Rates of growth and increase of <i>Myzus persicae</i> on virus‐infected potatoes according to type of virus‐vector relationship

Abstract

Abstract Growth, reproduction and survival (= performance) of the aphid Myzus persicae Sulzer was measured on virus‐free and virus‐infected potato plants. The principle objective was to evaluate if various viral infections affected aphid performance differently, and if so, whether any order in the performance response of the aphid was discernible according to the type of virus‐vector relationship. Three viruses varying in their dependency on M. persicae as a vector were used. Plants infected with potato leafroll virus (PLRV), a circulative virus highly dependent upon M. persicae for dispersal and transmission, were superior hosts as determined by the significantly greater mean relative growth rate (MRGR) and intrinsic rate of increase (r m ) of M. persicae compared with those of aphids reared on other plants. Plants infected with potato virus Y, a noncirculative virus less dependent upon M. persicae for dispersal than PLRV, were intermediate in their quality based upon intermediate MRGR and r m values. Plants infected with potato virus X, a nonvectored virus independent of M. persicae , were least suitable hosts along with the group of virus‐free plants according to the lower MRGR and r m values.