Sphegina (Asiosphegina) cerina, Hippa, Heikki, Steenis, Jeroen Van & Mutin, Valeri A., 2015

Hippa, Heikki, Steenis, Jeroen Van & Mutin, Valeri A., 2015, The genus Sphegina Meigen (Diptera, Syrphidae) in a biodiversity hotspot: the thirty-six sympatric species in Kambaiti, Myanmar, Zootaxa 3954 (1), pp. 1-67 : 44-45

Sphegina (Asiosphegina) cerina sp. n.

Figs 26 A–D

MALE. Body length 6.2 mm, wing length 6.0 mm. Head. Face moderately concave, moderately projected anteroventrally; frontal prominence weakly developed (similar to Fig. 1J). Width of vertex at anterior ocellus:width of head 1:5.0, depth of occipital fossa ca. 1/3 of the width of an eye in dorsal view. Width of face:width of head 1:4.9. Face yellow, pale pollinose. Gena shiny yellow. Frons and vertex semi-shiny brownish; lunula yellow; the pile short, erect and pale. Occiput mainly black with reddish margins. Antenna yellow; basoflagellomere 1.5 times longer than broad [ratio 1:0.7]; arista yellowish, pilose. Thorax. Colour dull yellow, scutum darker brownish; scutum with short, adpressed pale pile; postpronotum yellow; scutellum semi-circular, ratio of length:width 1:2.5, the pile similar to posterior part of scutum, a pair of convergent long pale setae at apical margin. Wing. Hyaline, stigma yellow. Legs. Pro- and mesoleg yellow, tarsomeres 4 and 5 brownish. Metaleg: coxa yellow; trochanter yellow, simple; femur yellow with a diffuse submedial brownish annulus and brownish extreme apex; tibia without apico-ventral tooth, mainly brownish with yellowish wide medial annulus; tarsus brownish, paler ventrally. Abdomen. Length ratio of tergites I, II, III and IV 1:3.0:2.0:1.3. Colour of tergites shiny brownish, tergite III with a yellow fascia on the anterior 1/2, the pile of tergites adpressed and pale, becoming longer towards the lateral margin; tergite I with an oblique row of 3 thin, pale setae laterally; sternite IV ( Fig. 26 A) brown anteriorly and yellow posteriorly, the pile pale; sternites VI–VIII brownish, the pile pale and short. Genitalia, Figs 26 B–D. Note the nearly symmetrical surstyli and slightly asymmetrical superior lobes. FEMALE. Body length 5.9–6.8 mm, wing length 5.6–6.5 mm. Similar to male except for the normal sexual dimorphism. Length ratio of tergites I, II, III and IV 1:3.5:2.7:2.0; tergites dark-brown to black, sometimes tergite I entirely orange-yellow and tergite II orangeyellow on anterior 1/5; tergite I with oblique row of 3–4 yellow setae; ratio of length:width of tergites III and IV 1:1.6 and 1:2.1; sternite IV rectangular, longer than broad; sternite V trapezoid with arcuate posterior margin.

Type material. HOLOTYPE. ♂, N.E. Burma, Kambaiti, 7000 ft, 26.v.1934, R. Malaise ( SMNH, strongly damaged specimen). PARATYPES. 2♀ with same data as holotype except 20.v. ( BMNH, NBC); 1♀ with same data except 23.v. ( SMNH); 1♀ with same data except 7.vi. ( BMNH); 1♀ with same data except without date ( BMNH); 1♀ with same data except 2000 m., 11.v. ( SMNH); 1♀ with same data except 2000 m., 12–17.vi. ( NBC).

Etymology. The name is Latin, cerina , wax-coloured or yellowish, referring to the extensively yellowish colouration of the fly.

Discussion. Sphegina cerina is not especially similar to any other species. It has a slight resemblance to such species as S. cultrigera , S. siculifera , S. ensifera , S. sinesmila , S. parvula , S. minuta and S. pusilla but is distinguished from all of these by its yellow, not brown or black, gena and extensively yellow, not brown or black, scutellum. In male genitalia the long sigmoid surstylus and the claw-like superior lobe tapering towards the apex distinguish the species.

Figures

FIGURE 26. Sphegina (Asiosphegina) cerina sp. n. (holotype). A. Posterior part of sternite IV, ventral view. B. Left surstylus, lateral view. C. Left superior lobe, lateral view. D. Genitalia, lateral view. Scale 0.5 mm.