IPM Methods: Monitoring Techniques & Supplies
Monitoring for insects and diseases and for plant or fruit injury is essential for effective pest management. Knowing what pests are active and when, optimizes pesticide treatments. Regular monitoring provides information on:
- early warning of potential pest problems
- which pest life stage is active
- presence or absence of natural enemies
- when to implement control measures
- whether pest control actions are working
How Often to Monitor
From spring through early summer, monitor at least once per week, and then every other week thereafter until late summer. Ideally, scouting should occur on the same day each week. Plan to spend up to an hour, depending on the orchard size, to do a thorough job.
Where to Monitor
Walk sections of the selected block in a diagonal or zigzag pattern. Randomly select trees, and include at least four trees of each cultivar in a block of 10 acres in size. The more trees that can be inspected, the better. Also include trees from the following areas:
- known hotspots
- where topography or soil type differs significantly
- orchard borders
Examine each tree for overall health and for insect or disease activity. On leaves, look for chewing injury, spots, changes in color, or stippling. On fruit, look for spots, dimples, and rot. On the stems and root collar, look for discoloration, oozing, cracking bark, and holes. Check to be sure the tree is not being over- or under-watered.
After this visual inspection, use a beating tray to perform a closer inspection for insects. A beating tray is a large (approximately 18” x 18”) flat surface on which to observe insects. To use, hold the tray under a limb and strike the limb with a padded stick three times. Examine the dislodged insects visually or with a hand lens.
Use a hand lens in the range from 10x-30x magnification to identify pests. To focus on the pest you are viewing, hold the lens approximately 1-2 inches above the specimen. You can either look down through the hand lens from above, or bring your eye directly to the hand lens.
Using pheromon traps is a very important component of IPM. All commercial fruit growers should use them, as they provide dates on first moth flight, an indication of pest population, and in some cases, provide a threshold of when to treat.
Pheromone traps are available for the major fruit pests shown below, plus many others:
- codling moth
- peach twig borer
- greater peachtree borer
- obliquebanded leafroller
Using pheromone and yellow sticky traps has more information.
If you find a pest or damage that you are unsure of, there are resources to help you.
Send the specimen to the Utah Plant Pest Diagnostic Lab at 5305 Old Main Hill, Logan, UT 84322. The fee is $7, and a submission form, which is available online, must accompany the specimen.
Contact your local county extension agent.
Send specimens to Western Colorado Research Center 3168 B 1/2 Road, Grand Junction, CO 81503-9621 with detailed information.
Send specimens to the main campus at Plant Diagnostic Clinic, E215 Plant Sciences Bldg., Colorado State University, Fort Collins, CO 80523-1177. Sample fees range from $7-20 and must be accompanied by a form. Phone: 970-491-6950.
Send insect or disease specimens to Idaho State Department of Agriculture 2230 Old Penitentiary Road, Boise, ID 83712, with a form and $55. Forms and more information can be found at the ISDA website.
Send plant and arthropod specimens to the the Schutter Diagnostic Lab, Montana State University, 121 Plant Bioscience Building, Bozeman, MT 59717. Forms and shipping instructions are available online. Routine diagnoses are free, but fees apply for multiple samples, out of state services, and special diagnostic services.
West Linn, OR
Mt. Horeb, WI
Great Lakes IPM
- 10x-30x magnification hand lens
- orange delta traps and codling moth, greater peachtree borer, and/or peach twig borer pheromone lures
- extra sticky liners for traps
- Pherocon AM yellow sticky traps plus external ammonium carbonate lure
- beating tray and padded stick
- vials of alcohol, tweezers, a small paintbrush, and plastic containers for collecting unknown specimens.
Pest monitoring provides information on pest activity and population size. To decide if control is required, pest density must be related to the potential crop damage and balanced against the cost of treatment. If the cost of treatment is more than the crop loss, do not treat. Activity of natural enemies must also be considered when determining whether to treat. For pests like aphids or spider mites, natural enemies can potentially keep these populations below economic injury levels. For specific pest threshold levels, see Pest Biology sections.