Sphegina (Asiosphegina) index Hippa, van Steenis & Mutin 2015
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 index

description: Sphegina (Asiosphegina) index Hippa, van Steenis & Mutin, 2015
Figs 45B, 50B, 52B
Sphegina (Asiosphegina) index Hippa, van Steenis & Mutin, 2015: 19. Type locality: Kambaiti, Myanmar (holotype, ♂, NHRS).
Material examined
CHINA • 1 ♀; “Fukien, S. China / Shaowu: Tachulan / 1000 m. T. Maa ”; “ 25–30.IV.1943 ”; BPBM.
MYANMAR • 1 ♀; “ N.E. Burma / Kambaiti 7000 ft / 26–5–1934 [leg] Malaise”; “ Paratype ♀ / Sphegina (Asiosphegina) / malaisei Hippa, / van Steenis & Mutin, 2015 ” [red label]; JSA.
THAILAND • 1 ♀; “ Thailand, Chiang Mai / Doi Inthanon NP / checkpoint 2 1700 m / 18°31.559 ʹ N, 98°29.941 ʹ E / 26.X–2.XI.2006 Malaise trap / Y. Areeluck leg. T 383”; QSBG • 1 ♀; “ Thailand, Chiang Mai / Doi Inthanon NP / summit marsh, 2500 m / 18°35.361 ʹ N, 98°29.157 ʹ E / 12.X–19.X.2006 Malaise Trap / Y. Areeluck leg. T 368”; JSA.
VIETNAM • 1 ♂, 1 ♀; “NW VIETNAM: Tonkin / Hoang Lien N.P., 15 km, / W Sa Pa c. 1900 m / 15–21.X.1999 Malaise traps / [leg] C. v. Achterberg, RMNH ‘99”; NBC • 1 ♀; same data as for preceding; JSA • 1 ♀; “NW Vietnam (Ton Kin) / Sin Chay / 15–21.X.1999 / 1900 mtr. Mal. Trap / C. van Achterberg ”; JSA.
Description
Female
LENGTH. Body 6.0– 6.9 mm, wing 4.8–5.5 mm
HEAD. Face in lateral view concave, strongly projected antero-ventrally; frontal prominence weakly developed. Ratio width of vertex at anterior ocellus: width of head 1: 2.9–3.3; ratio width of ocellar triangle: width of vertex 1: 2.5–2.9; ratio length of ocellar triangle: length of frons 1: 2.8–3.2. Face black; grey pollinose, long pilose along eye-margin. Hypostomal bridge black, long pale pilose. Gena and mouth edge dark brown to black with large subtriangular non-pollinose shiny area. Frons and vertex black, slightly pollinose, a rectangular non-pollinose and shiny area posterior of lunula; pile short, light yellow. Frons with wide circular pit and wide furrow medially. Occiput black, light grey pollinose, light yellow pilose. Antenna dark brown with black setae dorsally on scape and pedicel; basoflagellomere long-oval, ratio width: length 1: 1.5–1.6; arista long pilose, about 2.5 times as long as basoflagellomere.
THORAX. Colour black, postpronotum light yellow; weakly grey pollinose, pleuron entirely more heavily grey pollinose; scutum and pleuron with very short adpressed light yellow pile. Scutellum subtriangular, black, shiny, only slightly pollinose, with pile slightly longer than on scutum, with two closely set, long setae medially at posterior margin, ratio length of scutellum: length of seta 1: 1.9–2.3.
WING. Entirely microtrichose; hyaline, stigma yellowish, crossveins brown infuscated. 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. Metaleg, Fig. 52B, with coxa dark brown, trochanter yellow; femur black with basal ⅓ yellow, slightly incrassate and basally curved, with a long black seta anterodorsally near apex, ratio width: length 1: 5.0–5.4; tibia black and yellow biannulate, without apicoventral dens; tarsus entirely black, first tarsomere thin, ratio width: length 1: 3.2–3.4.
ABDOMEN. Length ratio of terga I: II: III: IV: V 1: 2.7–3.0: 2.3–2.6: 1.5–1.8: 0.6–0.7; ratio width at posterior margin: medial length of tergum II and III 1: 2.5–2.9 and 1: 0.8–0.9. Terga black, tergum II with anterior dark-orange fascia; tergum III with orange-yellow macula latero-medially; terga III and IV dark-orange; pile of terga short, light yellow; tergum I with one anterolateral strong black seta; sternum III rectangular, ratio width: length 1: 1.3–1.5; sternum IV rectangular, ratio width: length 1: 0.6–0.7 and sternum V squarish with convex posterior margin, width: length 1: 1.0–1.1.
Distribution and biology
Known from Myanmar, SE China, Thailand and Vietnam. A montane (1700–2500 m) species apparently with two flight periods: mid-May and from mid-October to early November. In Myanmar it was collected in a cloud forest with streams and swampy areas at an altitude of 2000 m. The specimen from Vietnam was collected in a Malaise trap near the Tram Ton Pass, the highest mountain pass in Vietnam (1900 m), near Fan Si Pan mountain. The Malaise trap had been set up in an area of montane forest disturbed by grazing buffaloes, containing muddy areas and small streams. Despite the cold and wet weather insects were rather abundantly flying (C. van Achterberg, pers. comm).
Remarks
The species was previously known only by the holotype from Myanmar, Kambaiti (Hippa et al. 2015). One of the female paratypes of Sphegina (Asiosphegina) malaisei turned out to be the hitherto undescribed female of S. (A.) index. This particular specimen has very faintly infuscated wing and a slightly darkened ventral side of the metatrochanter giving a false impression of a carina.
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 102-103, DOI: 10.5852/ejt.2018.489, http://zenodo.org/record/3830537