1. Department of Environmental Sciences, The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, Connecticut 06511.
2. United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Diagnostics and Biologics, National Veterinary Services Laboratories, 1920 Dayton Avenue, Ames, Iowa 50010.
3. Center for Vector Biology & Zoonotic Diseases, The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, Connecticut 06511.