Key to the genera of Smicromyrmini of Japan

1. Male: head with ocelli; flagellum 11 segmented; alate........................................................ 2

- Female: head without ocelli; flagellum 10 segmented; apterous................................................. 7

2. Genitalic volsella with long narrow cuspisand basal external lobe (Figs 13D, 23C, E)............................... 3

- Genitalic volsella with short robust cuspis and without basal external lobe (Figs 5C, 31C, 38A, C, E, 46I)............... 4

3. Mandible tridentate (Fig. 12C); mesopleuron beneath with one or two pairs of precoxal denticles or tubercles (Fig. 14C)........................................................................................... 2. Nemka Lelej

- Mandible bidentate; mesopleuron beneath without precoxal denticles or tubercles................ 3. Mickelomyrme Lelej

4. Mandible narrowed to apex, bidentate or tridentate, inner denticles smaller than apex (Figs 4F, 36C, 46G); ventral margin of mandible excised into large tooth or with weak lobe basally (Fig. 36H)........................................... 5

- Mandible widened to apex, tridentate, inner denticles as large as apex (Fig. 31B); ventral margin of mandible without tooth or lobe............................................................................... 4. Andreimyrme Lelej

5. S2 with short lateral felt line; parapenial lobe bifurcate; volsellar cuspis oval, with developed setal bunch on inner face (Figs 5C, 46I)............................................................................................. 6

- S2 without felt line; parapenial lobe slender, strongly bending; volsellar cuspis slender, without setal bunch (Figs 38A, C, E)...................................................................................... 5. Ephucilla Lelej

6. Clypeus with a pair of subapical teeth; F1 as long as wide; maxillary palpus much shorter than antenna; paramere with inner protuberance............................................................... 1. Smicromyrme s. str. Thomson

- Clypeus without subapical tooth; F1 length at most 0.9 × its width; maxillary palpus as long as antenna; paramere without inner protuberance............................................................................ 6. Sinotilla Lelej

7. Mandible slender, bidentate or tridentate (Figs 7C, 17C, 26C, 40C, F); prementum without posterior tubercle; scutellar scale more or less developed................................................................................. 8

- Mandible wide, tridentate (Fig. 30C); prementum with posterior tubercle; scutellar scale absent...... 4. Andreimyrme Lelej

8. Genal carina absent; pygidial area sculptured with distinct lateral carina (Figs 7J, 18D, 26J).......................... 9

- Genal carina present; pygidial area unsculptured, smooth, shining at most with weak indistinct lateral carina (Fig. 41).... 11

9. Pygidial area elongate (Figs 7J, 26J)..................................................................... 10 - Pygidial area short and oval (Fig. 18D)........................................................ 2. Nemka Lelej 10. T2 with one basomedial spot (Fig. 6B).......................................... 1. Smicromyrme s. str. Thomson - T2 with three basal spots disposed in horizontal line (Fig. 25B)............................... 3. Mickelomyrme Lelej 11. Lateral margins of pygidial area weakly carinate apically........................................ 5. Ephucilla Lelej - Lateral margins of pygidial area not carinate even apically........................................ 6. Sinotilla Lelej