Acosmetura mecyna Su, Wang & Shi, 2025, sp. nov.

Acosmetura mecyna sp. nov., Chinese name: KBḆ̈Dzdz (Figs. 1–2, 4A–B) Description. Male. Body small and stout (Fig. 4A). Head. Fastigium verticis conical, rounded apically and grooved dorsally (Fig. 1A). Eyes ovoid, slightly protruding forwards and outwards; apical segment of maxillary palpus faintly longer than subapical one (Fig. 1A– B). Thorax. Pronotum saddle-shaped, feebly short, anterior margin almost straight while posterior margin rounded; lateral lobe longer than deep, posterior margin faintly arc-shaped, narrowing, humeral sinus absent (Fig. 1A–B). Wings. Tegmina short, lightly surpassing posterior margin of pronotum, apices rounded; hind wings absent (Figs. 1A–B, 2A–C). Legs. All femora unarmed on ventral surfaces. Fore coxa with 1 anterior spine and tibial tympana open on both sides. Fore tibia with 3–5 internal and 2–5 external long spines on ventral surface. Middle tibia with 5–6 long spines on both sides of ventral surface respectively. Hind tibia with 23–27 internal and external short spines respectively, bearing 1 pair of dorsal apical spurs and 2 pairs of ventral apical spurs. Abdomen. The posterior margin of tenth abdominal tergite feebly concave (Fig. 1D–E). Cercus lightly depressed and elongate, moderately curved inwards; base stout, basal inner surface with a triangular tooth, whose apex curved backwards, tip lightly acute; apex of cercus rounded (Fig. 1C–F). Genitalia feebly sclerotized, with a pair of laminae, which connected at base, narrowing, posterior margins lightly concave (Fig. 1E). Subgenital plate prolonged, basal margin lightly concave, basal half markedly broad; apical half narrowing, prolonged backwards and bulging in the middle area, lateral margins of apical area arcuately concave; posterior margin with a small notch. Styli conical and short, inserted on ventral surface near the lateral margins of subapical area of subgenital plate (Fig. 1C). Coloration. Body yellowish green. Eyes reddish brown, dorsal area of head with 2 longitudinal light yellow stripes. Disc of pronotum with a longitudinal light brown stripe, of which lateral margins yellowish, as well as with a thin light yellow stripe along the midline. Dorsal surface of abdomen with a longitudinal dark brown stripe along the midline. Female. Body larger than male, tegmen lightly surpassing posterior margin of pronotum. Subgenital plate nearly rectangular, with a distinctly longitudinal furrow along the midline, basal half with a subcircular membranous area (Fig. 1G). Ovipositor significantly elongate and lightly upcurved, dorsal and ventral margins smooth, apex acute (Fig. 1H). Material examined. Holotype, ♂, Liziping, Shimian, Sichuan, China, 18 September, 2024, collected by Jie Su. Paratypes: 1♂ 3♀, same data as holotype. Other specimens: 6♂ 2♀, Shenguozhuang, Yuexi, Sichuan, 6 August, 2011, collected by Fuming Shi and Lehong Zhao; 6♂ 4♀, Shenguozhuang, Yuexi, Sichuan, 7 August, 2011, collected by Fuming Shi and Lehong Zhao; 9♂ 10♀, Shenguozhuang, Yuexi, Sichuan, 8 August, 2011, collected by Fuming Shi and Lehong Zhao; 7♂ 5♀, Daqiao, Mianning, Sichuan, China, 7 September, 2022, collected by Yifan Liu; 8♂ 7♀, Liziping, Shimian, Sichuan, China, 18 September, 2024, collected by Qing Liu; 1♂, Liziping, Shimian, Sichuan, China, 18 September, 2024, collected by Nie Wang; 3♀, Liziping, Shimian, Sichuan, China, 18 September, 2024, collected by Wenlei Xu. Measurements (mm). Body length: ♂ 7.9–8.4, ♀ 8.9–9.5; pronotum length: ♂ 2.8–3.2, ♀ 3.1–3.5; hind femur length: ♂ 8.1–8.6, ♀ 8.8–9.4; ovipositor length: 11.9–13.1. Etymology. The name of this new species is derived from the posterior area of male subgenital plate posteriorly prolonged, the Greek “ mecyn- ” means prolonged. Discussion. We collected numerous specimens of this new species on ferns and bamboos at altitudes above 2500 meters, where it predominantly inhabits low-growing vegetation. The male of this new species resembles Acosmetura longitubera Wang, Shi & Wang, 2018, but differs in the following: male cercus with a tooth on the inner surface near base, and genitalia bearing a pair of laminae that connected at base. The female is very distinct from other Acosmetura species in its significantly enlongated and slightly upcurved ovipositor. Distribution. Sichuan (China).