Key to species of Tetranodus

1. Pronotum reticulate (Figs. 19). Mexico (Chiapas), Guatemala, Honduras, Costa Rica .............. T. reticeps (Bates, 1880)

- Pronotum longitudinally striate (Fig. 21)................................................................... 2

2(1). Elytra behind fasciae closely punctate, scabrous appearing..................................................... 3

- Elytra behind fascia separately punctate, not scabrous........................................................ 4

3(2). Punctures on basal third of elytra linearly arranged. Mexico (Jalisco, Oaxaca).......... T. copei Chemsak & Linsley, 1988

- Punctures on basal third of elytra not linearly arranged. Mexico (Sinaloa), Guatemala, Nicaragua .................................................................................................... T. rugipennis Chemsak, 1969

4(2). Pronotum cylindrical, sides not angulate at middle; elytra with basal punctures dense, not linearly arranged; males with segments three to six of antennae strongly incrassate (Fig. 21). USA (Texas), Mexico (Oaxaca, Veracruz, Tamaulipas, Distrito Federal).......................................................................... T. niveicollis Linell, 1897

- Pronotum with sides somewhat expanded, angulate; elytra with basal punctures linearly arranged, lines separated; males with segments three to six slightly expanded. Honduras, Costa Rica .......................... T. angulicollis Chemsak, 1969