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Notice: Sterile Insect Release May Impact CM Traps Catches

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Written by Kacie Athey, WSU Entomology and Dustin Krompetz, M3 Consulting Group LLC. Mar 2020

Neighbors within 1/4 mile of sterile codling moth release sites may see their Delta traps fill up with sterile codling moth on a weekly basis this season. Do not panic, you are receiving a benefit!

There are over 2,000 acres of sterile codling moth treatment that is being applied near Tonasket, Brewster, Chelan, Wenatchee, Royal City, Othello, Basin City, Pasco, Wallula, Umatilla, Grandview, Wapato, and Yakima. An easy way to tell if your trap contains sterile moths is to squish the abdomen of the moth. If it is pink (Figure 1), it is sterile, if it is clear or gray, it is a wild moth. Sterile codling moths, like wild codling moths, will fly a distance in search of a mate. You may capture some sterile moths in your traps from a nearby block where a weekly release is occurring (Figure 2; click on image to enlarge).

To growers who are releasing moths: please tell your neighbors within ½ mile that they should expect to see some sterile moth spillover. Most of the released sterile moths will disperse within 400 yards of a release area over their 1+ week lifespan in the orchard. If neighbors see a large or consistent capture of moths this year, please be sure to check if they are sterile by squishing their abdomen. A map displaying approximate release areas will be posted in the spring. Please contact Dustin Krompetz at (989) 418-0456 if assistance is required for deconfliction. Additional information can be found at

Fig. 1. A sterile moth abdomen will appear pinkish compared to wild moths.
Fig. 2. CM trap showing squished moths. SIR moth abdomens are pink compared to the wild moths.


Portrait of Kacie AtheyKacie Athey
Washington State University
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