Osmylus atomatus ( Yang, 1988 )

Li, Zechuan, Zheng, Yuchen, Wang, Yongjie & Liu, Xingyue, 2025, A revision of the Osmylus hyalinatus species group (Neuroptera: Osmylidae), with description of seven new species, Journal of Natural History 59 (13 - 16), pp. 849-893 : 859-861

Osmylus atomatus ( Yang, 1988)

( Figures 3 , 14A, J )

Plethosmylus atomatus Yang, 1988: 194 ; Xu et al., 2020: 448. Type locality: China (Xizang: Medog: Gedang ) .

Osmylus atomatus Winterton et al., 2019: 38 .

Diagnosis

Head brown; vertex dark brown, anteriorly with a pale transversal band. Pronotum yellowish brown with some irregularly shaped dark brown markings. Fore wing gradate series area to apex, distal part of M and Cu area with several transversely arranged dots. Male tergum 9 with a long triangular process, 1.2 to 1.3 times as long as wide in lateral view; gonocoxites 9 with two pairs of tubercles, both digitiform, anterior pair slightly larger, posterior margin with a V-shaped concavity in ventral view; gonocoxites 10 curved sharply; ectoproct subtriangular in lateral view. Female sternum 7 with a pair of processes, sharp and slightly curved posteriorly; gonocoxite 8 small, curved ventrally; tergum 9 with anterior branch digitiform in ventral view.

Redescription

Head width 2.6 mm; fore wing length 30.1 mm; hind wing length 26.4 mm.

Head. ( Figure 3C ) Brown; vertex convex, dark brown, anteriorly with a pale transversal band, hairless. Ocelli distinct, with yellowish-brown long setae, darkening around anterior ocellus. Scape and pedicel dark brown, flagellum black, basally brown, filiform. Frons brown. Clypeus yellowish brown, lateral margin with a pair of dark dots, covered with some yellowish-brown setae. Mandibles basally brown, distally dark brown. Maxillary and labial palpi brown.

Thorax. ( Figure 3B ) Pronotum yellowish brown with some irregularly shaped dark brown markings. Meso- and metanotum yellowish brown with some dark brown markings, covered with many yellowish-brown setae.

Legs. Long and slender, yellow, protibiae dark along outer margin, covered with short setae. Tibia nearly twice as long as femur, tarsomere 1 relatively longer, nearly as long as entire length of tarsomeres 2–4; pretarsal claws curved. Metatibia longer than that of fore- and midlegs.

Wings. Ovoid, hyaline. Pterostigma dark brown alternating with pale. Fore wing gradate series area to apex, and distal part of M and Cu area with several transversely arranged dots; costal space broad basally, subcostal veinlets basally connected by some short oblique crossveins; RP with 14–15 branches; RP1 originating near origin of RP, M fork close to origin of RP1; RP with two distinct gradate series, CuP with numerous crossveins; A1 and A2 with pectinate branches and crossveins. Hind wing subcostal veinlets without interlinked crossvein; apex of hind wing with a dot.

Abdomen. Dark brown, covered with yellowish-brown setae. Male genitalia ( Figure 3D, E ): Tergum 8 long; scent gland large and ovoid; callus cerci relatively large and ovoid. Tergum 9 with a long triangular process, distal part slightly curved posteriad. Gonocoxites 9 slightly sclerotised distally, with two pairs of digitiform tubercles, posterior pair slightly larger, posterior margin forms a deep V-shaped concavity, gonocoxites 10 ( Figure 14A ) curved sharply. Female genitalia ( Figure 3F, G ): Sternum 7 with a pair of processes, sharp and slightly curved posteriorly; gonocoxite 8 small, curved ventrally; tergum 9 branched ventrad; anterior branch digitiform in ventral view. Gonocoxite 9 as a slender fusiform structure; in ventral view anterior angle triangular, relatively developed. Ectoproct subtriangular in lateral view. Spermatheca simple and rounded ( Figure 14J ).

Material examined

CHINA: 2♂ 4♀, Xizang, Nyingchi, Medog County [墨脱县], 80 K (= 80 km point of road from Bome County to Medog County ), 21 August 2020, 2115 m, leg . Yuchen Zheng ( CAU); 1♀, Xizang, Nyingchi, Medog County [墨脱县], Pelung Village [排龙村], 2056 m, 24 July 2018, leg . Tingting Zhang ( CAU); 1♂, Xizang, Nyingchi, Bome County [波密县], Tongmai , 9 September 2013, leg . Yao Gang ( CAU) .

Distribution

China (Xizang).

Remarks

This species is similar to O. flaviantennatus sp. n., O. gaoligongensis sp. n. and O. verticalis sp. n., and its distribution area overlaps with that of O. verticalis sp. n. However, O. atomatus differs from O. flaviantennatus sp. n. due to the dark brown or black antennae, whereas O. flaviantennatus sp. n. has yellow antennae. It can be distinguished from O. gaoligongensis sp. n. by two processes on female sternum 7, while in O. gaoligongensis sp. n. the processes on female sternum 7 are absent. The differences between O. atomatus and O. verticalis sp. n. mainly refer to the shape of male genitalia. In O. atomatus the process of tergum 9 is long and extended posterodorsally, with the tubercles of gonocoxites 9 closely positioned; whereas in O. verticalis sp. n. the tergum 9 is short and extended dorsad, with the tubercles of gonocoxites 9 widely spaced.

Figures

Figure 3. Osmylus atomatus (Yang, 1988). A. habitus; B. head and thorax, dorsal view; C. head; D. male genitalia, lateral view; E. male genitalia, ventral view; F. female genitalia, lateral view; G. female genitalia, ventral view. Scale bars: A = 10.0 mm; B = 2.0 mm; C = 1.0 mm; D–G = 0.5 mm.

Figure 14. Male gonocoxites 10 and female spermatheca. A, J. O. atomatus; B, K. O. decoratus; C, L. O. flaviantennatus sp. n.; D, M. O. gaoligongensis sp. n.; E. O. verticalis sp. n.; N. O. trituberatus sp. n.; F. O. wenii sp. n.; G, O. O. xiaohongae sp. n.; H, P. O. qinlinganus sp. n.; I, Q. O. zheanus.