The effect of previous host plant on the fecundity of Myzus persicae and its ability to transmit beet yellows virus

Myzus persicae transferred to rape produced offspring with higher survival, larger weight and faster development than aphids transferred to beet, irrespective of whether they had been reared on rape or beet. Aphids transferred from rape to beet produced fewer offspring than those reared continuously on rape. On beet, rape-reared adults produced progeny with lower survival, slower development, smaller adult size and lower fecundity than the progeny of beet-reared individuals, but there were no differences in these characteristics associated with host plant after one generation. Aphids from rape were less than half as efficient in transmitting beet yellows virus as aphids reared continuously on beet but after one subsequent generation on beet this difference had disappeared completely. These results are discussed in relation to field conditions.