Spidermites are arachnid pests that feed on a variety of landscape plants. Some are commonly found on evergreen trees such as hemlock and fir, while other species will target deciduous trees and shrubs. They cause damage similar to lacebugs in that they remove much of the sap from the foliage, and severe infestations could seriously injure the host tree. Heavy populations will sometimes leave noticeable webbing around the foliage.
Since this pest is not an insect, special materials are needed for treatment, and foliar applications are most common.