As reported by group of specialists from Bari, “Quick decline syndrome of olive” appeared suddenly a couple of years ago in the vicinity of Gallipoli, in the province of Lecce (Salento peninsula, Apulia, south-east Italy). It soon exploded in epidemic form, so as to affect an estimated surface area of about 8,000 hectares.
Symptoms consist in the apperance of withering and dessication of terminal shoots distributed at random which expand to the rest of the canopy, thus resulting in the collapse and death of the trees. In the affected groves all plants show symptoms.
Olive trees are new hosts of Xylella fastidiosa, which has never been found in a number of grapevines and citrus plants growing next to or within contaminated olive groves; the olive strain of Xf is close to the subspecies pauca. It is transmitted by xylem-sap-feeding leafhoppers
(Hemiptera:Cicadellidae) and spittlebugs (Hemiptera: Cercopidae).
There are strong indications that OQDS of aged (centenary) olive trees is a complex disorder, in which also a leopard moth (Zeuzera pyrina) and xylem inhabiting fungi Phaeoacremonium parasiticum are involved.
EU plant health measures are under the preparation while in Italy emergency measures have been already in place: ban on movement of host plants (olive, almond, oleander and oak), treatments of vectors and elimination of spontaneous host plant in the vicinity of nurseries.