Pear psylla, Psylla pyricola Foerster, had three generations in 1968 in Nova Scotia. Laboratory studies indicated that overwintering females require mating in the spring to produce fertile eggs. The adults started activity by the end of March, Psylla eggs and nymphs were preyed on by eight predacious species in the laboratory. These and the larvae of another six predacious species were associated with psylla in the field. A few psylla nymphs were parasitized by Trechnites insidiosus (Crawford). Psylla adults fly or are carried with the prevailing winds and a significant percentage occur above the tops of the trees.