Sphegina (Asiosphegina) dentata Steenis & Hippa & Mutin 2018, sp. nov.
Creators: name: Steenis, Jeroen Van
name: Hippa, Heikki
name: Mutin, Valeri A.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Syrphidae
Sphegina
Sphegina dentata

description: Sphegina (Asiosphegina) dentata sp. nov.
urn:lsid:zoobank.org:act: 210AF7E9-4BB2-4239-B7CF-BEA4886D7E87
Figs 26, 28B, 30 F–G, 43A, 47A, 65B
Differential diagnosis
In the key to the species, based on the non-genitalic characters, Sphegina (Asiosphegina) dentata sp. nov. is coupled with S. (A.) nigerrima and distinguished by the characters mentioned there. In the male genitalia, the species is similar to Sphegina (Asiosphegina) tricoloripes and S. (A.) umbrosa sp. nov. It is distinguished from the latter species by having a strongly sclerotized subapical tooth on the cercus and from the former by having only one cercal tooth instead a row of 3–4 teeth. All the three above mentioned species resemble the East-Palaearctic species Sphegina (Asiosphegina) elongata, S. (A.) freyana and S. (A.) grunini but differ from them by having entirely grey pollinose pleura (as opposed to having the pleura extensively non-pollinose and shiny). See also under S. (A.) nigerrima sp. nov. and S. (A.) umbrosa sp. nov.
Etymology
The specific epithet is from the Latin ‘ dentata ’, meaning ‘dentate’ and referring to the dentate male cercus.
Material examined
Holotype
TAIWAN • ♂; “Taiwan C: / Alishan, 2400 m / 3–9.VII.1972 ”, T.C. Maa / Collector / Bishop”; BPBM.
Paratypes
TAIWAN • 1 ♂; “Taiwan – Taichung / Haiduan road to / Siangyang National forest / Recreation area / 23°14 ′ 28 ″ N, 120°59 ′ 06 ″ E / 29–05–2016 2200 m asl / W. van Steenis wvs05883”; WSB • 1 ♂; “FO: 9006 Taiwan / 23°14 ʹ 50.5 ″ N, 120°59 ʹ 09.3 ″ E / Siangyang National forest Recreat / Taichung; 2820 mNN / A. Astilbe sp. / leg. A. Ssymank, 29.05.2016 ”; ASW • 1 ♂; “Supplementary label / TWN YILAN COUNTY / Mt. TAIPINGSHAN; alt. 1900m / (ŜẔÎDṞṪṮŔṪṮƜ) / 27 - June, 2010 / Kojirou Katsura leg.”; “[ŜẔ] ³ x $ NO.31288 / Î xx, ṪṮŔ Mt. ṪṮƜ / xx 1900 m / MC ū x B 2010.6.27; / Leg. Xxxx” “<xxxx.xx(xx).xx.MEMOx> / Sphegina x-x / (xxx) / MEMO ♂ / =ḣƚo K ”; KIM • 1 ♂; same data as for preceding, “31291”; JSA.
Description
Male
LENGTH. Body 7.1–7.9 mm, wing 5.4–5.9 mm.
HEAD. Face in lateral view (Fig. 30F) concave, strongly projected antero-ventrally; frontal prominence weakly developed. Ratio width of vertex at anterior ocellus: width of head 1: 3.7–4.0; ratio width of ocellar triangle: width of vertex 1: 2.2–2.5; ratio length of ocellar triangle: length of frons 1: 3.7–4.0. 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, slightly light grey pollinose; a large trapezoidal area posterior of lunula non-pollinose and shiny and posterior of this area a rectangular fascia of denser grey-pollinosity (Fig. 30G); pile short, light yellow. Frons with weak antero-medial pit and rather weak medial furrow. Occiput black, light grey pollinose, light yellow pilose. Eye with an area of slightly enlarged facets at anterior margin. Antenna dark brown to black with black setae dorsally on scape and pedicel; basoflagellomere (Fig. 43A) round, ratio width: length 1: 0.9–1.0; arista only basally short pilose; slightly more than 3 times as long as basoflagellomere.
THORAX. Colour black, weakly greyish pollinose sub-shiny, scutum submedially with more densely pollinose vitta and dense pollinosity along lateral margin; posterior margin of katepisternum widely nonpollinose, shiny (Fig. 65B); scutum and pleuron with very short adpressed light yellow pile. Scutellum semicircular, black, shiny and only weakly pollinose along posterior margin, with pile slightly longer
than on scutum, with two widely set, very long setae medially at posterior margin, ratio length of scutellum: length of seta 1: 2.3–2.7.
WING. Entirely microtrichose; hyaline, stigma brownish. Crossvein dm-cu meeting vein M obliquely and vein M 1 meeting vein R
4+5
perpendicularly.
LEGS. Pro- and mesoleg yellow on basal 1/10 of femora and basal ¼– ⅓ of tibiae, tarsomeres 1–2 dark yellow; metafemur black with basal 1/5 yellow, slightly incrassate, ratio width: length 1: 3.7–3.9; metatibia black and yellow biannulate, without apicoventral dens; metatarsus entirely black, basitarsomere rather thin, ratio width: length 1: 3.8–4.1.
ABDOMEN. Length ratio of terga I: II: III: IV 1: 4.5–4.9: 2.0–2.4: 1.6–1.9; ratio width at posterior margin: medial length of tergum II and III 1: 3.9–4.3 and 1: 1.0–1.2. Terga black, sub-anterior ⅓ of tergum III with yellow fascia or squarish lateral macula; pile pale, on terga short, laterally on terga I and II long; tergum IV slightly skewed to the right; tergum I with an oblique row of 4–5 strong light yellow setae at lateral margin (Fig. 47A); sternum III squarish, ratio width: length 1: 1.0–1.2; sternum IV, Fig. 26B; sterna VI, VII and VIII simple, with long yellow pile. Genitalia, Fig. 26 C–F: note the only slightly asymmetrical surstyli and superior lobes and asymmetrical dentate cerci.
Female
Unknown.
Biology
Flower visiting Astilbe longicarpa (Saxifragaceae) near a small brook with water percolating on a steep rocky slope within a mainly older Pinus taiwanensis afforestation (van Steenis et al. in prep).
description: Published as part of Steenis, Jeroen Van, Hippa, Heikki & Mutin, Valeri A., 2018, Revision of the Oriental species of the genus Sphegina Meigen, 1822 (Diptera: Syrphidae), pp. 1-198 in European Journal of Taxonomy 489 on pages 68-70, DOI: 10.5852/ejt.2018.489, http://zenodo.org/record/3830537