Effects of drought stress on oviposition preference and offspring performance of the lace bug Corythucha marmorata on its goldenrod host, Solidago altissima

Stress and vigor are endpoints on a continuum of the suitability of plants for insect herbivores. Senescence-feeding insects, such as the chrysanthemum lace bug, Corythucha marmorata (Uhler) (Hemiptera: Tingidae, Tingitini), are hypothesized to benefit from any stressor hastening the senescence of plant tissues, such as drought. They are also hypothesized to prefer feeding and ovipositing on stressed plants, due to increased performance of themselves and their offspring. We conducted choice and no-choice field-cage experiments to test the effects of drought stress on the oviposition preference and nymph survival of C. marmorata on its goldenrod host, Solidago altissima L. (Asteraceae). We placed lace bugs on high- and low-water treatment plants, surveyed egg and nymph densities twice weekly, and at the end of the experiment, collected newly developed adults, weighed them, and determined their nitrogen concentration. Low-water treatment plants experienced decreased growth and increased leaf senescence. Lace bug nymphs had significantly greater survival, faster maturation, and higher adult mass on low-water treatment plants than on high-water treatment plants. We observed a non-significant, though consistent trend toward increased oviposition preference for low-water treatment plants. Nitrogen concentrations of lace bugs did not differ by treatment, but lace bugs from low-water treatment plants contained more nitrogen in total due to their higher mass. These results suggest that lace bugs perform better on drought-stressed plants due to mobilization of structural nitrogen increasing the nutritional quality of stressed tissues.