Pine bark adlegids (Pineus strobi) are often referred to as bark aphids. Of all the pines in the Midwest, eastern white pine seems to be the one most often attacked. Light infestations do not do much to the tree. However persistent severely heavy yearly attacks can cause some stunting and possible death of the trees.
The adelgids produce a wax while feeding. The wax is a protective cover that resembles wool, making them look like wooly aphids to which they are related. Under this waxy wool the adelgid is teardrop shaped and black in color.
Insecticides can be used to control these insects. Check with your local land grant university (Cooperative) Extension Service for recommended insecticide. Apply in May or later when adelgids are present. In the spring use a spreader sticker in insecticide application.
Written by James Schuster, Extension Educator, Horticulture, and reviewed by Dr.Philip L. Nixon, Extension Specialist-Entomology, Department of Natural Resources and Environmental Sciences University of Illinois at Urbana-Champaign.