THE ‘LIFE CYCLE’ OF PEAR DECLINE PHYTOPLASMA IN THE VECTOR CACOPSYLLA PYRI
L. Carraro, N. Loi, P. Ermacora
The ‘life cycle’ of pear decline phytoplasma in the vector Cacopsylla pyri has been studied. For two consecutive years, groups of insects caught monthly from March to October were used for transmission trials. The psylla was equally infective throughout the experimental period. In the second year, insects were fed on dormant plants from November to March and regularly tested. Retention of infectivity of the pear decline phytoplasma in the vector lasted through the winter. The overwintering adults of C. pyri did not transmit the phytoplasmas to plants in dormancy, but they did, without any previous recharge feeding, after bud break in the spring. Control of the overwintering adults of C. pyri appears to be of fundamental importance for preventing the spread of pear decline.