1. Laboratory of Entomology, Wageningen University, P.O. Box 8031, NL-6700 EH, Wageningen, The Netherlands;
2. Department of Biology, University College London, Darwin Building, Gower Street, London WC1E 6BT, United Kingdom;
3. Netherlands Institute of Ecology (NIOO-KNAW), Rijksstraatweg 6, NL-3631 AC, Nieuwersluis, The Netherlands;