Heterosmylus aspersus Krüger 1913a: 37, original designation. Deposited in Stettiner Museum (National Museum Szczecin, Poland).

India: Sikkim.

Head brown or dark brown; compound eyes black; antennae shorter than half length of forewing; prothorax black and length longer than width, with yellow setae; meso- and metathorax dark brown with long setae; legs yellow with short brown setae; forewings oblong and subacute at apex, with few brown spots; nygmata clear surrounded by light brown spot; veins thickened; costal cross-veins simple and occasionally bifurcate; forewing Rs with 8–15 branches, distal to the base of wing; cross-veins among Rs branches forming two or three series of gradates; forewing M branching more basally than the divergence of basal branch of Rs; no more than four cross-veins present between the two branches of M; forewing Cu bifurcating near the base of wing; CuA and CuP with numerous pectinate branches; CuP longer than half length of CuA; hind wings similar to forewings in size and shape without any spot apart from pterostigma; hindwing M branching near the base of wing; hindwing CuA with numerous pectinate branches; CuP simple and shorter than half length of CuA; male genitalia with 9^th tergite narrow, and sternite approximately quadrate; ectoproct relatively large, callus cerci rounded and located at the middle or underside of ectoproct; male genitalia composed of gonarcus, entoprocesses and mediuncus, arched gonarcus similar to other genera of Protosmylinae; mediuncus attached with a membrane below gonarcus, mediuncus bent into C-shape laterally; female genitalia with 9^th tergite narrow; spermathecae bent into n-shape with base expanded and apex columniform.

Heterosmylus aspersus Krüger, H. curvagradatus Yang, H. flavidus Yang, H. limulus Yang, H. primus Nakahara, H. processus sp. n., H. shennonganus Yang, H. wolonganus Yang, H. yunnanus Yang.

Although the type species of Heterosmylus was not described in detail when the genus was established, Krüger provided a detailed description of the type species in a following paper later that year (Krüger 1913a, b). This subsequent work was overlooked by Nakahara (1955), and later Ghosh (2000) presented a brief description for the species without the genitalic characters. Consequently, the systematic status of Heterosmylus was not well defined, although it is clear that the monophyly of Heterosmylus is well supported in the recent phylogenetic work on Osmylidae by Winterton et al. (in press). Heterosmylus also can be distinguished from other genera (Gryposmylus Krüger, Lysmus Navás, Paryphosmylus Krüger) in Protosmylinae based mainly on wing venation. In Heterosmylus, the veins are thickened and branches of forewing M have no more than four ma-mp cross-veins. In both Gryposmylus and Lysmus these are slender and the M vein generally five ma-mp cross-veins. Moreover, the base of costal-field of forewing of Heterosmylus species is narrower compared with that of Gryposmylus. Heterosmylus differs from Paryphosmylus in that the wings are mostly hyaline and single cross-vein presents before the separation of basal branch of Rs (Martins et al. 2016).

Heterosmylus is mainly recorded in the Oriental Region and especially in China (Fig. 1), typically in warmer and humid environments. According to the distribution of the individual species, we find H. wolonganus, H. shennonganus and H. yunnanus with relatively wide distributions. It seems that H. wolonganus has a broad geographical distribution from central to western China, occurring in four geographically continuous provinces, Sichuan, Gansu, Shaanxi and Henan. Interestingly, most localities of H. wolonganus are along the boundary of Oriental and Palaearctic regions in China. Heterosmylus shennonganus is principally distributed in central China, representing a typical Oriental species. Heterosmylus yunnanus is another widespread species, distributed in Tibet, Yunnan and Sichuan. Considering the similar environment in these localities, it is estimated that these species might be present in the whole southwest of China. The other five species, H. curvagradatus, H. limulus, H. flavidus, H. primus and H. processus sp. n., are only recorded in a single region. Heterosmylus curvagradatus is restricted to Fujian, while H. flavidus is a distinctive species restricted in the west of Yunnan. Heterosmylus limulus is limited to Yadong (Tibet) and it could be found at the same altitude as H. yunnanus. Heterosmylus primus is only recorded in Taiwan. We did not examine this species so we could not compare it with the other species, but H. curvagradatus shows the similar appearance with this species, suggesting their potential close relationship. The new species H. processus sp. n. is highly distinctive (weakly defined pterostigma and hyaline and colourless membrane) is found in Shaanxi near the Qinling Mountains.

Figure 1. 

Distribution of Heterosmylus in China. ☆ = H. curvagradatus ▲ = H. flavidus ■ = H. limulus ★ = H. primus ● = H. processus sp. n. △ = H. shennonganus ♦ = H. wolonganus ◇ = H. yunnanus.

Holotype Male. CHINA: Shaanxi (Province): Taibai, [33°55'N, 107°43'E] 09.v.1982, leg. Guojun Qi. [Verbatim label data translated from Chinese]: CHINA: Shaanxi, Taibai/ 09.v.1982/ Guojun Qi/ CAU. Terminalia cleared in KOH, and stored in a micro-vial pinned below the specimen.

Pronotum with four brown spots at anterior margin, two round brown spots in middle and two brown spots at posterior margin; membrane hyaline, pterostigma yellow, without dark spots besides the pterostigma; veins light yellow at base but brown from middle to the end; mediuncus C-shaped in lateral view with a basal process and boat-shaped in dorsal view.

Body length 8.6 mm. Head. Vertex yellow with brown setae; ocelli distinctively brown; compound eyes black; antennae yellow with a brown stripe at base; frons with two brown stripes, genae with two round brown spots; maxillary palpi yellow and thick, labium short and brown. Thorax. Yellow dorsally and dark brown ventrally; pronotum with four brown spots at anterior margin, two round brown spots in middle and two brown spots at posterior margin linking to the mesonotum; mesonotum with two brown spots in middle on both sides; metanotum similar to the mesonotum, with two spots in middle. Legs. Yellow with brown setae; claws brown with a small tooth. Wings (Fig. 2): Forewing length 15.4 mm, width 6.2 mm; membrane hyaline without any spot besides the yellow pterostigma; veins yellow; costal field broad, cross-veins simple without forks. Cross-veins in radial sector few besides the gradate cross-veins. Rs with 8 branches. The basal cross-vein between R₁ and M edged with a brown mark. Hind wing length 14.4 mm, width 5.3 mm; membrane hyaline, veins light yellow at base but brown from middle to the end. Costal field narrow, pterostigma yellow, and Rs with 7 branches. Abdomen. Yellow dorsally, dark brown ventrally, covered with yellow setae.

Figure 2. 

Wings of Heterosmylus processus sp. n. Abbreviations: ng, nygmata; pt, pterostigma.

Male Terminalia (Figs 3–6). Ectoproct quadrate in lateral view; callus cerci rounded and small. Distal part of gonarcus bent upwards. Entoprocesses curved in middle and dilated apically. Mediuncus (Figs 4–5) C-shaped in lateral view with a basal process and boat-shaped in dorsal view; two mediuncus lobes fused at base and each one raised on both sides, the inner side larger than the outer one.

Figures 3–6. 

Heterosmylus processus sp. n. Male: 3 terminalia, lateral view 4 mediuncus, lateral view 5 mediuncus, dorsal view 6 genitalia, lateral view.

China (Shaanxi).

The specific name refers to the process at the base of the mediuncus.

This species is known from its type locality, Shaanxi province. It is easily distinguished from other species in the genus because of the body coloration, morphology and the genital characters. Heterosmylus processus sp. n. has a smaller body size and hyaline wings, while the others usually have a patterned membrane. Moreover, the mediuncus within the new species possesses a distinct process at the base whereas it is absent in the other species of Heterosmylus.

Holotype male. CHINA: Yunnan (Province): Lushuixian Gangfang, [25°57'N, 98°52'E], 29.ix.1980, leg. Dejing Zou. [Verbatim label data (translated from Chinese)]: CHINA: Yunnan, Lushuixian, Gangfang, 29.ix.1980/ Dejing Zou. Terminalia cleared in KOH, and stored in a micro-vial pinned below the specimen. 3 males, 1 female (type specimens of H. zhamanus), Tibet: Zhangmu, 06.vi.1981, leg. Shengchang Hu; 3 males, 5 females, Tibet: Hanmi, 24.viii.2005, leg. Dakang Zhou; 2 males, Sichuan: Luding, Hailuogou, 26.vi.2006, leg. Xiaoshuan Bai.

Pronotum black with two yellowish longitudinal stripes at anterior margin; mesonotum with two yellow spots in middle; apex of gonarcus bent upwards and relative long in lateral view.

Body length 9–11 mm. Head. Vertex dark brown, frons bright yellow; ocelli yellow; compound eyes dark grey; antennae entirely dark; clypeus brownish, maxillary and labial palpi dark brown. Thorax. Pronotum black with two yellowish longitudinal stripes at anterior margin; mesonotum with two yellow spots in middle. Wings (Fig. 7). Forewings length 18–21 mm, width 6–7 mm; membrane hyaline, and veins dark brown; pterostigma dark brown with yellowish center. Rs with 15–17 branches; Cu edged with three or four yellow spots. Hind wing length 15–18 mm, width 5–6 mm; membrane hyaline, cross-veins edged with brown marks between Sc and R₁.

Figure 7. 

Wings of Heterosmylus yunnanus Yang, 1986.

Male Terminalia (Figs 8–11). Ectoproct quadrate in lateral view. Gonarcus rod-like in lateral view, the apex bent upwards and relatively long; entoprocesses distally expanded, lobe-shaped; mediuncus fused at base and curved into C-shape in lateral view; each mediuncus lobe raised on both sides, boat-shaped in dorsal view.

Figures 8–13. 

Heterosmylus yunnanus Yang, 1986. Male: 8 terminalia, lateral view 9 mediuncus, lateral view 10 mediuncus, dorsal view 11 genitalia, lateral view Female: 12 terminalia, lateral view 13 spermatheca, lateral view.

Female Terminalia (Figs 12–13). Ectoproct trapeziform in lateral view; 9^th gonocoxite finger-shaped in lateral view, 9^th gonostylus brown and long. Spermathecae bent into C-shaped and basal part longer than distal.

China (Tibet, Yunnan, Sichuan)

Although the original identification of both H. yunnanus Yang and H. zhamanus Yang was based on the colour pattern of the head, there are no convincing differences to distinguish them after comparison of their genitalic features. So we believe that H. zhamanus should be a synonym of H. yunnanus.

Holotype Male, CHINA: Tibet: Yadong, [27°31'N, 88°55'E], 24.viii.1978, leg. Fasheng Li. [Verbatim label data (translated from Chinese)]: CHINA: Tibet, Yadong/ 24.viii.1978/ Fasheng Li/ CAU. 1 male, same data as Holotype. 1 female, China: Tibet: Yadong, 30.viii.1984, leg. Yongxiang Zhao.

Pronotum with two yellow stripes in middle, an oblique brown mark presenting from the pterostigma to the posterior outer margin of forewing; base of mediuncus slender and apex dilated as lobe-shape in lateral view.

Body length 8.0 mm. Head. Vertex dark brown, frons brown. Ocelli yellowish, eyes dark grey. Antennae brown, encircled by a yellowish stripe at base. Clypeus yellow, maxillary palpi and labial palpi dark brown. Thorax. Dark brown. Pronotum with two light yellow stripes medially; mesonotum brown at anterior part with black setae. Wings (Fig. 14). Forewing length 16–17 mm, width 5–6 mm; membrane hyaline, veins brown; pterostigma yellow, but brown on both sides; an oblique brown stripe presenting from the pterostigma to the posterior outer margin; Cu with four brown spots. Outer gradate series of cross-veins and wing margin bordered with fuscous spots. Rs with 13–15 branches. Hind wing length 13–14 mm, width 4–5 mm; membrane hyaline with some light brown spots between Sc and R₁.

Figure 14. 

Wings of Heterosmylus limulus Yang, 1987.

Male Terminalia (Figs 15–18). Ectoproct quadrate in lateral view; gonarcus rod-like in lateral view, distal part upswept and relatively small; mediuncus fused at base and curved into C-shape in lateral view; the base slender and apex dilated as lobe-shape in lateral view.

Figures 15–20. 

Heterosmylus limulus Yang, 1987. Male: 15 terminalia, lateral view 16 mediuncus, lateral view 17 mediuncus, dorsal view 18 genitalia, lateral view. Female: 19 terminalia, lateral view 20 spermatheca, lateral view.

Female Terminalia (Figs 19–20). Ectoproct approximately oblong in lateral view; 9^th gonocoxite fusiform in lateral view; 9^th gonostylus brown and small; spermathecae bent into C-shape.

China (Tibet).

Holotype Male. CHINA: Sichuan (Province): Wolong, [31°01'N, 103°10'E], 25.vii.1993, leg. Shuyong Wang. [Verbatim label data (translated from Chinese)]: CHINA: Sichuan Prov., Wonglong/ 25.vii.1993/ Shuyong Wang/ CAU. 1 male, CHINA: Shaanxi (Province): Ningshan, 18.vi.1981, leg. Chikun Yang. 1 female, CHINA: Shaanxi (Province): Huangniupu, 15.viii.1981, leg. Weidong Wang. 1 male, CHINA: Shaanxi (Province): Taibaishan, 09.iii.1982, leg. Chikun Yang. 1 male, CHINA: Shaanxi (Province): Taibaishan, 09.v.1982, leg. Guojun Qi. 1 female, CHINA: Shaanxi (Province): Taibaishan, 15.vii.1982, leg. Jingruo Zhou, Lan Liu. 1 male, 1 female, CHINA: Shaanxi (Province): Ningshan, 18.vii.1982, leg. Shenghui Lei. 1 female, CHINA: Shaanxi (Province): Ningshan, Xiangyang, Fengqi, 18.vii.1982, leg. Deqing Wang. 2 males, CHINA: Shaanxi (Province): Nanzheng, Yuanba, 27.v.1983, leg. Dahan He. 1 male, CHINA: Gansu (Province): Wenxian, Bikou, 25.vii.1998, leg. Jun Chen. 2 males, CHINA: Henan (Province): Songxian, Baiyunshan, 19.vii.1996, leg. Xiaocheng Shen. 10 males, 12 females, CHINA: Henan (Province): Songxian, Baiyunshan, 14-18.vii.2004, leg. Bingzhen Yan.

Pronotum with two yellow narrow stripes in middle; metanotum with two brown spots on anterior margin; gonarcus sclerotized distally and bent upward and hook-shaped in lateral view; base of mediuncus approximately finger-shaped in lateral view.

Body length 9–11 mm. Head. Vertex yellowish brown; frons yellow with one dark brown spot near antennae; ocelli brown, eyes blackish brown; antennae blackish brown; clypeus yellow, maxillary and labial palpi dark brown

Thorax. Pronotum with two yellow narrow stripes in middle with some dark setae on both sides; mesonotum with two yellow longitudinal spots; metanotum with two brown spots on anterior margin. Wings (Fig. 21). Forewing length 18–20 mm, width 6–7 mm; membrane hyaline, veins mostly brown; pterostigma light yellow but brown on both sides; Rs with 10 branches. Four cross-veins present between MA and MP. Hind wing length 16–17 mm, width 5–6 mm; Rs with 11–12 branches, without any distinct spot besides the pterostigma.

Figure 21. 

Wings of Heterosmylus wolonganus Yang, 1992.

Male Terminalia (Figs 22–25). Ectoproct quadrate in lateral view; gonarcus sclerotized distally and bent upwards as hook in lateral view; gonocoxite bent and distally dilated as lobe-shaped in lateral view mediuncus curved into C-shape in lateral view and spoon-shaped in dorsal view; base approximately finger-shaped in lateral view.

Figures 22–28. 

Heterosmylus wolonganus Yang, 1992. Male: 22 terminalia, lateral view 23 mediuncus, lateral view 24 mediuncus, dorsal view 25 genitalia, lateral view. Female: 26 terminalia, lateral view 27 spermatheca, lateral view 28 8^th sternite, ventral view.

Female Terminalia (Figs 26–28). Anterior part of 8^th sternite reduced and short finger-shaped, posterior part broad; ectoproct broad and trapezoid in lateral view; 9^thgonocoxite fusiform in lateral view; 9^th gonostylus long in lateral view; spermatheca bent into C-shape.

China (Sichuan, Shaanxi, Gansu, Henan).

Holotype Female. CHINA: Yunnan (Province): Lushui, Yaojiapin, [25°58'N, 98°42'E], 04.vi.1981, leg. Shuyong Wang. [Verbatim label data (translated from Chinese)]: CHINA: Yunnan Prov., Lushui, Yaojiaping/ 04.vi.1981/ Shuyong Wang/ CAU. Paratype Male, CHINA: Yunnan (Province): Lushui, Pianma, 29.v.1981. leg. Xuezhong Zhang. [Verbatim label data (translated from Chinese)]: CHINA: Yunnan Prov., Lushui, Pianma/ 29.v.1981/ Xuezhong Zhang/ CAU.

Pronotum with a dark brown longitudinal stripe medially; metanotum with a brown spot in middle; forewing light yellow; mediuncus C-shaped in lateral view and scoop-shaped in dorsal view.

Body length 7–9 mm. Head. Vertex dark brown, frons yellow; ocelli yellowish; Compound eyes brown with some small spots; antennae fuscous except for the yellow scape; clypeus yellow, maxillary and labial palpi black. Thorax. Mostly yellow. Pronotum with a brown longitudinal stripe, and with some long setae on both sides; mesonotum brown on margin; metanotum dark brown with a brown spot medially. Wings (Fig. 29). Forewing length 16–17 mm, width 5–6 mm; membrane light yellow, veins brown and thickened; pterostigma light yellow but brown on both sides; R₁ edged with some brown spots, Rs with 11 branches, cross-veins among branches of Rs forming three series of gradates. Hind wing length 12–14 mm, width 4–6 mm; membrane hyaline with small spots between Sc and R₁.

Figure 29. 

Wings of Heterosmylus flavidus Yang, 1992.

Male Terminalia (Figs 30–33). Ectoproct quadrate in lateral view; gonarcus rod-like, but apex not bent upwards in lateral view; gonocoxite bent in the middle; mediuncus C-shaped in lateral view and scoop-shaped in dorsal view.

Figures 30–35. 

Heterosmylus flavidus Yang, 1992. Male. 30 terminalia, lateral view 31 mediuncus, lateral view 32 mediuncus, dorsal view 33 genitalia, lateral view. Female: 34 terminalia, lateral view 35 spermatheca, lateral view.

Female Terminalia (Figs 34–35). 8^th sternite finger-shaped in lateral view; ectoproct broad and approximately elliptical in lateral view; 9^th gonocoxite finger-shaped in lateral view; 9^th gonostylus relatively long and finger-shaped in lateral view; spermathecae bent into C-shape, base thicker than apex.

China (Yunnan).

Holotype Male. CHINA: Hubei (Province): Shennongjia, [31°42'N, 110°38'E], 21.viii.1985, leg. Xiaoyuan Mao. [Verbatim label data (translated from Chinese)]: CHINA: Hubei Prov., Shennongjia, 21.viii.1985/ Xiaoyuan Mao/ CAU. Paratype 4 males, 3 females, same data as the holotype. 1 female, Henan: Luanchuan, Longyuwan, 1997.08.14, leg. RLS. 1 male, CHINA: Henan (Province): Luanchuan, Longyuwan, 18.viii.1997, leg. RLS. 1 male, CHINA: Henan (Province): Luanchuan, Longyuwan, 19.vii.2004, leg. Bingzhen Yan. 1 female, CHINA: Henan (Province): Neixiang, Baotianman, 23.vii.2004, leg. Bingzhen Yan. 1 male, CHINA: Henan (Province): Neixiang, Baotianman, 24.vii.2004, leg. Bingzhen Yan. 1 male, CHINA: Chongqing: Jiangjin, Simianshan, 21.ix.2007, leg. Weiwei Zhang. 1 female, CHINA: Shaanxi (Province): Xiangyangba, 24.viii.1982, leg. Shenghui Lei.

Pronotum with two narrow longitudinal dark brown marks in middle; ectoproct with a dorsal coniform process in lateral view; gonarcus with a short finger-like process distally in lateral view.

Body length 8–10 mm. Head. Vertex with a brown cross-stripe; frons yellow but brown on both sides; ocelli large and prominent, compound eyes shiny black; antennae dark brown; clypeus fulvous, maxillary and labial palpi brown.

Thorax. Pronotum with two narrow longitudinal dark brown marks in the middle; mesonotum with dark setae; metanotum without spots. Wings (Fig. 36). Forewing length 16–17 mm, width 6.4 mm; membrane hyaline, veins mainly brown; pterostigma yellowish but brown on both sides; costal field with three or four brown spots; r1-rs edged with brown marks; Rs with 8–9 branches, cross-veins among branches of Rs forming two series of gradates; the outer gradate cross-veins edged with brown spots. Hind wing length 15.5 mm, width 5.4 mm. Membrane hyaline with few spots.

Figure 36. 

Wings of Heterosmylus shennonganus Yang, 1997.

Male Terminalia (Figs 37–40). Ectoproct approximately quadrate with a dorsal coniform process in lateral view; gonarcus approximately rod-like and distally sclerotized with a short finger-like process in lateral view; gonocoxite curved as ancon and distally dilated as lobe; mediuncus curved and thickened in lateral view and boat-shaped with a cone-shaped apex in dorsal view.

Figures 37–43. 

Heterosmylus shennonganus Yang, 1997. Male 37 terminalia, lateral view 38 mediuncus, lateral view 39 mediuncus, dorsal view 40 genitalia, lateral view. Female: 41 terminalia, lateral view 42 spermatheca, lateral view 43 8^th sternite, ventral view.

Female Terminalia (Figs 41–43). 8^th sternite approximately finger-shaped in lateral view. Ectoproct trapeziform in lateral view; 9^th gonocoxite approximately finger-shaped in lateral view; 9^th gonostylus finger-shaped and brown; spermathecae bend into C-shape.

China (Henan, Shaanxi, Hubei, Chongqing).

Holotype Male. CHINA: Fujian (Province): Wuyishan, Huanghuacong, [27°48'N, 117°42'E], 13.x.1980, leg. Fan Jiang. [Verbatim label data (translated from Chinese)]: CHINA: Fujian Prov., Wuyishan, Huanghuacong/ 13.x.1980/ Fan Jiang/ CAU. Paratype Female. CHINA: Fujian (Province): Wuyishan, Xianfenling, 19.ix.1987. leg. Jiashe Wang.

Two yellow longitudinal stripes present from pronotum to mesonotum. mesoscutellum bright yellow, metanotum with a central yellow stripe; apex of gonarcus slightly dilated, short and curved dorsally.

Body length 7–10 mm. Head. Vertex shiny yellow with a brown round spot in middle and a greyish yellow transverse band near antennae; frons bright yellow with a black brown stripe; ocelli grey but black at base; compound eyes grey and glossy; antennae black; clypeus yellow, maxillary and labial palpi dark brown. Thorax. Dark brown with two yellow longitudinal stripes from pronotum to mesonotum. mesoscutellum bright yellow, metanotum with a central yellow stripe. Wings (Fig. 44). Forewing length 15–17 mm, width 5–6 mm; membrane hyaline, veins fuscous with numerous long setae; pterostigma yellow but brown on both sides. Crossveins r1-rs edged with dark brown spots. Rs with 8–9 branches, gradates cross-veins with brown marks. Hind wing length 13–14 mm, width 4–6 mm; membrane hyaline without spots besides the pterostigma.

Figure 44. 

Wings of Heterosmylus curvagradatus Yang, 1999.

Male Terminalia (Figs 45–48). Ectoproct approximately pentagonal in lateral view; gonarcus rod-like in lateral view, apex slightly inflated, short and curved dorsad; mediuncus fused at base and scoop-shaped in dorsal view and apex flat-bottomed in dorsal view.

Figures 45–50. 

Heterosmylus curvagradatus Yang, 1999. Male: 45 terminalia, lateral view 46 mediuncus, lateral view 47 mediuncus, dorsal view 48 genitalia, lateral view. Female: 49 terminalia, lateral view 50 spermatheca, lateral view.

Female Terminalia (Figs 49–50). 8^th sternite reduced into finger-shape in lateral view; ectoproct approximately trapezoid in lateral view; 9^th gonocoxite approximately finger-shaped in lateral view; 9^th gonostylus brown and short; spermathecae bend into C-shape.

China (Fujian).