1. USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR 97331, U.S.A.
2. Natural Resources Institute Finland, Latokartanonkaari 9, FI-00790 Helsinki, Finland
3. Natural Resources Institute Finland, Paavo Havaksen tie 3, FI-90570 Oulu, Finland
4. USDA Forest Service, Forest Health Protection, Coeur d’Alene, ID 83815, U.S.A.
5. University of Aberdeen, School of Biological Sciences, Aberdeen, Scotland, U.K.
6. USDA Forest Service, Rocky Mountain Research Station, Moscow, ID 83843, U.S.A.
7. Colorado State University, Department of Agricultural Biology, Fort Collins, CO 80525, U.S.A.
8. USDA APHIS, PPQ-PHP-IRM, Plants for Planting Policy, Riverdale, MD 20737, U.S.A.
9. Oregon State University, Department of Forest Engineering, Resources and Management, Corvallis, OR 97331, U.S.A.
10. North Carolina State University, Center for Integrated Pest Management, Raleigh, NC 27606, U.S.A.