1. USDA, ARS, NEA, Animal Parasitic Diseases Laboratory, BARC-East, Bldg. 307-C, Beltsville, Maryland 20705.
2. University of California–Riverside, Riverside, California 92521.
3. USDA, ARS, NEA, Statistics Group, BARC-West, Bldg. 003, Beltsville, Maryland 20705.
4. 53 Pamela Lane, College Station, Texas 77845.