Sphegina (Asiosphegina) siculifera, 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 : 47-48

Sphegina (Asiosphegina) siculifera sp. n.

Figs 28 A–D

MALE. Body length 5.0– 5.5 mm, wing length 4.1–4.4 mm. Head. Face moderately concave and weakly projected antero-ventrally; frontal prominence very weakly developed (similar to Fig. 1E). Width of vertex at anterior ocellus:width of head 1:3.7, depth of occipital concavity 1/5 of the width of an eye in dorsal view. Width of face:width of head 1:4.2. Face black, pollinose. Gena shiny brown. Frons and vertex black, lunula brownish, frontal prominence shiny dark brown, more posterior parts pale pollinose, the pile very short, infrequent, erect and pale. Occiput dull black. Eyes along face with area of enlarged facets. Antenna brown; basoflagellomere oval, ratio of length:width 1:0.8, baso-ventrally reddish; arista almost bare. Thorax. Colour black, mostly densely pale pollinose, the pile scattered, short, almost invisible, adpressed; scutellum trapezoidal, shiny, a pair of short, as long as scutellum, thin, pale, widely separated setae at apical margin. Wing. Hyaline, stigma yellow. Legs. Pro- and mesoleg yellow, tarsomeres 4 and 5 black. Metaleg: coxa brown; trochanter simple, yellow; femur yellow, the apical 1/6 and a broad annulus on the basal 1/2 brown; tibia without apico-ventral tooth, brownish, the basal 1/5 and an annulus on the apical 1/2 yellow; tarsus black. Abdomen. Length ratio of tergites I, II, III and IV 1:4.9:2.5:1.7. Tergites shiny black; tergite III with a subanterior reddish fascia, nearly 1/2 as wide as the length of tergite, the pile of tergites pale, very short, adpressed, becoming longer towards the lateral margin; tergite I with an oblique row of 3–4 pale setae laterally; sternite IV ( Figs 28 A, D) brownish, with short pale pile, the sword-like lobe on the left side pale; sternite VI ( Figs 28 A, D) with a small tubercle at the posterior margin, black, the pile pale; sternite VII simple, black, the pile short, pale; sternite VIII dark brown, the pile short and pale. Genitalia, Figs 28 B, C. Note the nearly symmetrical surstyli and the very large cercus. The superior lobes are symmetrical. FEMALE. Unknown.

Type material. HOLOTYPE. ♂, N.E. Burma, Kambaiti, 2000 m, 12.v.1934, R. Malaise ( SMNH). PARATYPES. 1♂ with same data as holotype except 7000 ft., 25.iv. ( NBC); 2♂ with same data except 7000 ft., 14. v. and Sphegina lateralis Dsbg det. v. Doesburg ( SMNH, NBC); 1♂ with same data except 8000 ft., 12. v. and Sphegina lateralis Dsbg det. v. Doesburg ( BMNH).

Etymology. The name is Latin, siculifera , bearing a small dagger, referring to the knife-like lobe on the male sternite IV.

Discussion. Sphegina siculifera is similar to S. cultrigera and S. ensifera . In the non-genitalic characters there is scarcely more to distinguish the species than the colour of gena and abdominal tergite III mentioned in the key; in S. cultrigera the small finger-like lobe at the posterior margin of male sternite VI seems to be smaller than in the two other species. In the male genitalia the differences between the three species are numerous: in S. cultrigera the cerci are shorter than surstylus, in S. siculifer a as long as and in S. ensifera much longer than surstylus, in S.cultrigera the dorsal lobe of surstylus has a prominent sublobe at the dorsal margin on the apical half and a small sublobe subbasally in dorso-medial position, in S. siculifera the dorsal lobe of surstylus is similar but the sublobes are scarcely discernible, in S. ensifera the surstylus is simple. Further, S. ensifera differs from the two others by longer and narrower superior lobe. All these species are similar to S. sinesmila . For further discussion, see under the latter. In non-genital characters all these species strongly resemble S. minuta , S. parvula and S. pusilla and the females may be very difficult to distinguish. For more discussion, see under S. parvula . Concerning other Oriental species, see under S. cultrigera .

Figures

FIGURE 28. Sphegina (Asiosphegina) siculifera sp. n. (holotype). A. Posterior part of abdomen, lateral view. B. Genitalia, lateral view. C. Left surstylus, lateral view. D. Posterior part of abdomen, ventral view. Scale 0.5 mm.