The Influence of Spray Programs on the Fauna of Apple Orchards in Nova Scotia. XVI. The Long-Term Effect of Mild Pesticides on Pests and Their Predators1

Abstract

This paper gives a summary of a 13-year test of the integration of chemical and biological control methods for apple pests in Nova Scotia. The test was a practical demonstration which showed that this method of approach has promise. The major pests in the orchard – the eye-spotted bud moth, Spilonota ocellana (Denis & Schiffermuller); the codling moth, Carpocapsa pomonella (L.); and the European red mite, Panonychus ulmi (Koch), became moderately abundant immediately after the change to integration. These pests soon readjusted to low densities and remained at low levels for the remainder of the period. In the latter half of the period the pests requiring special treatments were the winter moth, Operophtera brumata (L.); the fall cankerworm, Alsophila pometaria (Harris); and the apple brown bug, Atractotomus mali (Meyer). The control of these pests interfered some with the natural enemy populations but the interruptions were transitory because only relatively selective materials were used when required.