Sphegina (Asiosphegina) granditarsis, 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 : 88-90

Sphegina (Asiosphegina) granditarsis sp. nov.

urn:lsid:zoobank.org:act:8CA0261F-47AE-4A24-89F2-3C25376BC975

Figs 38H , 39 , 41C , 61B

Differential diagnosis

Sphegina (Asiosphegina) granditarsis sp. nov. is similar to S. (A.) atrimanus sp. nov., S. (A.) incretonigra sp. nov., S. (A.) nasuta , S. (A.) nigrotarsata sp. nov. and S. (A.) orientalis . Except for the characters mentioned in the key S. (A.) granditarsis sp. nov. differs from the other mentioned species by having only very sparse pile posteriorly on male sternum IV. The male genitalia are similar to those of S. (A.) orientalis , but the dorsal lobe of surstylus is not widened on the apical part and the ventral lobe is pointed, not obtuse. Moreover, the long seta-like pile on the cercus is much longer. See also under S. (A.) atrimanus sp. nov.

Etymology

The specific epithet is from the Latin ‘ granditarsis ’, meaning ‘having a large tarsus’ and referring to the enlarged and flattened protarsus.

Material examined

Holotype

CHINA • ♂; “ South China / Guandong Prov. / Chebaling; / [leg.] A. Lelej; 21 VI 1990 ”; NBC.

Description

Male

LENGTH. Body 6.6–7.0 mm, wing 5.2–5.8 mm.

HEAD. Face in lateral view concave, strongly projected antero-ventrally; frontal prominence strongly developed. Ratio width of vertex at anterior ocellus: width of head 1: 5.3; ratio width of ocellar triangle: width of vertex 1: 1.6; ratio length of ocellar triangle: length of frons 1: 2.0. Face black, ventral half yellow; light grey pollinose, long pilose along eye-margin. Hypostomal bridge dark yellow, long pale pilose. Gena and mouth edge yellow with large subtriangular non-pollinose shiny area. Frons and vertex black, slightly pollinose, a narrow subtriangular area posterior of lunula non-pollinose and shiny ( Fig. 38H ); pile short, light yellow. Frons with deep pit anteromedially and wide but weak medial furrow. 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 elongate, ratio width: length 1: 1.7; arista long pilose, about 2 times as long as basoflagellomere.

THORAX. Colour black, postpronotum and dorso-medial part of anepisternum and anepimeron yellow; weakly greyish pollinose, pleuron entirely more heavily grey pollinose; scutum and pleuron with very short adpressed light yellow pile. Scutellum semicircular, black, shiny, with pile slightly longer than on scutum, with two widely set, very short setae medially at posterior margin, ratio length of scutellum: length of seta 1: 0.7.

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 and on the wing apex. Crossvein dm-cu meeting vein M perpendicularly and vein M

1

meeting vein R

4+5

perpendicularly.

LEGS. Proleg yellow, tarsomere 1 black on apical half and tarsomeres 2–5 entirely black; protarsus, Fig. 61B , enlarged and flattened, ratio apical width of tibia: width of tarsomere 2 1: 1.8; basitarsomere about as long as combined length of tarsomeres 2 and 3. Metaleg with coxa black, trochanter yellow; femur black with basal 1/5 yellow, slightly incrassate and club shaped, ratio width: length 1: 5.3, anteroventrally with long white pile, pile almost twice as long as black setae; tibia black and yellow biannulate, without apicoventral dens; tarsus entirely black, basitarsomere thick, ratio width: length 1: 3.1.

ABDOMEN. Length ratio of terga I: II: III: IV 1: 2.9: 2.0: 1.5; ratio width at posterior margin: medial length of tergum II and III 1: 3.0 and 1: 1.4. Terga black, anterior 1/5 of tergum III with yellow fascia; pile pale, on terga short, laterally on terga I and II long; tergum I with 2 widely separated, strong, light yellow setae at lateral margin; sternum III not sclerotized; sternum IV, Fig. 39A ; sterna VI, VII and VIII simple, with long yellow pile. Genitalia, Fig. 39 B–E: note the very long setose pile on cercus, symmetrical surstyli and superior lobes and the small setae on the membrane between the ventral margin of tergum IX and the gonostylar apodemes.

Female

Unknown.

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. 39. Sphegina (Asiosphegina) granditarsis sp. nov., holotype, Ƌ. A. Posterior part of sternum IV, ventral view. B. Aedeagus, right side lateral view. C. Left surstylus, lateral view. D. Sternum IX and superior lobe, left side lateral view. E. Genitalia right side lateral view. Scale bars = 0.5 mm.

Fig. 41. Habitus, lateral view. A. Sphegina (Asiosphegina) gigantea sp. nov., holotype, Ƌ, China. B. S. (A.) gigas Hippa, van Steenis & Mutin, 2015, paratype, ♀, Myanmar. C. S. (A.) granditarsis sp. nov., paratype, Ƌ, Thailand. D. S. (A.) hamulata sp. nov., holotype, Ƌ, India. E. S. (A.) hansoni Thompson, 1966, holotype, Ƌ, Nepal, Malaysia. F. S. (A.) hauseri sp. nov., paratype, Ƌ, Nepal. Scale bars = 1.0 mm.

Fig. 61. Protarsus, dorsal view. A. Sphegina (Asiosphegina) atrimanus sp. nov., holotype, Ƌ, Vietnam. B. S. (A.) granditarsis sp. nov., holotype, Ƌ, China. C. S. (A.) incretonigra sp. nov., holotype, Ƌ, Vietnam. D. S. (A.) nigrotarsata sp. nov., paratype, Ƌ, Vietnam. E. S. (A.) orientalis Kertész, 1914, Ƌ, Taiwan. F. S. (A.) plautus sp. nov., holotype, Ƌ, China. Scale bars 0.5 mm.