Three aphid species, Cinara pruinosa (Hartig), Acyrthosiphon lactucae (Passerini) and Coloradoa bournieri (Remaudière & Leclant) are recorded for the first time in South America from specimens caught in the Argentinean Patagonia. Data are given on their biology and distribution and characters distinguishing each one, as well as proximate species known in South America.