Bagworm Control: How to Identify, Prevent, and Get Rid of Bagworms

Bagworms are caterpillar pests with spindle-shaped bags. They usually have a length of 1.5 to 2 inches and looks like pine cones. Their appearance will vary depending on their gender. Adult male bagworms are black and they have clear wings. Adult female bagworms, on the other hand, are white and wingless. One thing that makes the female different is that they remain in their pupation sack all throughout their life, which is also where they lay their eggs.

This perennial insect comes with a silken bag around its body, which is where it got its name. There are three common types: evergreen bagworm, snailcase bagworm, and grass bagworm. Between the three, only evergreen and grass bagworms are the ones that produce male moths with the ability to fly. The species differ in terms of the appearance of the bag that they create.

Bagworm’s Habitat

Bagworms are common in the United States, specifically in the east of the Mississippi River. New England, Nebraska, and Southern Texas are some of the places where they usually thrive. They usually feed on the leaves and needles of the plants. When they are younger, they feed on the plant’s upper epidermis.

Adult Male Bagworms on Wood

An adult male bagworm

In one bag, there are up to 1,000 eggs and they hatch only once in a year. The hatching usually takes place in May or the first weeks of June. They do not immediately cause damage to the plant, unless they are mature enough. They usually reach maturity by mid-August. This is where they move to other plants and live there. The male species, on the other hand, often appear in September.

Identifying Bagworm Damage 

Plants Affected

In terms of plants, on the other hand, they live in juniper, spruce, cypress, apple, birch, elm, oak, sycamore, willow, and pines, among others. For six weeks, bagworms feed, which causes their bag to grow larger. The infestation hat it brings will depend on the concentration of the worms, as well as the type of the plant where it is present.


Early detection is perhaps the most important to determine the presence of bagworms, and consequently, identify the best control and elimination measures. With this, here are some of the symptoms of bagworm infestation:

  • The presence of a cone-shaped bag is perhaps the most obvious symptom. They look pretty on a tree. Some people might think that they are simply pine cones and they also resemble the appearance of ornaments in a Christmas tree. In reality, inside those bags, there are already worms that can wreak havoc if you fail to deal with them as soon as possible.
  • Several parts of the tree will end up dying because of the infestation of bagworms, especially the barks. They will end up being dry or brittle. The appearance of unusual stains is also an indication of the presence of bagworms. It will girdle around the branch, although it will probably take a couple of years before the branch completely dies.
  • You will also quickly notice that some parts of the shrubs or trees are suffering from defoliation. 

Results of Infestation

When there is a heavy infestation, the tree at which bagworms feed will end up suffering from defoliation. Unfortunately, in most cases, it is too late before the results will be evident. With severe damages, the plant will not only look unsightly because of the lack of leaves, but it will also eventually die. In the case of deciduous trees, it is a good thing that they can re-foliate even after severe infestation.

Pine Tree Infected with Bagworm

Pine tree infected with bagworms

How to Get Rid of Bagworms 

Organic and Natural Solutions 

If you are looking for the safest and effective ways to get rid of bagworms, the following are some solutions that can yield significant benefits:

  • Manually remove the nests of the bags from the tree. This is an easy task since the bags are large and easily noticeable. Do this before the eggs hatch. Otherwise, it will be too late. Proper disposal of the bags is also necessary to have an assurance that the bagworms will not spread around the area.
  • Spraying an insecticide is another solution that works. The good news is that there are products containing natural ingredients, and hence, you do not have to worry about their hazards. A perfect example of this is a spray that contains bacillus thuringiensis. It is effective for younger bagworms. It is best to use the spray from May until the first week of July.
  • Another good way to get rid of bagworms is to attract natural predators and enemies. It is good to plant daisy and other plants from the aster family near trees where bagworm infestation is common. They will not only add color to your place, but they will also attract birds and wasps that help to kill bagworms.
  • Using a pheromone trap is also a common solution. This is an insect trap that comes with a sex hormone, which will be effective in luring bagworms. By trapping the male bagworms, they won’t be able to escape, and hence, will not be able to breed.

Chemical Solutions

While chemical solutions are promising in terms of their effectiveness, keep in mind that they contain toxic ingredients. They are harmful to both humans and the environment. It is important to pay attention to its proper application to achieve the best outcomes.

Malathion and carbaryl are some of the active ingredients in insecticides that kill caterpillars and worms. You do not need to spray them on the plant, but the problem is that they are unsafe. These solutions, however, will only work best when the bagworms are still young. 

How to Prevent Bagworms

Early detection is one of the best ways to prevent heavy infestation from bagworms. Take note of the physical characteristics so that you will know if they are already present. Look at the symptoms as well. If you are sure that there are bagworms, do not hesitate to try any of the solutions mentioned earlier. Do this as soon as possible.

Keeping the area clean also helps. When the egg sacks fall, it does not mean that they will no longer cause damage to the tree. Also, do not throw it in the compost as this is an attractive place for the larvae. It is best to keep them in a bag with seal and dispose of it.

Remove any portion of the plant that is already dead. This will prevent the problem from spreading to the healthy parts of the plant.


  1. Brenda Poage August 3, 2019
    • Homyden August 3, 2019

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