Key to species of Micronecta occurring in Vietnam (applicable to male specimens only)

1. Strigil absent ..................................................................................................................................... 2

– Strigil present .................................................................................................................................... 3

2. Body length 3.0– 3.1 mm; hemelytron translucent or greyish brown, usually with two broken longitudinal dark stripes (Fig. 5A); right paramere slender, distally curved, tapering from distal half towards narrowly rounded apex (Fig. 6C) ................................................... M. grisea (Fieber, 1844)

– Body length 2.0– 2.4 mm; hemelytron brown with yellowish longitudinal stripes usually fragmented into small dots (Fig. 5B); distal half of right paramere strongly broadened (Fig. 6G) ....................... ........................................................................................................ M. guttatostriata Lundblad, 1933

3. Palar claw subovate with deep lateral incision (Fig. 2H); middle tibia with combs of 25 to 29 short and thick, erect spines besides 10–11 longer setae.......................... M. jaczewskii Wróblewski, 1962

– Palar claw and middle tibia not as above .......................................................................................... 4

4. Pala with secondary narrow claw (Fig. 23A) ................................................................................... 5

– Pala without secondary claw ............................................................................................................ 7

5. Primary palar claw narrow, parallel sided; left paramere swollen before apex................................... ......................................................................................................... M. khasiensis Hutchinson, 1940

– Primary palar claw widened apically (Fig. 23A); left paramere slightly constricted and slightly twisted before apex (Fig. 23D, G) .................................................................................................... 6

6. Right paramere with a large swelling at the base of shaft (Fig. 23F) ....... M. polhemusi Nieser, 2000

– Right paramere with an indistinct swelling at the base of shaft (Fig. 23C)......................................... ..................................................................................... M. melanochroa Nieser, Chen & Yang, 2005

7. Free lobe absent; prestrigilar flap absent ........................................................... M. caperata sp. nov.

– Free lobe present; prestrigilar flap present ........................................................................................ 8

8. Palar claw slender with hooked apex or notch before apex (Fig. 25A, E) ....................................... 9

– Palar claw not modified as above ................................................................................................... 10

9. Palar claw with hooked apex and pointed pre-apical tooth (Fig. 25E)........... M. tarsalis Chen, 1960

– Palar claw broadly curved, with notch before apex (Fig. 25A)................ M. fugitans Breddin, 1905

10. Palar claw narrow and nearly straight (Fig. 2A) ..............................................................................11

– Palar claw broader and usually widened apically ........................................................................... 13

11. Body length 3.6–4.4 mm; apex of left paramere slightly bent and twisted (Fig. 2D); right paramere slightly expanded before apex (Fig. 2C) ................................................... M. scutellaris (Stål, 1858)

– Body length 2.7–3.4 mm; apex of left paramere blunt and not twisted; right paramere slender throughout ....................................................................................................................................... 12

12. Pronotum with three distinct transverse dark stripes (Fig. 1C); longitudinal stripes on hemelytra distinct and dark (Fig. 1C); shaft of right paramere curved at distal third ... M. siva (Kirkaldy, 1897)

– Pronotum without distinct transverse dark stripes; longitudinal stripes on hemelytra lighter or indistinct (Fig. 1B); shaft of right paramere slightly curved at distal fourth (Fig. 2F)........................ .................................................................................................................... M. sedula Horváth, 1905

13. Palar claw not or moderately widened apically (Fig. 22D); shaft of left paramere thicker, not platelike .................................................................................................................................................. 14

– Palar claw usually large, strongly widened apically (Figs 8A, 9F); shaft of left paramere flat, platelike with subparallel sides (Figs 7C, 8F, 9E) .................................................................................. 21

14. Median lobe of sternite VII elongate, tongue-shaped, with rounded tip; free lobe of tergite VIII sigmoid (Fig. 22A, E); left paramere with sickle-shaped apex (Fig. 22C, G) ................................ 15

– Median lobe of sternite VII less developed; free lobe of tergite VIII with expanded, truncate apex; left paramere not as above .............................................................................................................. 16

15. Shaft of right paramere longer, clearly thicker in basal half, then gradually tapering in apical half (Fig. 22F); curvature between base and shaft of left paramere, opposite basal lobe about 90° (Fig. 22G) .............................................................................................. M. altera Wróblewski, 1972

– Shaft of right paramere mostly parallel sided and only tapering on apical fifth towards narrowly rounded apex (Fig. 22B); curvature between base and shaft of left paramere, opposite basal lobe clearly greater than 90° (Fig. 22C) .................................................. M. quadristrigata Breddin, 1905

16. Median lobe of sternite VII usually with four long setae; shaft of left paramere stout, with knob-like apex ...................................................................................................... M. haliploides Horváth, 1904

– Median lobe of sternite VII with one or two long setae; apex of left paramere not knob-like ....... 17

17. Pronotum shorter than head; hemelytron with reticulate pattern; left paramere with a large triangular tooth near the middle section of shaft (Fig. 3I); right paramere with longitudinal striations on stout shaft (Fig. 3H) ..................................................................................... M. johorensis Fernando, 1964

– Pronotum length at least equal to median head length; hemelytron with linear pattern or pale pattern; left and right paramere not as above ............................................................................................... 18

18. Pronotum usually with pair of dark oval rings, which are sometimes fragmented, reduced to streaks or spots, or absent; hemelytron usually with four longitudinal brown stripes; left paramere with broad, flat, and subovate apex ............................................................... M. ludibunda Breddin, 1905

– Pronotum without dark oval marks; dark marks on hemelytra usually indistinct; apex of left paramere not modified as above ..................................................................................................................... 19

19. Apical part of left paramere sinuate and covered with small scales (Fig. 4G) .................................... ............................................................................................................. M. sahlbergi (Jakovlev, 1881)

– Shaft of left paramere not sinuate apically, without small scales (Fig. 3C, F) ............................... 20

20. Free lobe strongly widened distally, posterior margin produced into an obtuse angle (Fig. 3A); apical part of left paramere slightly twisted (Fig. 3C) .................................... M. decorata Lundblad, 1933

– Free lobe sub-rectangular, only slightly widened at distal part, posterior margin nearly straight (Fig. 3D); apical part of left paramere not twisted (Fig. 3F) ................... M. desertana Distant, 1920

21. Shaft of right paramere evenly curved, apex rounded (Figs 7B, E, 8E) ......................................... 22

– Shaft of right paramere strongly curved or bent on distal half to distal fourth (Figs 9D, J, 10E, 11E) ......................................................................................................................................................... 24

22. Hemelytra with distinct marks (Fig. 5D); palar claw broadened distally, apex rounded; shaft of left paramere with a distinct triangular projection on lateral margin (Fig. 7F).......................................... .............................................................................................. M. erythra Nieser, Chen & Yang, 2005

– Markings on hemelytra indistinct or absent; palar claw large, sub-triangular with straight apical margin; shaft of left paramere without distinct projection ............................................................. 23

23. Hemelytron with patchy, indistinct brown markings (Fig. 5C); left paramere with a short ridge running to lateral margin of shaft, apex broad (Fig. 7C) .............................. M. drepani Nieser, 2000

– Hemelytron generally light orangish, without dark marking (Fig. 5E); left paramere simple, without modification on shaft, apex narrow (Fig. 8F) .................................................... M. cultellata sp. nov.

24. Free lobe simple, sub-rectangular or moderately widened distally, posterior margin nearly straight or slightly concave; right paramere with simple, narrowly rounded apex .......................................... 25

– Free lobe distinctly widened distally, posterior margin usually modified; right paramere with strongly modified apex .................................................................................................................................. 33

25. Shaft of left paramere without projection on lateral margin ........................................................... 26

– Shaft of left paramere with distinct triangular projection on lateral margin .................................. 30

26. Left paramere with shaft straight, basal lobe trapezoid (Fig. 12F); shaft of right paramere slenderer and curved at distal third (Fig. 12E) ............................................................... M. vietnamica sp. nov.

– Left paramere with lateral margin of shaft sinuate, basal lobe subovate or sub-rectangular; shaft of right paramere bent or curved at distal fourth ................................................................................ 27

27. Distal part of right paramere strongly bent, forming angle of nearly 90° (Figs 9D, 10E) ............. 28

– Distal part of right paramere more gently curved, forming angle of ca 45° (Figs 9J, 11E) ........... 29

28. Base of right paramere with a distinct hump on mesial margin near the beginning of the shaft (Fig. 9D); basal lobe of left paramere long, tongue-shaped (Fig. 9E)... M. anatolica Lindberg, 1922

– Base of right paramere without hump on mesial margin near beginning of shaft (Fig. 10E); basal lobe of left paramere sub-rectangular (Fig. 10F).............................................. M. fulvopicta sp. nov.

29. Left paramere shaft evenly curved outwards, apex narrowly rounded (Fig. 9K)................................ .............................................................................................................................. M. arcuata sp. nov.

– Left paramere shaft strongly constricted before an acute apex (Fig. 11F) ...... M. acuminata sp. nov.

30. Shaft of left paramere with notch on lateral margin, set basally to triangular projection (Fig. 14D); right paramere strongly bent before club-shaped apex, forming angle of nearly 90° on lateral margin (Fig. 14C) ........................................................................... M. ornitheia Nieser, Chen & Yang, 2005

– Shaft of left paramere without a notch on lateral margin; pre-apical curve of right paramere forming an obtuse angle (Figs 14F, 15E) ...................................................................................................... 31

31. Right paramere with small notch on upper margin before flap-like apical part .................................. ................................................................................................................. M. pocsi Wróblewski, 1967

– Apex of right paramere not modified as above ............................................................................... 32

32. Pre-apical part of right paramere widened before truncate apex (Fig. 15E).......... M. clavata sp. nov.

– Pre-apical part of right paramere tapering towards rounded apex (Fig. 14F)...................................... ........................................ M. tuwanoni Nieser, Chen, Leksawasdi, Thanyakam & Duangsupa, 2004

33. Free lobe widened distally, posterior margin convex (Fig. 16D); shaft of left paramere tapering towards slightly swollen apex, sub-apically with small process (Fig. 16F); shaft of right paramere widened at distal part and folded into gutter-like structure, with lobe on mesial side (Fig. 16E) ...... .............................................................................................................................. M. sinuata sp. nov.

– Free lobe strongly modified (Figs 17D, 18D, 19D); shaft of left paramere with one or two triangular projections on lateral margin (Figs 17F, 18F, 19F); shaft of right paramere modified differently (Figs 17E, 18E, 19E) ...................................................................................................................... 34

34. Free lobe short, distally widened, and wavy, both angles nearly square, without long setae; left paramere with two triangular projections on lateral margin, apex of paramere truncate; apical part of right paramere modified as in Fig. 17E ............................................................. M. undulata sp. nov.

– Free lobe short, distally strongly widened, posterior margin convex, lateral angle notched, with long setae (Figs 18D, 19D); left paramere with one triangular projection on lateral margin ................. 35

35. Left paramere with triangular projection on lateral margin, near to base of shaft (Fig. 18F); right paramere strongly modified, as in Fig. 18E .......................................................... M. nieseri sp. nov.

– Left paramere with triangular projection on lateral margin, near to apex of shaft (Fig. 19F); right paramere strongly modified, as in Fig. 19E .......................................................... M. pingae sp. nov.