Six males morphotypes of the feather mite genus Rhytidelasma Gaud (Pterolichoidea, Pterolichidae) are known from Nex World parrots. The five described and one new species each represent a different morphotype, namely, R. dilatata (Trouessart) [= Pterolichus (Pseudalloptes) tritiventris dilatatusJ, n. comb., n. stat., l. from Ara nobilis (L.); R. tritiventris (Trouessart) and R. ulocerca (Trouessart) from Ara chloroptera Gray; R. tenuis (Trouessart) [= Pterolichus (Pseudalloptes) tenuis ] n. comb., from Pion us menstruus (L.); R. forficiventris (Trouessart) from Pionites leucogaster (Kiihl); and R.mesomexicana, n. sp. from Aratinga holochlora (ScIater). Each species is (re)described; the morphology of immatures and host-parasite associations are discussed. Another new combination: Rhytidelasma lambda (Trouessart) (= Pseudalloptes lambda).