1. Department of Terrestrial Ecology, Netherlands Institute of Ecology, 6708 PB Wageningen, The Netherlands;
2. Laboratory of Entomology, Wageningen University, 6700 EH Wageningen, The Netherlands;
3. Laboratory of Applied Entomology, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan;