Cottony Maple Scale
Cottony maple scale invaded our city in large numbers during the summer of 2006. It predominantly affects Linden and Maple trees but can affect other species as well.
The pest is most recognizable when the egg sac hatches and a sticky, cottony growth is found on the underside of small branches. The larvae hatch and then begin feeding on the underside of a leaf.
As a whole, this pest is a minor concern. Pruning out branches that are heavily infected, watering the tree during drought periods, reducing grass competition (installing woodchip mulch), and avoiding trunk injuries will help the tree cope.
Most trees do not die from this pest. If they do, there was probably something else affecting the tree that led to its decline.