Necrose das folhas da batatinha, causada por toxina de afídios

Abstract

Observations made in potato fields for manv vears have shown that there is a type of vein necrosis associated with the infestation of the plants with high populations of aphids. In insectary experiments, potato plants of several varieties were infested separately with non-viruliferous aphids of three species, Myzus persicae, Macrosiphum solanifolii, and Aphis gossypii. The results showed that the first two species can induce vein necrosis. It is pointed out that the symptoms induced by the toxicogenic action of the two aphid species may be confused with those resulting from potato virus Y infection and thus increase the difficulty hi diagnosing the presence of this virus in comercial or seed potato plantings.