Sphegina (Sphegina) guptai Mutin, 1998

Steenis, Jeroen Van, Hippa, Heikki & Mutin, Valeri A., 2018, Revision of the Oriental species of the genus Sphegina Meigen, 1822 (Diptera: Syrphidae), European Journal of Taxonomy 489, pp. 1-198 : 23-26

Sphegina (Sphegina) guptai Mutin, 1998

Figs 2C , 3D , 5

Sphegina (Sphegina) guptai Mutin, 1998: 240 . Type locality: India, Rahla (holotype, ♂, USNM).

Differential diagnosis

This species is slightly similar to Sphegina (Sphegina) elegans by general appearance and characters of the male genitalia. It differs from known Oriental species of Sphegina (Sphegina) by the shiny black abdomen with widened terga III and IV. Only Sphegina (Sphegina) quadriseta has a somewhat similar appearance and the differences are discussed under this species. Male genitalia with long, curved, widening towards the apex surstylus with subapical ventral sublobe.

Material examined

Holotype

INDIA • ♂; “ 12. VI. 1970, India / Northwest Himalaya / Rahla, 2743 m / ( M. Gupta) / No M 33”; USNM.

Paratype

INDIA • ♀; “India H. P. /Ahla [Rahla?] 2286m / 17. VI. 1971, / M. Gupta No M 51”; “Ghorpade / collection / Bangalore”; USNM .

Redescription

Male

LENGTH. Body 5.2 mm, wing 4.6 mm.

HEAD. Face in lateral view concave, rather weakly projected antero-ventrally; frontal prominence weakly developed. Ratio width of vertex at anterior ocellus: width of head 1: 3.2; ratio width of ocellar triangle: width of vertex 1: 2.5; ratio length of ocellar triangle: length of frons 1: 2.2. Face yellow, pale pollinose, long pilose along eye-margin. Hypostomal bridge yellow, long pale pilose. Gena and mouth edge yellow, yellowish pollinose with large subtriangular non-pollinose shiny area. Frons and vertex dark brown, predominantly grey pollinose, a narrow fascia posterior of lunula non-pollinose and shiny ( Fig. 3D ); pile short, light yellow to brown. Frons with very weak medial furrow. Occiput brown, light grey pollinose, light yellow pilose. Eye without enlarged facets at anterior margin. Antenna dark brown, with black setae dorsally on scape and pedicel; basoflagellomere squarish, ratio width: length 1: 1.1; arista pilose, about 3 times as long as basoflagellomere.

THORAX. Colour black, weakly greyish pollinose; postpronotum partly dark brown, remainder black; scutum and pleuron with very short adpressed pale-brown pile. Scutellum subtriangular, dark brown, grey pollinose, pile slightly longer than on scutum, with two closely set short setae medially at posterior margin, ratio length of scutellum: length of seta 1: 1.2.

WING. Entirely microtrichose; hyaline, stigma yellowish. Crossvein dm-cu meeting vein M obliquely and vein M

1

meeting vein R

4+5

perpendicularly.

LEGS. Proleg yellow, protarsus with tarsomeres 4 and 5 dark brown. Metaleg dark brown with femur yellow on basal half, very weakly incrassate, ratio width: length 1: 5.3; tibia dark brown and yellow biannulate, slightly club shaped, without apicoventral dens, basitarsomere thin, ratio width: length 1: 3.9.

ABDOMEN. Length ratio of terga I: II: III: IV 1: 3.3: 2.3: 2.2; ratio width at posterior margin: medial length of tergum II and III 1: 3.0 and 1: 1.3. Terga black, tergum III with sub-anterior dark yellow fascia covering almost half the tergum; pile mixed dark brown to light-brown, short, laterally on terga I and II long; tergum I with only normal pile; sternum I oval, ratio width: length 1: 1.3; sterna II–III sclerotized, ratio width: length respectively 1: 3.6 and 1: 2.1; sterna IV, VI, VII and VIII ( Fig. 5A ), with long yellow pile. Genitalia, Fig. 5 B–D: note the symmetrical surstyli and superior lobes.

Female

Similar to the male except normal sexual dimorphism.

LENGTH. Body 5.7 mm, wing 5.7 mm.

HEAD. Ventral half of face and mouth edge yellow; mouth edge ventrally of eyes wide; ratio width of vertex at anterior ocellus: width of head 1: 3.1; ratio width of ocellar triangle: width of vertex 1: 2.3; ratio length of ocellar triangle: length of frons 1: 2.1. Basoflagellomere round, as wide as long; arista pilose, about 3 times as long as basoflagellomere.

THORAX. Postpronotum yellow. Scutellum with two widely set short setae medially at posterior margin, ratio length of scutellum: length of seta 1: 1.1.

WING. Vein dm-cu meeting vein M obliquely.

LEGS. Pro- and mesotarsus with tarsomeres 3–5 dark brown. Metafemur with basal ⅓ yellow, slender, ratio width: length 1: 5.4; metatarsus with basitarsomere very thin, ratio width: length 1: 4.6.

ABDOMEN. Length ratio of terga I: II: III: IV: V 1: 4.0: 2.9: 2.8: 0.8; ratio width at posterior margin: medial length of tergum II and III 1: 1.7 and 1: 0.7. Tergum V predominantly yellow. Sternum I oval, as wide as long; sternum II rectangular, ratio width: length 1: 1.4; sternum III trapezoidal, ratio width: length 1: 1.6; sternum IV squarish, ratio width: length 1: 0.7; sternum V trapezoidal, posterior margin short, ratio width: length 1: 0.9.

Figures

Fig. 2. Habitus, lateral view. A. Sphegina (Sphegina) angustata sp. nov., paratype, Ƌ, Nepal. B. S. (S.) angustata sp. nov., paratype, ♀, Nepal. C. S. (S.) guptai Mutin, 1998, paratype, ♀, India. D. S. (S.) kumaoniensis Mutin, 1998, Ƌ, Myanmar. E. S. (S.) quadriseta Huo & Ren, 2006, ♀, China. F. S. (S.) uncinata Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. Scale bars = 1.0 mm.

Fig. 3. Head, lateral view (C, E), and dorsal view (A–B, D, F). A. Sphegina (Sphegina) abbreviata sp. nov., paratype, ♀, Nepal. B. S. (S.) angustata sp. nov., paratype, ♀, Nepal. C. S. (S.) angustata sp. nov., paratype, Ƌ, Nepal. D. S. (S.) guptai, 1998, holotype, Ƌ, India. E–F. S. (S.) quadriseta Huo & Ren, 2006, ♀, China. Abbreviations: a = width of head; b = width of vertex; c = width of ocellar triangle; d = length of frons; e = length of ocellar triangle. Scale bars = 0.5 mm.

Fig. 5. Sphegina (Sphegina) guptai Mutin, 1998, holotype, Ƌ. A. Sterna IV, VI and VII, ventral view. B. Aedeagus, right side, lateral view. C. Left surstylus, lateral view. D. Left superior lobe, lateral view. E. Genitalia, right side, lateral view. Scale bars = 0.5 mm.