Plant-aphid-parasitoid interactions and parasitism rates were assessed in adjacent cultivated and noncultivated habitats in an organic vegetable farm in a chaco serrano woodland, Córdoba, Argentina. Seven aphid species on eight vegetable species were found in the cultivated habitat. Macrosiphum euphorbiae was present on all vegetable species. Four parasitoid species were recorded, of which Diaretiella rapae was the most common. It provided 21.32% of parasitism on Brevicoryne brassicae. In the non-cultivated habitat, 36 plant species hosted 22 aphid species and five parasitoid species. The aphid Myzus persicae was present on 17 plant species of eight different families. Macrosiphoniella artemisiae was the most abundant aphid species, with the associated Aphidius sp. being the most abundant parasitoid. Aphidius polygonaphis provided 10% of parasitism on Uroleucon aeneus. We report several wild plant species as important reservoirs of parasitoids, which are potential controllers of many pest aphid species
