Sphegina (Asiosphegina) farinosa, Steenis & Hippa & Mutin, 2018

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 : 75-76

Sphegina (Asiosphegina) farinosa sp. nov.

urn:lsid:zoobank.org:act:2789161A-821F-47E3-9B80-83C8A0622DBB

Figs 28E , 31 , 38A , 47D

Differential diagnosis

In the key Sphegina (Asiosphegina) farinosa sp. nov. is coupled together with S. (A) apicalis and S. (A.) nubicola sp. nov. Except for the characters mentioned in the key, it differs from both by having asymmetrical cerci; from S. (A.) nubicola sp. nov. by having a large sublobe dorsally on the superior lobe; and from S. (A.) apicalis by having this sublobe longer than wide, instead of wider than long.

Etymology

The specific epithet is from the Latin ‘ farinosa ’, meaning ‘mealy’ and referring to the extensively pollinose body of the fly.

Material examined

Holotype

SABAH • ♂; “ British N. Borneo / Mt. Kinabalu Kam- / barangay 2140 m / X–22–30–1958 ”; “ T.C. Maa / Collector / No.”; prolegs missing; NHM.

Description

Male

LENGTH. Body 5.9 mm, wing 5.3 mm.

HEAD. Face in lateral view concave, weakly projected antero-ventrally; frontal prominence weakly developed. Ratio width of vertex at anterior ocellus: width of head 1: 5.3; ratio width of ocellar triangle: width of vertex 1: 1.9; ratio length of ocellar triangle: length of frons 1: 2.4. Face black, ventral half yellow, light grey pollinose, long pilose along eye-margin. Hypostomal bridge yellow, long pale pilose. Gena and mouth edge yellow with large subtriangular non-pollinose shiny area. Frons and vertex black, predominantly grey pollinose, a subtriangular area posterior of lunula non-pollinose and shiny ( Fig. 38A ); 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 brown-yellow with black setae dorsally on scape and pedicel; basoflagellomere oval, ratio width: length 1: 1.3; arista short pilose, about 3 times as long as basoflagellomere.

THORAX. Colour dark brown to black, weakly greyish pollinose, scutum with denser grey pollinose vitta submedially; postpronotum and dorso-medial part of anepisternum and anepimeron brown-yellow; posterior margin of katepisternum narrowly non-pollinose, shiny; scutum and pleuron with very short adpressed light yellow pile. Scutellum semicircular, black, shiny, with pile slightly longer than on scutum, with two widely set, long setae medially at posterior margin, ratio length of scutellum: length of seta 1: 1.9.

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

1

meeting vein R

4+5

perpendicularly.

LEGS. Mesoleg yellow, tarsomeres 3–5 brown to black. Metaleg with coxa black, trochanter yellow; femur black and yellow biannulate, slightly incrassate, ratio width: length 1: 4.1; tibia black and yellow biannulate, without apicoventral dens; tarsus entirely black, basitarsomere rather thin, ratio width: length 1: 4.0.

ABDOMEN. Length ratio of terga I: II: III: IV 1: 3.7: 1.6: 1.2; ratio width at posterior margin: medial length of tergum II and III 1: 3.4 and 1: 0.8. Tergum IV slightly skewed to the right. Terga black, anterior ½ of tergum III with brown-yellow fascia; pile pale, on terga short, laterally on terga I and II long; tergum I with an oblique row of five yellow setae at lateral margin ( Fig. 47D ); sternum III not sclerotized; sternum IV, Fig. 31A ; sterna VI, VII and VIII with long yellow pile. Genitalia, Fig. 31 B–C: note the asymmetrical cerci and slightly asymmetrical surstyli; the left superior lobe not drawn, similar to the right one.

Female

Unknown.

Figures

Fig. 28. Habitus, lateral view. A. Sphegina (Asiosphegina) cultrigera Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. B. S. (A.) dentata sp. nov., paratype, Ƌ, Taiwan. C. S. (A.) distincta sp. nov., paratype, Ƌ, Vietnam. D. S. (A.) exilipes sp. nov., holotype, Ƌ, Java, Indonesia. E. S. (A.) farinosa sp. nov., holotype, Ƌ, Sabah, Malaysia. F. S. (A.) fimbriata sp. nov., holotype, Ƌ, Thailand. Scale bars = 1.0 mm.

Fig. 31. Sphegina (Asiosphegina) farinosa sp. nov., holotype, Ƌ. A. Posterior part of sternum IV, lateroventral view. B. Left cersus and surstylus, lateral view. C. Genitalia, right side, lateral view. Scale bars = 0.5 mm.

Fig. 38. Head, lateral view (C, K), dorsal view (A–B, D, F–J, L) and frontal view (E). A. Sphegina (Asiosphegina) farinosa sp. nov.,holotype, Ƌ, Sabah, Malaysia. B. S. (A.) fimbriata sp. nov., holotype, Ƌ, Thailand. C–D. S. (A.) forceps Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. E. S. (A.) furva Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. F. S. (A.) ghatsi, sp. nov., holotype, Ƌ, India. G. S. (A.) gigantea sp. nov., holotype, Ƌ, China. H. S. (A.) granditarsis sp. nov., paratype, Ƌ, Thailand. I. S. (A.) hamulata sp. nov., holotype, Ƌ, India. J. S. (A.) hansoni Thompson, 1966, holotype, Ƌ, Nepal. K–L. S. (A.) hauseri sp. nov., paratype, Ƌ, Nepal. Scale bars = 0.5 mm.

Fig. 47. Tergum I, lateral view (A, C–D) and dorsal view (B, E–F). A. Sphegina (Asiosphegina) dentata sp. nov., paratype, Ƌ, Taiwan. B. S. (A.) distincta sp. nov., paratype, Ƌ, Vietnam. C. S. (A.) falcata Hippa, van Steenis & Mutin, 2015, holotype, Ƌ, Myanmar. D. S. (A.) farinosa sp. nov., holotype, Ƌ, Sabah, Malaysia. E. S. (A.) javana de Meijere, 1914, Paralectotype Ƌ, Java, Indonesia. F. S. (A.) lobulata sp. nov., paratype, Ƌ, Vietnam. Dotted line indicates unknown length of right sided setae, the right metaleg (erased in GIMP) obscured these setae. Scale bars = 0.5 mm,