Sphegina (Asiosphegina) nigerrima Shiraki, 1930

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 : 126-128

Sphegina (Asiosphegina) nigerrima Shiraki, 1930

Figs 54 I–J, 59E, 60, 63C, 65C, 72B, 77B

Sphegina nigerrima Shiraki, 1930: 425 . Type locality: Rantaisan, Taiwan (holotype, ♂, NTU).

Differential diagnosis

Similar to Sphegina (Asiosphegina) atricolor , S. (A.) dentata sp. nov., S. (A.) furva and S. (A.) umbrosa sp. nov. For distinguishing characters, see under S. (A.) dentata sp. nov.

Material examined

Holotype

TAIWAN • Ƌ “ Rantaisan / Formosa / 13.III.1926 / S. Issiki ”; “ Sphegina / nigerrima / Det. T. Shiraki ”; “ Type ”[round labelled with red circles]; “1029”; NTU.

Additional material

TAIWAN • 1 ♂; “ Taiwan N-Nantou Co. / Road No. 14, NE Puli / Reyen Shi-Reg., E Tsuifeng / to Yuanfeng ca 2500–2700 m / ca 24°07 ʹ N, 121°13 ʹ E / 1.VII.2000 leg. W. Schacht ”; JSA • 1 ♂; “Taiwan C: / Alishan 2400 m / 3–9.VII.1972 ”; T.C. Maa / Collector / Bishop”; BPBM • 1 ♂; “TW Taichung County / Dasyueshan Forest / elev 2589m / 24°277 ′ N, 121°023 ′ E / 21 III 2015 leg S. Bot ”; SBH .

Redescription

Male

LENGTH. Body 5.9–6.5 mm, wing 4.4–4.8 mm.

HEAD. Face in lateral view ( Fig. 54I ) concave, weakly projected antero-ventrally; frontal prominence weakly developed. Ratio width of vertex at anterior ocellus: width of head 1: 3.9–4.3; ratio width of ocellar triangle: width of vertex 1: 1.9–2.2; ratio length of ocellar triangle: length of frons 1: 2.3–2.6. Face black, light grey pollinose, long pilose along eye-margin. Hypostomal bridge black, long pale pilose. Gena and mouth edge black with large subtriangular non-pollinose shiny area. Frons and vertex black, predominantly grey pollinose, a rectangular area posterior of lunula non-pollinose and shiny and densely grey pollinose macula lateral of shiny area ( Fig. 54J ); pile short, light yellow. Frons with weak medial furrow. Occiput black, light grey pollinose, light yellow pilose. Eye without enlarged facets at anterior margin. Antenna black with black setae dorsally on scape and pedicel; basoflagellomere squarish, ratio width: length 1: 1.1–1.2; arista bare, a basally with short and scattered pile, about 3.5 times as long as basoflagellomere.

THORAX. Colour dark brown to black; scutum weakly greyish pollinose laterally and with wide greypollinose vitta submedially, otherwise non pollinose, shiny; katepisternum pollinose, posterior margin widely non-pollinose, shiny ( Fig. 65C ); katepimeron pollinose, anterior part non-pollinose, shiny; scutum and pleuron with very short adpressed light yellow pile. Scutellum subtriangular, black, shiny, with pile slightly longer than on scutum, with two widely set, very long setae medially at posterior margin, ratio length of scutellum: length of seta 1: 2.2–2.6.

WING. Microtrichose, basal ⅓ of cell cup bare; hyaline, stigma yellowish. Crossvein dm-cu meeting vein M obliquely and vein M

1

meeting vein R

4+5

perpendicularly.

LEGS. Profemur yellow with medial ½–3/5 black; mesofemur yellow with apical ¾ black; pro- and metatibia yellow, black on apical ½; pro- and metatarsus yellow with tarsomeres 3–5 black. Metaleg, Fig. 72B , with coxa black and trochanter yellow; femur black with basal ¼– ⅓ yellow, incrassate, ratio width: length 1: 3.4–3.8, in profile baso-dorsally slightly concave, with long seta-like pile apico-dorsally; tibia black and yellow biannulate, without apicoventral dens; tarsus entirely black, basitarsomere thick, ratio width: length 1: 3.1–3.4.

ABDOMEN. Length ratio of terga I: II: III: IV 1: 3.8–4.3: 1.6–2.0: 1.5–1.8; ratio width at posterior margin: medial length of tergum II and III 1: 5.3–5.8 and 1: 0.9. Tergum IV skewed to the right. Terga black, anterior ½ of tergum III with sub-anterior lateral brown-yellow squarish macula; pile pale, on terga short, laterally on terga I and II long; tergum I, Fig. 72B , with an oblique row of 5 light yellow setae at lateral margin; sternum III rectangular with concave posterior margin, ratio width: length 1: 1.3–1.5; sternum IV, Fig. 60A ; sterna VI, VII and VIII simple, with long yellow pile. Genitalia, Fig. 60 B–C: note the slightly asymmetrical surstyli and superior lobes.

Female

Unknown.

Figures

Fig. 54. Head, lateral view (D, F, I, K) and dorsal view (A–C, E, G–H, J, L). A. Sphegina (Asiosphegina) incretonigra sp. nov., holotype, Ƌ, Vietnam. B. S. (A.) inflata sp. nov., holotype, Ƌ, Philippines. C. S. (A.) inventum sp. nov., paratype, ♀, Sabah, Malaysia. D–E. S. (A.) karnataka sp. nov., paratype, Ƌ, India. F–G. S. (A.) licina sp. nov., holotype, Ƌ, Thailand. H. S. (A.) lucida sp. nov., paratype, Ƌ, Vietnam. I–J. S. (A.) nigerrima Shiraki, 1930, Ƌ, Taiwan. K–L. S. (A.) nigrotarsata sp. nov., paratype, Ƌ, Vietnam. Scale bars = 0.5 mm.

Fig. 65. Pleuron, lateral view. A. Sphegina (Asiosphegina) crinita sp. nov., holotype, Ƌ, Java, Indonesia. B. S. (A.) dentata sp. nov., holotype, Ƌ, Taiwan. C. S. (A.) nigerrima Shiraki, 1930, Ƌ, Taiwan. D. S. (A.) varidissima Shiraki, 1930, Ƌ, Taiwan. Scale bars 0.5 mm.

Fig. 72. Metaleg, anterior view (A–E) and dorsal view (F). A. Sphegina (Asiosphegina) malaisei Hippa, van Steenis & Mutin, 2015, paratype, ♀, Myanmar. B. S. (A.) nigerrima Shiraki, 1930, Ƌ, Taiwan. C. S. (A.) ornata sp. nov., holotype, Ƌ, China. D. S. (A.) philippina, Thompson, 1999, paratype, ♀, Philippines. E. S. (A.) bispinosa Brunetti, 1915, Ƌ, Nepal. F. S. (A.) bispinosa, ♀, India. Scale bars = 0.5 mm.

Fig. 60. Sphegina (Asiosphegina) nigerrima Shiraki, 1930, Ƌ from Puli, Taiwan. A. Sternum IV, ventral view. B. Posterior part of genitalia, left side, lateral view. C. Genitalia, right side, lateral view. Scale bars = 0.5 mm.