﻿First records of the crane fly genus Helius Lepeletier & Serville (Diptera, Limoniidae) in Guangxi, China with description of one new species

﻿Abstract The genus Helius Lepeletier & Serville, 1828 is recorded in Guangxi, China for the first time with the following three species belonging to the subgenus H. (Helius): H. (H.) damingshanussp. nov., H. (H.) nipponensis (Alexander, 1913) and H. (H.) stenorhynchus stenorhynchus Alexander, 1954. Among them, H. (H.) stenorhynchus stenorhynchus is also a new record in China. Their descriptions and illustrations, as well as the first key to Chinese H. (Helius) crane flies, are presented.

Guangxi Zhuang Autonomous Region (Guangxi) is located at the southeast edge of the Yunnan-Guizhou Plateau in China, with mountains, hills, platforms, plains and other types of landforms. There are many hills and plains in the middle and south of Guangxi, a basin-like region called "Guangxi Basin". Although Guangxi is a region with high biodiversity, there is no record of Helius crane flies. To improve the understanding of the diversity of crane flies in Guangxi and the distribution of Helius in China, some investigations on crane flies in Guangxi have been initiated by the authors together with other entomologists since 2011, resulting in the discovery of Helius in Guangxi for the first time.

Material and methods
Specimens for this study were collected from several localities in Guangxi, China ( (CAU). Genitalic preparation of males was made by macerating the apical portion of the abdomen in cold 10% sodium 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 Canon EF100 mm f/2.8L Macro IS USM lens.

Taxonomy Key to Chinese species of Helius (Helius)
1 Rostrum about equal in length to combined head (excluding rostrum) and thorax (Fig. 7b) (Brunetti 1912). Outer gonostylus with subtip not expanded. Interbase in the shape of pale scoop with stem short and stout (Alexander 1964 (Brunetti, 1912) -Prescutum and presutural scutum with three broad stripes (Fig. 5c). Outer gonostylus with subtip slightly expanded ( Fig. 6a, b, e). Interbase horn-like ( Fig. 6c, Fig. 7a), tibiae and tarsi pale yellow, outer tarsal segments brown. Wing with distance between tips of R 4 and R 5 about 5 times as long as distance between tips of R 1 and R 4 , Sc ending at middle of Rs (Alexander 1932c  16 Wing with distance between tips of R 4 and R 5 about 1.5 times as long as distance between tips of R 1 and R 4 . Abdominal sternites bicolored (Alexander 1937). Outer gonostylus with inner spine acute apically (Fig. 4j)  Diagnosis. Antenna with basal flagellomeres oval. Rostrum about equal in length to remainder of head. Prescutum and presutural scutum pale brown with a narrow darker median line. Femora of legs pale brown with base paler. Wing with oval brown stigma; Sc ending shortly before fork of Rs; m-cu beyond fork of M. Outer gonostylus slightly curved, inner spine flat apically. Interbase nearly globular, laterally with narrow, apically dilated outgrowth. Distal 2/3 of aedeagus arched dorsally.
Head (Fig. 2b). Dark brown. Setae on head brownish black. Antenna brown. Scape long cylindrical, 2.5 times as long as wide; pedicel oval; basal flagellomeres oval, with short brownish black verticils, outer flagellomeres tapering apically and elongated, with long brownish black verticils that exceed length of corresponding flagellomere. Rostrum about equal in length to remainder of head, brown with brownish black setae. Palpus brown with brownish black setae.
Thorax (Fig. 2c). Pronotum brown. Prescutum and presutural scutum pale brown with a narrow darker median line. Postsutural scutum pale brown, each lobe with a white spot. Scutellum brown, paler medially. Mediotergite pale brown. Pleuron (Fig. 2a) brownish yellow with anepisternum darker. Setae on thorax brownish black. Fore and mid coxae brownish yellow, hind coxa pale yellow; trochanters pale brownish yellow, tips narrowly black; femora pale brown with base paler; tibiae and tarsi pale brown. Setae on legs brownish black. Wing (Fig. 2d) tinged with pale brown. Stigma oval and brown. Veins brown. Venation: Sc long, ending slightly before fork of Rs; sc-r close to tip of Sc; distance between tips of R 4 and R 5 about 3 times as long as distance between tips of R 1 and R 4 ; cell dm short, about 1.5 times as long as wide; m-cu variable in position, from fork of M to 1/4 of cell dm. Halter brown with knob brownish yellow.
Etymology. The specific name refers to the type locality Mount Damingshan.

Helius (Helius) nipponensis (Alexander, 1913) Figs 5, 6
Rhamphidia nipponensis Alexander, 1913: 207 Diagnosis. Antenna with basal flagellomeres cylindrical. Rostrum about equal in length to remainder of head. Prescutum and presutural scutum brownish yellow with three broad brown stripes; median stripe longest, broadest, darker in front; lateral stripes extending onto lobes of postsutural scutum. Femora of legs brownish yellow to brown. Wing with stigma very indistinct; Sc ending near fork of Rs; m-cu beyond fork of M. Outer gonostylus curved with subtip slightly expanded; outer spine small, inner spine large and bent outwards. Interbase horn-like. Aedeagus straight.
Head (Fig. 5b). Dark brown. Setae on head brownish black. Antenna brown. Scape long cylindrical, twice as long as wide; pedicel oval; flagellomeres cylindrical, verticils brownish black, not exceeding flagellomere in length. Rostrum about equal in length to remainder of head, brown with brownish black setae. Palpus pale brown with dark brown setae. Thorax (Fig. 5c). Pronotum dark brown with two sides brownish yellow. Prescutum and presutural scutum brownish yellow with three broad brown stripes; median stripe longest, broadest, darker in front; lateral stripes extending onto lobes of postsutural scutum. Postsutural scutum dark brown, middle area pale brownish yellow, each lobe with a yellow spot. Scutellum brown with margins paler. Mediotergite dark brown. Pleuron (Fig. 5a) brownish yellow with anepisternum brown. Setae on thorax dark brown. Fore and mid coxae pale brownish yellow, hind coxa yellow; trochanters pale brownish yellow, tips narrowly black; femora brownish yellow to brown; tibiae and tarsi brown. Setae on legs dark brown. Wing (Fig. 5d) tinged with yellow. Stigma very indistinct. Veins pale brown. Venation: Sc long, ending opposite fork of Rs; sc-r close to tip of Sc; distance between tips of R 4 and R 5 about 2.5 times as long as distance between tips of R 1 and R 4 ; cell dm about twice as long as wide; m-cu more than 1/3 its length beyond fork of M, near 1/4 of cell dm. Halter pale yellow with knob darker. Abdomen (Fig. 5a). Tergites dark brownish yellow. Sternites brownish yellow with sternite 1 paler. Setae on abdomen brown. Hypopygium (Fig. 6). Yellow. Posterior margin of tergite 9 with a V-shaped emargination (Fig. 6a). Gonocoxite conical, outer side with long brown setae (Fig. 6a, b). Outer gonostylus curved with subtip slightly expanded; tip blackened and bispinous, outer spine small, inner spine large and bent outwards  ( Fig. 6a, b, e). Inner gonostylus curved, broad at basal half (Fig. 6a, b, e). Aedeagal complex with semen pump spherical (Fig. 6c, d), ejaculatory apodeme short and flattened (Fig. 6c, d); aedeagus straight, rod-shaped ( Fig. 6a-d). Parameres medially fused and expanded, basal parts short, apical elongated with tip bent outwards. Interbase horn-like (Fig. 6c, d, f).
Distribution. China (Guangxi, Zhejiang); South Korea; Japan. Remarks. Helius (H.) nipponensis is distributed in China, South Korea and Japan (Oosterbroek 2023). In China, this species was previously known in Zhejiang (Podenas et al. 2015) and is now recorded in Guangxi for the first time. For descriptions and illustrations of this species, also see Alexander (1913Alexander ( , 1920Alexander ( , 1929b and Podenas et al. (2015). Alexander, 1954 Figs 7, 8 Helius (Helius) stenorhynchus Alexander, 1954: 161 Diagnosis. Antenna with basal flagellomeres oval and crowded. Rostrum unusually long and slender, about equal in length to combined head (excluding rostrum) and thorax. Prescutum and presutural scutum brownish red with an indistinct darker median line, anterior region more or less infuscated. Femora of legs yellow with narrowly darker tips. Wing with oval brown stigma and inconspicuous dark seams; Sc atrophied, sc-r at its tip and ending slightly before fork of Rs; m-cu beyond fork of M. Outer gonostylus nearly straight; inner spine shorter and stouter. Interbase nearly globular with a curved, apically blackened spine-shaped outgrowth. Distal half of aedeagus curly dorsally.
Head (Fig. 7b). Brownish black. Setae on head dark brown. Antenna brown, scape and pedicel brownish black, flagellomeres brown with basal segments darker. Scape long cylindrical, 3 times as long as wide; pedicel nearly oval, widened distally; basal flagellomeres oval and crowded, with short brown verticils, outer flagellomeres tapering apically and elongated, with long brown verticils that exceed length of corresponding flagellomere. Rostrum unusually long and slender, about equal in length to combined head (excluding rostrum) and thorax, brownish black with dark brown setae. Palpus pale brownish yellow with pale brown setae. Thorax (Fig. 7c). Pronotum brownish red with middle darker. Prescutum and presutural scutum brownish red with an indistinct darker median line, anterior region more or less infuscated. Postsutural scutum brownish red, each lobe with a small white spot. Scutellum and mediotergite dark brown. Pleuron (Fig. 7a) dark brown. Setae on thorax dark brown. Fore and mid coxae pale  yellow, hind coxa paler; trochanters pale yellow, tips narrowly black; femora yellow, tips narrowly darker; tibiae and tarsi dark yellow to pale brownish yellow. Setae on legs brown. Wing (Fig. 7d) tinged with grayish yellow. Stigma oval and brown; inconspicuous dark seams on cord, outer end of cell dm and CuA, darker on anterior cord. Veins pale brown to brown. Venation: Sc atrophied; sc-r at tip of Sc, ending slightly before fork of Rs; distance between tips of R 4 and R 5 3-4 times as long as distance between tips of R 1 and R 4 ; cell dm about twice as long as wide; m-cu about 1/4 its length beyond fork of M. Halter yellow.
Abdomen (Fig. 7a). Brown with first abdominal segment short and paler, segments 6-9 slightly darker; caudal border of each segment narrowly brownish black. Setae on abdomen dark brown.
Distribution. China (Guangxi); Myanmar. Remarks. Helius (H.) stenorhynchus stenorhynchus was previously known only from Myanmar (Oosterbroek 2023) and is now recorded in China for the first time. For descriptions and illustrations of this subspecies, also see Alexander (1954).

Conclusions
Here, the crane fly genus Helius is recorded in Guangxi for the first time with three species, of which H. (H.) damingshanus sp. nov. is described and illustrated as new to science, H. (H.) stenorhynchus stenorhynchus Alexander, 1954, previously known only from Myanmar, is recorded in China for the first time, and H. (H.) nipponensis (Alexander, 1913), previously known from Zhejiang, China, as well as South Korea and Japan, is also added to the fauna of Guangxi. The known species and subspecies are also redescribed and illustrated. An identification key to H. (Helius) crane flies in China is presented for the first time.