Species similar to Platyomus bruchi in body shape and size. Platyomus mollis distinguishes mainly because the vestiture is red brown to dark brown, with two dorsal and two marginal cream stripes on the pronotum, and three cream "v-shaped" stripes on the elytra, which do not have tubercles.
Unknown.
It is associated with vegetation of the Chacoan and Paranaense biogeographic provinces.