I would suggest this reference for Rhodobaenus sp:

Vaurie, P. 1981. Revision of Rhodobaenus. Part 2, Species in North America (Canada to Panama) (Coleoptera, Curculionidae, Rhynchophorinae). Bulletin of the AMNH ; v. 171, article 2.

There are three species of Rhodobaenus in the U.S. (and 2 in Canada). The markings and color cannot be used to identify to GENUS, but once you've arrived at Rhodobaenus, the species IN THE U.S. (not South America) can be distinguished by markings.

All the Rhodobaenus on this site with ONLY black spots on red are Rhodobaenus tredecimpunctatus. All the Rhodobaenus on this site with large patches of black and a few spots on red are Rhodobaenus quinquepunctatus.

Rhodobaenus pustulosus is also recorded from the U.S., but only in the extreme Southwest.