Sphegina (Asiosphegina) tristriata Brunetti, 1913

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 : 181

Sphegina (Asiosphegina) tristriata Brunetti, 1913

Sphegina tristriata Brunetti, 1913: 165 . Type locality: Rotung, India (holotype, ♀, NZSI).

Differential diagnosis

Based on the description and the photo of the type specimens it looks similar to Sphegina (Asiosphegina) bidens and also slightly similar to S. (A.) orientalis . It is distinguished from these by the characters given in the key.

Material examined

Holotype

INDIA • ♀; “Ind. Mus. / Rotung / 1400 ft. / Kemp abor Exp. / 6–13–III–[19]12”; “ Sphegina / tristriata / Brun. Type ♀ / det. Brun. 1923”; “ Sphegina / tristriata / Brun. Type ♀ ”; “TYPE”; “1983 / HI”; “ Sphegina tristriata Brun. ”, Zoological Survey of India / barcode / ZSI0000004490 ”; photo of holotype in lateral and dorsal view studied; NZSI.

Description

Male

Unknown.

Female

See Brunetti (1913, 1923).

LENGTH. Body 6 mm, wing 4.5 mm.

HEAD. Face in lateral view concave. Faceblack, light grey pollinose. Hypostomal bridge black. Gena and mouth edge yellowish. Frons and vertex black, grey pollinose. Antenna brownish-yellow.

THORAX. Colour brownish-yellow, weakly greyish pollinose, with denser grey pollinose vitta submedially; pleuron with greyish pollinosity pile. Scutellum brownish-yellow, grey pollinose.

WING. Entirely hyaline, stigma yellowish, brown infuscated at junction of veins R 2+3 and R 4+5, along veins bm-cu, r-m and M 1, at apical end of vein R 2+3 and apical part of wing around vein R 4+5. Crossvein dm-cu meeting vein M almost perpendicularly and vein M

1

meeting vein R

4+5

perpendicularly.

LEGS. Pro- and mesoleg yellow, apex of tarsi brownish. Metafemur black and yellow biannulate.

ABDOMEN. Terga black; pile very short and white; tergum II slightly constricted anteriorly and long; colour of tergum III entirely whitish-yellow.

Remarks

The species is only known on the basis of the holotype from “Rotung, N. E. Frontier of India ” ( Brunetti 1913). It was described as female in Brunetti (1913, 1923), however, Brunetti (1923) mentioned after the description that the species was “Described from a unique ♂ ”. The holotype has lost the posterior part of abdomen from tergum III onwards and it is not possible to see if the actual specimen is male or female. Based on the very elongate tergum II and the seemingly narrow frons, the specimen is most likely a male, however, the entirely whitish-yellow coloured tergum III is more a female character.