Crown pests are hard to manage and eliminate since they’re at the higher areas. What you can do is hire a crown thinner to help prevent the growth of these insects. Through crown thinning, more are is allowed to pass. A great crown thinning service in Portland Oregon can be found at North Wood Tree Services. We also offer other types of tree-related services. Our people are the best in the business. You can trust us to do the job right the first time.