Failure of the aphid, Myzus persicae, to compensate for poor diet during early growth

ABSTRACT. Compensation in mean relative growth rate of M. persicae occurred when aphids normally kept on susceptible brussels sprout plants were starved for only 2 h daily or kept on 'resistant' plants (given low nitrogen:high potassium fertilization) for 48 h. More adverse conditions, e.g. 4 or 8 h daily starvation, 48 h on leaf discs or 60 h on 20% sucrose, resulted in a low aphid growth rate being maintained on transfer to susceptible plants. The low overall growth rate could not be explained in terms of a weight loss by the aphid at any stage and is assumed to be a behavioural phenomenon. It is concluded that it is unwise, in the study of aphid—plant relationships, to rely on pre-conditioning aphids in poor conditions with the hope that this might magnify differences in subsequent aphid response.