Key to Afrotropical species of the subgenus Omophron Latreille, 1802

1 Antennal scape bisetose at apex, antennomeres III and IV with setae along lateral margin; pronotum verrucate. “ africanum ” species group........................................................................................ 2

- Antennal scape unisetose at apex, antennomeres III and IV without setae along lateral margin; pronotum punctate......... 4

2 Elytral epipleura smooth; pronotum with sides broadly and evenly rounded. Elytra with striae 1–3 shallow on the disc and weakly punctate, intervals 1–5 completely flat and shiny.......................... africanum Rousseau, 1908 (Fig. 1)

- Elytral epipleura faintly punctate; pronotum with sides almost straight, evenly rounded only near the anterior angles....... 3

3 Elytra with intervals 1–4 almost as convex on the disc as on more lateral intervals, microreticulation on the sutural interval (interval I) almost isodiametric; pronotum with long rugae on the disc; apex of aedeagus truncate, apical lamella relatively long (Fig. 6)........................................................................... pallidum sp. n. (Fig. 3)

- Elytra with intervals 1–4 clearly flatter on the disc than on more lateral intervals; microreticulation on the sutural interval more transverse; pronotum with elongated verricate pits on the disc; apex of aedeagus rounded, apical lamella short (Fig. 5)............................................................................ distinctum Bänninger, 1918 (Fig. 2)

4 Last visible ventrite (VI) roughly and coarsely punctate throughout, or at least laterally, ventrites IV and V with transverse row of large punctures and a deep sulcus; Elytral epipleura punctate, either densely densely or at least with one or two punctures; disc of pronotum with a more or less visible transverse depression; maxillary palpi slender, with preapical palpomere slightly narrower than apical, apical palpomere fusiform with apex acute. “ minutum ” species group.......................... 5

- Last visible ventrite (VI) smooth, ventrites IV and V without punctures and with a weak sulcus; Elytral epipleura smooth; maxillary palpi with preapical palpomere as wide as or wider than apical palpomere, apical palpomere elongate, subparallel, with apex obtuse..................................................................................... 11

5 Clypeus smooth...................................................................................... 6

- Clypeus punctate, with at least a few punctures along posterior edge............................................. 8

6 Elytral epipleura punctate; size small, 3.3–5.1 mm ........................................................... 7

- Elytral epipleura with a single puncture; size large, 6.4 mm; disc of pronotum flattened, with wide transverse depression, sides with widely explanate borders; head black, without pattern................................. schuelei sp. n. (Fig. 22)

7 Very small, 3.3–3.5 mm; head, elytra, and pronotum brown, without metallic color; clypeo-frontal suture indistinct; elytra with striae on the disc of elytra shallow and with fine punctuation, intervals 1–7 flat................ secundum sp. n. (Fig. 18)

- Larger, 4.8 mm; head, pronotum, and elytra with metallic pattern; clypeo-frontal suture distinct; elytra with striae on the disc of elytra deep, strongly punctate, intervals convex........................................ mimeticum sp. n. (Fig. 23)

8 All striae of elytra very deep, all intervals equally convex..................................................... 9

- Elytral intervals 1–5th flattened on the disc; pronotum evenly and very densely punctate with punctures minute ................................................................................. clavareaui Rousseau, 1900 (Fig. 17)

9 Elytral epipleura punctate; ventrite VI punctate throughout................................................... 10

- Elytral epipleura almost smooth; ventrite VI punctate laterally only.......................... muellerae sp. n. (Fig. 21)

10 Punctures on the disc of pronotum small and sparse, twice as dense on the sides; pronotum and head reddish brown, with metallic tinge only faintly present ................................................ minutum Dejean, 1831 (Fig. 7)

- Pronotum uniformly, very coarsely and densely punctate; pronotum and head with bright green or bluish tinge......................................................................................... riedeli Emden, 1932 (Fig. 8)

11 Metacoxa with one setiferous pore bearing a long seta and 2–13 punctures without setae. “ severini ” species group....... 12

- Metacoxa with two setiferous pores bearing long setae, additional punctures only in species from Madagascar. “ capense ” species group....................................................................................... 15

12 Clypeus with a furrow near anterior margin................................................................ 13

- Clypeus without any trace of a furrow near anterior margin, smooth; elytral striae shallow................................................................................................ capicola Chaudoir, 1868 (Figs. 86–87)

13 Metacoxa with 11–13 punctures and one setiferous pore bearing a long seta...................................... 14

- Metacoxa smooth, or with 1–2 asymetrically placed punctures, and one setiferous pore bearing a long seta; endophallus with two large groups of long spines (Figs. 84–85)...................... oligoxanthum Kuntzen, 1919 stat. n. (Figs. 62–64)

14 Elytra elongate and flattened, with intervals clearly flattened on the disc; pronotum with wide yellow band along anterior margin; endophallus with two groups of spines (Figs. 74–75) ....................... severini Dupuis, 1911 (Figs. 76–78)

- Elytra rounded and convex, intervals moderately convex on the disc; green pattern of pronotum extended to anterior margin; endophallus with one, preapical group of spines (Fig. 92)................................... occultum sp. n. (Fig. 88)

15 Species from Madagascar .............................................................................. 16

- Species from mainland Africa.......................................................................... 17

16 Elytra with 14 complete striae, stria 11 very short and represented by few punctures; endophallus with large patch of relatively long spines ....................................................... madagascariensis Chaudoir, 1850 (Fig. 52)

- Elytra with 15 complete striae; endophallus with small patch of relatively short spines..... amandae Valainis, 2010 (Fig. 53)

17 Apex of aedeagus narrowly pointed (Fig. 65).............................. picturatum Boheman, 1860 (Figs. 59–61)

- Apex of aedeagus broad and truncate (Figs. 39–45). O. capense and its subspecies................................ 18

18 Aedeagus with apex moderately curved ventrally (Figs. 39–42)................................................ 19

- Aedeagus with apex strongly curved ventrally (Figs. 43–45).................................................. 20

19 Male front tarsomere 1 in males moderately dilated (Fig. 93); body more rounded.................................................................................................... capense capense Gory, 1833 (Figs. 27–30)

- Male front tarsomere 1 strongly dilated (Fig. 97); body elongate....................... capense kmecoi ssp. n. (Fig. 33)

20 Elytral striae punctured to apices, punctures in apical third fine but visible; dorsal dark areas with green tinge........... 21

- Elytral striae smooth in apical third; yellow pattern on elytra reduced, dorsal dark areas with purple tinge......................................................................................... capense isolatum ssp. n. (Fig. 34)

21 Body larger and slightly elongate; apex of aedeagus broader as in Fig. 43 ...................................................................................................... capense congoense Deleve, 1924 stat. n. (Fig. 31)

- Body smaller and more rounded, yellow pattern more extended; apex of aedeagus narrower as in Fig. 44 ......................................................................................... capense pumilum ssp. n. (Fig. 32)