1. Department of Plant Pathology, North Carolina State University, Campus Box 7616, Raleigh, North Carolina 27695;
2. Department of Plant Pathology, University of Georgia, 2309 Miller Plant Science Building, Athens, Georgia 30602-7274;
3. Department of Plant Pathology, Iowa State University, 351 Bessey Hall, Ames, Iowa 50011;
4. Department of Nematology, Wageningen University and Research Centre, Binnenhaven 10, PD Wageningen, 6709 The Netherlands;
5. Laboratoire de Biologie des Invertebres, Institut National de la Recherche Agronomique, 123 Boulevarde Francis Meilland, Cedex Antibes, 06600 France;