Key to the species of Oocyclus from Venezuela

1 Posterolateral corners of pronotum rounded, never forming a sharp angle or prolonged into a spine (e.g. Figs. 2 D, 4B) ............................................................................................................................................................................ 2

- Posterolateral corners of pronotum angulate or spinose (e.g. Figs. 1 A, 3A–C) ....................................................... 7

2(1) Pronotum and elytra usually with a marginal fringe of dense yellow setae (e.g. Fig. 4 B–C) (except O. maculatus). Elytra without bright blue, well-defined maculae and without a white posterior spot............................................. 3

- Pronotum and elytra without a marginal fringe of dense yellow setae. Elytra with bright blue iridescent maculae and a white spot posteriorly (Fig. 1 B). Coastal mountains .......................................................... O. sapphirus sp. n.

3(2) Elytra without distinct rows of systematic punctures (Figs 2 B, D). Procoxae without spine-like setae. Serranía de Perijá/ Andes............................................................................................................................................................. 4

- Elytra with distinct rows of systematic punctures. Procoxae very with distinct spine-like setae, at least basally. Guiana Shield region ................................................................................................................................................ 5

4(3) Elytra uniformly but sparsely covered with setae (Fig. 2 B). Anterolateral margin of pronotum without pale spot .. ........................................................................................................................................................ O. zulianus sp. n.

- Elytra glabrous, without fine setae (Fig. 2 D). Anterolateral margin of pronotum usually with distinct pale spot..... .................................................................................................................................................... O. maculatus Sharp

5(3) Anterolateral angle of pronotum with prominent pale margin. Elytra with systematic punctures bearing erect

clumps of setae (Fig. 4 C).......................................................................................................................................... 6 - Anterolateral angle of pronotum at most with small pale spot. Elytra with systematic punctures bearing long, thin decumbent setae which are rarely in clumps (Fig. 4 B) ................................................................. O. coromoto sp. n.

6(5) Setae on the process of the mesoventrite thickened but only weakly so, very long. Aedeagus with parameres evenly narrow in apical half (Fig. 6 D) ............................................................................................ O. bolivari sp. n.

- Setae on the process of the mesoventrite thicker than normal setae but not strongly spinose; shorter. Aedeagus with parameres gradually getting narrower apically and sinuate on inner margin (Fig. 5 D) ........... O. floccus sp. n.

7(1) Posterolateral corners of pronotum angulate to weakly prolonged posteriorly into a minute point. If weakly prolonged, body size never larger than 4.0 mm ............................................................................................................. 8

- Posterolateral corners of pronotum strongly and distinctly prolonged posteriorly into a spine. Body size always larger than 4.0 mm .................................................................................................................................................. 11

8(7) Elytra with first row of systematic puncture faint and indistinct, with punctures very fine and interrupted if present. Setae on abdominal ventrites sparse and varying in length, with some very long. Elytral margins not explanate. Smaller species (2.8–4.0 mm) ............................................................................................................................ 9

- Elytra with first row of systematic puncture distinct, with punctures usually very coarse and/or set with a continuous row of erect setae. Setae on abdomen short and very dense. Elytral margin slightly explanate posteriorly. Larger species (4.0– 5.5 mm) .................................................................................................................................. 10

9(8) Elytra without dorsal clumps of setae. Coastal Mountains and Mérida Andes .................................... O. pico sp. n.

- Elytra with clumps of erect setae, sometimes in short rows. Mérida Andes .................................... O. trujillo sp. n.

10(8) Abdominal ventrites entirely pale, appearing yellow. First row of systematic punctures continuous but not dense, without (or with only a few) erect setae (Fig. 2 A). Serranía de Perijá ............................................. O. galbus sp. n.

- Abdominal ventrites dark brown. First row of systematic punctures very dense, with continuous line of erect setae (Fig. 1 A). Coastal Mountains ........................................................................................................... O. pittieri sp. n.

11(7) Elytra with distinct rows of larger punctures. Ground punctation not set with setae. Apex of elytra without pale markings. Andes ..................................................................................................................................................... 12

- Elytra without rows of larger punctures. Ground punctation set with short, fine setae. Apex of elytra usually with pale markings (may be darkened and difficult to see). Guiana Shield region (Amazonas and Bolívar States) ......... ............................................................................................................................................................. O. petra sp. n.

12(11) First row of elytral systematic punctures continuous, without short breaks. Lateral rows of elytral systematic punctures much coarser than surrounding ground punctation, making them easy to discern ................................ 13

- First row of elytral systematic punctures not continuous, interrupted by short breaks. Lateral rows of elytral systematic punctures similar in size to surrounding ground punctation, making them difficult to discern .................... ....................................................................................................................................................... O. andinus sp. n.

13(12) Aedeagus with parameres inwardly curved at apex, not sinuate along outer margin (Fig. 5 G). Elytral margins distinctly explanate in posterior third. Dorsal ground punctation on pronotum and elytra fine but distinct................... .................................................................................................................................................... O. meridensis sp. n.

- Aedeagus with parameres slightly inwardly curved at apex, sinuate along outer margin (Fig. 5 C). Elytral margins not to very weakly explanate in posterior third. Dorsal ground punctation on pronotum and elytra very fine; present but appearing nearly effaced ................................................................................................... O. substillus sp. n.