Sphegina (Asiosphegina) incretonigra, 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 : 99-101

Sphegina (Asiosphegina) incretonigra sp. nov.

urn:lsid:zoobank.org:act:60F79E70-AE6A-443B-B23E-CEF39EC5D3A8

Figs 45A , 46 , 54A , 61C

Differential diagnosis

Similar to Sphegina (Asiosphegina) atrimanus sp. nov., S. (A.) granditarsis sp. nov., S. (A.) nasuta and S. (A.) nigrotarsata sp. nov. For distinguishing characters, see under S. (A.) atrimanus sp. nov. and S. (A.) granditarsis sp. nov.

Etymology

The specific epithet is from the Latin ‘ incretonigra ’, meaning ‘chalk-white and black’ and referring to the protarsus which is chalk-white on the basal segments and black on the apical segments.

Material examined

Holotype

VIETNAM • ♂; “ S. Vietnam: Lam Dong / Bidoup Nuiba N.P., nr Da Lat / Mal.[aise] trap 13–18; 1600– 1650 m / 12–19.x.2005 [leg] C. v. Achter- / berg & R. de Vries, RMNH ‘05”; NBC.

Description

Male

LENGTH. Body 6.2 mm, wing 4.8 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: 5.2; ratio width of ocellar triangle: width of vertex 1: 1.7. 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; frons largely shiny, non-pollinose except for narrow subtriangular grey pollinose macula at eye-margin ( Fig. 54A ); vertex sub-shiny, slightly pollinose; pile short, light yellow. Frons without medial furrow. Occiput black, light grey pollinose, light yellow pilose. Eye without enlarged facets at anterior margin. Antenna yellow with black setae dorsally on scape and pedicel; basoflagellomere elongate, ratio width: length 1: 1.8; arista pilose, about 2 times as long as basoflagellomere.

THORAX. Colour black; postpronotum, post-alar callus and dorso-medial part of anepisternum and anepimeron brown-yellow; weakly greyish pollinose, pleuron entirely more heavily grey pollinose; scutum and pleuron with very short adpressed light yellow pile. Scutellum sub-triangular, black, entirely 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: 0.9.

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

1

meeting vein R

4+5

perpendicularly.

LEGS. Pro- and mesoleg yellow, tarsomeres 4 and 5 black, tarsomere 3 of protarsus on apical half black. Protarsus, Fig. 61C , enlarged and flattened, ratio apical width of tibia: width of tarsomere 2 1: 1.3; basitarsomere about as long as combined length of tarsomeres 2 and 3, tarsomere 2 almost 1.5 times as long as tarsomere 3. Metaleg with coxa black, trochanter yellow; femur black and yellow biannulate, slightly incrassate and club shaped, ratio width: length 1: 5.1; tibia brown to light-brown, 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: 2.2: 1.7; ratio width at posterior margin: medial length of tergum II and III 1: 3.9 and 1: 1.8. Terga black, anterior ⅓ of tergum III and anterior 1/6 of tergum IV 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 rectangular, ratio width: length 1: 3.4; sternum IV, Fig. 46A ; sterna VI, VII and VIII simple, with long yellow pile. Genitalia, Fig. 46 B–D: note the long setose pile on cercus and the nearly symmetrical surstyli and superior lobes; the membrane between the lateral margin of tergum IX and the surstylar apodemes bears inconspicuous small setae similar to, e.g., Sphegina (Asiosphegina) orientalis .

Female

Unknown.

Distribution and biology

The specimen was collected in a Malaise trap in the Bidoup Nuiba National Park near Da Lat. The Malaise trap was set up in an area of undisturbed primary montane forest on rather steep slopes. The forest is rather isolated and protected. (C. van Achterberg, pers. comm).

Figures

Fig. 45. Habitus, lateral view. A. Sphegina (Asiosphegina) incretonigra sp. nov., holotype, Ƌ, Vietnam. B. S. (A.) index Hippa, van Steenis & Mutin, 2015, holotype, Ƌ, Myanmar. C. S. (A.) inflata sp. nov., holotype, Ƌ, Philippines. D. S. (A.) cf. inflata sp. nov., ♀, Philippines. E. S. (A.) inventum sp. nov., holotype, Ƌ, Sabah, Malaysia. F. S. (A.) javana de Meijere, 1914, lectotype Ƌ, Java, Indonesia. Scale bars = 1.0 mm.

Fig. 46. Sphegina (Asiosphegina) incretonigra sp. nov., holotype, Ƌ. A. Sternum IV, ventral view. B. Left surstylus, lateral view. C. Superior lobe with associated parts, left side, lateral view. D. Genitalia, right side lateral view. Scale bars = 0.5 mm.

Fig. 54. Head, lateral view (D, F, I, K) and dorsal view (A–C, E, G–H, J, L). A. Sphegina (Asiosphegina) incretonigra sp. nov., holotype, Ƌ, Vietnam. B. S. (A.) inflata sp. nov., holotype, Ƌ, Philippines. C. S. (A.) inventum sp. nov., paratype, ♀, Sabah, Malaysia. D–E. S. (A.) karnataka sp. nov., paratype, Ƌ, India. F–G. S. (A.) licina sp. nov., holotype, Ƌ, Thailand. H. S. (A.) lucida sp. nov., paratype, Ƌ, Vietnam. I–J. S. (A.) nigerrima Shiraki, 1930, Ƌ, Taiwan. K–L. S. (A.) nigrotarsata sp. nov., paratype, Ƌ, Vietnam. Scale bars = 0.5 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.