Sphegina (Asiosphegina) albolobata, 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 : 29-31

Sphegina (Asiosphegina) albolobata sp. nov.

urn:lsid:zoobank.org:act:46336777-023B-42E2-856A-3DB70790EDB4

Figs 6C , 7 , 21 A–B

Differential diagnosis

In addition to the characters in the key, Sphegina (Asiosphegina) albolobata sp. nov. differs from the similar S. (A.) licina sp. nov. by having the ventral lobe of both gonostyli narrower, apicodorsal part of the right superior lobe shorter and by having the ventral part of the left superior lobe with more prominent anterior, medial and posterior lobes ( Fig. 7 B–D).

Etymology

The specific epithet is from the Latin ‘ albolobata ’, meaning ‘white-lobed’, referring to the white subtriangular lobe posteriorly on male sternum IV.

Material examined

Holotype

VIETNAM • ♂; “ Vietnam: Cao Bang Province / Phia Oac Natl Park, near Phia Den / el. 1000m / 22°32 ʹ 20 ″ N, 105°51 ʹ 57 ″ E / [12–01] 22. III. 2012, coll: SD Gaimari / M Hauser, Pham HT”; CSCA.

Description

LENGTH. Body 6.0 mm, wing 4.9 mm.

HEAD. Face in lateral view ( Fig. 21A ) concave, strongly projected antero-ventrally; frontal prominence strongly developed. Ratio width of vertex at anterior ocellus: width of head 1: 4.2; ratio width of ocellar triangle: width of vertex 1: 2.5; ratio length of ocellar triangle: length of frons 1: 2.1. 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, slightly pollinose with densely grey pollinose subtriangular maculae antero-laterally along eyemargin, a large round area posterior of lunula non-pollinose and shiny ( Fig. 21B ); pile short, light yellow. Frons with deep pit antero-medially. Occiput black, light grey pollinose, light yellow pilose. Eye with an area of enlarged facets at anterior margin.Antenna with scape and pedicel yellow, basoflagellomere dark yellow with black setae dorsally on scape and pedicel; basoflagellomere oval, ratio width: length 1: 1.2; arista short pilose, nearly 3 times as long as basoflagellomere.

THORAX. Colour dark brown to black, weakly greyish pollinose, scutum with submedial more densely pollinose vitta and dense pollinosity along lateral margin, pleuron entirely grey pollinose; scutum and pleuron with very short adpressed light yellow pile. Scutellum semi lunular, black, sub-shiny and weakly 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: 1.2.

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, M 1, at the extra crossvein between R 2+3 and R 1, at the junction of veins M 1 and R 4+5 and at apical appendix of vein R 2+3. Crossvein dm-cu meeting vein M perpendicularly and vein M 1 meeting vein R 4+5 perpendicularly. Apical part of vein R 2+3 with long appendix, vein CuA 1 extending beyond vein dm-cu.

LEGS. Pro- and mesoleg yellow, tarsomeres 2–5 black, mesofemur darkened on apical ¼ and mesotibia darkened on medial ⅓. Metaleg with coxa black, trochanter yellow; femur black and yellow biannulate, slightly incrassate, ratio width: length 1: 3.6; tibia black and yellow biannulate, with short rounded apicoventral dens; tarsus entirely black, basitarsomere thick, ratio width: length 1: 3.3.

ABDOMEN. Length ratio of terga I: II: III: IV 1: 3.5: 2.0: 1.5; ratio width at posterior margin: medial length of tergum II and III 1: 4.7 and 1: 1.0. Terga black, anterior ⅓ of tergum III with yellow fascia; pile pale, on terga short, laterally on terga I and II long; tergum I with 3 evenly spaced strong light-brown setae at lateral margin; sternum III rectangular, ratio width: length 1: 3.9; sternum IV, Fig. 7A ; sterna VI, VII and VIII simple, with long yellow pile. Genitalia, Fig. 7 B–D: cerci small, round; surstyli symmetrical, elongate with rather long and narrow ventral lobe; superior lobes asymmetrical, rounded apically, with several sublobes.

Female

Unknown.

Figures

Fig. 6. Habitus, lateral view. A. Sphegina (Asiosphegina) achaeta Hippa, van Steenis & Mutin, 2015, holotype, Ƌ, Myanmar. B. S. (A.) achaeta, ♀, Myanmar. C. S. (A.) albolobata sp. nov., holotype, Ƌ, Vietnam. D. S. (A.) amplistylus sp. nov., holotype, Ƌ, Philippines. E. S. (A.) apicalis Shiraki, 1930, Ƌ, Taiwan. F. S. (A.) apicalis, ♀, Taiwan. Scale bars = 1.0 mm.

Fig. 7. Sphegina (Asiosphegina) albolobata sp. nov., holotype, Ƌ. A. Posterior part of sternum IV, ventral view. B. Left surstylus, lateral view. C. Left superior lobe, lateral view. D. Genitalia, right side, lateral view. Scale bars = 0.5 mm.

Fig. 21. Head, lateral view (A, D, F, J–K), dorsal view (B, C, G–H, L), frontal view (E, I). A–B. Sphegina (Asiosphegina) albolobata sp. nov., holotype, Ƌ, Vietnam. C. S. (A.) amplistylus sp. nov., holotype, Ƌ, Philippines. D. S. (A.) apicalis Shiraki, 1930, ♀, Taiwan. E. S. (A.) bifida sp. nov., holotype, Ƌ, Sabah, Malaysia. F–G. S. (A.) bracon sp. nov., paratype, Ƌ, Vietnam. H–I. S. (A.) bispinosa Brunetti, 1915, Ƌ, Nepal. J. S. (A.) brevipilis sp. nov., holotype, Ƌ, China. K–L. S. (A.) collicola sp. nov., paratype, Ƌ, Malaysia. Scale bars = 0.5 mm.