Key to the species of Sciasmomyia

1. Wing (Fig. 83) pale yellow hyaline with small black spots at tips of longitudinal veins Sc, R2+3, R4+5 and M1, and on crossveins r-m and dm-cu; abdomen (Figs 86, 87) brown with yellowish or grayish pruinosity (color variable in different specimens), tergites 2–6 with a pair of large yellowish or grayish lateral spots and a stripe-like middle spot; phallus curved knife-like apically in lateral view; female hypogynial valve papillary apically with sparse setulae in ventral view (see Lee & Han, 2009: fig. 2).................................................................................. S. supraorientalis (Papp)

- Wing (Figs 15, 71) mostly pale brown with various patterns of hyaline spots; abdominal pattern, phallus and female hypogynial valve not as above................................................................................. 2

2. Wing (Fig. 71) mostly hyaline with irregular brown spots on basal 5/6 of upper half, and brown with hyaline spots on lower half and in distal 1/6; abdomen (Figs 74, 75) yellow, tergites 2–6 (and 7 in female) with wide black or dark gray central area; phallus with two pairs of subuliform processes in ventral view (Fig. 78); female hypogynial valve broad, apically forming three round processes with sparse short setae, with dense tiny setulae and microscopic teeth in ventral view (Fig. 81)......................................................................................... S. quadricuspis sp. nov.

- Wing (Fig. 15) evenly brown with many irregular hyaline spots; abdominal pattern, phallus and female hypogynial valve not as above.............................................................................................. 3

3. Palpus yellow on apical 1/3–1/2; wing (Fig. 4) with small hyaline spot between each longitudinal hyaline spot along R2+3, and ultimate section of M1 with a rectangular hyaline spot constricted at middle and a C-shaped hyaline apical spot; abdomen entirely yellow without brown spots or posterior margin; phallus with a pair of small triangular subapical processes curled outwards and a pair of decussate apical processes in ventral view (Fig. 7); female hypogynial valve trapezoidal with dense setulae in ventral view (Fig. 10)................................................................ S. decussata sp. nov.

- Palpus entirely brown or only yellow on basal 1/3; wing pattern, abdomen pattern, phallus and female hypogynial valve not as above.............................................................................................. 4

4. Anepisternum entirely grayish black (Fig. 50); scutellum yellow except for dark brown stripes laterally; wing along R2+3 with paired small hyaline spots (one above and one below vein) between longitudinal spots along costal margin; epandrium with an apical incision in lateral view and a process projecting backward in posterior view (Fig. 55); phallus consisting of a pair of small blunt basal processes, a U-shaped sclerite with a pair of acuate processes on upper margin, a pair of acuate dorsal processes and a deep incision at tip of membranous part in ventral view (Fig. 56)............................ S. lui sp. nov.

- Anepisternum yellow to brownish yellow (sometimes partially grayish brown), but never entirely grayish black; scutellum variable, but never predominantly yellow through middle; wing lacking paired hyaline spots along R2+3; male genitalia not as above............................................................................................... 5

5. Face with pair of brown V or Y-shaped lateral stripes (Figs 13, 38, 59); wing with hyaline spot in cell r4+5 above dorsal tip of crossvein dm-cu (Figs 15, 40, 62)....................................................................... 7

- Face with pair of brown oblique lateral stripes (Figs 28, 102); wing with hyaline spots on M1 proximal and on basal crossvein dm-cu, but cell r4+5 brown between these spots (Figs 30, 105).................................................. 6

6. Femora black except yellow at apex; anepisternum yellow with a brown oblique I-shaped spot and katepisternum entirely blackish brown with grayish pruinosity (Fig. 101); abdominal tergites unicolorous black (Fig. 104); phallus tubular, broad apically with a pair of slender median subuliform sclerites and a pair of hooked dorsal processes in ventral view (Fig. 108)............................................................................................ S. tubata sp. nov

- Femora yellow, with some brown subapically; anepisternum with three brown spots respectively lying on anterodorsal corner, posterodorsal corner and posteroventral corner, and a brown median spot; katepisternum with brown spot on anterodorsal corner and an oblique blackish brown stripe along dorsal margin (Fig. 27); abdominal tergites with black posterior margin; phallus long columnar and J-shaped curved, round apically with a small dorsal incision and a pair of black long curved knife-like lateral processes in lateral view (Fig. 35).................................................. S. longicurvata sp. nov.

7. Male with thick hypandrial arms much shorter than anteriorly thickened hypandrial apodeme (Fig. 45); female hypogynial valve with dense ventral setulae throughout (Fig. 48)........................................ S. longissima sp. nov.

- Male with narrow hypandrial arms as long or longer than narrow hypandrial apodeme (Figs 19, 69); female hypogynial valve with dense ventral setulae except for entirely bare apex...................................................... 8

8. Male with surstylus deeply emarginate subapically, with bare medially-directed lobe below (Fig. 95); epandrium in lateral view 2 times thicker dorsally than apically (Fig. 94); hypandrial arms in dorsal view thicker than hypandrial apodeme (Fig. 97); female hypogynial valve (Figs 99, 100) with distinct basolateral wing-like processes; tip distinctly constricted into narrow, bare process (Fig. 100)..................................................................... S. thaii sp. nov.

- Male with surstylus rounded apically, lacking a lobe below (Figs 18, 65); epandrium in lateral view dorsally subequal to (Fig. 64) or slightly thicker than apically (Fig. 17); hypandrial apodeme thicker than hypandrial arms (Figs 19, 66); female hypogynial valve lacking basolateral wing-like processes; tip either constricted to broad bare apex (Fig. 22) or tapering to bare apex (Fig. 69)........................................................................................... 9

9. Male with syntergosternite 7+8 present as a short, narrow sclerite, with the spiracle embedded (Fig. 17); epandrium in lateral view thicker dorsally than apically, tapering to rounded apex with small anterior process subapically (Fig. 17); surstylus blackish; hypandrial arms subequal in length to hypandrial apodeme (Fig. 19); phallus weakly sclerotized, lacking strong lateral processes (Figs. 19, 20); female hypogynial valve with subapical constriction distinguishing subcircular apical knob, entirely bare and narrower than part basal to constriction (Fig. 22)....................................... S. leishanensis sp. nov.

- Male with syntergosternite 7+8 degenerate, with the spiracle embedded in membrane (Fig. 64); epandrium in lateral view narrow throughout, and distinctly spatulate apically (Fig. 64); surstylus yellow; hypandrial arms long, much longer than hypandrial apodeme (Fig. 66); phallus strongly sclerotized, with four pairs of strong lateral processes (Figs 66, 67); female hypogynial valve with subapical constriction distinguishing subtriangular apical knob, bare only in distal half and subequal in width to part basal to constriction (Fig. 69)................................................... S. meijerei Hendel