Detection of different types of phytoplasmas in stone fruit orchards in northern Italy

Phytoplasmas belonging to the ribosomal subgroup 16SrIII-A (X disease and related phytoplasmas) were identified in two plants of declining cherry during the monitoring of two experimental plum orchards. The same phytoplasmas were identified also in Phi-laenus spumarius samples collected in yellow sticky traps located inside the plum orchards. ‘Candidatus Phytoplasma prunorum’ was detected in one declining cherry plant and in samples of Fieberiella florii. Among the insect species tested for phytoplasma presence Cacopsylla pruni was only captured once, and the sample resulted negative to the molecular tests. Key words: Cherry decline, PCR/RFLP analyses, insects, epidemiology