The resistance of three Solanum species to Myzus persicae, Macrosiphum euphorbiae and Aulacorthum solani (Aphididae: Homoptera)

A study was made of the resistance of three wild potato species, Solanum chacoense, S. stoloniferum and S. demissum, to three aphid species, namely Myzus persicae (Sulz.), Aulacorthum solani (Kalt.) and Macrosiphum euphorbiae (Thomas), which all commonly infest the cultivated potato, S. tuberosum. The resistance of each Solanum species differed with the species of aphid, with the part of the plant and with the physiological condition of the leaf. As a result, it may be difficult to utilize such resistance, since it is ineffective against some of the pest aphid species and may break down as the physiological condition of the plant changes.