1. Department of Integrative Biology, University of California, Berkeley, California 94720;
2. Department of Pathology, University of Texas Medical Branch, Galveston, Texas 77555, and Florida Medical Entomology Laboratory, Vero Beach, Florida 32962
3. Natural History Museum, Biodiversity Research Center, and Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas 66045
4. Museum of Vertebrate Zoology, University of California, Berkeley, California 94720