A review of the genus Stratiomys Geoffroy (Diptera: Stratiomyidae) from India with description of a new species

. A review of the genus Stratiomys from India is presented. The new species Stratiomys brunettii sp. nov. is described based on male and female specimens collected from the Kashmir Himalayas. The only other congener previously recorded in India, Stratiomys approximata , is redescribed. A key to the species is presented.


Introduction
The fl ies belonging to the family Stratiomyidae Latreille, 1802 are commonly known as soldierfl ies.The global extant fauna of Stratiomyidae contains over 2800 species, distributed across 12 subfamilies and 378 genera (Woodley 2001(Woodley , 2011;;Hauser et al. 2022).The genus Stratiomys Geoffroy, 1762 is a medium-sized genus of soldierfl ies with above 90 species recorded worldwide (Woodley 2001(Woodley , 2011;;Nerudová et al. 2007).The members of the genus are mostly medium-sized fl ies with elongated antenna and a broad-fl attened abdomen (Nerudová et al. 2007).
The majority of Stratiomys are found in the Holarctic Region and just a few species from the Neotropics and Oriental Region (Woodley 2001;Nerudová et al. 2007).There are just fi ve species known from the Oriental Region (Nerudová et al. 2007) with a single valid species currently known from India (Wachkoo et al. 2017).Brunetti (1920) fi rst identifi ed the Indian specimens from Kashmir erroneously as S. barca (Walker, 1849); however, upon comparison with type material he later realized it was a new species and described it as S. approximata Brunetti, 1923.Brunetti also considered similar specimens collected from China to be the conspecifi c, although no direct comparison was made.
All the Oriental species have previously been presented by Brunetti (1920Brunetti ( , 1923) ) and Nerudová et al. (2007).However, the species name Stratiomys kashmirensis attributed to specimens deposited in ZSI by Brunetti has never been published.The name S. kashmirensis was coined by Brunetti in 1921 for specimens from Sonamarg, Kashmir, but he did not formally publish it.Stratiomys kashmirensis is therefore an unavailable name according to the International Code of Zoological Nomenclature.Because a combination of characters readily distinguishes the species from other congeners, we herein describe it as a species new to science, Stratiomys brunettii sp.nov.
In this study, we revise the taxonomy of the genus Stratiomys in India, describe S. brunettii as a new species from the Kashmir Himalayan Region and present a redescription of S. approximata Brunetti, 1923.In addition, we provide an illustrated identifi cation key to Indian species, as well as a map showing the known distribution ranges (Fig. 1).

Collection sites
This study is based on specimens collected in the Kashmir Valley, located in the north-western part of the Indian subcontinent between 33°22′ and 34°50′ N latitude and 73°55′ and 75°33′ E longitude ( Maqbool et al. 2018;Wachkoo et al. 2019).The Kashmir Valley represents a transitional zone between Oriental and Palaearctic regions, sharing boundaries with the north-western tip of the Oriental and midsouth of the Palaearctic Region (Das 1966;Maqbool et al. 2022).

Morphological studies
The morphological study was conducted using a G2Mark stereo microscope (G2Mark, India).Adult specimens of S. approximata were identifi ed using Nerudová et al. (2007) and compared with images of specimens of S. barca deposited at ZSI, which are identical with specimens (and possibly syntypes) of S. approximata.Direct comparisons were made with the images of specimens deposited at ZSI for S. brunettii sp.nov.Morphological terminology and abbreviations follow Cumming & Wood (2017) and Hauser et al. (2017), and for male terminalia Fachin & Hauser (2018).
Body length was measured as the outstretched length from the base of the antenna to the posterior end of the abdomen, in lateral view.Wing length was measured from the wing base to the wing apex.

Male terminalia preparation
For the extraction and preparation of male terminalia the procedure of Wachkoo et al. (2021) was followed with a little modifi cation.Terminal abdominal segments were removed and placed in a 10% KOH solution overnight at room temperature to achieve proper transparency.The material was then treated with 100% glacial acetic acid for 10 minutes to neutralise the effect of KOH.Subsequently, the material was given a quick dip in 75% ethanol and transferred to a cavity glass slide having glycerol as a temporary mount.The synsternite was detached from the epandrium and genital capsule for better visual analysis.To attain an appropriate angle, water based sterile lubricant transparent gel (K-Y Jelly), was used.A small drop of the gel was placed on the centre of the glass slide cavity, with the material to be photographed placed over it and carefully manipulated with fi ne tipped forceps to achieve appropriate orientation.A drop of glycerol was added on top of the gel to smoothen the surface and reduce the amount of light refl ection.

Images
Images of adult specimens were captured with a mirrorless digital camera (Nikon Z50).To achieve adequate exposure of specimens, a light box was used to produce diffused light (Wachkoo et al. 2021).Multiple images were focus stacked in the combine ZP programme to create one fi nal image (Yatoo et al. 2022).Final plates were assembled with Adobe Photoshop ® CS4.The above setup was also used for capturing terminalia (submersed in glycerol) microphotographs, with the addition of infi nite microscope objectives (Maqbool et al. 2021).

Distributional maps
Global distributional map (Fig. 1A) was prepared using Google maps and Google Earth Pro ver.7.3.6.9326.To prepare the map of Kashmir Valley showing the sampling sites (Fig. 1B), ArcMap module of the ArcGIS software package ver.10.1 was used.Geographical coordinates of the sampling sites were imported to mapping software and the sampling site was plotted.

Diagnosis
Among the Stratiomyini, the Asian species of the genus Stratiomys are characterized by having holoptic eyes in males, dichoptic ones in females; elongate scape, which is more than three times as long as the pedicel, and the cross section of the fl agellomeres are round and not oval-shaped; scutellum is with two prominent straight or curved spines; vein R 2+3 arises distinctly beyond the anterior cross vein r-m; vein R 4 is present; medial veins (M) originate from the discal cell and curve anteriorly toward apex, ending before the wing margin (Rozkošný 1973(Rozkošný , 1982;;Nagatomi 1977;Nerudová et al. 2007).

Diagnosis
Stratiomys approximata is diagnosed by having eye distinctly hairy, scutellar spines straight or slightly incurved, wing slightly brownish towards middle region, yellow angled spots at edges of abdomen on tergite II, III and IV not joining at middle, mostly black tibiae; black femur, and mostly yellow tarsi with apical 2 segments blackish brown.The species is somewhat similar to S. barca, which can be separated by having yellow spots on tergites joining at middle forming a narrow continuous band, and femur brown and tarsi black.

Redescription
MEASUREMENTS.Male (Fig. 2): body length, 11.7-12.2mm; wing length, 9.8-9.9mm; female (Fig. 3): body length, 11.9-12.5 mm; wing length, 9.6-10.6mm.HEAD.Elliptical in anterior view, eyes distinctly hairy, antenna with 5 fl agellomeres, black except for brownish pedicel and yellowish-brown base of 1 st fl agellomere, fl agellum longer than scape and pedicel combined; area around antenna black (Fig. 2D-E); face black with two small yellow spots in male, near eye margin below base of antenna (Fig. 2C-E), much wider spots in female starting above antennal base and extending almost to lower margin of eye, leaving black pattern extending along frontal depression and continuing as broad medial stripe on face (Fig. 3D-G).
THORAX.Black with yellowish white dense and long pilosity (Fig. 2H-I); scutellum mostly black except for narrow yellow band along apical margin with two prominent spines (Fig. 2J); wing generally hyaline but slightly brownish towards middle region with brownish veins; veins M 1 , M 2 , M 3 and M 4 curved, ending before wing margin; vein r-m < M 2 (Figs 2K, 3K); legs mostly black with tarsus, base and apex of tibia yellow.
ABDOMEN.Black, broader than thorax with whitish yellow angled spots at edges of abdomen on tergite II, III and IV; spots on 2 nd tergite wider (Fig. 2L-M); abdomen banded ventrally, sternites black with yellow margins, joined in middle forming a continuous yellow band from 2 nd -4 th sternite.
MALE TERMINALIA (Fig. 2N-P).Epandrium convex and semioval with emarginate anterior margin, transverse posteriorly, with short fi ne setae, denser towards lower and lateral margins and sparsely distributed towards centre; proctiger subtriangular with suboval cercus having posterior margin obliquely transverse, margins with large and small setae (Fig. 2N); in lateral view, cercus covering terminalia up to base of distal portion where aedeagal lobes are joined; synsternite triangular, with short and thick setae on middle portion and longer setae on lower middle and lateral margins; distal margin of synsternite arcuate medially, laterally produced into oval processes with round margin; gonostylus longer than wide, placed on distal third of synsternite, ending in short pointed edge; gonocoxal apodemes reaching up to anterior margin of genital capsule (Fig. 2O ); phallus smooth, distinctly longer than genital capsule, tripartite distally, medial lobe distinctly shorter and wider than outwardly divergent lateral lobes (Fig. 2P); medial lobe arcuate terminally, lateral lobes pointed.FEMALE TERMINALIA (Fig. 3N-O).Tergite 9 nearly rectangular, anterior margin sub-medially emarginate, creating nearly triangular process medially; tergite 10 strongly triangular, distal apex rounded; cerci ovate, narrow at base and wider towards apex (Fig. 3N); genital fork wide, anterior third more or less semicircular, narrower than posterior two-thirds; posterolateral process wider basally, narrower and strongly convergent towards apex; posterior bridge with shorter projections (Fig. 3O).

Diagnosis
The new species appears distinct among its congeners in having upcurved scutellar spines nearly perpendicular to the body axis.The species is somewhat similar to the Oriental species S. micropilosa (Brunetti, 1920) but has upcurved scutellar spines nearly perpendicular to the body axis, all tibiae are nearly completely yellow, the postocular area is relatively expanded, and black sternites with wide yellow margins are joined laterally, as opposed to the scutellar spines not upright, all tibiae are nearly completely black, the postocular area is not expanded that much, the sternites are yellow-orange with lateral dark spots and no dark continuous bands in addition to the other characters stated below.

Etymology
This species is named in memory of Enrico Adelelmo Brunetti (1862Brunetti ( -1927)), for his valuable contributions to our knowledge of the systematics of the Indian Diptera.Kashmir, Sonamarg;alt. 9000 ft;17-23 Jun. 1921; stn 7 Kashmir Survey Collection; ZSI 9824/H2 • 1 ♀; same collection data as for preceding; ZSI 9826/H2.Images match our specimens, but we have not examined the actual specimens.

Description
Male (Fig. 4) MEASUREMENTS. Body length,wing length, HEAD.Black, dorsally hemispherical, elliptical in anterior view, suboval in lateral view, ocellar triangle black (Fig. 4E-F); eye bare, facets markedly smaller in lower third; antenna long, black, fl agellum with 5 fl agellomeres, fl agellum longer than scape and pedicel combined, apical fl agellomere dull, relative lengths of scape : pedicel : fl agellum = 3 : 1 : 5 (Fig. 4G); face smooth with fi ne punctations, rugulose in lower middle portion (Fig. 4D); oral margin broadly black with black colouration continuing on gena below eye; face with long whitis h yellow pilosity; lower frons above antenna shiny black, fi nely punctate with long whitish yellow pilosity; median line between eyes with tuft of small black setae longer and brownish behind ocellar tubercle; vertex with brownish yellow pilosity (Fig. 4E-F); face yellow with broad median stripe, narrowing toward oral margin and there merging into black oral margin (Fig. 4C-E); postocular rim narrow, yellow and swollen in lower third; back of head mainly black only with some yellow from postocular rim continuing to back of head; occiput pilose (Fig. 4F).
LEGS.Bicoloured (Fig. 4C); coxa, trochanter and femur black, apical portion of femur, tibia and tarsus yellow; tarsal claws black with basal half yellow; yellowish white pilosity on legs, fi ner on tibia and tarsi, and longer on femur and trochanter.ABDOMEN.Rounded, broader than thorax, predomina ntly black; angled pale yellow spots at edges of abdomen (Fig. 4L-M); wider spots on II and III tergite, narrow posterior-lateral spots on tergite IV, lateral margins of tergite II-IV yellow; narrow longitudinal medial stripe on tergite V not reaching anterior margin and partly extending along posterior margin; abdomen mostly black ventrally with yellow bands, black sternites with wide yellow margins joined laterally; longer brownish yellow pilosity on tergites, fi ner, whitish pilosity on sternites.MALE TERMINALIA (Fig. 4N-P).Epandrium convex and semioval, posterior margin obtuse, arcuate anteriorly with short fi ne setae, denser towards lower and lateral margins and sparsely distributed towards centre (Fig. 4N); proctiger resembling low tri angle with subquadrangular cercus having posterior margin obliquely transverse with slightly produced posteromedial lobe, margins with large and small setae; cercus totally covering terminalia in lateral view; synsternite subquadrate, with short and thick setae on middle portion and longer setae on lower middle and later al margins; distal margin of synsternite medially obtuse, laterally produced into oval processes with round margin; gonostylus longer than wide, placed on distal third of synsternite, ending in two pointed edges, one smaller and short pointed edge and a longer gradually tapering pointed edge; gonocoxal apodemes reaching beyond anterior margin of genital capsule (Fig. 4O); phallus smooth, tripartite and slightly longer than genital capsule, lobes dilated in distal third, distinctly narrowing in apical one third; lateral lobes slightly inc urved, medial lobe straight and shorter than lateral lobes (Fig. 4O-P).
Female (Fig. 5) MEASUREMENTS.Body length, 12.60-13.7 mm; wing length, 10.85-11.9mm.Differs from male in the following aspects: body pilosity less dense than male (Fig. 5A-C); frons broad and black with two yellow spots extending towards middle but not joined (Fig. 5D); vertex wide and prominent, with areas densely covered with short black pilosity; area arou nd base of antenna black, black pattern narrowly extending along frontal depression and continuing as broad medial stripe on face (Fig. 5D, G); oral margin broadly black with black colouration continuing on gena below eye (Fig. 5G); postocular rim contrasting yellow and continuing on posteroventral margin of eye; median occipital sclerite with large yellow spots (joined in most specimens); occiput yellow smooth with fi ne yellow pilosity (Fig. 5F); scutellar spines pale yellow with brownish apical region (Fig. 5I-J); pale yellow abdominal spots on tergite III (Fig. 5L-M) slightly narrower th an in male, spots on tergite IV joined in the middle forming continuous band.FEMALE TERMINALIA (Fig. 5N-O).Tergite 9 nearly square-shaped, emarginate base with deep notch medially; circus 2 very small, appearing as bud on cercus 1 (Fig. 5N); tergite 10 triangular, distal apex rounded; genital fork nearly uniformly wide, with slightly arcuate anterior margin; posterior bridge without projections; posterolateral process wider basally, narrower and strongly convergent towards apex (Fig. 5O).

Key to the Indian species of Stratiomys Geoffroy, 1762
1. Eye distinctly hairy; scutellar spines straight or slightly incurved (Fig. 2J); wing slightly brownish towards middle region; tibiae mostly black; phallus distinctly longer than genital capsule, tripartite distally, medial lobe distinctly shorter and wider than outwardly divergent lateral lobes (Fig. 2N-P

Fig. 1 .
Fig. 1. A. Distribution map of the species of Stratiomys Geoffroy, 1762 from India.B. Map showing sampling sites for Stratiomys species in the Kashmir Valley.