Sphegina (Asiosphegina) carinata, 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 : 18

Sphegina (Asiosphegina) carinata sp. n.

Figs 2 G, 3E, 8A–E

MALE. Body length 6.8–8.0 mm, wing length 5.3–6.5 mm. Head. Face strongly concave dorsally and moderately projected antero-ventrally; frontal prominence weakly developed (similar to Fig. 1J). Width of vertex at anterior ocellus about 1/4 of the width of head; the depth of occipital fossa ca. 1/4 of the width of an eye in dorsal view. Width of face:width of head 1:4. Face black, pale pollinose. Gena shiny black. Frons and vertex dull black, lunula shiny brown. Occiput dull black, pale pollinose. Antenna brown, basoflagellomere darker dorsally; arista distinctly pilose. Thorax. Colour black, weakly pollinose laterally and denser dorsally; postalar callus brownish; scutum with short adpressed reddish pile; scutellum short [ratio of length:width 1:2.5], apically rounded, the pile similar to that on the posterior part of scutum; with a pair of long, thin, dark convergent setae at apical margin. Wing, Fig. 2 G. Hyalinous, the infuscated pattern brownish, stigma yellowish. Cross vein dm-cu perpendicular to vein M1+2, straight; cross vein M1 slightly s-curved. Legs. Pro- and mesoleg yellow, tarsomeres 4 and 5 black; metaleg ( Fig. 3 E): coxa dark; trochanter yellow, with dark transverse carina ventrally on apical part; femur black, the narrower curved basal part yellow, with a prominent dark seta antero-dorsally near the apex and erect very long pile posteroventrally on black part; metatibia without an apico-ventral tooth, black, the basal 1/6 and a broad annulus on the apical 1/2 yellow; metatarsus entirely black. Abdomen. Length ratio of tergites I, II, III and IV 1:3.3:1.8:1.2; tergites black, anterior 1/3 of tergite III yellow; the pile short and adpressed, reddish, becoming longer and paler towards the lateral margin; tergite I with 2 widely separated strong black setae at lateral margin; sternite IV ( Figs 8 A, B) black, the pile pale, the strong setae and bristles black; sternite VI ( Fig. 8 A) with two processes of which the more anterior one is long and curved, the more posterior one short and conical, colour black, the pile very long and pale; sternites VII and VIII simple, with long pale pile. Genitalia, Figs 8 C–E. Note the strong asymmetry of the surstyli and the superior lobes. FEMALE. Body length 7.1–7.5 mm, wing length 6.5–7.0 mm. Similar to male except for the normal sexual dimorphism. Length ratio of tergites I, II, III and IV 1:3.5:2.5:1.3; tergite I with one long black seta antero-laterally; tergite III semi-circular, gradually broadening towards the posterior margin; tergite IV semi-circular, gradually narrowing towards the posterior margin; colour of tergites mainly shiny black, tergite II with a brown macula antero-medially and tergite III with a roundish or semiquadrangular yellow macula anteromedially; tergite VI brownish, medially divided by a pale membranous vitta; sternite IV trapezoid, ca. 1.5 times as broad as long, black, pile pale, longer along posterior margin; sternite V a little shorter than broad, semiquadrangular to rounded posteriorly, brown, with very long pale pile posteriorly.

Type material. HOLOTYPE. ♂, N.E. Burma, Kambaiti, 2000 m., 4.vi.1934, R. Malaise ( SMNH). PARATYPES. 1♂ with same data as holotype except 29.v. ( NBC); 1♀ with same data except 12–17.vi. ( SMNH); 1♂ male with same data except 1800 m., 28.v. ( SMNH); 1♂ with same data except 7000 ft., 9.v. ( BMNH); 1♀ with same data except 7000 ft., 7.vi. ( NBC).

Etymology. The name is Latin, carinata , keeled, referring to the keeled hind trochanter.

Discussion. Sphegina carinata is similar to S. index . For further discussion, see under the latter. Both these species are similar to S. malaisei even if they do not key out together because S. malaisei lacks the infuscated wing pattern. S. carinata and S. malaisei are similar in having a transverse ventral carina on their metatrochanter unlike any other Sphegina , so far we know, and they have the two lateral strongest setae on the left side of male sternite IV longer than the other more medial setae, unlike the other similar species. Even the male genitalia in the three species are rather similar but differ easily in the details of e.g. the superior lobe: in S. carinata there is a curved sharp finger-like lobe basodorsally (a rounded low lobe in S. index and S. malaisei ) and there is a large flip-like lobe in ventral position on the right side (homologic lobe smaller and more dorsal in S. index and S. malaisei ). S. carinata resembles S. gigas , S. bispinosa Brunetti, 1915 , and S. hansoni Thompson, 1966 in having long subapical, antero-dorsal seta/e on metafemur and by having its sternite VI with a finger-like process, covered with long pile. S. bispinosa differs from S. carinata by having 7 long strong setae on the left side of male sternite IV instead of two and by having 2–3 long subapical anterolateral setae on metafemur instead of only one; S. hansoni differs by having the number of mentioned setae on sternite IV 3 instead of 2 and by having nearly symmetrical surstyli.

Within those species which have male sternite IV asymmetrical and armed with spinose setae and which have male sternite VI with one or two processes, Sphegina carinata belongs to a group with the right side surstylus broader than the left side one, together with S. crassispina , S. gigas , S. index , S. malaisei and S. trispina .

According to its original description Sphegina nigerrima Shiraki, 1930 could be similar to S. carinata and similar species in having long subapical, antero-dorsal seta/e on metafemur. S. nigerrima differs from S. carinata and S. crassispina by hyalinous wing without infuscated pattern as well as from S. gigas , S. index and S. malaise by pollinose submedial vittae on scutum.

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 3. Metaleg, prolateral view (A, D female, B, C, E male). A. Sphegina (Asiosphegina) bilobata sp. n. (paratype). B. S. (A.) forceps sp. n. (paratype). C. S. (A.) minuta sp. n. (paratype). D. S. (A.) gigas sp. n. (paratype). E. S. (A.) carinata sp. n. (paratype). Scale 1.0 mm.

FIGURE 8. Sphegina (Asiosphegina) carinata sp. n. (A, B, paratype, C, D, E holotype). A. Posterior part of abdomen, lateral view; the unmodified pilosity omitted. B. Posterior part of sternite IV, ventral view; the unmodified pilosity omitted. C. Genitalia, lateral view. D. Left surstylus, lateral view. E. Left superior lobe, lateral view. Scale 0.5 mm.