1. Illinois Natural History Survey, University of Illinois, 1816 S Oak Street, Champaign, IL 61820, USA
2. Department of Forestry, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia
3. Department of Forest Science, Tokyo University of Agriculture, Setagaya, Tokyo, Japan
4. Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
5. Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu, Japan