1. Institute for Biodiversity and Ecosystem Dynamics, University of AmsterdamPO Box 94084, 1090 GB Amsterdam, the Netherlands
2. Department of Theoretical Biology, Institute of Entomology, Czech Academy of SciencesBranišovská 31, 37005 České Budjovice, Czech Republic
3. Department of Ecology and Environmental Science, Umeå University90187 Umeå, Sweden