Sphegina (Asiosphegina) hauseri, 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 : 96-98

Sphegina (Asiosphegina) hauseri sp. nov.

urn:lsid:zoobank.org:act:6D61A95A-E548-41FC-8282-569D50970BE0

Figs 38 K–L, 41F, 43C, 44, 50A

Differential diagnosis

Sphegina (Asiosphegina) hauseri sp. nov. resembles those other Sphegina which have a strongly asymmetrical male sternum IV posteriorly armed with many strong black setae, but is easily distinguished by the characters given in the key. Among these species the male genitalia of S. (A.) hauseri sp. nov. are unique in having the curved surstylus expanded on apical half.

Etymology

The species is named after Dr. Martin Hauser who provided the type material.

Material examined

Holotype

NEPAL • ♂; “517 Nepal Solukhamba / above Nunthala 2500– / 2300 m 27°35′ N, 86°38′ E / leg. Hauser; 13.V. [19]97”; CSCA.

Paratypes

NEPAL • 2 ♂♂; same data as for holotype; CSCA • 2 ♂♂; same data as for holotype; JSA • 1 ♂; “ 28°00ʹ N, 85°00ʹ E / Mal.[aise] tr.[ap] 6, 10.500’ [feet] / 1 June 1967 / Can. Nepal Exped. ”; “CNC Diptera / # 143325” [white label with blue border]; CNC • 1 ♀; same data as for preceding; “ Mal. tr. 7 9900’ / 21–27 May 1967 ”; “CNC Diptera / # 143327”; JSA • 1 ♀; “ 27°56ʹ N, 85°00ʹ E / Mal.[aise] tr. [ap] 8, 10.100’ [feet] / 28 May 1967 / Can. Nepal Exped. ”; “CNC Diptera / # 143326” [white label with blue border]; CNC.

Description

Male

LENGTH. Body 5.8–6.5 mm, wing 4.9–5.4 mm.

HEAD. Face in lateral view ( Fig. 38K ) concave, strongly projected antero-ventrally; frontal prominence weakly developed. Ratio width of vertex at anterior ocellus: width of head 1: 3.4–3.6; ratio width of ocellar triangle: width of vertex 1: 2.3–2.4; ratio length of ocellar triangle: length of frons 1: 2.2–2.4. 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, slightly pale pollinose, a narrow semi-circular area posterior of lunula non-pollinose and shiny ( Fig. 38L ); pile short, light yellow. Frons with deep wide pit antero-medially. Occiput black, light grey pollinose, light yellow pilose. Eye without enlarged facets at anterior margin. Antenna dark yellow to brown with black setae dorsally on scape and pedicel; basoflagellomere, Fig. 43C , short oval, ratio width: length 1: 1.3–1.4; arista rather long pilose, about 3 times as long as basoflagellomere.

THORAX. Colour black, postalar callus brown-yellow; weakly greyish pollinose, pleuron entirely grey pollinose; scutum and pleuron with very short adpressed light yellow pile. Scutellum subtriangular, brown-yellow, shiny, with pile slightly longer than on scutum, with two closely set short setae medially at posterior margin, ratio length of scutellum: length of seta 1: 0.8–1.2.

WING. Entirely microtrichose; hyaline, stigma yellowish, membrane brown infuscated at junction of veins R 2+3 and R 4+5, along veins bm-cu, r-m, dm-cu, M 1, appendices of vein R 2+3 and apical part of vein R 4+5. Crossvein dm-cu meeting vein M perpendicularly and vein M 1 meeting vein R 4+5 perpendicularly. Short appendices at medial part of vein R

2+3

and at apical part of vein R

2+3.

LEGS. Pro and mesoleg yellow, tarsomeres 4 and 5 dark brown, in some specimens tarsomere 3 light brown. Metaleg with coxa black, trochanter yellow; femur black with basal ¼–⅓ yellow, slightly incrassate and club shaped, ratio width: length 1: 4.8–5.0; tibia black and yellow biannulate without apicoventral dens; tarsus entirely black, basitarsomere rather narrow, ratio width: length 1: 3.8–4.2.

ABDOMEN. Length ratio of terga I: II: III: IV 1: 2.7–2.9: 1.9–2.2: 1.3–1.5; ratio width at posterior margin: medial length of tergum II and III 1: 3.5–3.7 and 1: 1.0–1.1. Terga black, anterior ⅓ of tergum III with yellow sub-anterior fascia and posterior dark brown fascia; tergum IV with posterior dark brown fascia; pile pale, on terga short, laterally on terga I and II long; tergum I with 2 widely separated strong black setae at lateral margin; sternum III rectangular with sharply concave posterior margin, ratio width: length 1: 1.6–1.9; sternum IV, Fig. 44A ; sterna VI, VII and VIII with long yellow pile, sternum VII anteriorly with a narrow sharp-tipped process. Genitalia, Fig. 44 B–D: note the asymmetrical surstyli and superior lobes and the subbasal conical lobe on the medial side of both surstyli.

Female

Similar to male except for the usual sexual dimorphism.

LENGTH. Body 5.6–6.2 mm, wing 5.2–5.8 mm.

HEAD. Ratio width of vertex at anterior ocellus: width of head 1: 2.9–3.2; ratio width of ocellar triangle: width of vertex 1: 2.4–2.6; ratio length of ocellar triangle: length of frons 1: 2.2–2.4. Basoflagellomere short oval, ratio width: length 1: 1.2–1.4; arista long pilose, about 3 times as long as basoflagellomere.

THORAX. Scutum submedially with dense brown-grey pollinosity. Scutellum with two closely set, very short setae medially at posterior margin, ratio length of scutellum: length of seta 1: 0.42–0.86.

LEGS. Metafemur with basal third yellow, ratio width: length 1: 4.7–5.2; metatarsus with basitarsomere rather thin, ratio width: length 1: 3.8–4.1.

ABDOMEN. Length ratio of terga I: II: III: IV: V 1: 3.3–3.8: 2.5–2.9: 1.9–2.3: 0.4–0.6; ratio width at posterior margin: medial length of tergum II and III 1: 2.4–2.8 and 1: 0.7–0.8. Tergum II medially with oval yellow macula and posteriorly with brown-yellow fascia; tergum III with yellow fascia on anterior 2/5; tergum IV with posterior ¾ brown-yellow; tergum V predominantly brown-yellow; tergum VI with posteromedial membranous cleft; sternum III rectangular, ratio width: length 1: 2.1–2.4; sternum IV trapezoidal with anterior part narrower and posterior margin slightly concave, ratio width: length 1: 0.6–0.7; sternum V rectangular with convex posterior margin, ratio width: length 1: 0.7–0.9.

Figures

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. 43. Basoflagellomere, lateral view. A. Sphegina (Asiosphegina) dentata sp. nov., paratype, Ƌ, Taiwan. B. S. (A.) distincta sp. nov., paratype, Ƌ, Vietnam. C. S. (A.) hauseri sp. nov., paratype, Ƌ, Nepal. D. S. (A.) tricoloripes Brunetti, 1915, ♀, India. Abbreviations: a = length of basoflagellomere; b = width of basoflagellomere; c = length of arista. Scale bars 0.25 mm.

Fig. 44. Sphegina (Asiosphegina) hauseri sp. nov., holotype, Ƌ. A. Sterna IV, VI and VII, ventral view. B. Left surstylus, lateral view. C. Left superior lobe,lateral view. D. Genitalia, right side lateral view. Scale bars = 0.5 mm.