Monitoring Adult Codling Moth

Thursday May 22, 2025

Adult codling moth (CM) are monitored with traps baited with either CM pheromones or a mixture of pheromones and an attractant (Combo D/A lure). Pheromone traps should be placed in the upper 1/3 of the tree canopy before first apple blossoms open or by 100 DD since January 1 whichever comes first. If you are not using mating disruption...

Ways to Reduce Drift

Thursday May 15, 2025

Spray drift is one of the most important issues facing pesticide applicators. Movement to off-site locations can be caused by wind, poor calibration/adjustment, and operator error.

Bt Applications for Leafrollers

Thursday May 08, 2025

Bacillus thuringiensis (Bt) is a bacterium that must be eaten by lepidopteran larvae (caterpillars) to be effective. Bt is a great material for leafroller control because it is specific and has little effect on natural enemies. However, it must be applied 2-3 times to be effective when leafroller populations are high. Experience has also shown that in the spring, the high temperatures need to be above 65°F for 3 or more days so that larvae have a chance to feed on it before sunlight breaks it down. DAS provides forecast temperatures for all stations in the "Weather Forecast" and in the "Show Data Grid" table so that you can decide whether or not to use Bt or other recommended chemicals.

Use Pesticides Wisely to Avoid Resistance

Thursday May 08, 2025

Repeated use of pesticides with the same mode-of-action used in the orchard can accelerate the development of insecticide resistance. WSU recommends that when you choose insecticides, keep track of which ones are being used so that you alternate materials with the different modes-of-action (shown in DAS) between generations.

Campylomma Bug

Thursday May 01, 2025

Campylomma can be a pest during the bloom period when it feeds on young developing fruit. However, it is a beneficial predaceous insect that is valuable in control of soft bodied insects (such as spider mites) throughout the rest of year. DAS predicts the phenology of Campylomma during the spring, but beating tray samples need to be taken before and during the spring bloom period to determine if Campylomma is present and whether treatment is necessary.