Sphegina (Asiosphegina) brevipilis, 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 : 52-55

Sphegina (Asiosphegina) brevipilis sp. nov.

urn:lsid:zoobank.org:act:E967A246-E746-46E5-A344-3E45C733EA58

Figs 15 B–C, 18, 19D, 21J

Differential diagnosis

Similar to Sphegina (Asiosphegina) plautus sp. nov. and S. (A.) simplex . For distinguishing characters, see under the latter.

Etymology

The specific epithet is from the Latin ‘ brevipilis ’, meaning ‘short-haired’ and referring to the unusually short pile on the male cercus.

Material examined

Holotype

CHINA: ♂; “Fukien, S. China, / Shaowu: Tachulan / 1000 m. T. Maa ”; “ 3.VI.1942 ”; BPBM.

Paratypes

CHINA: 1 ♂; same data as for holotype; “. IV.1942 ”; JSA • 1 ♀; same data as for holotype; “ 25–30. IV.1943 ”; BPBM .

Description

Male

LENGTH. Body 5.4–5.8 mm, wing 4.3–4.6 mm.

HEAD. Face in lateral view ( Fig. 21J ) concave, very weakly projected antero-ventrally; frontal prominence very weakly developed. Ratio width of vertex at anterior ocellus: width of head 1: 3.6–4.0; ratio width of ocellar triangle: width of vertex 1: 1.7–1.9; ratio length of ocellar triangle: length of frons 1: 1.9– 2.1. Mouth edge ventrally of eyes very narrow ( Fig. 21J ). 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, predominantly brown-grey pollinose, a subtriangular area posterior of lunula non-pollinose and shiny and a narrow more densely grey pollinose fascia posterior of shiny part; pile short, light yellow. Frons with rather deep pit antero-medially. Occiput black, light grey pollinose, light yellow pilose. Eye without enlarged facets at anterior margin. Antenna brown-yellow to brown with black setae dorsally on scape and pedicel; basoflagellomere oval, ratio width: length 1: 1.2–1.4; arista long pilose, about 2.5 times as long as basoflagellomere.

THORAX. Colour dark brown to black, weakly greyish pollinose, pleuron more heavily grey pollinose; scutum and pleuron with very short adpressed light yellow pile. Scutellum subtriangular, black, pale pollinose, with pile longer than on scutum, with two widely set, short setae medially at posterior margin, ratio length of scutellum: length of seta 1: 0.1–1.1.

WING. Entirely microtrichose; hyaline, stigma yellowish, infuscated at junction of veins R 2+3 and R 4+5, along crossveins dm-cu and M 1 and at the apex of vein R 1+2. Crossvein dm-cu meeting vein M obliquely and vein M

1

meeting vein R

4+5

perpendicularly. Vein CuA

1

extended, ending at about vein dm-cu.

LEGS. Pro- and mesoleg yellow, protarsus with tarsomeres 1 and 2 dark brown, tarsomeres 3–5 yellow; mesotarsus with tarsomeres 3–5 brown to black. Metaleg, Fig. 19D , with coxa black, trochanter yellow; femur black and yellow biannulate, very slightly incrassate and club shaped, ratio width: length 1: 6.7–7.2; tibia black and yellow biannulate, with short black apically rounded apicoventral dens; tarsus entirely black, basitarsomere thick, ratio width: length 1: 3.3–3.6.

ABDOMEN. Length ratio of terga I: II: III: IV 1: 5.0–5.3: 2.8–3.2: 1.9–2.2; ratio width at posterior margin: medial length of tergum II and III 1: 3.9–4.2 and 1: 1.2–1.4. Terga black, anterior ⅓ of tergum III with brown-yellow fascia; tergum IV with anterolateral squarish brown-yellow macula; pile pale, on terga short, laterally on terga I and II long; tergum I with 3 strong brown-yellow setae at lateral margin; sternum III rectangular, ratio width: length 1: 2.7–3.0; sternum IV, Fig. 18A ; sterna VI, VII and VIII with long yellow pile. Genitalia, Fig. 18 B–C: note the unusual pilosity of cercus and the sclerite lying posteriorly from cerci and between the bases of surstyli.

Female

Similar to male except for the usual sexual dimorphism.

LENGTH. Body 6.0 mm, wing 5.4 mm.

HEAD. Face and mouth edge black. Basoflagellomere oval, ratio width: length 1: 1.4; arista long pilose, about 3 times as long as basoflagellomere.

LEGS. Mesoleg predominantly brown; metafemur with ratio width: length 1: 6.3; metatarsus with ratio width: length 1: 3.2.

ABDOMEN. Length ratio of terga I: II: III: IV: V 1: 3.6: 3.0: 2.2: 0.7; ratio width at posterior margin: medial length of tergum II and III 1: 1.6 and 1: 0.9. Tergum I with 3 large brown setae at lateral margin. Tergum III with fascia 1: 3.8; sternum III with ratio width: length 1: 2.5; sternum IV rectangular, ratio width: length 1: 1.6; sternum V squarish, ratio width: length 1: 1.1.

Remarks

The sclerite between the bases of surstyli and posteriorly from the cerci is an unusual structure which Sphegina (Asiosphegina) brevipilis sp. nov. shares with only one other species known to us, S (A.) plautus sp. nov. For more discussion, see under the latter.

Figures

Fig. 15. Habitus, lateral view. A. Sphegina (Asiosphegina) bracon sp. nov., paratype, Ƌ, Vietnam. B. S. (A.) brevipilis sp. nov., paratype, Ƌ, China. C. S. (A.) brevipilis sp. nov., paratype, ♀, China. D. S. (A.) carinata Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. E. S. (A.) cerina Hippa, van Steenis & Mutin, 2015, paratype, ♀, Myanmar. F. S. (A.) clavigera sp. nov., holotype, Ƌ, Vietnam. Scale bars = 1.0 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.

Fig. 19. Metaleg, anterior view. A. Sphegina (Sphegina) abbreviata sp. nov., paratype, ♀, Nepal. B. S. (S.) angustata sp. nov., paratype, ♀, Nepal. C. S. (S.) uncinata Hippa, van Steenis & Mutin, 2015, Ƌ, Myanmar. D. Sphegina (Asiosphegina) brevipilis sp. nov., paratype, Ƌ, China, abbreviations: a = length of basitarsus of metatarsus; b = width of basitarsus of metatarsus. E. S. (A.) collicola sp. nov., holotype, Ƌ, Malaysia. F. S. (A.) crinita sp. nov., paratype, ♀, Java, abbreviations: a = length of metafemur; b = width of metafemur. Scale bars = 0.5 mm.

Fig. 18. Sphegina (Asiosphegina) brevipilis sp. nov., holotype, Ƌ. A. Sternum IV, ventral view. B. Posterior part of genitalia, left side, lateral view. C. Genitalia, right side, lateral view. Scale bars = 0.5 mm.