellow; tibiae pale brownish yellow; tarsi brownish yellow with terminal segments darkened. Setae on legs brown. Wing ( Fig. 6E View Figure 6 ) tinged with yellow. Veins pale yellow to yellow. Venation: Sc ending before fork of Rs, sc-r at its tip; distance between tips of R 4 and R 5 about 2.5 times as long as distance between tips of R 1 and R 4; cell dm about twice as long as wide; m-cu from just before to just beyond fork of M. Halter pale yellow.

Abdomen ( Fig. 6A View Figure 6 ). Yellow to brownish yellow with pale brown setae.

Hypopygium ( Fig. 7 View Figure 7 ). Pale brown. Posterior margin of tergite 9 with a broad V-shaped emargination ( Fig. 7A View Figure 7 ). Gonocoxite cylindrical with base slightly expanded. Setae on gonocoxite brown; shorter, slender and denser on inner side ( Figs 7A–B View Figure 7 ). Outer gonostylus slightly curved with subtip slightly constricted; tip blackened and bispinous, outer spine slightly smaller ( Figs 7A–B, E View Figure 7 ). Inner gonostylus curved with basal 2/3 expanded ( Figs 7A–B, E View Figure 7 ). Aedeagal complex with semen pump oval ( Figs 7C–D View Figure 7 ), ejaculatory apodeme short and stout ( Figs 7C–D View Figure 7 ); aedeagus rod-shaped with tip curled dorsally ( Figs 7A–D View Figure 7 ). Parameres fused forming flattened transverse plate with short basal and apical parts, tip of apical part bent dorsally ( Figs 7C–D View Figure 7 ). Interbase oval, tip slightly expanded; laterally producing into a narrow, apically blunt outgrowth, hook-like in lateral aspect ( Figs 7C–D, F–G View Figure 7 ).

Female. Body length 7.3–7.7 mm (excluding rostrum), wing length 6.7–7.0 mm, rostrum length 0.5–0.6 mm, antenna length 1.0– 1.1 mm. Generally similar to male by body coloration. Ovipositor ( Fig. 8 View Figure 8 ): tergite 9 yellow with middle area darker, tergite 10 yellow; sternite 8 yellow; cercus yellow to brownish yellow, distal part curved dorsally; hypogynial valve brownish yellow with middle of base paler, tip reaching approximately middle of cercus.

Material examined. 2♂ 2♀ ( LHEL002 B01– LHEL002 B04), China: Sichuan Province, Chongzhou City, Anzihe Nature Reserve , Shaoyaogou Protection Station (30°48′08″N, 103°12′58″E, 1434 m), 2016.VII.30, Yuqiang Xi, light trap. 2♂ ( LHEL002 B05– LHEL002 B06), China: Sichuan Province, Chongzhou City , Anzihe Nature Reserve , Shaoyaogou Protection Station (30°47′59″N, 103°13′05″E, 1450 m), 2016.VII.31, Yuqiang Xi, light trap GoogleMaps .

Distribution. Sichuan (Emeishan, Chongzhou).

Remarks. Alexander (1930b) firstly described this species based on two females from Sichuan, China and provided figure of the wing for this species. In this study, the description and illustration for male are provided for the first time. In addition, more detailed description and illustration for female ovipositor are also provided.

Funding This work was supported by the National Natural Science Foundation of China (32100356) and the National

Animal Collection Resource Center, China.

Acknowledgements We are also very grateful to Dr. Zehui Kang (Qingdao, Shandong, China) and Dr. Yuqiang Xi (Zhengzhou, Henan, China) for collecting the specimens.