Sphegina (Asiosphegina) perlobata, 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 : 145-147

Sphegina (Asiosphegina) perlobata sp. nov.

urn:lsid:zoobank.org:act:4FB34389-E0E6-4B9A-BED2-BD2F5DEB3E16

Figs 67E , 73 , 84 D–E

Differential diagnosis

Similar to Sphegina (Asiosphegina) crinita sp. nov., but with very different genitalia. For distinguishing characters, see under Sphegina (Asiosphegina) crinita sp. nov.

Etymology

The specific epithet is from the Latin ‘ perlobata ’, meaning ‘exceedingly lobed’ and referring to the unusually many-lobed surstylus.

Material examined

Holotype

TAIWAN • ♂; “ Taiwan Nantou / Sanlinchi / 19.V.1991 / [leg] C.C. Chiang / Sweeping & Sucking”; “ NMNS ENT / 1128–98 ”; NMNS.

Paratype

TAIWAN • 1 ♀; “ Taiwan Siangyang National / Forest Recreational Area / trails 23.247361° N, 120.985917° E 29.v.2016 / J.H. Skevington, A.D. Young / JSM8521 CNC571926 ”; DNA voucher specimen; CNC .

Description

Male

LENGTH. Body 6.7 mm, wing 5.2 mm.

HEAD. Face in lateral view, Fig. 84E , concave, weakly projected antero-ventrally; frontal prominence weakly developed. Ratio width of vertex at anterior ocellus: width of head 1: 4.7; ratio width of ocellar triangle: width of vertex 1: 1.7; face as wide as vertex; ratio length of ocellar triangle: length of frons 1: 2.8. 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, grey pollinose, a wide trapezoidal area posterior of lunula nonpollinose and shiny ( Fig. 84D ); pile short, light yellow. Frons with deep pit antero-medially. Occiput black, light grey pollinose, light yellow pilose. Eye without enlarged facets at anterior margin. Antenna with scape and pedicel dark brown, with black setae dorsally on scape and pedicel; basoflagellomere oval, ratio width: length 1: 1.2; arista long pilose, about 3 times as long as basoflagellomere.

THORAX. Colour black, weakly greyish pollinose, pleuron entirely grey pollinose; 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, medium long setae medially at posterior margin, ratio length of scutellum: length of seta 1: 1.5.

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 yellow, tarsomeres 4 and 5 black. Metaleg with coxa black and trochanter yellow; femur black with basal ⅓ yellow, slightly incrassate, ratio width: length 1: 4.8 in profile basodorsally slightly concave; tibia black and yellow biannulate without apicoventral dens; tarsus entirely black, basitarsomere rather thin, ratio width: length 1: 3.8.

ABDOMEN. Length ratio of terga I: II: III: IV 1: 3.5: 2.3: 1.9; ratio width at posterior margin: medial length of tergum II and III 1: 4.0 and 1: 1.1. Terga black, anterior ½ of tergum III with yellow fascia; pile pale, on terga short, laterally on terga I and II long; tergum I with oblique row of 5 light yellow setae at anterolateral margin; tergum IV with posterior margin skewed to the right; sternum III rectangular with concave posterior margin, ratio width: length 1: 2.8; sternum IV, Fig. 73A ; sterna VI, VII and VIII simple, with long yellow pile. Genitalia, Fig. 73 B–C: note the unusually many-lobed and almost symmetrical surstyli; the left side superior lobe is deformed and not drawn, it is similar to the right side one.

Female

Similar to male except for the usual sexual dimorphism.

LENGTH. Body 6.3 mm, wing 5.4 mm.

HEAD. Ratio width of vertex at anterior ocellus: width of head 1: 3.6; ratio width of ocellar triangle: width of vertex 1: 2.2; ratio length of ocellar triangle: length of frons 1: 2.8. Basoflagellomere yellow, slightly elongate, ratio width: length 1: 1.3; arista long pilose; about 3 times as long as basoflagellomere.

THORAX. Postpronotum, post-alar callus and medio-dorsal part of pleuron yellow; Scutellum subrectangular, black, rather long pilose, with two closely set, very short setae medially at posterior margin, ratio length of scutellum: length of seta 1: 0.7.

WING. Hyaline, entirely microtrichose; vein dm-cu meeting vein M slightly oblique.

LEGS. Protarsus with tarsomeres 2–5 dark brown to black; metafemur yellow on basal ½; metatarsus with basitarsomere thick, ratio width: length 1: 3.0.

ABDOMEN. Length ratio of terga I: II: III: IV: V 1: 4.6: 2.5: 2.5: 1.5; ratio width at posterior margin: length of tergum II 1: 2.6. Tergum III with yellow fascia on anterior ¾; sterna not visible due to wrinkling of the abdomen.

Figures

Fig. 67. Habitus, lateral view. A. Sphegina (Asiosphegina) orientalis Kertész, 1914, Ƌ, Taiwan. B. S. (A.) orientalis, ♀, Taiwan. C. S. (A.) parvula Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. D. S. (A.) bispinosa Brunetti, 1915, Ƌ, India. E. S. (A.) perlobata sp. nov., holotype, Ƌ, Taiwan. F. S. (A.) philippina Thompson, 1999, paratype, ♀ from Culasi, Philippines. Scale bars = 1.0 mm.

Fig. 73. Sphegina (Asiosphegina) perlobata sp. nov., holotype, Ƌ. A. Sternum IV, ventral view. B. Left surstylus, lateral view. C. Genitalia, right side, lateral view. Scale bars = 0.5 mm.

Fig. 84. Head, lateral view (E, H), dorsal view (A–D, F, I, K–L) and frontal view (G, J). A. Sphegina (Asiosphegina) nasuta Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. B. S. (A.) nubicola sp. nov., holotype, Ƌ, Thailand. C. S. (A.) orientalis Kertész, 1914, ♀, Taiwan. D. S. (A.) parvula Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. D–E. S. (A.) perlobata sp. nov., holotype, Ƌ, Taiwan. F. S. (A.) philippina, Thompson, 1999, paratype, ♀, Philippines. G. S. (A.) philippina, holotype, Ƌ, Philippines. H. S. (A.) plautus sp. nov., holotype, Ƌ, China. I–J. S. (A.) prolixa sp. nov., holotype, Ƌ, Malaysia. K. S. (A.) cf. spathigera sp. nov., ♀, Philippines. L. S. (A.) taiwanensis sp. nov., paratype, Ƌ, Taiwan. Scale bars = 0.5 mm.