Occurrence and epidemiology of European stone fruit yellows phytoplasma in Spain

The results of studies carried out in two fruit producing areas of Spain (Catalonia and Extremadura) have shown that phytoplasmas related to the European stone fruit yellows group are harmful to plum, peach, apricot, nectarine and cherry trees. The occurrence of affected plum trees was very high in some fruit fields of Baix Llobregat (Catalonia) (25-78%), whereas in Extremadura the incidence of affected trees in the surveyed plots was low (1-5%). The European stone fruit yellows phytoplasma was the only one detected in the tests on the plum, peach, cherry, apricot and nectarine samples. The identification of vectors for the European stone fruits yellows was done in the Baix Llobregat area (Catalonia), studying species known to be liable to transmit phytoplasmas. Two species of Cacopsylla were captured in all affected fruit fields, Cacopsylla pruni and Cacopsylla pulchella. PCR analyses showed that most individuals of C. pruni were carriers of the phytoplasma, therefore C. pruni could also transmit the phytoplasma in this area.