1. (AGW) Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634-0310, U.S.A. (e-mail: awhlr@clemson.edu)
2. (ICS) USDA, APHIS, PPQ, 10300 Baltimore Avenue, Beltsville, MD 20705, U.S.A. (e-mail: Ian.C.Stocks@aphis.usda.gov)