Key to males of the Pselaphodes complex from Vietnam and Laos

1 Maxillary palpi small, palpomeres 3–4 symmetric, lacking tubercle or expansion on lateral margins. .... 2

– Maxillary palpi much larger, palpomeres 3–4 asymmetric, with tubercle or expansion on lateral margins. .................................................................. 7

2 Pronotum lacking antebasal sulcus (B EKCH I EV et al. 2013: fig. 1). Lasinus Sharp, 1874 . .......................... ......................... Lasinus mandarinus Raffray, 1890

– Pronotum with antebasal sulcus connecting lateral antebasal foveae. Paralasinus Hlaváč & Nomura, 2001 (couplets 3–6 adopted from H LAVÁČ & N OMURA 2001). ................................................................ 3

3 Head regularly narrowed anteriad without constriction. ........................................................................ 4

– Head strongly constricted and impressed at anterior margin of eyes. ....................................................... 5

4 Scape long, 4.5 times as long as wide (H LAVÁČ & N OMURA 2001: fig. 2A); each mesotrochanter with one small spine close to apex, mesofemur with small spine at basal third; horn-like metaventral processes conical. ...................................................................... .. Paralasinus antennatus Hlaváč & Nomura, 2001

– Scape short, at most 4 times as long as wide (H LAVÁČ & N OMURA 2001: fig. 2B); mesotrochanter with two spines, mesofemur lacking spine; horn-like metaventral processes prominent, with tip oriented towards abdomen. ..................................................... ....... Paralasinus thayerae Hlaváč & Nomura, 2001

5 Antennomere 9 short and large, no more than 1.5 times as long as wide (Hl AVÁČ & N OMURA 2001: fig. 2D); mesotrochanter with one apical spine. .............. ........ Paralasinus humilis Hlaváč & Nomura, 2001

– Antennomeres 9 long and slender, distinctly more than twice as long as wide; mesotrochanter with two spines. ..................................................................... 6

6 Scape relatively long, 4.5 times as long as wide and 5 times as long as pedicel (H LAVÁČ & N OMURA 2001: fig. 2C). ...................................................................... ............ Paralasinus gigas Hlaváč & Nomura, 2001

– Scape relatively short, 3.5 times as long as wide and 3.6 times as long as pedicel (H LAVÁČ & N OMURA 2001: fig. 2E). ............ Paralasinus namcatienicus Hlaváč & Nomura, 2001

7 Tarsomeres 2 greatly extending beneath, and reaching more than half length of tarsomeres 3. ............. 8

– Tarsomeres 2 normal, not extending beneath tarsomeres 3. ................................................................ 10

8 Pronotum with complete antebasal sulcus connecting median and lateral antebasal foveae, apical portion lacking modification (B EKCH I EV 2010: fig. 1). Taiwanophodes Hlaváč, 2003. ............................................ ................ Taiwanophodes magnus Bekchiev, 2010

– Pronotum lacking antebasal sulcus, apical portion with modification. Nomuraius Hlaváč, 2003 (couplet 9 adopted from H UAN G & Y I N 2018). .................... 9

9 Head with broad, deep cavity on posterior half (Y I N & L I 2013 b: fig. 1A); antennomere 9 much longer than 10 (Y I N & L I 2013 b: fig. 2A); pronotum strongly modified in anterior portion (Y I N & L I 2013 b: fig. 2B); metatibia simple, not expanded mesally. .......... ...................... Nomuraius piaoacus Yin & Li, 2013

– Head weakly concave at posterior margin (Y I N & L I 2013 b: fig. 4A); antennomere 9 slightly longer than 10 (Y I N & L I 2013 b: fig. 5A); pronotum slightly modified in anterior portion (Y I N & L I 2013 b: fig. 5B); metatibia expanded mesally near apex (Y I N & L I 2013 b: fig. 5H). ............. Nomuraius vietnamicus Hlaváč, 2003

10 Head with indistinct vertexal and frontal foveae; head and pronotum with dense and coarse punctation (Y I N & L I 2013 a: fig. 4A). Linan Hlaváč, 2003 . ...... ............................ Linan fortunatus Yin & Li, 2013

– Head with distinct vertexal and frontal foveae; head and pronotum finely punctate. .............................. 11

11 Metaventral fovea present. Labomimus Sharp, 1883 . ..................................................................... 12

– Metaventral fovea absent. Pselaphodes Westwood, 1870 ...................................................................... 16

12 Antennomere 9 with disc-like process near or on apex; antennomere 11 curved in middle or at base. .......... 13

– Antennomere 9 lacking disc-like process; antennomere 11 not curved. .............................................. 14

13 Antennomere 9 greatly broadened, disc-like process occupying more than 4/5 of antennal width, antennomere 10 slightly elongate, antennomere 11 curved at base (Y I N et al. 2013a: fig. 3); horn-like metaventral processes relatively long (Y I N et al. 2013a: fig. 5); metacoxa lacking ventral protuberance. .................... ..................... Labomimus bannaus Yin & Li, 2013

– Antennomere 9 slightly broadened at apex, disc-like process much smaller, antennomere 10 distinctly elongate, subcylindrical, antennomere 11 curved in middle (ZH AN G et al. 2019: fig. 14A); horn-like metaventral processes relatively short (ZH AN G et al. 2019: fig. 14C); metacoxa with triangular ventral protuberance (ZH AN G et al. 2019: fig. 14G). ............. ........... Labomimus maolan Zhang, Li & Yin, 2019

14 Antennomere 9 with angulate process on anteromesal margin (Y I N et al. 2012: fig. 4A). ........................ ........................... Labomimus shii (Yin & Li, 2012)

– Antennomere 9 lacking an angulate process on anteromesal margin. .................................................... 15

15 Size larger, body length 3.09–3.23 mm; antennomeres 9–11 each impressed or excavated on dorsal or ventral surface (Fig. 2A); aedeagus with median lobe asymmetrical dorso-ventrally (Figs 2I, E). ............... .............................. Labomimus cavicornis sp. nov.

– Size smaller, body length 2.84 mm; antennomere 9 with round cavity near apex, antennomere 10 strongly constricted at base to form nodule, antennomere 11 unmodified (Fig. 3A); aedeagus with median lobe symmetrical dorso-ventrally (Figs 3H, J). ................. ............................. Labomimus cucphuong sp. nov.

16 Antennomeres 9–11 simple, lacking modification (Fig. 9A). ................... Pselaphodes nongfa sp. nov.

– Antennomeres 9–11 with at least one antennomere modified. ............................................................... 17

17 Antennomere 9 lacking disc-like process/projection................................................................................18

– Antennomere 9 with disc-like process/projection. ...................................................................................20

18 Antennomere 9 and 10 obliquely constricted at apex and at base, respectively (H UAN G et al. 2018b: fig. 4A); aedeagus with parameres each transversely expanded before apex, then with one elongate process on apical margin of each expansion, with two short preapical and two long apical setae at apex of process (H UAN G et al. 2018: figs. 4I –E). ............................... ........... Pselaphodes incisus Huang, Li & Yin, 2018

– Antennomere 9 and 10 not modified as in P. incisus; aedeagus with parameres lacking transverse expansion before apex. ..................................................... 19

19 Size much smaller, body length 3.05 mm; antennomeres 9 and 10 each with small tubercle at apex and at base, antennomere 11 truncate at base (Fig. 5A); protibia simple. .... Pselaphodes banphabat sp. nov.

– Size much larger, body length 3.85 mm; antennomere 9 strongly excavated on mesal surface, apical portion forming irregular lamina-like projection, antennomere 10 moderately curved in lateral view, with mesal margin projected at base, antennomere 11 strongly constricted at base (Fig. 6A); protibia with two roundly triangular projections on ventral margin on apical half (Fig. 6E). ............................................. ............................. Pselaphodes dalatensis sp. nov.

20 Metatibia either with small spine at apical 1/3 or with preapical setose tuft. ............................................. 21

– Metatibia simple, lacking modification. .............. 22

21 Antennomere 10 with lateral surface impressed in middle, antennomere 11 slightly curved (Y I N et al. 2012: fig. 2A); protibia somewhat sinuate, lacking protuberance in middle (Y I N et al. 2012: fig. 1), mesotrochanter with tiny ventral spine (Y I N et al. 2012: fig. 2E). .............. Pselaphodes linae Yin & Li, 2012

– Antennomere 10–11 neither impressed nor curved (H UAN G et al. 2018a: fig. 12A); protibia almost straight, with triangular protuberance in middle (H UAN G et al. 2018a: fig. 12E), mesotrochanter with large ventral spine (H UAN G et al. 2018a: fig. 12F). ............ .... Pselaphodes paraculeus Huang, Li & Yin, 2018

22 Protibia with large projection before apex. .......... 23

– Protibia lacking projection. .................................. 24

23 Protibia broadened throughout, slightly curved, lacking tooth before middle, preapical projection broad and truncate (Fig. 11E); mesotrochanter with acute short ventral spine (Fig. 11F). ................................... ..................................... Pselaphodes olexai sp. nov.

– Protibia not broadened, strongly curved in apical half, with triangular tooth before middle, preapical projection elongate, with blunt apex (Fig. 12E); mesotrochanter lacking spine on ventral margin (Fig. 12F). ............. Pselaphodes parapectinatus sp. nov.

24 Antennomere 10 with thin, elongate protuberance at base (B EKCH I EV et al. 2019: fig. 3a). ......................... ... Pselaphodes fansipanensis Bekchiev & Yin, 2019

– Antennomere 10 lacking protuberance at base. … 25

25 Horn-like metaventral processes relatively short, in lateral view apically bifid, upper apex acute, lower apex truncate (Fig. 8C); median lobe of aedeagus less extended, endophallus composed of one triangular and two markedly elongate sclerites (Fig. 8I –E). ..... ................................... Pselaphodes jendeki sp. nov.

– Horn-like metaventral processes relatively long, in lateral view straight, with acute apex (Y I N et al. 2013b: fig. 12C); median lobe of aedeagus much more extended, endophallus composed of two elongate sclerites (Y I N et al. 2013b: fig. 12I, E). ............. ............... Pselaphodes hainanensis Yin & Li, 2013