﻿New species and records of the genus Antocha Osten Sacken (Diptera, Limoniidae) from Tibet, China with a key to species in Qinghai-Tibet region

﻿Abstract Thirty-four known species and subspecies of the genus Antocha Osten Sacken, 1860 have been recorded from China, of which four occur in Tibet. Herein, two new Antocha species, A. (Antocha) curvativasp. nov. and A. (A.) tibetanasp. nov., are described and illustrated from Tibet. The new species are distinguished from congeners mainly by their male genitalia. Antocha (A.) spiralis Alexander, 1932 and A. (A.) setigera Alexander, 1933, which are newly recorded in Tibet, are redescribed and illustrated. A key to Antocha species in the Qinghai-Tibet region of China is also presented.

Tibet is located in the Qinghai-Tibet region of China, which also includes all of Qinghai, western Sichuan, and small parts of Gansu, Xinjiang, and Yunnan. The main body of the region is the Qinghai-Tibet Plateau, which is known as the "roof of the world" because of its high terrain and extensive grasslands. The Qinghai-Tibet region is also the source of many rivers in China.
At present, 34 Antocha species and subspecies are recorded from China, of which 22 are known in the Qinghai-Tibet region, while only four are distributed in Tibet (Oosterbroek 2023). In this study, specimens of Antocha from Tibet have been examined, and four species are added to the fauna of Tibet (Fig. 1), of which A. (A.) curvativa sp. nov. and A. (A.) tibetana sp. nov. are described and illustrated as new to science, and A. (A.) spiralis Alexander, 1932 and A. (A.) setigera Alexander, 1933 are newly recorded from Tibet. More comprehensive redescriptions and illustrations for the two known species, as well as a key to the Antocha crane flies in Qinghai-Tibet region, are also presented.

Materials and methods
All specimens for this study were collected from Tibet, China by various entomologists in 2014-2018. Type specimens are deposited in Entomological Museum of China Agricultural University, Beijing, China (CAU). The holotype of A. (A.) setigera, deposited in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA (USNM), was also examined. Genitalic preparations of males were made by macerating the apical portion of the abdomen in cold 10% hydroxide (NaOH) for 12-15 hours. Observations and illustrations were made using a ZEISS Stemi 2000-C stereomicroscope. Photographs were taken with a Canon EOS 90D digital camera through a macro lens. Details of coloration were examined in specimens immersed in 75% ethanol (C 2 H 5 OH).
The morphological terminology mainly follows Cumming and Wood (2017) and de Jong for wing venation (2017). The term "inner branch of paramere" is adopted from Kato and Tachi (2019). The general distribution of species is given according to Oosterbroek (2023).
Head (Fig. 2b). Dark brown, with brown setae. Antenna dark brown. Scape cylindrical; pedicel oval; flagellomeres oval, apically tapering and shortened. Setae on antenna brown. Rostrum light brown; palpus brown to dark brown; setae on rostrum and palpus brown. Thorax (Fig. 2c). Pronotum dark brown. Prescutum and presutural scutum brown, with four more or less confluent dark brown stripes. Postsutural scutum brown; scutal lobes each with a darker brown spot. Scutellum brown, with side edges dark brown. Mediotergite dark brown. Pleuron brown (Fig. 2a). Legs with light brown coxae; trochanters light yellow with side edges brown; femora yellowish, becoming brown towards apex; tibiae and tarsal segments brown. Setae on legs brown. Wing light brown, without stigma; anal angle nearly right-angled (Fig. 2d). Veins light brown. Venation: Sc ending before fork of Rs, at about 2/3 of Rs; basal section of R 5 about as long as r-m; m-cu shortly before fork of M, distance approximately 1/4 its own length; basal section of M 3 about four times as long as m-m; cell m 1 about as long as cell dm. Halter with stem pale.
Female. Body length 5.0-5.5 mm, wing length 4.5-5.0 mm. Generally similar to male by body coloration.
Etymology. The specific name refers to the curved apical part of paramere. Distribution. China (Tibet).  Diagnosis. Antocha (A.) setigera can be recognized by thorax with four brown stripes, wing lacking a stigma, basal section of M 3 as long as m-m, and slightly curved outer gonostylus with blackened, blunt tip. Aedeagal complex with interbase distally small and parameres apically fused, arch-shaped.
Head (Fig. 4b). Dark brown with brown setae. Antenna brown with light brown scape. Scape cylindrical; pedicel and flagellomeres elongate oval, apically tapering; terminal segment short, about half as short as other segments. Rostrum yellow; palpus light brown; setae on rostrum and palpus brown.
Thorax (Fig. 4c). Pronotum brown. Prescutum and presutural scutum brown four brown stripes. The central stripes fused in the anterior third, the rest is separated by pale narrow vitta. Postsutural scutum dark brown, middle area yellow, scutal lobes each with brown spot. Scutellum pale yellow, with side edges dark brown. Mediotergite brown to dark brown. Pleuron brown (Fig. 4a). Legs with fore coxa brown; mid coxa brownish yellow; hind coxa yellow; trochanters yellow; femora and tibiae brownish yellow; tarsi brown with terminal segments darker brown. Wing light brown, without stigma; anal angle nearly right-angled (Fig. 4d). Veins brown. Venation: Sc ending nearly at fork of Rs; basal section of R 5 about twice as long as r-m; m-cu shortly before fork of M, distance approximately 1/3 its own length; basal section of M 3 as long as m-m; cell m 1 longer than cell dm. Halter pale with stem light yellow.
Female. Body length 4.5-5.5 mm, wing length 5.0-6.0 mm. Generally similar to male by body coloration.

Distribution. China (Sichuan, Tibet).
Remarks. In China, this species was previously only known in Sichuan province and is now recorded in Tibet for the first time. For descriptions and illustrations of this species, also see Alexander (1933b) and Markevičiūtė et al. (2019Markevičiūtė et al. ( , 2021. Diagnosis. Antocha (A.) spiralis can be recognized by thorax having no stripes, wing without stigma, basal section of M 3 about one and half times as long as m-m, posterior margin of tergite 9 having shallow, median emargination and slightly curved, blackened in distal 2/3 of outer gonostylus. Aedeagal complex with interbase nearly Ushaped; paramere apically slender and twisted into a spiral; inner branch of paramere with bifid tip.
Thorax (Fig. 6c). Pronotum brown. Prescutum and presutural scutum dark brown, without stripe. Postsutural scutum brownish yellow in middle; scutal lobes each with brown spot. Scutellum brown with middle of base brownish yellow. Mediotergite dark brown, with middle brownish yellow. Pleuron brown (Fig. 6a). Legs with fore and mid coxae brown; hind coxa yellow; trochanters yellow with side edges brown; femora brownish yellow to brown; remaining segments dark brown. Wing light brown, without stigma; anal angle nearly right-angled (Fig. 6d). Veins brown. Venation: Sc ending before fork of Rs, at about 5/6 of Rs; basal section of R 5 about 1½ times as long as r-m; m-cu shortly before fork of M, distance approximately 1/4 its own length; basal section of M 3 about 1½ as long as m-m; cell m 1 longer than cell dm. Halter pale.
Female. Body length 4.5-5.5 mm, wing length 5.0-6.0 mm. Generally similar to male by body coloration.
Distribution. China (Sichuan, Tibet), India. Remarks. In China, this species was previously only known in Sichuan and is now recorded in Tibet for the first time. For descriptions and illustrations of this species, also see Alexander (1932) and Markevičiūtė et al. (2019Markevičiūtė et al. ( , 2021. Both A. (A.) spiralis and A. (A.) bella from China have the twisted structure of the hypopygium. In A. (A.) spiralis, the apical part of the paramere is slender and twisted into a spiral, and the tip of the inner branch of the paramere is bifid (Figs 6e, 7), while in A. (A.) bella, the tip of the inner branch of the paramere is twisted (Markevičiūtė et al. 2019 (Fig. 8b). Dark brown, with brown setae. Antenna brown, with brown setae. Scape nearly cylindrical; pedicel oval; flagellomeres oval, apically shortened. Rostrum and palpus brown, with brown setae.

Head
Thorax (Fig. 8c). Pronotum brown. Prescutum and presutural scutum brownish yellow, with three dark brown stripes. Postsutural scutum brownish yellow; scutal lobes each with a brown spot. Scutellum brown, with middle brownish yellow. Mediotergite brown with side edges light brown. Pleuron brownish yellow (Fig. 8a). Legs with coxae and trochanters yellow; rest of segments brownish yellow. Wing light brownish yellow, with very indistinct stigma; anal angle nearly right-angled (Fig. 8d). Veins brownish yellow. Venation: Sc ending before fork of Rs, at about 5/6 of Rs; basal section of R 5 about 1½ as long as r-m; m-cu shortly before fork of M, distance approximately 1/3 its own length; basal section of M 3 about twice as long as m-m; cell m 1 longer than cell dm. Halter pale with stem light yellow.
Female. Body length 5.0-5.3 mm, wing length 5.5-5.7 mm. Generally similar to male by body coloration.
Etymology. The species is named after the type locality, Tibet. Distribution. China (Tibet). Remarks. The new species is somewhat similar to A. (A.) spiralis from China and India with the similar wing venation and bifid tip of inner branch of paramere, but it can be easily distinguished by the three stripes on the thorax (Fig. 8c) and the triangular apex of the paramere (Figs 8e, 9). In A. (A.) spiralis, the thorax has no obvious longitudinal stripes (Fig. 6c), while the apex of the paramere is slender and twisted into a spiral (Figs 6e, 7).