Key to Asian species of Parasyscia based on the worker caste

Notes. We follow Bharti & Akbar (2013) and treat P. keralensis (Karmaly, et al, 2012) as a species inquirenda, thus excluding it from this key.

1. Eye degenerate, small, its maximum diameter smaller than or equal to the width of basal funicular segment, not breaking the lateral margins of head (Fig. 1A–B)....................................................................... 2

-. Eye large and protruding, its maximum diameter two times more than the width of basal funicular segment, breaking lateral margins of head (Fig. 1C–D)............................................................................ 7

2. Mid-dorsal portion of mesosoma smooth and shiny, without puncta (Fig. 2A)...................................... 3

-. Mid-dorsal portion of mesosoma punctate (Fig. 2B).......................................................... 4

3. Maximum diameter of eye equal to the basal width of scape; ventral margin of subpetiolar process straight; in lateral view petiolar node subrectangular, the front and the back parallel (Fig. 3A)................... P. wittmeri (Collingwood, 1985)

-. Maximum diameter of eye smaller than the basal width of scape; ventral margin of subpetiolar process concave; in lateral view petiolar node trapezoid, with top narrower than bottom (Fig. 3B)............................ P. piochardi Emery, 1882

4. Lateral surface of head and mesosoma densely and coarsely reticulate (Fig. 4A).................................... 5

-. Lateral surface of head and mesosoma smooth and shiny, or with small, sparse puncta, interspaces between puncta smooth and shiny (Fig. 4B)....................................................................................... 6

5. In lateral view, anterodorsal corner of petiolar node angular, level with posterodorsal corner; in dorsal view, petiole subrectangular, lateral margins parallel (Fig. 5A–B).................................................. P. reticulata (Emery, 1923)

-. In lateral view, anterodorsal corner of petiolar node rounded, and lower than posterodorsal corner; in dorsal view, petiole trapezoid, broader posteriorly (Fig. 5C–D)........................................ P. hashimotoi (Terayama, 1996)

6. Antennae 12-segmented...................................................... P. wighti (Bharti & Akbar, 2013)

-. Antennae 11-segmented...................................................... P. ganeshaiahi Aswaj et al, 2021

7. In lateral view, petiole trapezoid, anterior and posterior faces convex (Fig. 6A–B).................................. 8

-. In lateral view, petiole subrectangular, anterior and posterior faces flat, parallel (Fig. 6C–D)......................... 12

8. Abdomen clearly concolorous (Fig. 7A)................................................................... 9

-. Abdomen clearly bicolored (Fig. 7B)..................................................................... 10

9. Body dark reddish-brown; in lateral view, dorsal outline of mesosoma strongly convex; in dorsal view, anterolateral margin of first gastral segment relatively more convex (Fig. 8A–B)........................................................................................................................... P. muiri (Wheeler & Chapman, 1925)

-. Body light yellow; in lateral view, dorsal outline of mesosoma slightly convex; in dorsal view, anterolateral margin of first gastral segment relatively less convex, tapering more evenly to juncture with third abdominal segment (Fig. 8C–D)................................................................................................ P. shii sp. nov.

10. In full-face view, head rounded, posterolateral corner broadly rounded (Fig. 9A)............... P. fossulata (Forel, 1895)

-. In full-face view, head subrectangular, posterolateral corner narrowly rounded or clearly angular (Fig. 9B–C)........... 11

11. In full-face view, posterior margin of head slightly convex, posterolateral corner narrowly rounded (Fig. 9B); head with tiny piligerous puncta; posterodorsal margin of propodeum without carina; if carina present, it is extremely degraded (Fig. 10A).................................................................. P. rufithorax (Wheeler & Chapman, 1925)

-. In full-face view, posterior margin of head strongly concave, posterolateral corner clearly angular (Fig. 9C); head with coarse puncta; posterodorsal margin of propodeum with strong carina (Fig. 10B).......................... P. tibetana sp. nov.

12. Abdomen clearly bicolored (Fig. 11A).................................................................... 13

-. Abdomen concolorous or nearly so (Fig. 11B–C)........................................................... 14

13. In lateral view, posterodorsal corner of propodeum rounded; mesosoma and petiole with shallow puncta (Fig. 12A)......................................................................................... P. aitkenii (Forel, 1900)

-. In lateral view, posterodorsal corner of propodeum angular; mesosoma and petiole with deep puncta (Fig. 12B)................................................................................................ P. wilsoni sp. nov.

14. In full-face view, center of head with longitudinal groove, almost reaching to the posterior margin of the head (Fig. 13A)............................................................................. P. conservata (Viehmeyer, 1913)

-. In full-face view, center of head without longitudinal groove (Fig. 13B)......................................... 15

15. In dorsal view, petiole longer than wide (Fig. 14A)........................................ P. indica (Brown, 1975)

-. In dorsal view, petiole broader than long (Fig. 14B)......................................................... 16

16. In full-face view, the front of head with a wide and deep arc-shaped groove (Fig. 15A)....... P. kodecorum (Brown, 1975)

-. In full-face view, the front of head without a wide and deep arc-shaped groove (Fig. 15B)........................... 17

17. In full-face view, head coarsely and densely punctate, margins of puncta partially connected to reticulation (Fig. 16A–B)...................................................................................................... 18

-. In full-face view, head smooth and shiny, or, if punctate, with margins of puncta not connected to reticulation (Fig. 16C–D).................................................................................................... 21

18. In lateral view, petiolar node higher than long (Fig. 17A)............................. P. foveolata (Radchenko, 1993)

-. In lateral view, petiolar node longer than high (Fig. 17B)..................................................... 19

19. In full-face view, posterolateral corner of head angular; in dorsal view, tergite of postpetiole with scattered shallow puncta (Fig. 18A–B)................................................................................ P. nigrita sp. nov.

-. In full-face view, posterolateral corner of head rounded; in dorsal view, tergite of postpetiole rugoso-reticulate (Fig. 18C–F)................................................................................................... 20

20. The mid-dorsal portion of mesosoma with confluent puncta; posterior face of propodeum rugose (Fig. 19A)................................................................................... P. browni (Bharti & Wachkoo, 2013)

-. The mid-dorsal portion of propodeum with separated puncta; posterior face of propodeum smooth and shiny (Fig. 19B).................................................................................... P. dohertyi (Emery, 1902)

21. Small size (TL ≤ 2 mm)........................................................... P. bryanti (Wheeler, 1919)

-. Large size (TL> 2.8 mm).............................................................................. 22

22. In full-face view, posterior margin of head distinctly concave, posterolateral corner forming prominent lobe; the maximum diameter of eye larger than the maximum diameter of the apical funicular segment; body black (Fig. 20A–B)…….................................................................................... P. salimani (Karavaiev, 1925)

-. In full-face view, posterior margin of head straight, posterolateral corner not forming prominent lobe; the maximum diameter of eye slightly smaller than or equal to the maximum diameter of the apical funicular segment; body yellow to dark brown (Fig. 20C–D)............................................................................................ 23

23. In lateral view, posterodorsal margin of propodeum rounded; anterodorsal corner of petiole lower than posterodorsal corner; in dorsal view, posterodorsal margin of propodeum without carina (Fig. 21A–B)............... P. luteoviger (Brown, 1975)

-. In lateral view, posterodorsal margin of propodeum angular; anterodorsal corner of petiole and posterodorsal corner at the same level; in dorsal view, posterodorsal margin of propodeum with carina (Fig. 21C–D)................................ 24

24. Petiole slightly broader than long, PI=114–116; head subrectangular, lateral margins parallel (Fig. 22A–B)...................................................................................... P. schoedli (Bharti & Akbar, 2013)

-. Petiole distinctly broader than long, PI>140; head lateral margins converging anteriorly and posteriorly (Fig. 22C–D).... 25

25. Eye small, its maximum diameter equal to the width of base of scape (Fig. 23A)....... … P. seema (Bharti & Akbar, 2013)

-. Eye large, its maximum diameter almost two times more than width of the base of scape (Fig. 23B–C)................. 26

26. Lateral mesosoma with small puncta, their maximum diameter smaller than the diameter of spiracle of propodeum; declivity of propodeum straight (Fig. 24A–B)................................................ P. rifati Sharaf & Akbar, 2018

-. Lateral mesosoma with large puncta, their maximum diameter equal to or larger than the diameter of spiracle of propodeum; declivity of propodeum concave (Fig. 24C)....................................................... P. xui sp. nov.