Key to species of Piriana

1. Distance between lateral spines of the elytral apex distinctly greater than humeral width (Figs 22–23). Colombia ....................................................................................... P. migsominea (Gilmour, 1950)

- Distance between spines of the elytral apex, at most, as wide as humeral width (Fig. 28)............................. 2

2(1). Elytra distinctly widened after middle (Figs 18–19). Peru ................................... P. bosqi (Gilmour, 1954)

- Elytra not widened after middle (e.g. Fig. 32)............................................................... 3

3(2). Pronotum with moderately wide lateral dark brown bands (in addition to wider, dark brown central band). Bolivia .......................................................................................... P. tricuspis (Belon, 1903)

- Pronotum with lateral dark brown bands either very narrow or absent (in addition to wider, dark brown central band)....... 4

4(3). Scape asperate punctate (Figs 40, 42); prothorax with distinct lateral spine. Brazil (Rio Grande do Sul).... P. svachai sp. nov.

- Scape smooth, not asperate punctate; prothorax without lateral spine............................................ 5

5(4). Elytral apex distinctly oblique. Colombia, Ecuador, Brazil (Amazonas)..................... P. cincticornis (Bates, 1865)

- Elytral apex not oblique................................................................................ 6

6(5). Elytra with 3 longitudinal dorsal carinae. Brazil (Pará) ........................................... P. nearnsi sp. nov.

- Elytra with, 2 or less longitudinal dorsal carinae............................................................. 7

7(6). Body sub-parallel, slender, narrower appearing (Fig. 32)....................................................... 8

- Body slightly inflated laterally, wider appearing (Fig. 28)..................................................... 9

8(7). Metatibiae in male slender, without distinct bristly pubescence. Bolivia, Peru ..................... P. mima (Belon, 1903)

- Metatibiae short, with distinct bristly pubescence in both sexes. Ecuador .......................... P. consimilis sp. nov.

9(7). Elytra with light colored area restricted to small narrow fascia laterally (along margins) on basal half. Brazil (Pará)................................................................................................. P. birai sp. nov.

- Light colored area much broader, extending past middle of elytra. Nicaragua, Costa Rica, Panama. P. pygmaea (Bates, 1881)