This study reports seven species of whiteflies in the genera Aleurothrixus, Dialeurodicus, and Trialeurodes, as well as parasitism of Aleurothrixus floccosus by Signiphora sp. and Cales noacki. Three new hosts of Aleurothrixus aepim are reported. Dialeurodicus cockerellii and Trialeurodes vaporariorum are reported for the first time in Rio Grande do Sul State, Brazil.