Benefits to Aphids from Feeding on Galled and Virus-infected Leaves

Abstract

IT has been shown that robust green leaves which have ceased growth and not yet entered upon senescence are unsuitable, by comparison with growing or senescing leaves, for colonization by Aphis fabæ Scopoli and Myzus persicæ (Sulzer)^1–3. Abnormally extended growth or premature senescence-like changes, or both, are characteristic of both the ‘pseudo-galls’ (curling and pocketing of leaves) and the virus diseases which plants can develop as a result of aphid attack. Experiments were therefore undertaken to see whether such pathological changes in the plants might not be beneficial to the aphids initiating them.