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About Enviroweather's Codling Moth Assist Chart

By Enviroweather staff

More information on codling moth at IPM Resources

About the model:

The current codling moth model is designed to help the user time insecticides for preventing entry of larvae into fruit. The model is initiated on March 1st. Using 50 degree F as a base, degree-days (DD) for codling moth activity are:

1st generation

  • 0 DD--first adult emergence (biofix 1)
  • 250 DD--first eggs hatch β treat*
  • 350 DD--20% egg hatch
  • 550 DD--peak egg laying

2nd generation

  • 1,060 DD--first emergence of second generation adults (biofix 2)
  • 1,250 DD--first egg hatch β treat*
  • 1,600 DD--peak emergence of second-generation adults
  • 1,700 DD--peak egg laying by second-generation adults

*Note: biofix is based on monitoring with pheromone traps. Place pheromone traps prior to bloom. Begin accumulating degree days (base 50 F) on the day (biofix) at which the first moth is trapped, provided moths are captured on two successive trapping dates.

*Note: spray timing given here is based on traditional insecticides such as organophosphates or carbamates. Newer insecticides with different modes of action may need different timing for best effectiveness.

Using this report:

Locate the Biofix Date (first date of sustained catch) on the top row. Follow that column down to determine the Base 50F Growing Degree Days (GDD) that have accumulated between the biofix date and the date listed at the left side of that row.

Illustration of Chart

In this example, June 5 was set as the biofix. By June 17, 207 degree days had accumulated.

  • Forecast data is provided (where available) to help with planning in the near-term.
  • Control is recommended at 100-250 GDD (check product) from the biofix date.
  • Repeat for additional blocks with a different biofix date.
  • More information on codling moth at IPM Resources
  • MSU Extension
  • Michigan State University Ag Bio Research
  • Project Greeen