Fig. 1. Protein–carbohydrate intake arrays for solitarious (A) and gregarious (B) desert locust nymphs. Filled symbols represent intake points for locusts provided with a single food, whose protein and digestible carbohydrate content is indicated at the end of each dotted line (%protein:%carbohydrate). Open symbols show the mean intake points for locusts provided with a choice of either food 28:14 with food 14:28, or food 14:7 with food 14:28. Values are means ± S.E.M. (N=7–20). Intake did not differ between these latter two treatments, indicating regulation of protein–carbohydrate intake. This selected point of intake (‘intake target’, labelled IT) provides a reference for interpreting the intake array across the no-choice treatments (see Fig. 2). The data indicate cumulative intake from ecdysis (day 0) until day 3 (squares), day 5 (triangles), day 8 (inverted triangles), and across the entire stadium until adult ecdysis (circles).