Sphegina (Sphegina) abbreviata, 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 : 17-20

Sphegina (Sphegina) abbreviata sp. nov.

urn:lsid:zoobank.org:act:5B6794F9-A978-499D-996F-922B91C12F45

Figs 1 , 3A , 19A

Differential diagnosis

Similar to Sphegina (Sphegina) angustata sp. nov., except for the characters given in the key, Sphegina (Sphegina) abbreviata sp. nov. is distinguished by both dorsal and ventral sublobes posteriorly on male superior lobe instead of just a dorsal one and by having the latter apically short and truncate, not long and pointed.

Etymology

The specific epithet is Latin ‘ abbreviata ’, meaning ‘shortened’, referring to the unusually short abdomen.

Type material

Holotype

NEPAL • ♂; “ 27°58 ʹ N, 85°00 ʹ E / Mal. Tr. 1, 11.100’ [feet] / 25 June 1967 / Can. Nepal Exped.”; “ CNC DIPTERA / # 143316”; CNC.

Paratypes

NEPAL • 1 ♀; same data as for holotype; “ 3– 5 June 1967 ”; CNC • 1 ♀; same data as for preceding; JSA • 1 ♀; same data as for holotype; “ 18 June 1967 ”; JSA • 1 ♀; same data as for holotype; “ 19 June 1967 ”; CNC • 1 ♀; same data as for holotype; “ 24 June 1967 ”; CNC .

Description

Male

LENGTH. Body 4.6 mm, wing 4.7 mm.

HEAD. Face in lateral view concave, very strongly projected antero-ventrally; frontal prominence very strongly developed. Ratio width of vertex at anterior ocellus: width of head 1: 2.8; ratio width of ocellar triangle: width of vertex 1: 2.8; ratio length of ocellar triangle: length of frons 1: 2.0. Face dull dark brown, ventral half light-brown to yellow, grey pollinose, long pilose along eye-margin. Hypostomal bridge 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 to brown coloured. Frons with rather 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 elongate, ratio width: length 1: 1.5; arista pilose, short and relatively thick, about 2.0–2.5 times as long as basoflagellomere.

THORAX. Colour dark brown, weakly greyish pollinose; postpronotum 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: 1.0.

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

1

meeting vein R

4+5

perpendicularly.

LEGS. Pro- and mesoleg light-brown, protarsus brown to dark brown; mesotibia apical ¼ dark brown; mesotarsus with apical half of basitarsomere and tarsomeres 2–5 dark brown. Metaleg, coxa and trochanter dark brown, metafemur dark brown with basal ⅓ yellow, very weakly incrassate, ratio width: length 1: 6.1; metatibia dark brown and yellow biannulate, club shaped without apicoventral dens; basitarsomere thin, ratio width: length 1: 4.0.

ABDOMEN. Length ratio of terga I: II: III: IV 1: 4.0: 3.3: 3.3; ratio width at posterior margin: medial length of tergum II and III 1: 2.0 and 1: 1.3. Terga brownish; pile mixed dark brown to light-brown, short; tergum I with only normal pile; sternum I elongate oval, ratio width: length 1: 1.9; sterna II–III not sclerotized, sternum IV, Fig. 1A ; sterna VI, VII and VIII with long yellow pile. Genitalia, Fig. 1 B–D: note the almost symmetrical surstyli and symmetrical superior lobes.

Female

Similar to male except normal sexual dimorphism.

LENGTH. Body 4.9–5.4 mm, wing 5.4–6.1 mm.

HEAD. Ratio width of vertex at anterior ocellus: width of head 1: 2.7–3.1; ratio width of ocellar triangle: width of vertex 1: 2.7–3.1; ratio length of ocellar triangle: length of frons 1: 1.9–2.2. Basoflagellomere round, ratio width: length 1: 1.0–1.2; arista pilose, short and relatively thick, about 3 times as long as basoflagellomere.

THORAX. Scutellum with two closely set medium long setae medially at posterior margin, ratio length of scutellum: length of seta 1: 1.3–1.6.

LEGS. Metaleg, Fig. 19A with basal ½ of femur yellow, slender, evenly incrassate, ratio width: length 1: 5.4–6.1, basitarsomere thin, ratio width: length 1: 3.9–4.2.

ABDOMEN. Length ratio of terga I: II: III: IV: V 1: 2.7–3.1: 2.6–2.9: 2.4–2.6: 0.8–0.9; ratio width at posterior margin: medial length of tergum II and III 1: 0.74–0.92 and 1: 0.5–0.7. Sternum I rectangular, ratio width: length 1: 0.51–0.61; sternum II rectangular, ratio width: length 1: 1.8–2.3; sternum III trapezoidal, ratio width: length 1: 1.2–1.6; sternum IV squarish, ratio width: length 1: 0.82–1.0; sternum V rectangular at anterior margin slightly narrowed, ratio width: length 1: 0.3–0.5.

Figures

Fig. 1. Sphegina (Sphegina) abbreviata sp. nov., holotype, Ƌ. A. Sternum IV with associated parts, right side, latero-ventral view. B. Left surstylus, lateral view. C. Left superior lobe, lateral view. D. Genitalia, right side, lateral view. Scale bar = 0.5 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. 19. Metaleg, anterior view. A. Sphegina (Sphegina) abbreviata sp. nov., paratype, ♀, Nepal. B. S. (S.) angustata sp. nov., paratype, ♀, Nepal. C. S. (S.) uncinata Hippa, van Steenis & Mutin, 2015, Ƌ, Myanmar. D. Sphegina (Asiosphegina) brevipilis sp. nov., paratype, Ƌ, China, abbreviations: a = length of basitarsus of metatarsus; b = width of basitarsus of metatarsus. E. S. (A.) collicola sp. nov., holotype, Ƌ, Malaysia. F. S. (A.) crinita sp. nov., paratype, ♀, Java, abbreviations: a = length of metafemur; b = width of metafemur. Scale bars = 0.5 mm.