Four newTriozaspecies associated with mistletoes are described, diagnosed and illustrated from Brazil and Chile. They are monophagous on the LoranthaceaeStruthanthusuraguensis(Triozastruthanthisp. n.),Tripodanthusacutifolius(Triozatripodanthisp. n.) and narrowly oligophagous onTristerixspp. (Triozatristericissp. n.). For a fourth species (Triozavagatasp. n.) host information is unavailable but its association with mistletoes is likely. The four species form a putative monophyletic group, together with three North American species (TriozaacuminataTuthill,T.incidataTuthill andT.phorodendraeTuthill), based on the apically incised paramere, the highly modified valvulae of the female ovipositor and the host association with mistletoes.T.acuminatastat. n. from California is raised to species rank (originally described as subspecies ofT.phorodendrae). TheTriozastruthanthi-group is diagnosed and a key for the identification of its constituent members is provided. New host data are provided forCalophyasp. from Brazil as well as forNotophorinafuscaBurckhardt andZonopelmaaustralisBurckhardt from Chile. Host plant and biogeographical patterns of mistletoe feeding psyllids around the world are briefly discussed.

Four new Trioza species associated with mistletoes are described, diagnosed and illustrated from Brazil and Chile. They are monophagous on the Loranthaceae Struthanthus uraguensis (Trioza struthanthi sp. n.), Tripodanthus acutifolius (Trioza tripodanthi sp. n.) and narrowly oligophagous on Tristerix spp. (Trioza tristericis sp. n.). For a fourth species (Trioza vagata sp. n.) host information is unavailable but its association with mistletoes is likely. The four species form a putative monophyletic group, together with three North American species (Trioza acuminata Tuthill, T. incidata Tuthill and T. phorodendrae Tuthill), based on the apically incised paramere, the highly modified valvulae of the female ovipositor and the host association with mistletoes. T. acuminata stat. n. from California is raised to species rank (originally described as subspecies of T. phorodendrae). The Trioza struthanthi-group is diagnosed and a key for the identification of its constituent members is provided. New host data are provided for Calophya sp. from Brazil as well as for Notophorina fusca Burckhardt and Zonopelma australis Burckhardt from Chile. Host plant and biogeographical patterns of mistletoe feeding psyllids around the world are briefly discussed.