Sphegina (Asiosphegina) simplex, 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 : 38-39

Sphegina (Asiosphegina) simplex sp. n.

Figs 2 I, 4A, F, 22A–D

MALE. Body length 4.5–5.8 mm, wing length 4.0– 4.7 mm. Head. Face strongly concave, moderately projected antero-ventrally; frontal prominence weakly developed (similar to Fig. 1J). Width of vertex at anterior ocellus:width of head 1:3.5; depth of occipital fossa ca. 1/3 of the width of an eye in dorsal view. Width of face:width of head 1:3.9. Face ventrally semi-shiny yellow, dorsally brownish, densely pale pollinose. Gena yellow, darker posteriorly. Frons with a week medial furrow, shiny black; lunula brown, an obscure medially almost interrupted pale pollinose cross band just posterior to the frontal prominence, the pile short, erect and pale; vertex shiny black, the pile pale. Occiput dull black, semi-shiny dorso-medially. Antenna brown, basoflagellomere oval [ratio length:width 1:0.9], baso-ventrally reddish; arista pilose. Thorax. Colour black, postpronotum, postalar callus and anepimeron brownish, baso-lateral part of scutellum yellow, mostly dull but scutellum shiny; scutum with adpressed pale pile; scutellum semicircular, the pile rather long, semi-adpressed, a pair of thin, long, pale setae at apical margin of the same length as the scutellum. Wing. ( Fig. 2 I). Rather hyalinous, stigma yellow, with infuscated transversal veins. Legs. Pro- and mesoleg yellow, tarsus darkened from apex of tarsomere 2 to apex of tarsomere 5, blackish. Metaleg: coxa brownish; trochanter simple, yellow; femur brown, basal 1/4 and a broad annulus on the apical 1/2 yellow; tibia without apico-ventral tooth, brown, the basal 1/5 and an annulus on the apical 1/2 yellow tarsus brown. Abdomen. ( Figs 4 A, F). Length ratio of tergites I, II, III and IV 1:3.0:1.9:1.5. Colour of tergites shiny black, tergite III with interrupted yellow anterior fascia, tergite IV with a pair of narrowly medially separated reddish maculae anteriorly; the pile of tergites rather long, adpressed, black or brown on dark parts and pale on pale marks of tergites III and IV, becoming longer towards the lateral margin; tergite I ( Fig. 4 A) with 2–3 long, pale, widely separated setae at lateral margin, in some specimens a fourth seta present posteriorly and positioned dorsally from the third; sternite IV ( Fig. 22 A) unusually symmetrical, yellowish, the posterior part medially membranous, the pile pale, the longer setose pile reddish; sternites VI–VIII simple, black, the pile pale. Genitalia, Figs 22 B–D. Note the symmetrical surstyli, asymmetrical superior lobes and the large lateral lobe and elongated postero-medial part of aedeagus marked in broken lines. FEMALE. Body length 5.8–6.30 mm, wing length 5.2–5.6 mm. Similar to male except for the normal sexual dimorphism. Abdominal colour as in male; length ratio of tergites I, II, III and IV 1:3.2:2.2:1.5; tergite I with 3 well separated strong yellow setae laterally; ratio of length:width of tergites III and IV 1:1.1 and 1:1.6; tergite V with long, pale, erect pile; sternite IV broadly trapezoid, about 1.5 times as broad, posterior margin arcuate with triangular excisition, brown, pile short, pale; sternite V rectangular, with very long pale pile posteriorly.

Type material. HOLOTYPE. ♂, N.E. Burma, Kambaiti, 2000 m., 26.iv.1934, R. Malaise ( SMNH).

PARATYPES. 1♂ with same data except 31.iii ( SMNH); 1♂ with same data except 19.iv. ( SMNH); 2♂ with same data except 26.iv. ( SMNH, NBC); 1♀ with same data except 25.v. ( SMNH); 1♂ with same data except 8000 ft., 12.v. ( NBC); 1♂ with same data except 7000 ft., 12.iv. ( BMNH); 1♀ with same data except 7000 ft., 19.iv. ( SMNH); 1♂ with same data except 7000 ft., 30.iv. ( BMNH); 2♂ with same data except 7000 ft., 9.v. ( BMNH, NBC); 1♀ with same data except 7000 ft., 2.vi. ( NBC).

Etymology. The name is Latin, simplex , simple, referring to weakly modified male sternite IV.

Discussion. Sphegina simplex is similar to S. forficata , S. crucivena and S. nasuta . Except for the characters mentioned in the key it differs from S. nasuta by the very small and inconspicuous ventral lobe on the surstylus (long and conspicuous) and from S. forficata and S. crucivena by long, narrow, superior lobe which is curved ventrad (in S. forficata short, narrow and straight, in S. crucivena long, broad and curved dorsad).

Figures

FIGURE 2. Wing. A. Sphegina (Sphegina) uncinata sp. n. (paratype). B. S. (Asiosphegina) furva sp. n. (paratype). C. S. (A.) nasuta sp. n. (paratype). D. S. (A.) crucivena sp. n. (paratype). E. S. (A.) crassispina sp. n. (paratype). F. S. (A.) bidens sp. n. (paratype). G. S. (A.) carinata sp. n. (paratype). H. S. (A.) index sp. n. (paratype). I. S. (A.) simplex sp. n. (paratype). Scale 0.5 mm.

FIGURE 4. Tergite I (A – E), lateral view, abdomen (F, G, H), dorsal view. A, F. Sphegina (Asiosphegina) simplex sp. n. (paratype). B. S. (A.) gigas sp. n. (paratype). C. S. (A.) radula sp. n. (paratype). D, H. S. (A.) crassispina sp. n. (paratype). E, G. S. (A.) parvula sp. n. (paratype). Scale 0.5 mm for A – E, 1 mm for F, G, H.

FIGURE 22. Sphegina (Asiosphegina) simplex sp. n. (holotype). A. Sternite IV, ventral view. B. Left surstylus, lateral view. C. Left superior lobe, lateral view. D. Genitalia, lateral view. Scale 0.5 mm.