1. Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Boterhoeksestraat 48, 6666 Heteren, The Netherlands
2. Laboratory of Nematology, Wageningen University and Research Centre, PO Box 8123, 6700 Wageningen, The Netherlands
3. Department of Biology, Georgia Southern University, Statesboro, GA 30460-8042, USA