Gyorgy Csoka, Hungary Forest Research Institute, Bugwood.org

Gyorgy Csoka, Hungary Forest Research Institute, Bugwood.org

Gyorgy Csoka, Hungary Forest Research Institute, Bugwood.org

Jean-Paul Grandjean, Office National des Forêts, Bugwood.org

Claude-Bernard Malphettes, Institut National de la Recherche Agronomique, Bugwood.org

Claes Hellqvist, Swedish University of Agricultural Sciences, Bugwood.org

Gyorgy Csoka, Hungary Forest Research Institute, Bugwood.org

Claes Hellqvist, Swedish University of Agricultural Sciences, Bugwood.org

François-Xavier Saintonge, Forest Health Department, Bugwood.org

Claes Hellqvist, Swedish University of Agricultural Sciences, Bugwood.org

Claes Hellqvist, Swedish University of Agricultural Sciences, Bugwood.org

Petr Kapitola, Central Institute for Supervising and Testing in Agriculture, Bugwood.org