Theresponses and impacts ofÞve insect species that feedonCentaureadiffusaLamarck, diffuse knapweed, to soil nitrogen and phosphorus additions were studied in grasslands east of the ColoradoFrontRange.Wepredicted that fertilizationwasunlikely tohave adirect effect onherbivory but that if the insects preferentially select vigorous plants, increased tissue nitrogen, plant density, or plant mass re...

Biological control of spotted knapweed (Centaurea stoebe) is an ongoing topic of research that holds ecological importance due to the extent to which knapweed has spread across the Western United States. Using herbivores (insects) as biological controls of spotted knapweed can be successful at reducing plant density in certain habitats. However, the exact relationship among the insects, knapwee...