Sphegina (Asiosphegina) strigillata 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 strigillata

description: Sphegina (Asiosphegina) strigillata sp. nov.
urn:lsid:zoobank.org:act: E2A984A9-0B7B-47B4-BE19-1E7DCA8A28FF
Figs 82F, 87, 88 D–E, 90B–C, 95C
Differential diagnosis
This species is not very similar to any described species of Sphegina and should be easily distinguished by the characters given in the key.
Etymology
The specific epithet is from the Latin ‘ strigillata ’, meaning ‘with a scraper’ and referring to the scraperlike posterior part of male sternum IV.
Material examined
Holotype
VIETNAM • ♂; “ N. Vietnam Tonkin / Hoang Lien N.P. Pansi Pan Mt / 2320 m. prim. Forest 24.iv– / 2.v.2000 [leg] Mai Phu Quy & / Nguyen M. Tam, RMNH’00”; NBC.
Paratypes
VIETNAM • 1 ♂; same data as for holotype; JSA • 1 ♀; same data as for holotype; NBC.
Description
Male
LENGTH. Body 7.8–8.1 mm, wing 5.6–5.9 mm
HEAD. Face in lateral view, Fig. 88E, concave, weakly projected antero-ventrally; frontal prominence strongly developed. Ratio width of vertex at anterior ocellus: width of head 1: 3.5–3.7; ratio width of ocellar triangle: width of vertex 1: 1.9–2.1; ratio length of ocellar triangle: length of frons 1: 1.8– 2.1. Face black, light grey pollinose, long pilose along eye-margin. Hypostomal bridge black, long pale pilose. Gena and mouth edge dark brown, pale pollinose with large subtriangular non-pollinose shiny area. Frons and vertex black, large rectangular vitta posterior of lunula non-pollinose and shiny (Fig. 88D); pile short, light yellow. Frons with very weak and narrow medial furrow. Occiput black, light grey pollinose, light yellow pilose. Eye without enlarged facets at anterior margin. Antenna brown-yellow with black setae dorsally on scape and pedicel; basoflagellomere oval, ratio width: length 1: 1.2–1.4; arista long pilose, about 3.5 times as long as basoflagellomere.
THORAX. Colour dark brown to black, weakly greyish pollinose, scutum with densely grey pollinose vitta submedially, pleuron entirely grey pollinose; scutum and pleuron with very short adpressed light yellow pile. Scutellum sub-triangular, black, shiny, with pile slightly longer than on scutum, with two widely set short setae medially at posterior margin, ratio length of scutellum: length of seta 1: 1.1–1.4.
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, dm-cu and M 1, and at medial and apical appendices of vein R
2+3. Crossvein dm-cu meeting vein M perpendicularly and vein M 1 meeting vein R
4+5
perpendicularly.
LEGS. Pro- and mesofemur yellow, baso-medial ¼–½ black; pro- and mesotibia yellow, apico-medial 1/5–¼ black; pro- and mesotarsus yellow, tarsomeres 3–5 brown to black. Metaleg, Fig. 95C, with coxa and trochanter black; femur black and yellow biannulate, incrassate, ratio width: length 1: 3.8–4.0; tibia
black and yellow biannulate without apicoventral dens; tarsus entirely black, basitarsomere rather thin, ratio width: length 1: 3.7–3.9.
ABDOMEN. Length ratio of terga I: II: III: IV 1: 4.7–4.9: 2.8–3.1: 1.5–1.7; ratio width at posterior margin: medial length of tergum II and III 1: 5.4–5.6 and 1: 1.4–1.6. Terga black, anterior ¼– ⅓ of tergum III with yellow fascia; pile pale, on terga short, laterally on terga I and II long; tergum I with a horizontal row of 3–4 strong black setae at lateral margin; sternum III elongate, ratio width: length 1: 2.6–2.8; sternum IV, Fig. 87A; sterna VI, VII and VIII simple, with long yellow pile. Genitalia, Fig. 87 B–D: note the almost symmetrical surstyli and asymmetrical superior lobes.
Female
Similar to male except for the normal sexual dimorphism.
LENGTH. Body 7.2 mm, wing 6.1 mm.
HEAD. Ratio width of vertex at anterior ocellus: width of head 1: 3.4; ratio width of ocellar triangle: width of vertex 1: 2.2; ratio length of ocellar triangle: length of frons 1: 3.0. Frons with densely grey pollinose fascia anteriorly of shiny part. Basoflagellomere oval, ratio width: length 1: 1.3; arista about 3 times as long as basoflagellomere.
THORAX. Scutellum with two very widely set, short setae medially at posterior margin, ratio length of scutellum: length of setae 1: 1.1.
LEGS. Metafemur incrassate, ratio width: length 1: 3.9; metatarsus with basitarsomere rather thin, ratio width: length 1: 3.7.
ABDOMEN. Length ratio of terga I: II: III: IV: V 1: 2.8: 2.2: 1.6: 0.7; ratio width at posterior margin: medial length of tergum II and III 1: 2.4 and 1: 0.8. Tergum I brown, terga II–V orange-yellow; tergum I with 2 widely separated strong black setae at lateral margin; sternum III rectangular, ratio width: length 1: 3.0; sternum IV trapezoidal, ratio width: length 1: 1.1 and sternum V squarish, ratio width: length 1: 1.0.
Distribution and biology
The specimen from Vietnam was collected in a Malaise trap near Fan Si Pan Mountain at a height of about 2300 m a.s.l. The Malaise trap was set up in an area of open and low montane forest partly grazed by buffalos, containing muddy areas and small streams. Despite the cold and wet weather, insects were still rather abundantly flying (C. van Achterberg, pers. comm.).
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 169-172, DOI: 10.5852/ejt.2018.489, http://zenodo.org/record/3830537