Published online by Cambridge University Press: 31 May 2012
Annual assessments from 1953 to 1977 of insect damage to the preharvest crop in apple orchards in Nova Scotia show a general decline in injury, except for 1966–68. Laspeyresia pomonella (L.) and fruit chewing insects (chiefly Operophtera brumata (L.), Alsophila pometaria (L.), Orthosia hibisci Guenee, Lithophane spp., and Xylena spp.) caused the greatest amount of fruit damage. Dysaphis plantaginea (Pass.), Campylomma verbasci (Meyer), and Atractotomus mali (Meyer) were serious in some years. In integrated control program orchards the proportion of fruit damaged was twice that in preventative pesticide orchards. Fruit destined for processing had more injury than fruit destined for the fresh fruit market.
Population levels of the major insect pests and their natural enemies were monitored regularly and gave early warning of threatening levels of pests. Generally predator population levels were high during periods of selective insecticide use but were low when widely toxic insecticides were introduced into the integrated control program.