Key to separate species of the subgenus Plesiominettia

(modified from Shi et al., 2015)

1. Mesonotum with presutural dorsocentral setae.............................................................. 2

- Mesonotum without presutural dorsocentral setae............................................................ 4

2. Head with orbits yellow (Figs. 81, 101)................................................................... 3

- Head with orbits not as above....................................................... M. (P.) ishidai (Sasakawa)

3. Face with one yellow median longitudinal stripe; first flagellomere yellow; acrostichal setulae in six rows; mesonotum with five white longitudinal stripes (Fig. 84)................................................. M. (P.) orbitalis sp. nov.

- Face without yellow longitudinal stripe; first flagellomere only yellow at base (Fig. 101); acrostichal setulae in eight rows; mesonotum with three white longitudinal stripes (Fig. 104)............................. M. (P.) spiniphallata sp. nov.

4. Mesonotum without strong acrostichal seta before prescutellar setae............................................. 5

- Mesonotum with 1–2 pairs of strong acrostichal setae before prescutellar setae.................................... 11

5. Body entirely yellow.................................................................. M. (P.) filia (Becker)

- Body partly black or entirely brown to black................................................................ 6

6. Acrostichal setulae in eight irregular rows; male genitalia: epandrium and surstylus fused; phallus broad and truncate apically ................................................................................................... 7

- Acrostichal setulae in six rows; male genitalia: epandrium and surstylus articulate; phallus narrow or rounded apically..... 8

7. Frons with two black longitudinal stripes along fronto-orbital rows and one triangular black longitudinal stripe extending from ocellar triangle to anterior margin of frons; abdominal tergites bicolored (Fig. 5); syntergosternite circular (Fig. 8); phallapodeme slightly shorter than phallus (Fig. 9).................................................. M. (P.) bicolorata sp. nov

- Frons without longitudinal stripe; parafacial with one blackish brown spot between eye and antennal bases; abdominal tergites blackish brown; syntergosternite semicircular; phallapodeme shorter than 1/4 length of phallus.............................................................................................. M. (P.) tridentata Shi, Gaimari et Yang

8. Face yellow with a large black round median spot above ventral margin; arista bare; abdominal tergites 2–5 each with brownish yellow posterior margin............................................................ M. (P.) gemmata Shatalkin

- Face brown to black without black medial spot; rays of arista with longest setulae shorter than 1/3 height of 1st flagellomere or longer than half height of 1st flagellomere; abdominal tergites 2–5 without brownish yellow posterior margin............ 9

9. Arista pubescent, rays of arista with longest setulae shorter than 1/3 height of 1st flagellomere; abdomen black or blackish brown with pruinescence.............................................................................. 10

- Arista plumose, rays of arista with longest setulae as long as 3/5–4/5 height of 1st flagellomere; abdominal tergites brownish yellow along medial line and dark brown to black on lateral margins.......................... M. (P.) gemina Shatalkin

10. Frons with a pair of black longitudinal stripes along fronto-orbital rows, extending from ocellar triangle to occiput; parafacial without black spot (Fig. 110); hind femur without anterior ventral seta; male genitalia (Figs. 115–119): syntergosternite circular, surstylus scabbard-shaped, with one forward spiny process near base........................ M. (P.) surstylata sp. nov.

- Frons without black longitudinal stripes; parafacial with one black spot between eye and base of antenna; hind femur with a row of anterior ventral setae; male genitalia: syntergosternite semicircular, surstylus with narrow double processes in lateral view.................................................................. M. (P.) nigrantennata Shi, Gaimari et Yang

11. Mesonotum with two pairs of strong acrostichal setae....................................................... 12

- Mesonotum with one pair of strong acrostichal setae........................................................ 14

12. Body black except frons, face, mesonotum, scutellum and metanotum yellow; male genitalia: surstylus less prominent (Remm and Elberg 1979: Fig. 13).............................................................. M. (P.) loewi (Schiner)

- Body entirely brown to black; male genitalia: surstylus short broad or otherwise shaped............................ 13

13. Arista with longest setulae as long as 1/7 height of 1st flagellomere; frons and legs entirely brown; male genitalia: surstylus widened apically and narrow subapically, with a small concavity at middle of apical edge.......... M. (P.) helvola (Becker)

- Arista short plumose, rays of arista with longest setulae at least longer than 1/3 height of 1st flagellomere; frons yellow on anterior 1/5; legs dark brown except base of tibiae and tarsi yellowish; male genitalia: surstylus consisting of outer process narrow basally and bifurcated apically, and inner process clubbed and slender in lateral view... M. (P.) divaricata Sasakawa

14. Body entirely yellow................................................................................. 15

- Body mostly brown to black........................................................................... 16

15. Mesonotum without long acrostichal setulae; scutellum without large black lateral spots on lateral margin................................................................................................... M. (P.) helva Czerny

- Mesonotum with a pair of distinct acrostichal setulae as long as first postsutural dorsocentral setae; scutellum with a pair of large black lateral spots on lateral margin.............................................. M. (P.) punctata Sasakawa

16. Mesonotum with acrostichal setulae in four to six rows...................................................... 17

- Mesonotum with acrostichal setulae in eight to ten rows...................................................... 27

17. Mesonotum with acrostichal setulae in six rows............................................................ 18

- Mesonotum with acrostichal setulae in four rows........................................................... 24

18. Frons with a pair of black longitudinal stripes along fronto-orbital rows......................................... 19

- Frons without black longitudinal stripes along fronto-orbital rows.............................................. 20

19. Head brownish yellow (Fig. 11); fore femur with seven posterior ventral setae; surstylus fused with epandrium; connected by one U-shaped sclerite behind cercus in posterior view (Fig. 17)................................. M. (P.) caii sp. nov

- Head blackish brown (Fig. 91); fore femur with five posterior ventral setae (Fig. 93); surstylus separated from epandrium, without connected sclerite (Fig. 97)................................................... M. (P.) prominens sp. nov.

20. Frons with two brownish yellow longitudinal stripes along fronto-orbital rows extending to ocellar triangle (Fig. 71).................................................................................... M. (P.) nujiangensis sp. nov.

- Frons without brownish yellow longitudinal stripe.......................................................... 21

21. Anterior margin of mesonotum brownish yellow, with two brownish yellow longitudinal stripes along dorsocentral rows almost reaching the third post-sutural dorsocentral setae (Fig. 44).................................. M. (P.) huangi sp. nov.

- Anterior margin of mesonotum blackish brown, without brownish yellow longitudinal stripe along dorsocentral rows..... 22

22. Ocellar setae almost 2 times longer than anterior fronto-orbital setae; rays of arista with longest setulae as long as 1/2 height of 1st flagellomere; stem vein brown; surstylus near cylindrical, curved apically (Fig. 67); phallus with one median elongate oval sclerotized structure (Fig. 69)...................................................... M. (P.) mediclavata sp. nov

- Ocellar setae as long as or slightly longer than anterior fronto-orbital setae; rays of arista with longest setulae as long as 1/4 height of 1st flagellomere; stem vein not as above; surstylus slender; phallus not as above........................... 23

23. Haltere pale yellow (Fig. 53); male genitalia (Figs. 56–60): syntergosternite with a pair of small ventral processes; surstylus bifurcated in lateral view; phallus without sharp apical processes........................... M. (P.) ludingensis sp. nov.

- Haltere with knob brown; male genitalia: syntergosternite with one broad ventral processes; surstylus not bifurcated; phallus with four sharp apical processes..................................................... M. (P.) crassulata Shatalkin

24. Rays of arista with longest setulae as long as 1/4 or 1/2 height of 1st flagellomere; male genitalia: surstylus articulated with epandrium.......................................................................................... 25

- Rays of arista with longest setulae as long as or slightly longer than basal height of arista; male genitalia: epandrium and surstylus fused...................................................................................... 26

25. Arista with longest setulae as long as 1/4 height of first flagellomere (Fig. 21); surstylus long clavate (Fig. 27); postgonite cylindrical and shorter than phallus (Fig. 29)............................................... M. (P.) cuiae sp. nov.

- Arista with longest setulae as long as 1/2 height of first flagellomere; surstylus long falcate; postgonite poorly developed..................................................................... M. (P.) flavoscutellata Shi, Gaimari et Yang

26. Halter dark brown except stem yellowish at base; male genitalia: surstylus slender and curved, claviform, acute apically................................................................................. M. (P.) fuscescens Shatalkin

- Halter entirely yellow; male genitalia: surstylus short and rounded apically.................. M. (P.) tenebrica Shatalkin

27. Body yellow to dark yellow; male genitalia: surstylus with a pair of very long aciculiform processes................................................................................... M. (P.) longaciculiformis Shi, Gaimari et Yang

- Body brown to black; male genitalia with short claviform process or process shaped otherwise....................... 28

28. Mid tibia with one strong apicoventral setae............................................................... 29

- Mid tibia with two strong apicoventral setae............................................................... 30

29. Wing brown at base (Fig. 32); male genitalia (Figs. 36–40): syntergosternite semicircular; surstylus absent; pregonite longer than phallus; phallus with one trident sclerotized structure inside...................... M. (P.) dulongjiangensis sp. nov.

- Wing yellow at base; male genitalia: syntergosternite circular; surstylus claviform narrowing gradually, with a tiny median process and tiny setulae in lateral view; postgonite shorter than phallus; phallus without trident sclerotized structures inside.................................................................................... M. (P.) omei Shatalkin

30. Acrostichal setulae in ten irregular rows; male genitalia: surstylus with a long clubbed process, curved ventrally at tip................................................................................... M. (P.) longistylis Sasakawa

- Acrostichal setulae in eight rows; male genitalia: surstylus with an acute geniculate outer process and a curved aciculiform inner process......................................................... M. (P.) zhejiangica Shi, Gaimari et Yang