Overwintering of psyllids in South Moravia (Czech Republic) with respect to the vectors of the apple proliferation cluster phytoplasmas.

Abstract

We studied the overwintering of psyllids on conifers in two hilly sites in the Czech Republic, South Moravia: the Drahanska vrchovina Highlands and the Pavlovske vrchy Hills. Using a sweeping net on a long stick we collected altogether 3304 specimens of Psylloidea. In the Drahanska vrchovina, 27 species were found; 80 % of specimens belonged to the potential phytoplasma vectors Cacopsylla pruni (Scopoli), Cacopsylla picta (Forster), Cacopsylla melanoneura (Forster), and Cacopsylla pyrisuga (Forster). In the Pavlovske vrchy, 10 species were ascertained and C. melanoneura as the only phytoplasma vector was represented in 2.9 % of specimens. A high representation of phytoplasma vectors on conifers in the Moravian highlands can be explained by a long-distance migration of freshly mature psyllid specimens which would be carried from lowlands by ascending thermic currents, drifted by winds and deposited on hills by turbulence.