Four new species of eriophyoid mites (Acari: Trombidiformes: Eriophyoidea) were collected from native plant species from Pampa biome, in the state of Rio Grande do Sul, Brazil, and are described and illustrated herein. They have been named: Aculus pampae sp. nov. on Elephantopus mollis Kunth (Asteraceae); Costarectus lanceatus sp. nov. on Sebastiania brasiliensis Spreng. (Euphorbiaceae); Dichopelmus sigfeminae sp. nov. and Rhynacus symflori sp. nov. both on Symplocos uniflora (Pohl) Benth. (Symplocaceae). All new species appeared to be vagrants and no apparent symptom was associated to them.