Pesticide Use and Levels of Insect and Scab Injury on Fruit in Nova Scotia Apple Orchards

A commercial pest management company recorded pesticide use and levels of insect and scab injury to apples from 1980 to 1983. Mean numbers of insecticide and miticide applications were 2.5 and 0.5 per year, respectively. Mean costs of insecticides and miticides (material only) were $44.44 and $23.50/ha. These totals varied little from year to year despite large variations in costs of controlling individual pests. Scouting costs rose from $25.00/ha in 1980 to $37.50/ha in 1983. Targets of most insecticide applications were winter moth, Operophtera brumata (L.); codling moth, Cydia pomonella (L.); and apple maggot, Rhagoletis pomonella (Walsh). European red mite, Panonychus ulmi (Koch), was the target of most miticide applications. Despite low frequencies and low total costs of insecticide applications, total insect injury averaged only 2.3% of the fruit, declining from 3.8% in 1980 to 2.0% in 1983. Scab injury averaged 1.9%, varying from 0.9% in 1981 to 3.7% in 1983. Success of the integrated pest management (IPM) program is attributed to pest monitoring and use of economic thresholds as well as to a range of tactics designed to minimize impact of pesticides on natural enemies and to delay onset of resistance among the pests.