Do Bagworms Turn Into Moths? – [Bagworms facts]

Unlike any other insects, bagworms are also a species of insect. Bagworms are unique since they stay above the ground till they turn into a moth. And yes, bagworms do turn into moths.

The reason why bagworms are called bagworms is that they remain inside a bag. The cocoon of a bagworm wraps around it till it fully grows into a moth and is ready to leave its house. You might think bagworms are somewhat close to butterflies since they both start from a cocoon and turn into flying insects.

In reality that is not the case. Butterflies come from a homing environment, whereas bagworms will leave destruction behind.  There will be many things to discuss and know about bagworms before you can conclude.

What are bagworms, and what do they turn into?

Bagworms or Psychidae belong to the family of Lepidoptera. The bagworm family is relatively small, with around 1350 species of bagworms found worldwide. Bagworms have a dark brown color and feed on plants to survive.

Among 128 plants, bagworms ‘ favorite plants are arborvitae, juniper, spruce, pine, and red cedar. Bagworms grow from a caterpillar and can grow up to an inch in length. Bagworms cover their body with silk, making a cocoon that protects them from predators like birds and the human eye.

Unlike most cocoons, bagworms have light brown cocoons, and by the looks of it, their cocoons can even deceive human eyes. The cocoons have a cone shape and can range between one and a half to two inches in length. By looking at the cocoons, it seems like a part of the plant.

Although bagworms might look harmless, they can be devastating for plants. The female bagworms can move along with the cocoons themselves. By doing so, females can feed on different parts of the plant and destroy the plant completely.

Female bagworms do not leave the cocoons, while the male moths that are black come to the cocoons and mate. A female bagworm can lay 1000 eggs at a time, and you can guess the damage those bagworms can infest your plants when they hatch. 

A bagworm is a caterpillar that develops under seven stages before turning into pupae and later into a moth. A fully grown is about an inch long and takes about four months before turning into a larva. Temperature is an important factor and can speed up or slow down a bagworm’s growth process. 

Bagworm Moth – Animal of the Week >> Check out the video below:

How much time do bagworms need to turn into moths?

After an egg hatches into a caterpillar and makes a cocoon, it will take about three to four weeks until the bagworm turns into a moth and takes off. The life of a bagworm begins with an egg.

A female bagworm can lay up to 500-1000 eggs at a time, and they sit inside the bag of a female bagworm. The best time for a female bagworm to lay eggs is during late summer. The eggs stay inside the bag throughout the winter and finally hatch into a caterpillar during spring.

When the egg hatches, the newly born caterpillar needs the energy to build their cocoons, so they eat a bit and quickly start to build a cocoon for themselves. They use the trees, leaves, and bushes around them to build a cocoon.

A caterpillar will eventually dangle down from a tree, and by doing so,it can move around from one part of the tree to another part. The best position for the caterpillar to be is by putting its head on top while its body stays inside the bag. It allows them to hold onto the bag with their feet and feed on the plant with their mouth.

Throughout spring and early spring, the caterpillar will feed and grow inside the bag, and by mid-spring, the caterpillar will form a cocoon inside the bag.

A cocoon is where a caterpillar stays and develops into a butterfly or moth. The cocoon of a bagworm is called pupae, and during this stage, the bagworm stays inside the pupae until it becomes a moth. It generally takes about two to four weeks, depending on the temperature. 

By late summer, bagworms inside the pupae turn into adult moths and leave their cocoons. It is when the mating season begins for the adult moths. The adult moths will fly around the tree looking for females to mate with. An adult moth will mate if possible and then die. 

Are bagworm moths harmful?

Are bagworm moths harmful?
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Although they might look like regular moths, the amount of damage that bagworms can cause to your plants is devastating. If you don’t know already, bagworms are inhabitants of plants, and they only feed on plants.

It might be sensible to think some insects survive by feeding on your lawn plants, but the damage can be greater when hundreds of bagworms feed on your plant. Bagworms threaten plants like arborvitae, juniper, spruce, pine, and red cedar since these trees are their favoritefood source.

What bagworms do is survive on the leaves and branches of a tree, similar to a leech that sucks the blood of mammals. You will notice that some part of your tree has started to die and turned brown. Those parts will look like someone has sucked out their life. The main part is that you can hardly notice bagworms when they start growing on your trees.

Bagworms cover themselves with a brown cover called bags. They can mix well with the greenery of your trees till you notice some parts of your tree are dying. Bagworms should not be taken lightly as they can spread fast and quickly take over your tree. Immediate actions must be taken when bagworms are noticed. 

What does a bagworm moth look like?

Bagworms are like any other caterpillars with dark brown and come out of their cocoons like a regular moth you see in the open. Bagworms are mainly recognized for their bag since they completely hide inside their bag. By doing so, they can be safe from predators.

Their bag is brown and green, and it blends with the color of a tree quite well. Bagworms suspend themselves vertically from the tree.

By doing so, they can stick to the tree facing upwards and feed on the tree.  The bag of a bagworm can be about 30-50 mm long, whereas an adult female can be about 16-25 mm long. The male moth is black and has transparent wings.

On the other hand, the female doesn’t have a physical appearance like a male moth. A female moth lacks wings, legs, eyes, and a mouth. 


Looking at a moth in the open doesn’t worry about it, but having them around your trees can surely make you terrified. Moths are harmless and do not cause any threat to human beings, but they are the exact opposite of plants.

One of the main reasons for a dying plant could be pest problems such as bagworms. The damage can be optimal if dealt with early on. Even if bagworms take your tree, it is still possible for your tree to come back to life. If things go out of control, you can always seek professional assistance. 

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