They are not Christmas ornaments in your trees. They are bagworms. Bagworms are caterpillars that make distinctive spindle-shaped bags on a variety of trees and shrubs. During daylight, the caterpillars remain inside the cocoon/bag to avoid predators. They come out at night to feed on plant foliage. They attack both deciduous trees and evergreens, but are especially damaging to juniper, arborvitae, spruce, pine and cedar. Large populations of bagworms can strip plants of their foliage and eventually cause them to die. Infestations often go unnoticed because people mistake the protective bags for pine cones or other plant parts.
If only a few small trees or shrubs are infested, picking the bags off by hand and disposing of them may afford satisfactory control. This approach is most effective during fall, winter or early spring before the eggs have hatched. When many small bagworms are infesting evergreens, an insecticide is needed to prevent serious damage. The best time to apply an insecticide is while the larvae are still small (less than l/2-inch long). This is usually in June. Small larvae are more vulnerable to insecticides, and inflict less damage. Carefully inspect susceptible landscape plants, especially evergreens. Young bagworms are harder to see: look closely for the small, upright bags which have the appearance of tiny ice cream cones constructed of bits of plant material.
Preventive treatment is often justified on plants that were heavily infested with bagworms the previous year. When infested, it is important to get to the top of the trees when treating these caterpillars. If you need help, text or call Don Felan at 214-738-0833.