How to identify and get rid of bagworms

Are your backyard trees adding their own early Christmas ornaments this year? No, that’s the handy work of bagworms.

Bagworms aren’t really worms. They are moths that use silk and materials around them to form these cozy homes that they carry with them on branches of trees and shrubs. The caterpillar will live its life tucked inside the bag, camouflaged in its natural surroundings. That way, predators won’t know there’s a tasty snack inside. The bag will have an opening on one end, where the caterpillar can poke its head out to eat.

As the caterpillar grows, so does the bag! Once the caterpillar is ready to transform into a moth, it will seal up the bag and suspend it from the branch. Males will emerge, flying away to look for females. The females, however, remain in the bag. Her wings are underdeveloped and not capable of flying. She will mate and develop eggs inside her. She then dies and the caterpillars hatch inside the bag (along with their decomposing mother) and will set out in search of foliage and make their own cases.

Bagworms can become a problem for certain landscape trees, such as cedars, junipers, and spruces. Overall, they don’t cause too much harm, but if there are too many on a tree, they can defoliate it and weaken it.

Bagworms are best identified by their camouflaged bags. Often, they are difficult to spot until they start to pupate when they dangle from the branches. You can also tell by how the trees may be more defoliated or sad-looking. They often start at the tops of trees, so look for a bronze coloration at the very top of pines, cedars, and evergreen trees.

How big are bagworms?

Bagworms can grow up to 2 inches long.

What other pests look like a bagworm?

Bagworms are unique in their appearance, and you are more likely to mistake them for pinecones than other pests. You could mix up the name with webworms that make big silky webs all over trees.

Bagworms are found throughout the eastern United States, from Nebraska to Texas and eastward.

You'll find bagworms hanging out on the trees and shrubs in your yard. They're usually found outside the house since they prefer to stay in trees.

There’s no real silver bullet when it comes to bagworm control. Once the caterpillars are in their bags, pesticides, insecticidal soaps, or oils aren’t as effective.

The best thing to do is hand-pick the bags and drop them in soapy water. You can also prune off infested branches to quickly clean them up.