Sphegina (Asiosphegina) taiwanensis, 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 : 173-176

Sphegina (Asiosphegina) taiwanensis sp. nov.

urn:lsid:zoobank.org:act:F8585237-DC89-4AA0-9DD4-98A5F28C3E7F

Figs 84L , 86 D–E, 89, 90D

Differential diagnosis

Sphegina (Asiosphegina) taiwanensis sp. nov. is not very similar to any other species and is distinguished by the characters given in the key. It keys out together with Sphegina (Asiosphegina) orientalis and three other similar species and should be easily distinguished by the non-genitalic character given there. The male genitalia differ greatly, e.g., the surstyli are unilobed, not bilobed, and the cercal pilosity is normal, not with an area of very long seta-like pile.

Etymology

The specific epithet is from the Latin ‘ taiwanensis ’, meaning ‘of Taiwan’ and referring to the type locality in Taiwan.

Material examined

Holotype

TAIWAN • ♂; “Taiwan N-Nantou Co. / Road No. 14, NE Puli / Reyen Shi-Reg., E Tsuifeng / to Yuanfeng ca 2500–2700 m / ca 24°07 ʹ N, 121°13 ʹ E / 1.VII.2000 leg. W. Schacht ”; NMNS.

Paratypes

TAIWAN • 1 ♀; same data as for holotype; “ Meifeng / ca 24°06 ʹ N, 121°10 ʹ E / 2200m 9–11.IX.2002 ”; ZSM • 1 ♂, 1 ♀; “ Taiwan / Alishan, Chaiayi / Hsien 2400 m / 12–16.VI.1965 ”; “ T. Maa & K.S. Lin / Collectors / Bishop Museum”; BPBM • 2 ♂♂; “ Taiwan Arisan / 2130 m (7300’) / 17.VIII.1947 ”; “J.L. Gressitt / collector / Bishop Museum”; BPBM • 1 ♂; same data as for preceding; JSA • 1 ♂, 2 ♀♀; same data as for preceding; “ 19.VII.1947 ”; BPBM • 2 ♂♂, 1 ♀; same data as for preceding; JSA • 1 ♀; same data as for preceding; “ 22.VII.1947 ”; BPBM • 1 ♂, 3 ♀♀; “Taiwan C.: / Alisan 2400 m / 3–9.VII.1972 ”; “T.C. Maa / Collector / Bishop”; BPBM • 1 ♂, 2 ♀♀; same data as for preceding; JSA • 1 ♂; “ Taiwan Nantou / Meifeng / VI.11–VII.9.2002 / C.S. Lin & W.T. Yang / Malaise trap ( KCN)”; NMNS ENT / 4477–806”; NMNS • 1 ♀; same data as for preceding; “4477–523”; NMNS • 1 ♂; same data as for preceding; “VIII.6–IX.11.2001”; “6014–2294”; JSA • 1 ♂; same data as for preceding; “IX.10–XI.15.2002”; “4913–331”; NMNS • 1 ♂; “ Taiwan Nantou / Sanlinchi / 19.V.1991 / [leg] C.C. Chiang / Sweeping & Sucking”; “ NMNS ENT / 1128–74 ”; NMNS • 1 ♂; “ Taiwan Taichung / Anmashan / 1.V.1990 / C.C. Chiang / Sweeping net ”; “ NMNS ENT / 583–45”; JSA • 1 ♀; “ Taiwan Nantou / Sungkang / III.11.1999 / W.T Yang / UV light”; “ NMNS ENT / 3151–1284”; JSA • 1 ♀; “ Taiwan Nantou / Hsini Patungkuan / 20–22.VI.1990 / J.T. Yang / Sweeping net ”; “ NMNS ENT / 611–129”; NMNS • “ 1 ♀; Taiheizan / 26 VIII 1923 / Col T. Shiraki ”; “ barcode / 12153014180090”; NTU • 1 ♀; same data as for preceding; “barcode / 91”; NTU • 1 ♀; “ Arisan / 1912–X–20 / Col. I Nitobe ”; “3508”; “barcode / 12153014180067”; NTU • 1 ♀; “ Formosa / Karenko – 19 / VII. 20–VIII 4 / T. Okuni / J. Sonan / K. Miy, M. Yosh ”; “barcode / 12153014180077”; NTU • 1 ♂; “Taiheisan / Formosa / VII–5–34”; “ L. Gressitt / Collector”; “ Frank M. Hull / Collection / C.N.C. 1973”; “ CNC DIPTERA / # 179653” [white label with blue border]; CNC • 1 ♀; “ Taiwan Siangyang National / Forest Recreational Area / trails, 23.247361° N, 120.985917° E, 29.v.2016 / J.H. Skevington, A.D. Young / JSM8520, CNC571925 ” [DNA voucher specimen, in alcohol]; CNC • 1 ♀; “ Taiwan, Yilan, Datung / Mingchih forest rec. area / 24°39 ʹ 05 ″ N, 121°28 ʹ 24 ″ E / 17–5–2016, 1182 m / leg. J. van Steenis ”; JSA • 1 ♀; same data as for preceding; “leg. W van Steenis ”; WSB • 1 ♀; “ Taiwan Taichung Haiduan / Siangyang For. recr. Area / 23°14 ʹ 50 ″ N, 120°59 ʹ 09 ″ E / 29–05–2016, 2310– 2400m / leg. J. van Steenis ”; JSA • 1 ♀; same data as for preceding; NMNS • 1 ♀; same data as for preceding; NTU • 1 ♀; “ Taiwan – Taichung / Haiduan road to / Siangyang National forest / Recreation area / 23°14 ʹ 28 ″ N, 120°59 ʹ 06 ″ E / 29–05–2016, 2200m asl / W. van Steenis; wvs05884”; WSB • 1 ♀; same data as for preceding; “leg. J. van Steenis ”; JSA • 2 ♂♂; “[Taiwan] / Mt Lalashan / 1300-1500 m / Taoyuan Hsien / 17.iv.1981 / Kenji Ohara”; KIM • 1 ♂; “[Taiwan] / Alishan- Chushan / Alishan Chiai / 13.iv.1984 / Kenji Ôhara”; KIM .

Description

Male

LENGTH. Body 4.8–6.1 mm, wing 4.2–5.1 mm.

HEAD. Face in lateral view concave, weakly projected antero-ventrally; frontal prominence weakly developed. Ratio width of vertex at anterior ocellus: width of head 1: 3.8–4.1; ratio width of ocellar triangle: width of vertex 1: 1.8–2.2; ratio length of ocellar triangle: length of frons 1: 2.1–2.4. Face black, ventral half yellow; light grey pollinose, long pilose along eye-margin. Hypostomal bridge black, long pale pilose. Gena and mouth edge yellow, pale pollinose with large subtriangular non-pollinose shiny area, posterior part of mouth edge dark brown to black. Frons and vertex black, frontal prominence shiny with grey pollinose subtriangular macula antero-laterally at eye-margin ( Fig. 84L ); pile short, light yellow. Frons with deep antero-medial pit and weak but wide furrow medially. Occiput black, light grey pollinose, ocellar triangle non-pollinose shiny, light yellow pilose. Eye without enlarged facets at anterior margin. Antenna with scape and pedicel dark yellow to brown with black setae dorsally, basoflagellomere dark brown to black; basoflagellomere elongate, ratio width: length 1: 1.7–1.9; arista long pilose, about 2.5 times as long as basoflagellomere.

THORAX. Colour dark brown to black, weakly greyish pollinose; postpronotum, postalar callus and dorsomedial part of anepisternum and anepimeron yellow; posterior part of anepisternum and katepisternum very weakly pollinose, shiny; scutum and pleuron with very short adpressed light yellow pile. Scutellum semicircular, black, sub-shiny and weakly pollinose, with pile slightly longer than on scutum, with two widely set, very short setae medially at posterior margin, ratio length of scutellum: length of seta 1: 0.6.

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 and M 1 and at apical end 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 mesoleg yellow, tarsomeres 4 and 5 dark-grey to black. Metaleg with coxa black, trochanter yellow; femur black and yellow biannulate, slender, ratio width: length 1: 4.1–4.9; tibia black and yellow biannulate without apicoventral dens; tarsus entirely black, basitarsomere rather thin, ratio width: length 1: 3.4–3.9.

ABDOMEN. Length ratio of terga I: II: III: IV 1: 3.4–3.7: 2.2–2.5: 1.8–2.1; ratio width at posterior margin: medial length of tergum II and III 1: 3.8–4.1 and 1: 1.1–1.3. Terga black, lateral margin of terga I and II narrowly brown-yellow; terga III and IV on anterior ¼– ⅓ with brown-yellow fascia; pile pale, on terga short, laterally on terga I and II long; tergum I with row of 2–3 strong dark brown setae at lateral margin; sternum III elongate, ratio width: length 1: 2.8–3.4; sternum IV, Fig. 89A ; sterna VI, VII and VIII simple, with long yellow pile. Genitalia, Fig. 89 B–D: note the almost symmetrical surstyli and superior lobes.

Female

Similar to male except the usual sexual dimorphism.

LENGTH. Body 4.8–6.1 mm, wing 4.3–5.7 mm.

HEAD. Ratio width of vertex at anterior ocellus: width of head 1: 3.3–3.6; ratio width of ocellar triangle: width of vertex 1: 2.1–2.4; ratio length of ocellar triangle: length of frons 1: 2.9–3.1. Hypostomal bridge dark brown to black. Frons sub-shiny, slightly grey pollinose, with deep, wide antero-medial pit and wide but weak medial furrow. Basoflagellomere slightly elongate, ratio width: length 1: 1.2–1.5; arista long pilose; about 2.5 times as long as basoflagellomere.

THORAX. Scutellum with two widely set, very short setae medially at posterior margin, ratio length of scutellum: length of seta 1: 0.8–0.9.

LEGS. Metafemur slightly enlarged, ratio width: length 1: 4.7–5.3; metatarsus with basitarsomere thick, ratio width: length 1: 3.5–4.0.

ABDOMEN. Length ratio of terga I: II: III: IV: V 1: 2.8–3.1: 2.2–2.8: 2.1–2.7: 0.8–0.9; ratio width at posterior margin: medial length of tergum II and III 1: 1.7–2.1 and 1: 0.7–0.9. Terga II, III and IV with yellow to dark yellow fascia on respectively anterior 1/10, ⅓ and 1/5; sternum III rectangular, ratio width: length 1: 2.4–2.6; sternum IV rectangular with concave posterior margin, ratio width: length 1: 1.4–1.6; sternum V rectangular, ratio width: length 1: 1.0–1.3.

Distribution and biology

Widespread in Taiwan. Low to high montane (1182–2700 m) species with flight period from mid- March until mid-September. Abundantly collected on a cold misty day along lakeshore and roadside in semi-shady humid forest margins with a dense herb layer dominated by Oenanthe javanica . Also collected near a small brook, with water percolating from a steep rocky slope within a mainly older Pinus taiwanensis afforestation. Other flowers visited were Oenanthe javanica , Astilbe longicarpa and Erigeron annuus (van Steenis et al. in prep).

Figures

Fig. 84. Head, lateral view (E, H), dorsal view (A–D, F, I, K–L) and frontal view (G, J). A. Sphegina (Asiosphegina) nasuta Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. B. S. (A.) nubicola sp. nov., holotype, Ƌ, Thailand. C. S. (A.) orientalis Kertész, 1914, ♀, Taiwan. D. S. (A.) parvula Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. D–E. S. (A.) perlobata sp. nov., holotype, Ƌ, Taiwan. F. S. (A.) philippina, Thompson, 1999, paratype, ♀, Philippines. G. S. (A.) philippina, holotype, Ƌ, Philippines. H. S. (A.) plautus sp. nov., holotype, Ƌ, China. I–J. S. (A.) prolixa sp. nov., holotype, Ƌ, Malaysia. K. S. (A.) cf. spathigera sp. nov., ♀, Philippines. L. S. (A.) taiwanensis sp. nov., paratype, Ƌ, Taiwan. Scale bars = 0.5 mm.

Fig. 86. Habitus, lateral view. A. Sphegina (Asiosphegina) spenceri sp. nov., paratype, Ƌ, Vietnam. B. S. (A.) spenceri sp. nov., paratype, ♀, Vietnam. C. S. (A.) subradula Hippa, van Steenis & Mutin, 2015, paratype, ♀, Myanmar. D. S. (A.) taiwanensis sp. nov., paratype, Ƌ, Taiwan. E. S. (A.) taiwanensis sp. nov., paratype, ♀, Taiwan. F. S. (A.) trichaeta Hippa, van Steenis & Mutin, 2015, paratype, Ƌ, Myanmar. Scale bars = 1.0 mm.

Fig. 89. Sphegina (Asiosphegina) taiwanensis sp. nov., holotype, Ƌ. A. Posterior part of sternum IV, ventral view. B. Left surstylus, lateral view. C. Left superior lobe with associated parts, lateral view. D. Genitalia, right side, lateral view. Scale bars = 0.5 mm.