1. Università degli Studi della Tuscia, Department of Forest Environment and Resources (DISAFRI), Via S. Camillo de Lellis, I‐01100 Viterbo, Italy;
2. University of Antwerpen, UIA, Department of Biology, Universiteitsplein 1, B‐2610 Wilrijk, Belgium;
3. IBIMET‐CNR, P.le delle Cascine, 18 I‐50145 Firenze, Italy