Reconciling contradictory findings of herbivore impacts on spotted knapweed (Centaurea stoebe) growth and reproduction.

The article evaluates the responses of Centaurea stoebe knapweed to herbivores. The growth of this plant is greatly reduced by nitrogen limitation and competing vegetation while Centaurea stoebe's seed production in low-nitrogen soils is reduced by Larinus minutus, a seed feeder. The results show that plant growth responses to herbivory can be generated. It was also found that insect herbivores increase the dominance of such invasive plant.