Bagworms commonly attack our Middle Tennessee evergreens (fir, hemlock, spruce, juniper and pine, among other evergreen species). Adult male bagworms are clear-winged moths with black bodies and an approximately 1-inch wingspan, while females are eyeless, legless and wingless.
Female bagworms spend their lives inside small cone-shaped bags created from silk and evergreen tree parts. After mating, the females will lay between 500 – 1,000 eggs inside the self created bag and die off. The eggs spend the winter in the bag and hatch during April & May, causing major damage to our evergreens during and throughout summer months.
Bagworm eggs hatch in late spring or early summer. The young larvae grow to around 2 inches long, build bags that they carry with them as they move around and feed on evergreen foliage. They strip evergreens of their needles, causing extensive defoliation; infestations in most cases can cause death to stressed evergreen trees.
Chemical insecticides can be applied to trees when bagworm larvae are small; older and larger worms are more difficult to kill.