Episyrphus nigromarginatııs, Vockeroth J.R., 1973

Vockeroth J. R., 1973, Some New or uncommon Syrphini (Diptera: Syrphidae) from Southern Africa, Annals Natal Mus. 21.3.595 - 607. pdf 21 (3), pp. 595-607 : 600

Episyrphus trisectus (Locw) Syrphus trisectus Loew, 1858 , Öfvers. Vetensk Akad. Forh. (1857) 14379; 1860, Dipt-Fauna Südafrikas 1:307; Bezzi, 1915, Syrph. Elhíop. Reg., p. 34; Curran, 1939, Am.Mus. Novít. 1010:11. trisectus Vockerotli u ‘ l:. ':. Episyrphur Loew,, l96 9, 1 \/lem., ent. Soc Can 62 125

This species is very similar to the common Palaearctic Episyrphus balteatus (DeG.). The male terminalía of trisectus (fig. 2b, c) do not differ from those of balteatus . The two species may be distínguished as follows: trisectus : front shining black anteriorly; tergites (fig. 2a) with black markings smaller: anterior black mark of tergite 2 widely separated from posterior black band or in female sometimes absent, subbasal black band of tergites 3 and 4 present or absent; sternite 2 and sometimes sternite 3 of male with subapical black or brown band. balteatus : front yellow anteriorly; tergites with black markings larger: anterior black mark of tergite 2 always present and at least narrowly joined to posterior black band, subbasal black band of tergites 3 and 4 present; sternites 2 to 4 of male with median longi- tudinal black or brown marks. Specimens examined: 1 Q, Caffraria (accepted by me as holotype; Naturhistoriska Riksmuseum, Stockholm); 12 33, 19 QQ from Kenya, Uganda, Tanzania, Rhodesia, Natal Can. Nat. Coll.; Staatl. Mus. Naturk., Stuttgart). Episyrphus nigromarginatııs n. sp. Rather small, moderately slender species, the tergites mostly yellow with subbasal and apical or subapical black bands and narrow black lateral margin. Length 7,4 mm. Male. Face slightly narrowed below, at widest point 0,37 times maximum width of head. Front and face densely olive-yellow pollinose so yellow ground colour is obscured; cheek yellow; facial tubercle and semicircular area above antennae brownish-black, only slightly pollinose. Postcranium black, lightly grey pollinose above, densely greyish-yellow pollinose below. Hairs of vertical triangle dark, extremely short (apparently abraded); hairs of front mode- rately long, black; other head hairs yellow to white. Antenna yellow, upper g, and apex of third segment and apical half of arista dark brown, third segment 1,3 times as long as broad. Mesonotum black, densely yellow-brown pollinose, on each side with an obscure narrow presutural submedian stripe and a broader sublateral stripe extending almost to scutellum, the stripes due to sparser pollen. Mesonotal hairs yellow. Scutellum dull yellow, scutellar hairs mostly black on median third, otherwise mostly yellow. Subscutellar fringe yellow, moderately long, rather dense medially but sparse laterally, in one to two rows. Pleura black, densely yellow-brown pollinose, the hairs yellow. Anterior mesopleuron with erect hairs posterodorsally and on lower half. Sternopleuron without anterior hairs; upper and lower sternopleural hair patches broadly separated. Metasternum with about 12 long hairs. Wing very slightly greyish; stigma pale brown. Alula broad, its posterior margin convex. Wing membrane almost entirely trichose, with bare areas as follows: a narrow cen-