Key to Genera of Anisotomini of Latin America (modified from Miller and Wheeler, 2005a)

1a Antenna 11- or 10-segmented, with “interrupted” 5-segmented club, second club segment (segment 8 or 7, respectively) distinctly narrower than first club segment; elytral-abdominal stridulatory (?) system usually present, consisting of striate area on inflexed part of ventrite VII and short ridges on underside of elytron............................................. 2

1b Antenna 11-segmented with 3-segmented club, segment 8 not or very slightly narrower than 7; elytral-abdominal stridulatory (?) system, if present, consisting of striate area at side of tergum 6 and very long parallel ridges on underside of elytron.... 3

2a Antenna 11-segmented; male tarsi 5-5-4 segmented, female tarsi 5-4-4 or 4-4-4 segmented.................... Anisotoma

2b Antenna 10-segmented; male and female tarsi all 4-segmented............................................ Decuria

3a Head extremely broad, scarcely narrowed behind eyes, with supraocular carina extending posteriorly from each eye; epistomal suture usually obsolete medially; elytral-abdominal stridulatory (?) system absent.................................. 4

3b Head broad but distinctly narrowed behind eyes, without supraocular carina; epistomal suture complete; elytral-abdominal stridulatory (?) system present, as in couplet 1b above.................................................... Gelae

4a Tarsal formula 5-5- 5 in males, 5-4- 4 in females; aedeagal parameres present.............................. Agathidium

4b Tarsal formula 4-4- 4 in both sexes; aedeagal parameres absent................................... Pseudoagathidium