Fig. 5. Bivariate plots for cumulative protein and carbohydrate consumption by S. littoralis caterpillars over the successive days during their final larval stadium. (A–D) Nutrient consumption of caterpillars provided with the four equal-ratio 21:21 diets containing 0% (A), 20% (B), 50% (C) and 80% (D) zein in their protein component, respectively. The two dotted lines represent the protein:carbohydrate (P:C) ratio of the two choice foods presented to the insects (21:21 and 35:7 diets). Values are means ± 1 s.e.m. (N=8–10).