Key to the genera of adult Agaocephalini of Colombia

1. Body surface tomentose, grayish brown color............................................. 2 – Body surface glabrous, irregularly punctate ................................................ 3

2. External edge of mandibles with 3 teeth (Fig 3). Prosternal process short or moderately long. Pronotum with strong horn, short to large, flat, narrow, usually directed upwards (Fig 4)....................................... Lycomedes Bréme

– External edge of mandibles with 2 teeth (Fig 5). Prosternal process absent. Pronotum with large horn, directed forward, thin and curved (Fig 6) .......... ................................................................................... Spodistes Burmeister

3. Protibia quadridentate, basal tooth short in minor males. Head of males with two large, divergent, forward directed horns; horns curved upward, apices rounded (Fig 7). Females lacking horns........................ Aegopsis Burmeister

– Protibia tridentate. Head with thick horn, curved upward, apex bifurcated ..... 4

4. Males with frontal horn short and thick, slightly curved. Pronotum with forward directed knob with acute apex, surface smooth. Females lacking horn on head and knob on pronotum. Head and pronotum black, elytra reddish brown .................................................................... Mitracephala Thomson

– Males with frontal horn large, curved upwards, apex bifurcate. Pronotum convex or with high knob. Body black, brown, or with dark spots ............. 5

5. Apex of frontal horn in males bifurcate. Pronotum with wide, high knob; apex rounded, surface densely punctate. Females lacking frontal horn. Elytra with punctures strongly impressed. Prosternal process high, apex dilated. Body black or brown................................................. Horridocalia Endrődi

– Apex of frontal horn in males emarginated or bifurcated. Head of females with 2 transversal tubercles. Pronotum convex, smooth. Elytra strongly reticulated and finely punctate. Prosternal process absent. Body yellowish brown with dark spots ............................................................. Brachysiderus Prell