Ten years implementing codling moth mating disruption in the orchards of Washington and British Columbia: starting right and managing for success!

In 1991, Isomate C (Pacific Biocontrol Corp., Ridgefield, WA.) became the first commercial product registered by the United States EPA for control of codling moth. Currently, there are 5 products available including Isomate C+, CheckMate CM (Consep, Inc., Bend, OR), NoMate CM (Scentry, Inc., Billings, MT) and Disrupt CM (Hercon, Inc., Emigsville, PA). In Washington State in 1991, codling moth mating disruption (CMMD) was used on approximately 600 hectares. By 1999, use of CMMD had increased to approximately 25,000 hectares. In British Columbia, the efficacy of CMMD was first demonstrated in organic orchards in 1990. In 1999, Isomate C+ (currently the only registered product in Canada) was used on approximately 700 hectares. Research into new CMMD technologies including sprayable pheromones and large aerosol dispensers is underway in both countries. Due to increased regulatory restrictions of conventional insecticides and other factors, a large increase in the commercial use of CMMD is forecast for both countries. The careful selection of orchards and the adoption of a pheromone-based IPM approach can minimize the risk and control problems associated with CMMD. Most importantly in orchards with high resident populations, the application of supplemental insecticides and/or intensive sanitation is essential to achieve commercially acceptable levels of control. CMMD works best in orchards where the physical characteristics and environmental conditions ensure a uniform distribution of pheromone concentration. Dispensers should be deployed within 1 meter of the top of the canopy prior to spring emergence. Borders of pheromone-treated orchards are susceptible to high levels of codling moth infestation and growers generally treat the border areas with supplemental insecticides or an increased application rate of pheromone. Border problems can also be reduced by the area-wide application of CMMD technology. Monitoring codling moth adult activity in orchards treated with CMMD is difficult. Capture of moths in pheromone traps baited with 1 mg of codlemone is an unreliable indicator of efficacy. The sensitivity of pheromone traps can be improved by using traps baited with 10 mg lures and locating them in the upper part of the canopy. False negatives (no or low captures of moths in orchard sustaining economic damage) do occur even with the deployment of 10 mg-baited traps and it is important to interpret trap capture data carefully. Fruit should be inspected on a regular basis to ensure that economically acceptable levels of control are achieved. Economic studies show that the selective application of CMMD in conjunction with the judicious use of insecticides can be more cost effective than conven-