Bagworms are a serious insect pest of many ornamental shrubs and trees in the eastern half of the United States. Conifers, especially arborvitae, cedar, juniper and pine, are the most frequently damaged host plants, but I’ve seen them on deciduous trees such as sycamore, maple, locust, boxelder, walnut, fruit trees and linden.
Do not get this pest confused with the fall webworm, which many local people call bagworms. Fall webworms create large silky webs in trees in the fall of the year. True bagworm caterpillars make distinctive 1½- to 2-inch-long spindle-shaped bags that can be seen hanging from twigs of a variety of trees and shrubs. Sometimes the bags are mistaken for pine cones or other plant structures.