1. Laboratory of Socioecology and Socioevolution, KU Leuven; Naamsestraat 59 BE-3000 Leuven Belgium
2. Royal Belgian Inst. of Natural Sciences; Entomology Dept; Vautierstraat 29 BE-1000 Brussels Belgium
3. Dept of Earth and Environmental Sciences; KU Leuven; BE-3000 Leuven Belgium