Key to species of the genus Ateralphus

1. Upper ocular lobes separated by three or more times their width; lower ocular lobes narrow and rectangular-shaped, with height less than gena height (e. g. Fig. 22); genae parallel to divergent; tibiae with one ring or spot of dark brown setae on subapical region (e. g. Fig. 25)............................................................................ 2

- Upper ocular lobes separated by less than or equal to twice their width; lower ocular lobes large and rounded, with height subequal or larger than gena height (e. g. Fig. 107); genae convergent; tibiae with dense ring of dark brown setae on apical region, at least on protibiae (e. g. Fig. 94)......................................................................... 4

2 (1). Elytra covered with golden setae, with one macula of white setae on center of dorsum and, on each side, two smaller patches posterolateral to central macula; apical margin of elytra with a slight spine in external apical angle (Fig. 20); ventral surface of abdomen, completely covered with setae, without glabrous areas (Fig. 21). Venezuela (Distrito Capital), Bolivia (Santa Cruz

and Cochabamba) and Brazil (Amazonas and Mato Grosso) (Figs. 29–30)................. A. lacteus Galileo & Martins - Elytra covered with yellowish setae and irregular patches of whitish setae on dorsum; apical margin of elytron truncate; elytral carinae and punctation distinctly pronounced and evident; ventral surface of abdomen with glabrous areas on lateral edges of sternites II–IV (Fig. 24)............................................................................... 3

3 (2). Mesosternal process flat at posterior half (e. g. Figs. 87–88); tarsomere V with dark brown setae only on apical third (Fig. 25). French Guiana (Cayenne), Brazil (Minas Gerais, Espírito Santo, Rio de Janeiro, São Paulo and Paraná), Bolivia (Santa Cruz) and Argentina (Misiones) (Figs. 31–32).................................................. A. variegatus (Mendes)

- Mesosternal process tumescent at posterior half (Figs. 26–27); tarsomere V with dark brown setae on base and apical third (Fig. 28). Brazil (São Paulo, Paraná and Santa Catarina) and Argentina (Misiones) (Figs. 33–34)... A. tumidus new species

4 (1). Pronotum without prominent elevations posterolateral to median tubercles; legs entirely covered with setae............. 5

- Pronotum with prominent elevations posterolateral to median tubercles; meso- and/ or metafemora glabrous on inner surface..................................................................................................... 6

5 (4). Pronotum median tubercles with lunate apex (Figs. 1A; 48); scutellum with apical margin sinuous, with one median longitudinal depression and covered with uniform color setae; basal-crests slightly elevated, without tubercles. Brazil (Pernambuco, Bahia, Rondônia, Mato Grosso, Minas Gerais, Espírito Santo, São Paulo, Rio de Janeiro, Paraná, Santa Catarina and Rio Grande do Sul), Bolivia (Santa Cruz and Paz), Paraguay (San Pedro, Central and Alto Paraná) Argentina (Salta, Tucumán, Catamarca and Misiones) (Figs. 95–96)...................................................... A. subsellatus (White)

- Pronotum median tubercles with rounded apex; scutellum with apical margin rounded, with one median slight longitudinal depression and one differentiated stain of dark brown setae on median region (Fig. 104); basal-crests elevated, with slight tubercles Brazil (Espírito Santo) (Fig. 97).............................................. A. auritarsus new species

6 (4). Pronotum with elevations posterolateral to median tubercles prominent, appearing as two tubercles, punctate and completely covered with setae (Figs. 1 B); basal-crests elevated, adorned by a row of six evident and aligned tubercles (Fig. 109). Brazil (Amazonas). (Fig. 100)................................................................ A. javariensis (Lane)

- Pronotum with elevations posterolateral to median tubercles slightly prominent, appearing just as two small projections; basalcrests with tubercles not aligned and slightly elevated........................................................ 7

7 (6). Region between basal-crests covered with sparse dark brown setae, denser near scutellum but without wrapping it (Fig. 106); scutellum covered with setae coloration similar to pronotum; only metafemora glabrous on inner surface… Peru (Madre de Dios). (Fig. 103).................................................................. A. lucianeae new species

- Region between basal-crests covered with dense light brown setae which covers scutellum, forming a circumscutellar macula (Figs. 110; 111); meso- and metafemora glabrous on inner surface............................................. 8

8 (7). Pronotum and region between basal-crests with punctation poorly defined and partly covered with setae (Fig. 111); elytra with longitudinal carinae evident, with patches of dense and salient white setae irregularly distributed. Brazil (Bahia, Minas Gerais, Goiás, Espírito Santo, São Paulo, Rio de Janeiro, Paraná, Santa Catarina and Rio Grande do Sul), Argentina (Misiones) and Paraguay (Alto Paraná). (Fig. 101–102)...................................................... A. dejeani (Lane)

- Pronotum and region between basal-crests with punctation evident and not covered with setae (Fig. 110); elytra with longitudinal carinae not evident at apical two thirds, with patches of white setae irregularly distributed but not salient. Guyana (Upper Demerara-Berbice Region), French Guiana (Cayenne), Brazil (Amapá, Amazonas Pará, Maranhão, Rondônia and Mato Grosso), Peru and Bolivia (Cochabamba and Santa Cruz). (Figs. 98–99)............................. A. senilis (Bates)