The indirect effects of native generalist insect herbivores on interactions between exotic and native grassland plants have received limited attention. Crested wheatgrass (Agropyron cristatum) is the most common exotic rangeland grass in western North America. Crested wheatgrass communities are resistant to colonization by native plant species and have strong competitive effects on native species, imposing problems for the restoration of native grasslands. Grasshoppers are generalist herbivores that are often abundant in Crested wheatgrass?dominated sites in the northern Great Plains. We conducted two experiments in a Crested wheatgrass?dominated grassland in western North Dakota to test the hypothesis that grasshopper herbivory influences [...]