Key to the genera of adult Pentodontini of Colombia

1. Body black or dark brown, almost black .................................................... 2

– Body brownish-yellow, brown, red or reddish brown ................................. 6

2. Mandibles with 3 teeth (Fig. 22). Propygidium with stridulatory area........ 3

– Mandibles with 2 teeth or without teeth. Propygidium without stridulatory area............................................................................................................ 4

3. Protibia quadridentate. Pronotum with apical tubercle, subapical fovea deep (Fig. 23). Elytra smooth or moderately punctate. Propygidium elongated, pygidium short ................................................................... Bothynus Hope

– Protibia tridentate. Pronotum convex, without tublercle. Elytra with rows of impressed punctures. Propygidium short, pygidium normal......................... ................................................................................... Hylobothynus Ohaus

4. Clypeus truncate or relatively contracted at apex, bidentate. Pronotum with or without apical tubercle and subapical fovea............................................ 5

– Clypeus acuminate, strongly reflexed. Pronotum with large apical tubercle, fovea wide and deep. Both sides of pronotum with obtuse carina................. ........................................................................................ Oxyligyrus Arrow

5. Mandibles with 2–3 teeth, third tooth obtuse. Pronotum with apical tubercle and deep subapical fovea (Fig. 24)................................... Tomarus Erichson

– Mandibles without teeth, external edge sinuate, rounded. Pronotum convex, without tubercle and fovea (Fig. 25).................................... Euetheola Bates

6. Mandibles small, narrow, external edge curved. Clypeus truncate. Pronotum convex, with deep transverse fovea or with 2 small tubercles behind anterior margin. Protibia tridentate......................................................................... 7

– Mandibles broad, with 2 apical teeth. Clypeus contracted, emarginate. Pronotum in males with high and wide knob, apex bifurcate. Fovea broad. Females with convex pronotum. Head of males with small horn, apex rounded; females with tubercle. Protibia quadridentate............ Thronistes Burmeister

7. Frontal suture impressed (Fig. 26). Frons without tubercles or horns. Pronotum convex, with 2 small tubercles behind anterior margin ......................... ......................................................................................... Parapucaya Prell

– Frontal suture absent. Frons with tubercle or semiconical horn close to each eye. Pronotum binodose, with transversal fovea (Fig. 27) ...... Pucaya Ohaus