Myospila himalayensis Jana, Hazari & Sinha, sp. nov.

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Diagnosis: Myospila himalayensis sp. nov. can be easily distinguished from other closely related species by the combination of characteristics basisternum of prosternum hairy; ia 0+1; presence of setulae on wing vein R 4+5 dorsally and ventrally; eyes with microscopic hairs; scutellum fuscous brownish and bare laterally.

Description

Male (Figs 1A, 2A, 2B and 2E)

Size: Large fly, length 8.0–9.0 mm; wing length 8.5–9.5 mm.

Coloration: Body overall fuscous black with greyish to silvery pollinosity; parafacial and parafrontal plate fuscous black to dark brownish with greyish pollinosity; pedicel and postpedicel dark brownish colour, pedicel appearing darker than postpedicel; genal and postgenal areas blackish with greyish pruinosity; occiput same colour as gena; anterior and posterior spiracles dark brown to blackish; wings smoky brown; basicosta and tegula dark brown to blackish; lower and upper calypters light brownish to light yellowish; haltere yellowish orange; all femoral, coxal, and tarsal segments dark brown to blackish; all tibia testaceous at apical 2/3 and darker at basal 1/3; abdomen dorsally fuscous blackish with silvery reflection in posterior view.

Head: (Fig. 2E) Rounded with two large sub-contiguous compound eyes, covered with sparse or microscopic hairs; inner facets of the compound eyes slightly larger than outer facets; frons narrow, the narrowest part approximately narrower than the ocellar triangle; frontal vitta dark brownish in colour distinctly visible between the compound eyes, narrower than parafrontal plate; parafacial bare; fronto-orbital plate projecting, with 8–9 inclinate and 1–2 reclinate fronto-orbital setae; postpedicel about 2.0–2.5 times as long as wide; arista long plumose, longest hair of arista is about the length of postpedicel; vibrissae prominent and projected just above mouth margin; genal and postgenal areas covered with numerous hairs; palpus slender, slightly dilated at apex and blackish; proboscis with prominent labellum and prementum.

Thorax: Four distinct, dark, longitudinal stripes; median pair reaches posterior margin of scutum and lateral pair ends beyond the suture; scutellum covered with a broad dark median stripe. Chaetotaxy: acr 0+1 (fine); dc 2+4; pra 1 (fine), sa 2; pab 3 (posterior one fine); ia 0+1; ds indistinct; lateroscutellar setae 2 pairs (anterior pair fine); katepisternal setae 1+2 (not equilateral, lower one close to posterior one); notopleural disc bare; basisternum of prosternum hairy; propleural depression bare; anepisternum hairy; anterior anepisternal setae 2 (anterior most very fine); axillary prostigmal setae upcurved; metepisternum of metapleuron hairy just above hind coxa; greater ampulla below the wing base, vallar ridge, anatergite, suprasquamal ridge, anepimeron, katepimeron, meron and post alar wall all bare; convexity above the posterior spiracle covered with small microscopic pile; lateral side of scutellum bare below marginal setae.

Wings: (Fig. 3) Hyaline, wholly covered with microtrichia; costa spinose ventrally; Sc sinuous along R 1 and upcurved at apex; vein R 1 bare dorsally and ventrally; R 4+5 hairy dorsally and ventrally and slightly upcurved at apex; dorsal surface has 7–9 hairs which extended to front third of r–m; ventrally with a few fine hairs restricted at node; stem vein bare; M 1+2 slightly upcurved at apex; basicosta brownish; lower calypter Phaonia type, tongue shaped and diverging from lateral margin of the scutellum and with light yellowish marginal cilia.

Legs: Fore femur with two complete rows of strong pd and a row of strong pv; fore tibia devoid of median setae; mid femur with 3–4 setae at middle region of anterodorsal to anteroventral surface, av in basal half, pv 5–7 and 2–3 strong p in distal part; mid tibia with 3 setae on posterodorsal to posteroventral surface; hind femur with a row of ad and av; hind tibia ad 2 and av 2 (upper one fine) respectively; claws and pulvillus prominent.

Abdomen: 3 rd and 4 th tergites have a narrow median whitish longitudinal stripe; sternites are dark brownish to black and hairy except 1 st sternite; all tergites with strong lateral marginal setae along with tergites 4 th and 5 th having strong setae at apical margin.

Terminalia: In posterior view (Figs 4B and 5B), cercal plate with a broad V-shaped emargination on basal edge and developed setae on upper 1/3 and along median surface, apical margin clearly flattened with shallow median emargination; surstylus curved strip-like; hypopygium broad semicircular. In profile (Figs 4D and 5D), cercal plate with apical angle pointed; surstylus hooked, somewhat pointed apically. 5 th sternite (Figs 4A and 5A) deeply Vshaped, longer than wide and its lateral lobe as long as length of basal portion, with setae and setulae. Aedeagus (Figs 4C and 5C), pregonite straight, thumb-shaped, with apex bluntly rounded; distiphallus strip-shaped, with angular apex; acrophallus narrow angular, membranous; postgonite curved thin strip-like; epiphallus developed plate like, slightly bent, with rounded apex.

4+5 Female: (Figs 2C, 2D and 2F) Large size with length is about 8.0–9.0 mm; body fuscous black, covered with greyish to silvery pollinosity; compound eyes dichoptic and separated by the distance of combined length of pedicel and postpedicel; frons broad and wider, frontal stripe dark brownish; interfrontal cruciate bristles absent; vertical and post vertical bristles distinct; parafrontal plate with 6 inclinate and 2 reclinate setae; wing vein R 4+5 hairy dorsally and ventrally; rest of the characters same as male.

Etymology: As the new fly specimens were collected from the Darjeeling Himalayan region thus the specific name given is himalayensis .

Type specimen: Holotype: ♁, INDIA: Bijanbari, Darjeeling, West Bengal, 27°04’01.5”N, 88°11’25.6”E, alt. 760 m, 20.IV.2023, Coll. Jana N, Hazari P & Sinha SK . Paratypes: 2♁, 2♀, Same data as holotype .

Type locality: India, West Bengal, Darjeeling, 27°04’01.5”N, 88°11’25.6”E, 760 m, 20.IV.2023 .

Collection habitats: (Figs 1B and 1C) Flies were collected from shady environment near a stream. Collection spots were moist and full of vegetation. Flies were mainly observed on big stones over running stream water.

Distribution: India, West Bengal (Darjeeling).

Remarks: This new species with a characteristic dorsal and ventrally setulose vein R 4+5 is rare in the genus Myospila . However, this feature is also seen in M. setipennis Malloch, 1930 . Such similarities may be homologous and should be seen as a synapomorphy in these two species. They can be distinguished as follows. In M. setipennis, scutellum yellow entirely and setulose laterally, wing with basicosta yellow, R 1 setulose and hind tibia with av 3 (Emden 1965; Xue and Tian 2014). Contrastingly, M. himalayensis has the scutellum entirely fuscous brownish and bare laterally, wing with brownish basicosta, R 1 bare and hind tibia with av 2.