[1] Hellen Agr Org DEMETER, Forest Res Inst, Vassilika 57006, Greece
[2] Nat Resources Inst Luke, Helsinki, Finland
[3] UMR BIOGECO INRAE, 69 Route Arcachon, F-33612 Cestas, France
[4] Univ Tuscia, DIBAF, Via S Camillo Lellis snc, I-01100 Viterbo, Italy
[5] CNR, Ist Protez Piante, Via Madonna Piano 10, I-50019 Florence, Italy
[6] Univ Catania, Dept Agr Food & Environm Di3A, Appl Entomol Div, Via Santa Sofia 100, I-95123 Catania, Italy