<p>(<b>A</b>) Carbon isotope ratios of plant and insect species used in dietary switching experiment. Carbon isotope ratios (mean δ<sup>13</sup>±SD) of plants (cotton and maize), aphids from cotton and maize, and <i>P. japonica</i> adults. Adult (C3) was raised on cotton aphids. Adult (C4) was raised on maize aphids. MV, middle δ<sup>13</sup>C values of <i>P. japonica</i> adults was −16.71‰ as the proportion of aphids from a C<sub>3</sub>-based resource and a C<sub>4</sub> -based resource was 50%. Error bars indicate the SD. (<b>B</b>) Carbon isotope ratios of <i>P. japonica</i> adults in dietary switching experiment. Carbon isotope ratios (mean δ<sup>13</sup>±SD) of laboratory-reared <i>P. japonica</i> adults (▴) before and after a shift in diet from a C<sub>3</sub>-based resource (cotton aphids reared on cotton) to one based on C<sub>4</sub> plants (maize aphids reared on maize). (<b>C</b>) Relationship of δ<sup>13</sup>C values of <i>P. japonica</i> and proportions of aphids form C<sub>3</sub> and C<sub>4</sub>-based resource. Aphids were from a C<sub>3</sub>-based resource and a C<sub>4</sub> -based resource on which they were grown in the laboratory. The ladybird beetles were grown from eggs to adults on five food mixtures consisting of, respectively, 100% cotton aphids/0% maize aphids, 75% cotton aphids/25% maize aphids, 50% cotton aphids/50% maize aphids, 25% cotton aphids/75% maize aphids and 0% cotton aphids/100% maize aphids. Linear equation Y = 0.120X-22.723 (<i>F</i> = 57.08, <i>P</i> = 0.005, <i>R</i><sup>2</sup> = 0.95): where Y is δ<sup>13</sup> values of <i>P. japonica</i>, X is proportion of aphids from a C<sub>3</sub>-based resource and a C<sub>4</sub>-based resource.</p
