Mating disruption for codling moth and oriental fruit moth (Isomate-CM/OFM TT)

Mating disruption alone will not provide adequate control of codling moth (CM) in most commercial orchards. When used together with existing IPM programs, pest populations and pesticide use can be reduced over a number of seasons.

  • During the first year of using mating disruption for CM, follow a standard spray program for both generations and monitor extensively for this pest.
  • In the second year of a mating disruption program, and where populations are low, limit insecticides to the first generation.
  • In subsequent years, use results from monitoring and damage assessments to determine if insecticide applications can be reduced further when mating disruption products are used.

Many of the new reduced-risk products and the granulovirus (Virosoft, CYD-X) work very effectively together to reduce CM populations to levels where insecticide use may be reduced in subsequent years.

Apply Isomate-CM/OFM TT (fixed-point twin tubes) prior to CM emergence in the spring. Set dispensers in the upper third of the canopy, in a uniform grid. In older orchards interplanted with small numbers of replacement trees, bias the application to adjacent larger trees. In sections with large numbers of interplanted rows, insecticides may be required to supplement control from mating disruption.

The dispenser is designed to provide sufficient pheromone to control CM for the entire season and OFM for up to 90 days. While some OFM may have emerged prior to deployment of the dispensers, several petal fall insecticides have activity against this pest. Insecticides may be needed in late varieties when high OFM populations exist or when immigration from untreated blocks late in the season may occur.

Monitoring for codling moth flight in mating disruption blocks

Codling moth populations in disrupted orchards must be monitored to determine pest pressure and the need for supplemental insecticides. Because of the high concentration of pheromone used for mating disruption, traps loaded with standard lures are not effective and specialized lures are needed. The industry standard is the CM DA Combination Lure, which contains a chemical extracted from ripe pears to attract both male and female codling moths. These lures last up to 8 weeks.

Traps should be placed in the upper third of the canopy in disrupted blocks (same height as the mating disruption dispensers). Use a minimum of 1 trap per hectare, with traps located near high-risk areas and borders (5-6 rows in).

Thresholds for the application of insecticides are based on the number of moths captured per trap per week in disrupted blocks. As a general guideline, 3-5 moths per trap per week indicate a need for caution. More than 5 moths per trap per week indicate the need for insecticides to supplement control from mating disruption. Do not average the number of moths per trap per week. Trap captures are an indication of potential local hot spots where intervention may be required.

Damage assessments

Conduct in-season visual assessments for fruit damage toward the end of each generation and whenever moths are caught in traps. Fruit damage can occur even when no moths are caught in traps.

At the end of the first CM generation, examine a minimum of 500 fruit from throughout the orchard as well as in high-risk and border areas. If damage exceeds 0.5%, insecticides are required for the next generation. Where damage is localized, insecticides may be directed to those areas and along borders. Continue to assess damage weekly (200 fruit) throughout the season, to ensure the pheromones are working and to allow for timely intervention with insecticides, if required.

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