The impact of total dietary nitrogen on the body weight of fresh aphids reared on chemically defined diets for 7 days. Open bars, clone IS; closed bars, clone AISTIS; all data represent means ± standard errors (n = 5). ANOVA results: clone, F(1,32) = 7.8 (0.01 > P > 0.001); diet, F(3,32) = 175.8 (P < 0.001); interaction, F(3,32) = 1.4 (P > 0.05).