Added in 1999 – Deleted in 2000
Reasons for deletion
The association of the pest Olive phytoplasma disease with a phytoplasma has not been shown. In 2000, it was therefore considered that sufficient alert has been given and the pest was deleted from the Alert List.
Olive phytoplasma diseases
Why These phytoplasma diseases of olive came to our attention because two 'similar' reports were made approximately at the same time from Italy and Spain. Symptoms appear very similar, but it cannot be said whether these diseases are caused by the same or related phytoplasmas.
Where A phytoplasma disease has been reported in 1996 from many olive orchards of central Italy. In Spain, it is reported in 1998 that a new disease has been observed since 1993 in several olive orchards near Badajóz (Extremadura).
On which plants Olive trees (Olea europaea).
Damage In Spain: affected trees showed abnormal shoots, shortened internodes and proliferation (witches' broom).
In Italy: diseased plants showed dwarfed branches with shortened internodes, leaf deformation and chlorosis, proliferation of axillary buds with witches’ broom.
Possible identity In both cases, PCR analysis revealed the presence of phytoplasmas in diseased olive trees. In Spain, it is noted that it belongs to the stolbur group. In Italy, the name: olive witches’ broom disease has been given.
Transmission It is suspected that the cicadellid Hyalesthes obsoletus can transmit the phytoplasma in the field.
Pathway Plants for planting (fruits?) of olive from Italy and Spain.
Possible risks Olive is a significant crop for the whole Mediterranean area. In Italy, severe economic problems are reported.
Source(s) Del Serrone, P.; Barba, M. (1997) Olive witches’ broom: a new olive disorder associated with phytoplasmas. Abstract of a paper presented at the ISHS XVII International Symposium on virus diseases of fruit trees, Bethesda, US, 1997-06-23/27, p 119.
Font, I.; Abad, P.; Dally, E.L.; Davis, R.E.; Jordá, C. (1998) Nueva enfermedad en el olivar español. Phytoma España, no. 102, 211-212.
EPPO RS 99/008, 97/195
Panel review date - Entry date 1999-01