Invasion and Subsequent Biological Control of St. John's Wort (Hypericum perforatum): Rapid Evolution of Herbivore Resistance?

University Of Washington, Seattle WA

Investigators

Abstract

0098377 John Maron The invasion of native communities by introduced organisms is causing tremendous economic damage to our natural ecosystems. Biological control programs often fail, which places additional burdens on the environment because invasives must then be controlled with chemical pesticides and herbicides. The foundation of this study is one of the most successful weed biological control programs in the US. It is focused on St. John's Wort (Hypericum perforatum), an important invasive plant that has been successfully controlled using introduced herbivores. The project can help us to understand the evolution of herbivore resistance, and loss of resistance, and can reveal the coevolutionary dynamics between plants and their insect biocontrol agents. The project has strong relevance for basic ecology as well as numerous economic applications in the fields of conservation biology and agriculture. The experiments can determine if plants can rapidly lose, then accrue, resistance in the absence and presence of biocontrol agents, and will also demonstrate if plant resistance to one herbivore provides resistance to multiple herbivores. Currently there are few empirical studies on these questions.