Sphegina (Asiosphegina) exilipes, 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 : 72-74

Sphegina (Asiosphegina) exilipes sp. nov.

urn:lsid:zoobank.org:act:BB30096D-780C-4C5C-B40F-A60EC7E4BB3D

Figs 28D , 29 , 30L , 33C

Differential diagnosis

Sphegina (Asiosphegina) exilipes sp. nov. is similar to S. (A.) javana . In addition to the characters mentioned in the key, S. (A.) exilipes sp. nov. differs by a slightly narrower metafemur (see measurements in the descriptions) and the following differences in male genitalia: ventral lobe of right surstylus rectangular (more elongate and with pointed apex in S. (A.) javana ); dorsal lobe of right surstylus straight with a ventral sublobe (the apical part curved dorsally and without ventral sublobe); sternum IX with strong transverse ridge-like lobe (a weak ridge present on dorsal part only); superior lobe posteriorly simple (with two triangular teeth).

Etymology

The specific epithet is from the Latin ‘ exilipes ’, meaning ‘thin-legged’ and referring to the slender metafemur.

Material examined

Holotype

INDONESIA • ♂; Java; “Pangrango / 2000 m / 14.VI.’19 DvL”; terga III–VIII missing; NBC.

Description

Male

LENGTH. Body not measurable due to missing part of abdomen, wing 5.2 mm.

HEAD. Face in lateral view concave, very weakly projected antero-ventrally; frontal prominence very weakly developed. Ratio width of vertex at anterior ocellus: width of head 1: 5.3; ratio width of ocellar triangle: width of vertex 1: 2.0; ratio length of ocellar triangle: length of frons 1: 2.7. Face yellow, light grey pollinose, long pilose along eye-margin. Hypostomal bridge yellow, long pale pilose. Gena and mouth edge yellow, pale pollinose, with large subtriangular non-pollinose shiny area. Frons and vertex black, sub-shiny, slightly grey pollinose, a circular area posterior of lunula non-pollinose and shiny and with narrow more densely grey pollinose fascia posterior of the shiny part; pile short, light yellow ( Fig. 30L ). Frons with long, very wide but shallow medial furrow. Occiput black, light grey pollinose, light yellow pilose. Eye with enlarged facets at anterior margin. Antenna dark brown to black with black setae dorsally on scape and pedicel; basoflagellomere oval, ratio width: length 1: 1.3; arista short pilose on basal half only, about 3 times as long as basoflagellomere.

THORAX. Colour dark brown to black, scutum with densely grey pollinose vitta submedially; postpronotum and dorso-medial part of anepisternum and anepimeron brown-yellow; posterior margin of katepisternum narrowly non-pollinose, shiny; scutum and pleuron with very short adpressed light yellow pile. Scutellum semicircular, black, shiny, with pile slightly longer than on scutum, with two closely set medium long setae medially at posterior margin, ratio length of scutellum: length of seta 1: 1.6.

WING. Microtrichose, basal 1/5 of cell cup bare; hyaline, stigma yellowish. Crossvein dm-cu meeting vein M strongly oblique and vein M

1

meeting vein R

4+5

perpendicularly.

LEGS. Proleg yellow, tarsomeres 4 and 5 black; mesofemur nearly entirely dark yellow, tibia dark yellow on apico-medial ¼, tarsomeres 4 and 5 black. Metaleg, Fig. 33C , with coxa black, trochanter dark brown; femur with basal ⅓ yellow, slightly incrassate, ratio width: length 1: 5.1; tibia nearly entirely dark brown to black, without apicoventral dens; tarsus entirely black, basitarsomere rather thin, ratio width: length 1: 3.9.

ABDOMEN. Length ratio of terga I and II 1: 5.3; ratio width at posterior margin: length of tergum II is 1: 3.8. Terga black; pile pale, on terga short, laterally on terga I and II long; tergum I with an oblique row of 4–5 light yellow setae at lateral margin; sternum IV, Fig. 29A ; VI, VII and VIII lost. Genitalia, Figs 29B , 24C : tergum IX, cerci, and left side surstylus and superior lobe destroyed.

Female

Unknown.

Figures

Fig. 28. Habitus, lateral view. A. Sphegina (Asiosphegina) cultrigera Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. B. S. (A.) dentata sp. nov., paratype, Ƌ, Taiwan. C. S. (A.) distincta sp. nov., paratype, Ƌ, Vietnam. D. S. (A.) exilipes sp. nov., holotype, Ƌ, Java, Indonesia. E. S. (A.) farinosa sp. nov., holotype, Ƌ, Sabah, Malaysia. F. S. (A.) fimbriata sp. nov., holotype, Ƌ, Thailand. Scale bars = 1.0 mm.

Fig. 29. Sphegina (Asiosphegina) exilipes sp. nov., holotype, Ƌ. A. Sternum IV, ventral view. B. Right surstylus, lateral view. C. Right sternum IX and superior lobe, lateral view. Scale bars = 0.5 mm.

Fig. 30. Head, lateral view (A, F, H, J), dorsal view (B–D, G, I, K–L) and frontal view (E). A–B. Sphegina (Asiosphegina) crinita sp. nov., paratype, Ƌ, Java, Indonesia. C. S. (A.) crucivena Hippa, van Steenis & Mutin, 2015, paratype, ♀, Myanmar. D–E. S. (A.) culex Hippa, van Steenis & Mutin, 2015, holotype, Ƌ, Myanmar. F–G. S. (A.) dentata, sp. nov., paratype, Ƌ, Taiwan. H–I. S. (A.) distincta sp. nov., paratype, Ƌ, Vietnam. J–K. S. (A.) ensifera Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. L. S. (A.) exilipes sp. nov., holotype, Ƌ, Java, Indonesia. Scale bars = 0.5 mm.

Fig. 33. Metaleg, anterior view. A. Sphegina (Asiosphegina) crassispina Hippa, van Steenis & Mutin, 2015, paratype, ♀, Myanmar. B. S. (A.) crucivena Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. C. S. (A.) exilipes sp. nov., holotype, Ƌ, Java. D. S. (A.) forficata Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. E. S. (A.) ghatsi sp. nov., holotype, Ƌ, India. F. S. (A.) gigantea sp. nov., holotype, Ƌ, China. G. S. (A.) gigas Hippa, van Steenis & Mutin, 2015, paratype, ♀, Myanmar. Scale bars = 0.5 mm.

Fig. 24. Sphegina (Asiosphegina) crinita sp. nov., holotype, Ƌ (B–D), paratype, Ƌ, Malaysia (A). A. Sternum IV, ventral view. B. Left sternum IX and superior lobe, lateral view. C. Left surstylus, lateral view. D. Genitalia, right side, lateral view. Scale bars = 0.5 mm.