1. Environmental Studies Institute, Santa Clara University, Santa Clara, CA 95053, USA
2. Department of Entomology, University of Arizona, Tucson, AZ 85721-0036, USA
3. Department of Botany and Plant Sciences, University of California at Riverside, Riverside, CA 92521-0124, USA
4. Department of Plant Sciences, University of California at Davis, Davis, CA 95616-8780, USA
5. The Nature Conservancy, Seattle, WA 98105, USA
6. Department of Biology, Loyola University Chicago, Chicago, IL 60626, USA
7. Department of Biology, University of Nebraska, Omaha, NE 68182-0040, USA