If you have arborvitae, junipers, Leyland cypress, cedar, spruce, or other evergreen trees on your property, now is the time to inspect them for bagworms.
Bagworms are currently hatching and beginning their feeding cycle throughout East Tennessee and much of the eastern United States. The small caterpillars emerge from eggs that spent the winter inside last year's bags and immediately begin feeding on tree foliage while constructing their own protective bags. Early June is considered the most effective treatment window because young bagworms are highly susceptible to control measures before their protective bags become larger and more resistant to treatment.
What Do Bagworms Look Like?
Young bagworms create tiny cone-shaped bags made from silk and pieces of the host plant. As they grow, these bags become larger and more noticeable, eventually reaching 1–2 inches in length. The bags often resemble small pinecones or dead foliage hanging from branches, making infestations easy to overlook until significant damage has occurred.
Why Are Bagworms Dangerous?
Bagworms feed aggressively on evergreen foliage throughout the summer. While deciduous trees can often recover from defoliation, evergreens such as arborvitae and junipers cannot replace lost foliage as easily. Heavy infestations can cause permanent branch damage, thinning canopies, and even tree death if left untreated.
Signs You May Have Bagworms
- Small hanging bags attached to branches
- Browning or thinning foliage
- Dead spots developing in evergreens
- Increased visibility through dense shrubs
- Bags attached to fences, gutters, and nearby structures
Bagworms can also spread by "ballooning," where newly hatched larvae ride silk strands to neighboring trees and shrubs.
The Best Time to Treat Is Right Now
Treatment is most effective when bagworms are young and actively feeding. Once the bags become larger later in the summer, control becomes significantly more difficult because the insects are protected inside their cases. Many extension services recommend monitoring and treating during late May and June for the highest success rates.
Don't Wait Until Damage Is Visible
By the time most homeowners notice bagworms, substantial feeding damage has already occurred. Early detection and treatment can save valuable landscape trees and prevent costly removals or replacements.
If you notice suspicious bags hanging from your evergreens, have your trees inspected as soon as possible. Catching bagworms early can mean the difference between a simple treatment and the loss of an otherwise healthy tree.
Schedule a Bagworm Inspection
The team at Monster Tree Service of Knoxville is currently monitoring and treating active bagworm infestations throughout the area. If you're concerned about your arborvitae, junipers, cypress, or other evergreens, contact us today for a professional inspection and treatment recommendation before damage becomes severe.