Tumeochrysa (Nineta) acuta Wu & Liu, 2024, sp. nov.

[26] Tumeochrysa (Nineta) acuta sp. nov. (Figs 34, 83) Diagnosis. This species is characterized by the presence of the head and thorax of without spots or markings, the outer gradate series of forewing darker than inner gradate series, the male sternum IX elongated and curved towards dorsal apically, the median arch of gonarcus with small V-shaped invagination, and the length of female subgenitale about 1.5 times width. Description. Male. Body length 14.3–15.4 mm, forewing length 17.1–17.4 mm, hindwing length 16.0– 17.1 mm. Head without spots, vertex raised. Compound eyes prominent and black. Antennae yellow, scape and pedicel wider than flagellum. Frons, clypeus and gena without spots. Maxillary palpi with brown stripe on outer side, labial palpi brownish yellow. Pronotum short and quadrate, sometimes with small reddish spots on anterolateral angle. Mesonotum and metanotum without markings. Legs with dense setae and without spots. Pretarsal claws brown, with basal dilation. Forewing broad, without shadings. Pterostigma indistinct. Costal area with 26–30 crossveins; 17–19 radial crossveins present. m1 smaller than m2; im ovoid; 11 psm-psc crossveins present. c1 smaller than c2, dcc opened. A1 forked, A2 and A3 simple. CuP brown. Inner gradate series with 9–13 crossveins, outer gradate series with 9–14 crossveins. Hindwing slightly narrow. Pterostigma indistinct. Costal area with 22–26 crossveins; 18 radial crossveins and 10 psm-psc crossveins present. Inner gradate series with 8–13 crossveins, outer gradate series with 8–13 crossveins. Abdomen with dense setae. Tergum VII and sternum VII subquadrate in lateral view; tergum VIII and sternum VIII about 1/3 as long as tergum VII; sternum IX elongated and curved towards dorsal apically; tergum IX fused with ectoproct; ectoproct rounded. Callus cerci ovoid. Gonarcus arcuate, median arch with acute V-shaped invagination, lateral arms expanded; entoprocessus broad; arcessus broad and curved. Female. Body length 13.9–15.0 mm, forewing length 20.7–23.3 mm, hindwing length 17.1–20.9 mm. Sternum VII slightly longer than tergum VII; tergum VII subquadrate in lateral view; tergum VIII shorter than tergum VII obviously; tergum IX fused with ectoproct. Callus cerci ovoid. Subgenitale bilobed apically, length about 1.5 times of width; spermatheca thin; vela short; ventral impression absent; duct long and coiled. Type material. Holotype ♂, China, Qinghai, Menyuan, Zhuguke, Magou, 2021.VII.01, Rongrong Shen (CAU); Paratypes: 2♀, same as holotype (CAU); 1♂, China, Qinghai, Huzhu, Beishan Forestry Station, 2100 m, 2015. VII.26, Chunlai Wang (CAU); 2♂, China, Sichuan, Jiangyou, Pingwu, Wanglang National Nature Reserve, 2596 m, 2015.VII.06, Lu Yue (CAU); 1♀, China, Sichuan, Muli, Wujiao, 2823 m, 2020.VIII.24, Yuezheng Tu (CAU); 1♀, China, Xizang, Nyingchi, 2014.VIII.19, Huilin Han (CAU); 1♀, China, Shaanxi, Xi’an, Zhouzhi, 2057 m, 2014. VIII.19, Xuankun Li (CAU); 1♀, China, Gansu, Zhouqu, Wuping, Chagang Forestry Station, light, 1800 m, 2018. VII.12, Aili Lin (CAU). Etymology. The specific epithet ‘ acuta ’ refers to the acute V-shaped invagination on median arch of male gonarcus in the new species. Distribution. China (Gansu, Qinghai, Shaanxi, Sichuan, Xizang). Remarks. This new species is similar to T.vittata in external morphological characters.However,the invagination on median arch of the male gonarcus of this new species is V-shaped, and the arcessus is broad compared to T. vittata, which has gonarcus with a U-shaped invagination and narrower arcessus.