1. Julius-Kuehn-Institute; Institute for National and International Plant Health; Messeweg 11/12 D-38104 Braunschweig Germany
2. Julius Kühn-Institute; Institute for Strategies and Technology Assessment; Stahnsdorfer Damm 81 D-14532 Kleinmachnow Germany
3. INRA; UR633, Zoologie Forestière; F-45075 Orléans France