1. Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana Champaign, 1816 South Oak Street, Champaign, IL 61820, USA
2. Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, WI 53716, USA
3. Museum of Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA
4. Biological Interactions, Universidade Federal do Paraná, Cx Postal 19073, Curitiba, Brazil
5. Department of Ecology and Evolutionary Biology, University of Toronto (emeritus), Toronto, ON, Canada
6. Harold W. Manter Laboratory of Parasitology, University of Nebraska-Lincoln, NE 68588-0514, USA
7. Institute for Evolution, Centre for Ecological Research, Karolina ut 29, Budapest, Hungary H-1113