Cacopsylla costalis (Flor 1861), as a Vector of Apple Proliferation in Trentino

Recently\ a epidemic of apple proliferation "AP# in an orchard area of Trentino "North Italy# occurred[ The most a}ected cultivars were Golden Delicious\ Florina and Renetta Canada grafted on di}erent rootstocks[ In this area the known or supposed vectors of the disease were not present[ At the same time as the AP symptoms appeared\ a notable increase of the presence of psyllids was observed on apple trees so a correlation between these insects and the AP was hypothesized[ Four di}erent psyllid species were found in the orchard] Cacopsylla melanoneura "Fo rster 0737#\ Cacopsylla costalis "Flor 0750#\ Cacopsylla mali "Schmidberber 0725# and Trioza urticae "Linnaeus 0647#[ The _rst two were more frequent in spring at the adult stage[ In 0886 C[ costalis was par! ticularly numerous and was used to plan AP transmission trials[ The transmission from infected AP apple trees to the insect in _eld and from the psyllids to non!infected Golden Delicious and Florina plants in the greenhouse were conducted[ For the control of phytoplasma presence in the psyllids and in the apple plants polymerase chain reaction "PCR#\ nested PCR and restriction fragment length polymorphism analysis were used[ In autumn 0886\ some inoculated plants showed symptoms of AP[ Molecular results were consistent with the presence of phytoplasma in C[ costalis and in inoculated apple culti! vars[