Since its discovery in Oregon in 1946, the pear psylla, Psylla pyricola Forster, has become the most serious insect pest of pear. Damage to pear trees include the transmission of pear decline disease which has caused losses of trees, injection of a phytotoxic toxin resulting in tree shock and injury,...
Published April 1977. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog