Issue link: https://www.e-digitaleditions.com/i/1463529
PEST MANAGEMENT ALMOND ORCHARD 2025 GOAL Monitoring for Bugs Takes Guesswork Out of Management Determining when and if to spray is something growers face many times throughout the year as it relates to various insect pressures. Applying a product too early may be an unnecessary cost, with the potential to upset the natural biological balance between beneficial predators and harmful pests. Making an application too late may not be enough to ward off a full-blown insect infestation, resulting in damage to tree health and kernel quality – not to mention a poor return on investment. Fortunately, growers can rely on various in-orchard monitoring techniques for determining the need for a spray application – particularly for spider mites. Years of scientific field research funded by the Almond Board of California (ABC) provides clear treatment thresholds, removing the guess work for growers of when – and if – to spray for these webspinning pests. According to David Haviland, University of California Cooperative Extension (UCCE) Kern County entomology farm advisor, the monitoring protocol for determining the need for a spider mite application is "pretty quick and easy and worth the time because a grower can save a lot of money." The monitoring protocol for spider mites includes taking a sample of 15 leaves per tree, with a minimum of five trees sampled. 1 Research dating back to the 1980s – and reaffirmed by more recent field investigation by Haviland over the past decade – indicates a spray treatment is necessary if 25-40% of sampled leaves are infested by mites. The treatment threshold range depends on whether a biological control is present in the orchard, and in the case of spider 1 More specific guidelines for monitoring spider mites are available at the UC Statewide IPM website: https://bit.ly/3G5d9jL Spider Mite Spider Mite Webbing Continue on page 3 Almond Board of California 2