If you see these hanging from you tree, you need to know what it means


Even though their name sounds harmless, Evergreen Bagworms can cause major problems.

These creatures are not worms but rather a moth in its larval stage, and pose serious risks to both deciduous and evergreen trees – causing damage and even death if they are not removed.

Scientifically known as Thyridopteryx ephemeraeformis, Evergreen Bagworms are named so because of the unique protective casing they make around themselves, almost like a bag.

The larvae create these bags by producing a silk-like thread and using it to attach debris like twigs and leaves to their bodies. Ever so slowly, this casing grows bigger, providing the worms with camouflage and shelter.

Bagworm insects hanging on a branch of an evergreen tree. Credit / Getty.

What is the lifecycle of an Evergreen Bagworm?

The female adult begins the reproductive cycle by laying eggs inside her casing, which stays attached to the tree even after she dies. The eggs remain in the casing throughout the winter and eventually hatch in late spring or early summer, giving rise to tiny larvae. Then, using their silk-like thread to make their own bags, these larvae set out to find a suitable tree to attach to.

Although they may begin small, these bags eventually grow larger as the larvae develop and occasionally come out to gather more plant material for their casing. As the larvae advance through each stage, new bags are produced.

The larvae transform into adult moths in two weeks, with the small males flying off to look for females to mate with.

Evergreen Bagworm treatment

Evergreen bagworms may appear harmless, but they can seriously harm trees because they attack the foliage and stop the absorption of nutrients. This renders the tree frail and prone to other ailments, which can ultimately result in the tree’s death.

How then can you maintain the health of your trees while avoiding Evergreen Bagworm damage? There are a few options available to you, such as:

  1. Manually removing the bagworms by hand;
  2. Pruning the affected branches;
  3. Encouraging natural predators like birds and parasitic wasps in your garden; and
  4. Chemically controlling the infestation by using insecticides specifically formulated for bagworms.

Evergreen Bagworm infestation prevention can be accomplished by using techniques like:

  1. Regularly inspecting trees, especially during spring and summer when the larvae hatch, to detect bagworms early on;
  2. Maintaining trees by pruning and ensuring they’re receiving proper nutrients;
  3. Removing bagworms;
  4. Maintaining proper spacing between trees to reduce the risk of bagworm infestation; and
  5. Monitor neighboring trees and plants, especially because bagworms can migrate from one tree to another.

The lesson to be learned? Evergreen Bagworms can actually do a lot of damage, despite the fact that they are not particularly dangerous and don’t seem to be too obvious. Consistently check on your trees and plants, and make sure you are aware of the harm they can do.

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