1.
.
.
Elytral margin with clear, membranous border (best seen
at apex of elytra). Central Chile and Argentina to Tierra del
Fuego (Brachysternina)
.
2
 

1'.
.

Elytral margin without clear membranous border. Central México to northern Argentina
.
4
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2(1).
.
.
Unguitractor plate with 3 or more setae. Elytron bearing white, scale-like setae (sometimes absent due to abrasion). Claws simple. Tarsomere 5 with ventromedial tooth
 

2'.
.
.
.

 Unguitractor plate with 2 setae. Elytron glabrous or bearing white to orange, hair-like, slender or thick setae. Claws split, toothed, or simple (if simple, then tarsomere 5 without tooth). Tarsomere 5 with or without ventromedial tooth
.
.
.
3
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3(2).
.
.
.
.
Dorsal color green. Pygidium and abdominal sternites with distinct thick, white setae (especially laterally at base) when viewed without magnification. Apex of female terminal abdominal sternite moderately to deeply emarginate. Male paramere with ventral and lateral sclerites
 

3'.
.
.
.
.

 Dorsal color brown to olive green. Pygidium and abdominal sternites usually with hair-like, slender, inconspicuous setae when viewed without magnification. Apex of female terminal abdominal sternite rounded. Male paramere lacking ventral and lateral sclerites
.
.
.
.
Aulacopalpus
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4(1).
.
.
.
 Protibial spur absent. Mesotibia and metatibia robust,
similar in thickness to femora. Tarsomeres robust, thickened, often wider than long. Central México to Panamá. (Phalangogoniina)
 

4'.
.
.
.

Protibial spur present. Mesotibia and metatibia slender in comparison with femora. Tarsomeres not thickened, often longer than wide. Central México to northern Argentina. (Platycoeliina)