Mating disruption for control of codling moth represents a drastic new departure from all previous insecticide-based approaches.  Knowledge of how this method works and how it should be used to optimize its impact has been fragmented and remains incomplete on some issues.  After several years of evaluation in numerous small orchards in the western USA (California, Oregon, and Washington), recommendations on how to use mating disruption effectively are in place.  For example, mating disruption should not be used under certain conditions (steep orchard slope, exposed windy site, uneven orchard canopy, or close proximity to unmanaged populations) but should be used in conjunction with a reduced insecticide program (moderate to high overwintering codling moth population density).  In apple and pear orchards with low codling moth pressure, mating disruption has generally worked as good as conventional insecticide spray programs.

Information on the impact of mating disruption on other aspects of the orchard ecosystem is limited.  The benefit of adopting mating disruption for codling moth is  the elimination of organophosphate sprays which would enhance biological control of a number of secondary pests.  However, population trends of secondary pests and their associated natural enemies in pheromone-treated orchards varied among years and are strongly impacted by the continued use of insecticides for those secondary pests, particularly for leafrollers.

Research findings gathered for individual orchards treated with pheromone, but surrounded by sprayed orchards, are unlikely to predict population trends in pests and natural enemies under areawide use of mating disruption. A previous study of organic versus conventional orchards in Washington (USA) demonstrated that pest populations of aphids and leafminers were lower and their natural enemies higher in the organic orchards.  Removal of broad-spectrum insecticides from a large number of contiguous orchards may allow sufficient reservoirs of natural enemies to survive and create unique orchard ecological communities. Demonstration of this potential benefit of adopting mating disruption may require a coordinated program involving a number of growers.

The major problems associated with implementing grower adoption of mating disruption have been its higher cost and the increased risk associated with its use.  The cost of the recommended rates of pheromone dispensers and the associated applications costs are high.  Economic studies have shown that use of mating disruption at current prices is more expensive than conventional programs if the use of pheromone is replacing three organophosphate sprays for codling moth.  Due to the continued need to apply mineral supplements and fungicides, savings from reduced machinery and labor costs appear to be minimal.  However, in orchards where mating disruption can replace 4-6 sprays for codling moth, or if the use of mating disruption can reduce the need for sprays for secondary pests, then the economics of its use are favorable in comparison with conventional programs.  In addition, the number of dispensers needed per acre is likely lower when large contiguous areas are treated and border effects are reduced.  This economy of scale is seen as a major incentive for adopting an areawide program using mating disruption for codling moth.

Recently in western USA, mating disruption has been adopted and tested in over 150 grower orchards.  In this small subset of orchards, mating disruption has been successful in over 95% of the cases.  However, in the few celebrated failures, mating disruption has created some perception problems which will likely slow its rate of adoption.  Successful use of mating disruption depends on maintaining the flexibility for supplementary controls.  The recent establishment of moth catch thresholds to trigger the use of insecticide sprays is an important research accomplishment.  The common occurrence of fruit injury along the edges of pheromone-treated orchards due to poor pheromone coverage is another factor which must be addressed.  Grower options to combat this problem include the use of border sprays and placing pheromone along windbreaks or some border outside the orchard.  However, the use of mating disruption in large contiguous areas may reduces the importance of this edge effect.

The adoption of mating disruption for codling moth is truly a revolutionary approach in pest management. Efforts of research, extension, and the environmental community to study and develop this technology are currently too fragmented.  Concerted effort in a short time span is needed for environmental value to be documented, management systems fine tuned, and an educational package produced by the experts.  Numerous areas of research remain to be more fully investigated including both basic studies with pheromone chemistry, moth behavior, moth movement, and atmospheric pheromone transport and applied areas such as the streamlining of dispenser application, effects on other pests, biological control, and environmental impacts.

Adoption of mating disruption for codling moth has some potential negative aspects which must be addressed. Because of the narrow spectrum of activity, certain pest problems may develop which were previously controlled by the broad-spectrum insecticides applied against codling moth.  For example, in Washington (USA) fruit injury from leafrollers has increased in some pheromone-treated apple orchards.  Intensification of injury by secondary pests increases the cost of adopting mating disruption because selective controls are now needed for these pests (e.g. microbial insecticides or mating disruption).  Also, monitoring (pheromone traps, fruit sampling) may have to be more intensive with mating disruption to minimize the risk of fruit damage.  So far, there is no evidence of resistance to sex pheromones developing, but the potential does exist.