1. Department of Biology and The Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, PA 16802 USA;
2. USDA‐ARS, South Peach Avenue, Fresno, CA 93727 USA;
3. Department of Horticulture and The Intercollege Graduate Degree Program in Ecology, 102 Tyson Building, The Pennsylvania State University, University Park, PA 16802 USA