Parental rearing temperature, rearing nutrition, and morph influenced progeny birth weight and postnatal bionomic processes in the apple aphid,Aphis pomiDe Geer. Parental rearing at high temperature resulted in severely reduced progeny birth weight, postnatal relative growth and developmental rates, number of eyed embryos in the ovaries at maturity, and reproductive rate. Values of these parameters were also reduced by parental rearing at low temperature but less severely. Progeny of apterae reared with poor nutrition and progeny of alatae were also small at birth but partially compensated with greater relative growth. Progeny of alatae developed more slowly than progeny of apterae but had as many eyed embryos at maturity. Progeny of malnourished apterae developed at the same rate as progeny of well-fed apterae but contained fewer eyed embryos. Weight of the largest embryo in the aphid ovary was linearly correlated with aphid weight. A linear relationship was found for number of eyed embryos versus mature weight, but the regression slope was steeper for aphids reared below 10°C than for those reared above. Reproductive rate of apterae reared and kept at 20°C peaked 1 week after maturity, then declined exponentially. During the first 2 weeks, reproductive rate was proportional to number of eyed embryos. Adult aphid weight and embryo weight declined with reproductive age. Apterae reared at high or low temperatures had fewer eyed embryos and lower reproductive rates. Reduction in reproductive rate was greater than reduction in embryo number, and was most severe when aphids reared at low temperatures were transferred to high temperatures for reproduction, or vice versa.