Key to the South American Platynectes (s. str.) species groups
1 Venter primarily pale colored, at most infuscate medially on metaventrite, metaventral wings, and abdomen. Northern South America. .................................... 2
– Venter primarily dark colored, mostly black to brown except on the prosternum and epipleura and in some species, the abdomen as well. Brazil. ........................... 3
2 Venter not infuscate, reddish-orange throughout. ........ ................................... P. submaculatus species group
– Venter distinctly infuscate, usually with metaventrite, metacoxal wing, and abdomen medially infuscate. ...... ................................. P. agallithoplotes species group
3 Abdomen darkly colored. ................................................. ........................................ P. nigerrimus species group
– Abdomen lightly colored. ................................................. ....................................... P. ornatifrons species group