Larval development and mortality of the painted lady butterfly, Vanessa cardui (Lepidoptera: Nymphalidae), on foliage grown under elevated carbon dioxide

To determine the indirect effects of elevated CO₂ on larval Lepidoptera, we compared the growth and development of larvae of Vanessa cardui Linnaeus (Lepidoptera: Nymphalidae) on Glycine max Linnaeus (soybean) foliage grown under ambient or elevated levels of CO₂ from first instar to pupation. There was no significant difference in larval survivorship or the duration of larval development between the two treatments. The usual sexual difference in pupal size in V. cardui was lost when individuals were reared on a diet of G. max foliage grown under elevated CO₂ conditions. Despite the fact that increases in levels of atmospheric CO₂ are projected to increase the susceptibility of soybean foliage to coleopteran pests, impacts of such exposure may vary with herbivore taxon, making projections of future yield losses challenging.