Sphegina (Sphegina) angustata Steenis & Hippa & Mutin 2018, sp. nov.
Creators: name: Steenis, Jeroen Van
name: Hippa, Heikki
name: Mutin, Valeri A.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Syrphidae
Sphegina
Sphegina angustata

description: Sphegina (Sphegina) angustata sp. nov.
urn:lsid:zoobank.org:act: 94A6F831-FFFF-49E3-BF04-C13C309E0B48
Figs 2 A–B, 3B–C, 4, 19B
Differential diagnosis
Similar to Sphegina (Sphegina) abbreviata sp. nov. For distinguishing characters, see under that species.
Etymology
The specific epithet is Latin ‘ angustata ’, meaning ‘narrowed’, referring to the unusually narrow abdomen.
Type material
Holotype
NEPAL • ♂; “ 27°58 ʹ N, 85°00 ʹ E / Mal. Tr. 1, 11.100’ [feet] / 29 June 1967 / Can. Nepal Exped.”; “CNC DIPTERA / # 143315”; CNC.
Paratypes
NEPAL • 1 ♂; same data as for holotype; “ 19 June 1967 ”; JSA • 1 ♀; same data as for holotype; “ 3–5 June 1967 ”; CNC • 1 ♀; same data as for holotype; “ 24 June 1967 ”; JSA • 1 ♀; same data as for holotype; “ 27 June 1967 ”; CNC.
Description
Male
LENGTH. Body 5.2–5.4 mm, wing 4.9–5.2 mm.
HEAD. Face in lateral view, Fig. 3C, concave, very strongly projected antero-ventrally; frontal prominence very strongly developed. Ratio width of vertex at anterior ocellus: width of head 1: 2.7–3.0; ratio width of ocellar triangle: width of vertex 1: 2.4–2.6; ratio length of ocellar triangle: length of frons 1: 2.5–2.8. Face dull dark brown, ventral half light-brown to yellow, pale pollinose, long pilose along eye-margin. Hypostomal bridge light-brown, long pale pilose. Gena and mouth edge yellow, pale pollinose with large subtriangular non-pollinose shiny area. Frons and vertex dark brown, predominantly grey pollinose, a subtriangular area posterior of lunula non-pollinose and shiny; pile short, light yellow brown. Frons with deep antero-medial pit and wide 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 oval, ratio width: length 1: 1.1–1.3; arista pilose, short and relatively thick, about 2.0–2.5 times as long as basoflagellomere.
THORAX. Colour dark brown, weakly greyish pollinose; postpronotum yellow to light-brown; scutum and pleuron with very short adpressed pale-brown pile. Scutellum subtriangular, dark brown, grey pollinose, with pile slightly longer than on scutum, with two widely set short setae medially at posterior margin, ratio length of scutellum: length of seta 1: 0.9–1.1.
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 brown to brown-yellow, tarsomeres 3–4 dark brown to black. Mesofemur yellow with apical ⅔ dark brown; mesotibia yellow with basal ¾ dark brown; mesotarsus with tarsomeres 2–5 dark brown. Metaleg dark brown with yellow; femur dark brown on basal 2/5, weakly incrassate, ratio width: length 1: 4.2–4.6; tibia black and yellow biannulate, club shaped, without apicoventral dens; basitarsomere thin, ratio width: length 1: 3.9–4.2.
ABDOMEN. Length ratio of terga I: II: III: IV 1: 3.4–3.6: 2.7–3.0: 2.2–2.5; ratio width at posterior margin: medial length of tergum II and III 1: 3.4–3.8 and 1: 2.1–2.4. Terga dark brown; pile mixed dark brown to light-brown, short, laterally on terga I and II long; tergum I with only normal pile; sternum I elongate oval, ratio width: length 1: 1.9–2.1; sterna II–III not sclerotized; sternum IV, Fig. 4A; sterna VI, VII and
VIII with long yellow pile. Genitalia, Fig. 4 B–D: note the almost symmetrical surstyli and symmetrical superior lobes.
Female
Similar to the male except normal sexual dimorphism.
LENGTH. Body 4.8–5.2 mm, wing 5.0– 5.5 mm.
HEAD. Ratio width of vertex at anterior ocellus: width of head 1: 3.2–3.4; ratio width of ocellar triangle: width of vertex 1: 2.1–2.4; ratio length of ocellar triangle: length of frons 1: 2.1–2.5 (Fig. 3B). Basoflagellomere round to slightly oval, ratio width: length 1: 1.0–1.2; arista pilose, short and relatively thick, about 2.5 times as long as basoflagellomere.
THORAX. Scutellum with two closely set, short setae medially at posterior margin, ratio length of scutellum: length of seta 1: 0.9–1.1.
LEGS. Metaleg, Fig. 19B, with femur slender, only very slightly incrassate, ratio width: length 1: 6.1–7.4, basitarsomere thin, ratio width: length 1: 4.2–4.6.
ABDOMEN. Length ratio of terga I: II: III: IV: V 1: 4.1–4.5: 3.8–4.2: 3.4–3.7: 1.0–1.3; ratio width at posterior margin: medial length of tergum II and III 1: 1.1–1.4 and 1: 0.5–0.7. Sternum I oval, ratio width: length 1: 0.6–0.8; sternum II oval, ratio width: length 1: 1.7–2.1; sternum III rectangular, ratio width: length 1: 1.2–1.6; sternum IV squarish, ratio width: length 1: 0.9–1.2; sternum V trapezoidal, posterior margin short, ratio width: length 1: 0.5–0.7.
description: Published as part of Steenis, Jeroen Van, Hippa, Heikki & Mutin, Valeri A., 2018, Revision of the Oriental species of the genus Sphegina Meigen, 1822 (Diptera: Syrphidae), pp. 1-198 in European Journal of Taxonomy 489 on pages 20-22, DOI: 10.5852/ejt.2018.489, http://zenodo.org/record/3830537