How To: Identify fall web worms in trees

Curtis Smith (Extension Horticulturist) and Rick Daniell (Bernalillo Co. Horticulture Agent) examine the bark of a poplar tree. The young bark is smooth and will furrow as it grows older. There are straight horizontal lines on the bark that look like sap-sucker damage but in this case, the markings on the poplar is the normal bark development of the poplar. They also look at and discuss Fall Web Worm cocoons which look like bird nests on a tree. Web worms do not do as much damage to the tree as over-pruning does. Park trees in their natural form (not been topped) are also featured. These include the Valley Cottonwood, the Upright Poplar and the Elm tree. They recommend that growers think about the ultimate size of the tree fitting the landscape before deciding to plant it rather than topping and "mutilating" the monster-sized tree later.