Spider Mite Control During the Summer

Saturday Jun 01, 2024

There are currently lots of options to control spider mites in orchards. However, preventing outbreaks by avoiding pesticides toxic to predatory mites and their alternative prey is always first choice. If uncontrolled, spider mites can go through a single generation in 7-10 days during summer and increase their numbers exponentially. Monitoring helps to follow spider mite population growth and to intervene when necessary.

Monitoring Adult Codling Moth

Wednesday May 22, 2024

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

Wednesday May 15, 2024

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

Wednesday May 08, 2024

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

Wednesday May 08, 2024

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.