Skip to main content Skip to navigation

WSU Decision Aid System Update May 2024

Written by Liesl Oeller, Washington State University, April 23, 2024

Spring is here and many DAS models are starting. Codling moth (CM) flight is occurring along the corridor from Wenatchee to Yakima to the Tri Cities. CM flight in areas north of Wenatchee up to the British Columbia border is expected to begin next week. If CM flight is happening in your area, you can look at the DAS CM model to stay updated on the timing of egg presence and larval emergence. If you are using mating disruption, this should be in place by 120 degree days.

Due to the unseasonably warm weather we had a few weeks ago, so far in 2024 we have accumulated far more degree days than this time last year. In 2024, we are ahead of 2023 by an average of 128 degree days.

Degree Days 2023-2024

Comparing degree days between 2023 and 2024 for five different locations in Washington and Oregon.

Location 2023 DD 2024 DD
Wenatchee 72 211
Moxee 61 194
Pasco 137 290
Hood River 46 154
Omak 36 145
Average 70.4 198.8

map of Washington with varying size blue circles

Codling moth degree day accumulations. Darker blue circles indicate higher degree days.

Now is the perfect time to subscribe to DAS!

Keep track of pest emergence and see management options as the season progresses. You can use our time machine tool to look back on weather data from the last 5 years, and see how 2024 compares. You can also set up alerts to remind you when key pests are emerging for timely management.

For weekly updates on DAS models and tools, subscribe to our mailing list. Now is the perfect time to subscribe to weather stations on DAS, get started today!


Liesl Oeller
Liesl Oeller
Washington State University
(509) 335-5815


Fruit Matters articles may only be republished with prior author permission © Washington State University. Reprint articles with permission must include: Originally published by Washington State Tree Fruit Extension Fruit Matters at and a link to the original article.

Use pesticides with care. Apply them only to plants, animals, or sites listed on the labels. When mixing and applying pesticides, follow all label precautions to protect yourself and others around you. It is a violation of the law to disregard label directions. If pesticides are spilled on skin or clothing, remove clothing and wash skin thoroughly. Store pesticides in their original containers and keep them out of the reach of children, pets, and livestock.

YOU ARE REQUIRED BY LAW TO FOLLOW THE LABEL. It is a legal document. Always read the label before using any pesticide. You, the grower, are responsible for safe pesticide use. Trade (brand) names are provided for your reference only. No discrimination is intended, and other pesticides with the same active ingredient may be suitable. No endorsement is implied.

Washington State University