We are shifting our focus in trees and shrubs from disease and insect control to insect control only. Most of our northwest disease issues are almost past their treatable stages due to the warmer, drier weather conditions, bringing about new challenges.

“Soft bodied” insects such as aphids, lace bugs and cutworms may still be present, but a whole new set of destructive, “hard” bodied insects take center stage as it heats up.

Spider mites start showing up in a wide variety of landscape trees and shrubs, especially arborvitae. These tiny arachnids are difficult to see with the naked eye. They cause fading (called bronzing) by sucking the chlorophyll from their host plant. In large numbers they can cause serious damage and may produce webbing. An easy way to check if they are a present is to vigorously shake the foliage of a suspected area of infestation over a piece of white paper. If you see tiny “dots” on the paper, brush your hand firmly against the paper. If you leave little red smears, chances are spider mites are present.

Another common culprit of the summer is the root weevil. The adult insect is a nocturnal feeder, so is rarely observed. They leave distinctive “notching” in the leaves as they feed due to their hooked snout. The more severe the notching is, the more severe the infestation. Although root weevil damage is unsightly, it is generally not life threatening to the host plant. The greater danger, especially in high populations, is the larval stage of the insect. The larvae feed on the roots of the plant, which can cause girdling and death. This makes proper treatment techniques critical to successful control.

We will be starting the change in control focus soon. But, as always, we encourage our clients to call if they notice any problems between our regular visits. Your applicator will point out any problems or recommendations while doing your regularly scheduled treatment, but in may be 4 to 6 weeks between visits (assuming you are on a full maintenance program). You may never have had summer insect problems before, but do now and need an application(s) or advise. Our job includes being a resource and a partner to you in your landscape maintenance needs.