Key to all the groups and treated species of Rhinusa

1. Protibiae and mesotibiae with premucro, more pronounced in female (Figs 25 and 26); in male protibiae distinctly arcuate in apical quarter, and profemora distinctly swollen with distinct tooth (Fig. 25); ventrites 3–5 in male along midline with dense and ruffled hairlike scales..................................................................... R. tetra group

- Protibiae and mesotibiae without premucro in both sexes (Figs 23 and 24); in male protibiae at most moderately arcuate in apical quarter, and profemora less swollen at most with small tooth (Figs 23 and 24); ventrites 3–5 in male along midline without hairlike scales........................................................................................ 2

2. Rostrum in dorsal view from base to antennal insertion with a trapezoidal outline, with dorsal part narrower than ventral part. Rostrum of male in dorsal view with clearly visible scrobes (Fig. 22).............................. R. antirrhini group

- Rostrum otherwise.................................................................................... 3

3. Scales of dorsal vestiture short, oval to elliptical (Fig. 9).............................................. R. mauritii

- Scales of dorsal vestiture long, setiform (Figs 1–8)........................................................... 4

4 Meso- and metafemora at most with a small tooth similar to that on profemora..................................... 5

- Meso- and metafemora with distinct sharp tooth, usually larger than that on profemora............................. 14

5. Dorsal vestiture composed of erect very long setiform scales, at least 20× as long as wide................. R. pilosa group

- Dorsal vestiture composed of recumbent and suberect setiform scales, at most 12× as long as wide..................... 6

6. Tibiae with outer margin distinctly curved outward at apex (Fig. 24). Rostrum in lateral view strongly arcuate (Figs 10 and 11)................................................................................... R. linariae group 7

- Tibiae with outer margin curved inward near apex (Fig. 23). Rostrum in lateral view weakly to moderately curved........ 9

7. Elytra and legs black (Fig. 1)..................................................................... R. linariae

- Elytra and legs reddish (Figs 2 and 3)..................................................................... 8

8. Integument completely reddish. Elytra longer, subelliptical (El/Ew 1.20–1.24). Pronotum less transverse (Pw/Pl 1.37–1.40) (Fig. 3). Outer margin of tibiae weakly carinate.................................................. R. kumatschevi

- Integument partly blackish. Elytra short, suboval (El/Ew 1.10–1.14). Pronotum more transverse (Pw/Pl 1.44–1.49) (Fig. 2). Outer margin of tibiae strongly carinate............................................................. R. brisouti

9. Elytra short (El/Ew <1.20) (Figs 7 and 8). Rostrum poorly sexually dimorphic and short in both sexes (Figs. 16–19)............................................................................................. R. melas group 10

- Elytra elongate (El/Ew> 1.30) (Figs 4–6). Rostrum in female distinctly different in shape and moderately to distinctly longer than in male (except for R. mateui, but in this case rostrum distinctly thinner in both sexes, figs 14–15)................ 11

10. Legs blackish. Scales of dorsal vestiture greyish without sericeous reflection (Fig. 7). Tarsomere 3 distinctly bilobed and distinctly wider than tarsomere 2..................................................................... R. melas

- Legs reddish. Scales of dorsal vestiture greyish with distinct sericeous reflection (Fig. 8). Tarsomere 3 weakly bilobed and moderately wider than tarsomere 2.............................................................. R. korotyaevi

11. Rostrum in lateral view distinctly tapered from base to apex (Figs 12 and 13)..................................... 12

- Rostrum in lateral view of subequal width from base to apex (Figs 15 and 16).................................... 13

12. Pronotum more transverse (Pw/Pl 1.34–1.37) and with rounded sides. Elytral integument reddish (Fig. 4)...... R. herbarum

- Pronotum less transverse (Pw/Pl 1.28), subconical, with weakly rounded sides. Elytral integument blackish (Fig. 5)................................................................................................. R. vulpeculus

13. Tarsomere 3 weakly bilobed and slightly wider than tarsomere 2. Elytral integument blackish. Length 1.3–1.6 mm ..................................................................................................... R. mateui

- Tarsomere 3 distinctly bilobed and distinctly wider than tarsomere 2. Elytral integument usually partly reddish. Length 1.5–3.5 mm ................................................................................. R. bipustulata group

14. Rostrum stout in both sexes, in female in lateral view gradually tapered from antennal insertion to apex, usually shorter (Rl/Pl in male <0.75, in female <0.85). Elytra with distinctly pronounced humeri, distinctly flattened on disc...... R. vestita group

- Rostrum slender in both sexes, especially in female where in lateral view it is cylindrical and of equal width from antennal insertion to apex, usually longer (Rl/Pl in male> 0.80, in female> 0.90). Elytra with weakly pronounced humeri, slightly to moderately convex on disc.................................................................... R. neta group