1. Institute of Phytopathology and Applied Zoology, Justus Liebig University Giessen, Heinrich‐Buff‐Ring 26‐32, D‐35392 Giessen, Germany;
2. Plant Protection Institute, Hungarian Academy of Sciences, Herman Ottóút 15, H‐1022, Budapest, Hungary;
3. The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30‐239 Cracow, Poland