Knowledgebase

Codling Moth, optimum time to spray #929177

Asked April 21, 2026, 10:01 PM EDT

I've never accessed this service, but hear that it is available. As a small orchard family, what do I need to know to successfully treat for codling moth larvae? Do you advise best time to spray, based on weather and codling moth population densities? Do I need to check a www site regularly to get the information, or do I signup on a list serve and have the information sent directly to me? Appreciate any information you can give me to successfully treat Codling Moth.

Benton County Oregon

Expert Response

I set out traps for codling moth and send out email notifications once I know the spray dates. I will go ahead and add you to the list so that you receive the email. Traps are used to monitor when the moths emerge. Catches in the traps determine the biofix date, which is the first capture of multiple male moths in a trap or consistent capture of multiple males over more than one trap. The biofix date is used as the point to start accumulating degree-days for the Stanley and Hoyt (1987) degree-day model. This link to the degree-day model gives a map to let you select the weather station closest to your orchard. Enter the biofix date and then the calculations will give the appropriate dates for spraying. As I noted above, I set out traps around Eugene to monitor moth emergence and the spray dates, and I will add you to the list. 
With regards to control, pesticides are often needed to manage the pest. You can find a list of pesticides that are registered for use in the PNW Pest Management Handbook: https://pnwhandbooks.org/insect/tree-fruit/apple/apple-codling-moth. In terms of low toxicity pesticides, CYD-X (a granulosis virus), Spinosad (a biological made from soil bacterium), or a horticultural oil are the best options. Horticultural and neem oils are effective in smothering the eggs and tiny larvae that hatch out. These neonate, or newly hatched larvae, are very tiny and they do a bit of feeding before they are able to find and enter the fruit. Once they enter the fruit they can no longer be treated. For the later sprays, materials that target the larval stage should be used. When using pesticides, always read and follow all label directions. 
There are a few cultural practices that can be used in lieu of or in conjunction with pesticides.
  • Sanitation is the most important practice that is environmentally safe. If you remove and dispose of damaged young fruit throughout the season, you can help reduce future generations. Larvae continue to feed inside the fruit after it falls from the tree, so remove infested and fallen fruit promptly.
  • “Fruit sox” or bagging individual fruit in paper or mesh bags can be effective, but you need to get the bags/sox on about 4 to 6 weeks after petal fall. Thin clusters to one fruit before placing the bags over them. Fruit will mature completely within bags, however color development on red varieties may be affected.
  • Homeowners can also place corrugated bands of cardboard around the lower trunk to attract larvae looking for a place to pupate. Place bands in May and remove before the adults begin to emerge in early to mid-June. The same technique can be used for the subsequent generation(s) later in summer.

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