Population Increases of the Green Peach Aphid, Myzus persicae (Sulzer) and Cotton Aphid, Aphis gossypii Glover

The reproduction of Myzus persicae (Sulz.) on raddish and Aphis gossypii Glover on cucumber was studied at different temperatures. The parameters of population growth in these aphids were calculated by the age-specific fecundities (mx) and survival rate (lx). The net reproductive rate (R0) and intrinsic rate of natural increase (r) of M. persicae were 61.50 and 0.21 at 15℃, and 60.60 and 0.33 at 20℃, respectively. The net reproductive rate (R0) and intrinsic rate of natural increase (r) of A. gossypii were 37.90 and 0.22 at 15℃, 45.70 and 0.32 at 20℃, and 40.60 and 0.42 at 25℃, respectively.