Where Do Bagworms Come From? Unraveling The Origins of These Pests

Bagworms are caterpillar pests known for the unique protective cases they construct around themselves. 

These cases, often referred to as “bags,” are made using silk and materials from the plants they feed on. 

At a glance, these bags can resemble small pinecones or clusters of pine needles, making them easily mistaken for natural parts of the trees or shrubs they inhabit. 

Inside these bags, one might find the developing larvae, eggs, or even the adult female bagworms preparing for the next generation. 

Where Do Bagworms Come From
Bagworm Cocoon

As the larval form of the bagworm moth, these creatures play a significant role in their life cycle, transitioning from feeding larvae to reproductive adults.

In this article, let’s understand where these bagworms come from and how they can be a pest in your garden and home.

What Are Bagworms?

Bagworms are the larval stage of the bagworm moth, a species that has evolved a unique method of protection during its developmental phase

These larvae create and reside within bags, which serve both as a shield against predators and as a means of camouflage within their environment. 

These bags are meticulously crafted using silk produced by the larvae, combined with bits of leaves, needles, and other plant materials from their host plants.

While the term “bagworm” might suggest a worm-like creature, it’s essential to understand that these are, in fact, caterpillars

As they mature, they undergo a transformation within these bags. 

Male bagworms eventually metamorphose into winged moths, leaving their bags to seek out females for mating. 

In contrast, female bagworms remain wingless and largely resemble their larval form throughout their lives. 

They stay within their bags, laying their eggs inside, which will hatch into the next generation of bagworms.

Where Do Bagworms Come From? Origin and Distribution

Bagworms, particularly the North American bagworm, have a widespread presence throughout the continental U.S. and southern Canada. 

This species has counterparts that extend their range into Central and South America, reaching as far south as Argentina.

Bagworm

Where Do Plaster Bagworms Come From? – Origin and Distinguishing Features

Plaster bagworms are a species of moth known as Phereoeca Uterella. Their larvae form casings, which they live inside during their vulnerable period. 

These casings are around half an inch in length and feature slits at both ends, allowing the larvae to move in and out. 

The most distinguishing characteristic of plaster bagworms is their bag, which looks like a small cocoon. 

This bag, resembling a watermelon or pumpkin seed in shape, is made up of silk fiber and other organic materials, such as lint, sand, or dry plaster debris. 

The cocoon’s color is light gray and hangs discreetly on walls. Inside this protective casing, the larva, primarily white with a brown head, resides. 

These pests are especially prevalent in humid environments, such as the Southeastern United States, with a significant presence in Florida.

Bagworm Life Cycle

Bagworms begin their life cycle with eggs laid by the female inside the protective bag. 

This bag serves as a safeguard, shielding the eggs from cold temperatures throughout the late fall and winter months. 

Depending on the location, these eggs typically hatch in the spring to early summer.

Feeding Habits 

After hatching, the young caterpillars venture out to feed on the needles and leaves of their host tree. 

Contrary to what one might assume, bagworms are not stationary creatures. 

Young worms can transport their bags with them, moving around in search of food. 

This mobility allows them to feed on various parts of the host plant, causing potential defoliation and other damage.

As the seasons progress, bagworms transition into the pupal stage by fall. During this phase, they transform into adults. 

Female adults, being wingless, remain in their bags, while males leave their bags to locate females for mating. 

Post-mating, the female lays over 300 eggs inside her bag, which will endure the winter and hatch the following spring, completing the life cycle.

Female Bagworm Moth

Habitats and Host Plants

Bagworms have a preference for certain trees and plants, which serve as their primary habitats. 

These insects are known to reside in a variety of trees such as willow, spruce, maple, oak, and pine. 

Among these, arborvitae and juniper trees are their favorites. However, bagworms are adaptable creatures. 

In the absence of their preferred trees, they can settle in decorative shrubs that provide a suitable food source.

Do Bagworms Come From the Ground?

A common misconception is that bagworms originate from the ground. In reality, bagworms do not come from the soil. 

Instead, they begin their life cycle in the protective bags, usually attached to host trees or plants. 

These bags shield the eggs during the colder months, and once hatched, the larvae feed on the foliage of their host plant. 

The bags can sometimes be found on the exteriors of structures or other locations, but this is typically the result of caterpillars moving their bags to pupate rather than an indication of ground origin.

Signs of Bagworm Presence in Residential Areas

One of the most evident signs of bagworm presence in residential areas is the distinctive bag they create. 

These bags can be easily spotted hanging from tree branches or leaves. 

At first glance, a bagworm’s bag might resemble a small pine cone or a collection of pine needles stuck together. 

When freshly constructed, these bags can range in color from green to light brown. 

However, as they age, especially throughout the winter months, they fade to a grayish-brown hue. 

If you notice a tree or shrub appearing as though it’s losing its foliage, it’s essential to inspect it closely to determine if bagworms are the cause.

Why Certain Trees and Bushes Are More Susceptible

Bagworms are not random in their choice of habitat. They specifically look for places that can also serve as food sources for themselves and their offspring. 

While they can survive on a variety of trees, they have a particular preference for conifers. 

The reason for this preference is that conifers do not produce a new crop of foliage every year, making them more vulnerable to the damage caused by bagworms. 

Trees like evergreens, which retain their leaves or needles throughout the winter, are at a higher risk of severe damage or even death due to defoliation by bagworms. 

On the other hand, deciduous trees can often survive a bagworm infestation, but it’s always better to address the issue before it escalates.

How Do You Prevent Bagworms?

Preventing bagworms involves a combination of regular monitoring, physical removal, and, if necessary, the use of specific treatments. Here are some steps to prevent bagworm infestations:

  • Regular Inspection: Regularly inspect trees and shrubs, especially those known to be preferred by bagworms such as juniper, arborvitae, spruce, and pine. Early detection is crucial to managing and preventing a full-blown infestation.
  • Physical Removal: If you spot bagworm bags on your trees or shrubs, especially during the winter months, physically remove them. This is effective because each bag can contain hundreds of eggs that will hatch the following spring. Use scissors or shears to snip off the bags and place them in a bucket of soapy water to kill the larvae, or seal them in a plastic bag and dispose of them.
  • Biological Control: Introduce natural predators like birds and beneficial insects that feed on bagworms. For instance, certain parasitic wasps can help control bagworm populations.
  • Biorational Insecticides: If you detect an infestation early, typically in May or June, you can use biorational insecticides like Bt (Bacillus thuringiensis), neem, or Spinosad. These are especially effective on younger bagworms.
  • Chemical Control: For more severe infestations or when bagworms are discovered later in the season, consider using synthetic insecticides like bifenthrin, sevin or carbaryl. However, always use chemical controls as a last resort and follow label directions carefully. It’s also essential to note that while these insecticides can reduce the number of bagworms, they might not eliminate the population entirely.
  • Maintain Tree Health: Healthy trees are more resilient to pests, including bagworms. Ensure your trees are well-watered, appropriately pruned, and receive the necessary nutrients.
  • Consult with Experts: If you’re unsure about the presence or severity of a bagworm infestation, consult with a local extension service or a professional arborist. They can provide guidance tailored to your specific situation.
  • Educate and Collaborate: Share information about bagworm prevention with neighbors. Collaborative efforts can be more effective in preventing the spread of bagworms across a larger area.

Remember, the key to preventing bagworms is early detection and intervention. Regularly inspecting your trees and shrubs and taking prompt action can help keep these pests at bay.

Health and Environmental Implications

Bagworms, despite their potential to cause significant damage to trees and shrubs, are not harmful to humans or animals. 

If you happen to come into contact with a bagworm or its bag, there’s no cause for concern; they won’t harm you or cause any sickness. 

However, it’s essential to note that while the bagworms themselves are harmless, the pesticides often used to treat bagworm-infested trees can be toxic. 

These pesticides can pose risks to humans, animals, and even beneficial insects if not used correctly. 

Therefore, while addressing a bagworm infestation, it’s crucial to be cautious and informed about the chemicals being used.

Frequently Asked Questions

How harmful are bagworms?

Bagworms are harmful primarily to trees and shrubs, causing defoliation which can lead to plant death, especially in evergreens. It’s advisable to manage bagworms to protect your plants. To get rid of bagworms, physically remove their bags from plants, drown them in soapy water, or use specific insecticides, ensuring early detection for effective control.

Should I kill bagworms?

Yes, if bagworms are infesting your plants, it’s advisable to manage and control them. Left unchecked, they can cause significant defoliation and potentially kill plants, especially evergreens. Early intervention can prevent extensive damage to your landscape.

How do I get rid of bagworms?

To get rid of bagworms, manually remove the bags from trees and drown them in soapy water. If infestations are caught early, use biorational insecticides like Bt (Bacillus thuringiensis), neem, or Spinosad. For older bagworms, synthetic insecticides like bifenthrin or carbaryl may be effective. Always consult with a pest control expert for severe infestations and follow label directions for any pesticide.

Conclusion

Bagworms, the larval form of the bagworm moth, are fascinating creatures with a unique life cycle. 

Originating primarily from North America, they have spread to various parts of the world, with their distinctive bags serving as a protective home during their larval stage. 

These bags, made from silk and materials from their host plants, are a clear sign of their presence in residential areas. 

While they prefer certain trees, especially conifers, they are adaptable and can infest a range of trees and shrubs. 

Though harmless to humans and animals, their potential to damage trees makes it essential to manage and control their populations effectively.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Bagworm from South Africa

 

Hi,
My dad just sent me this photo, he lives is Johannburg, south africa. We have never seen anything like it. Could it be the bagworm?
Thank you
Tracey



Hi Tracey,
We agree that this is a Bagworm.

Letter 2 – Bagworm Moth from New Zealand

 

Subject: Found a pair of these, metallic blue with orange and black Location: New Zealand March 12, 2013 6:57 pm Hi we found two of these on our deck, it’s summer over here at the moment. The bug looks like a form of ladybug with black and orange wings, and possibly a set of metallic blue wings over the top? The antenna has white tips, and the legs look black, The abdomen is the part that makes me think it’s not a ladybug…. We have never seen one before, and wondering what they are Thanks heaps Signature: Gizmo_RA2
Moth, We believe
Female Bagworm Moth
Dear Gizmo_RA2, We believe this is a moth and that its wings haven’t fully expanded, but we have been unable to find a matching image online.  Perhaps one of our readers will have better luck than we had. Chad provides an identification:  Bagworm Moth Chad provided this link to a Bagworm Moth, Cebysa leucotelus.  According to the Landcare Research Manaaki Whenua website:  “Caterpillar forms an untidy bag to live in Found on rock walls and houses. Feeds on minute algae and lichen Adult female is often mistaken for a beetle. Adult female can fly, but only in short hops Male is fully winged”

Letter 3 – Flightless Bagworm Moth from New Zealand

 

Subject: “Australian” Bagworm Moth Location: Epsom, Auckland March 14, 2014 2:54 pm Never seen one before but I spotted and I think correctly identified an Australian Bag Moth yesterday 14 March 2014 in Epsom, Auckland Signature: Lindsay
Bagworm Moth
Female Bagworm Moth
Dear Lindsay, Thanks for submitting your photo of a flightless, female Bagworm Moth, Cebysa leucotelus.  According to Nature Watch:  “It is found in New Zealand and the southern half of Australia (Tasmania, Victoria and Western Australia).  The adult female moth has black wings with yellow wingtips and patches, but they do not expand properly, so she is not able to fly. The male has a similar pattern and colouring, but has no iridescence. His wings are fully developed and adult males can fly normally.  The larvae feed on lichen.”

Letter 4 – Flightless Female Bagworm Moth from Australia

 

Subject: BUG Location: SYDNEY AUSTRALIA October 19, 2013 2:11 pm I PHOTOGRAPHED THIS INSECT IN MY BACKYARD LAST SUMMER. CAN YOU PLEASE IDENTIFY THIS STRANGE AND BEAUTIFUL INSECT. I HAVE SEARCHED MANY SITES WITH NO RESULTS. ITS ONLY SMALL NO MORE THEN 2CM HAS SMALL COLORFUL WINGS AND APPEARS FLIGHTLESS ONLY CRAWLS AND HOPS. I HOPE YOU RECEIVE MY FILES Signature: WHAT BUG IS IT
Female Bagworm Moth
Female Bagworm Moth
This is a flightless female Bagworm Moth, Cebysa leucotelus.  Your photos are excellent.  You can find additional information on Butterfly House.  We will be postdating your submission to go live in early November while we are out of the office. 
Female Bagworm Moth
Female Bagworm Moth

Letter 5 – Bagworm from the Philippines

 

Subject: What kind of bug is this? Location: Cebu, Philippines July 17, 2015 6:01 am I don’t know what this bug is and I’m dying to find out. My curiosity is killing me. It’s a very tiny bug supporting a huge shell of some kind of wood shavings , if you will. Hoping for an answer!! Signature: What
Bagworm
Bagworm
This is a Bagworm, the caterpillar of a moth in the family Psychidae.  Bagworms construct shelters from bits of plant that act as camouflage as well as protection.

Letter 6 – Bagworm from Singapore

 

Subject: Bug Location: Singapore August 24, 2012 1:07 am Dear Sir, I live in Singapore, and I found this but that look as carry pieces of wood on his back the size is +- 2-3cm crawling on the wall but have king of string connect as a spider. I gave him a name Xpus just sound cool 🙂 thanks in advance. Frank Signature: Bug
Bagworm
Hi Frank, This is a Bagworm in the family Psychidae.  We located an Ecological Observations in Singapore Blog posting of Bagworms that has one image that somewhat resembles the head of your Bagworm.  We cannot be sure they are the same species.  Bagworms construct their bags from pieces of the plants they feed upon.  The bags act as camouflage and protection.

Letter 7 – Flightless Female Bagworm Moth from Australia

 

What’s this funny insect? Location: Sydney, Australia April 13, 2011 7:03 am This creature was on the wall the other day. I have never seen anything like it. Any idea what it is? Is it dangerous? The spike on the back looks a bit scary! Signature: Carey
Bagworm Moth
Dear Carey, Just a few days ago, we had another identification request for this flightless female moth from Australia, and it was identified as a Bagworm Moth, Cebysa leucotelus.  Only the females are flightless.  We suspect that is an ovipositor protruding from her abdomen.
Female Bagworm Moth
Dear Daniel, Thank you for that! I hope she laid her eggs outside first. Carey

Letter 8 – Bagworm from Greece

 

Subject:  Bug that carries its home with it Geographic location of the bug:  Larisa, Greece Date: 04/04/2018 Time: 07:56 AM EDT Your letter to the bugman:  I find this one bug occasionally in my garden and I believe its always the same one I see (I’ve never spotted two or more together). It doesn’t seem harmful but I’m scared to touch it and I don’t want to bother it. It always carries something on its back as you can see in the photo. Sometimes I find it immobile with it being entirely inside the thing on its back. It has six legs from what I can see. I’d really like to identify it. How you want your letter signed:  EntomologistWannaBe
Bagworm
Dear EntomologistWannaBe, This is a Bagworm, the caterpillar of a moth in the family Psychidae.  We located a beautiful poster on Etsy with images of the Hairy Sweep, Canephora unicolor/Canephora hirsuta, which is described as “a moth of the family Psychidae. It is found in Europe. The female has no wings. The wingspan of the male is 20–25 mm. The moth flies in one generation from May to July. The larvae feed on shrubs, deciduous trees and herbaceous plants.”  There are also images on Papillon en Macro, Project Noah and BioLib.  Bagworms construct a bag from bits of plants that they drag around and use for protection, eventually pupating inside the bag. 

Letter 9 – Mystery Caterpillar from Costa Rica similar to Bagworm

 

mysterious large cocoon with a caterpillar inside. April 5, 2010 I found him on the ground in my yard in Costa Rica. I brought it inside to hatch, but he just comes partially out to eat and poops round pellets out of the bottom, and spends most of his time inside. I have had him for about 5 days now. He has moved about to different locations, until i found a place he likes with leaves he likes to eat. He attached himself to a branch i provided with a small silk thread, and has remained there. Is it normal for a caterpillar to continue to eat after spinning a cocoon, or is this his protective living space? Will it eventually pupate? Jan Betts Costa Rica, Central America 3000 feet altitude.
Bagworm

Read more

What Eats Bagworms? Tips and Tricks To Manage These Pests

Bagworms, scientifically known as Thyridopteryx ephemeraeformis, are a common pest that many North American gardeners are unfortunately familiar with. 

These unique insects are easily identified by their spindle-shaped cocoons, which they meticulously craft using silk and materials from their host plants, such as leaves or needles. 

These cocoons not only serve as a protective shield but also camouflage the bagworms, allowing them to blend seamlessly into their environment.

The significance of bagworms extends beyond their intriguing appearance.

In North American gardens, particularly in the eastern regions, they pose a considerable threat to a variety of trees and shrubs.

What Eats Bagworms
bagworm

While they might seem harmless at first glance, bagworms are voracious eaters. 

They feed on the foliage of over 100 different species, including many that are commonly found in gardens and landscapes, such as arborvitae, juniper, and pine. 

When left unchecked, these pests can defoliate and severely weaken plants, leading to long-term damage or even the death of the host plant. 

Given their potential for destruction, understanding and managing bagworm populations is crucial for maintaining healthy and vibrant gardens.

In this article, we will look at one of the most ecologically friendly ways of managing bagworms – by introducing natural predators of these pests. We will also look at other ways of doing this.

Life Cycle and Identification of Bagworms

Bagworms have a fascinating and distinct life cycle that sets them apart from many other garden pests.

Lifecycle Stages: From Egg to Adult

  • Egg: The lifecycle of a bagworm begins inside the protective bag, where the female lays between 500 to 1000 eggs. These eggs overwinter inside the bag, awaiting the warmth of spring to hatch.
  • Larva: As spring arrives, usually around May and June, the eggs hatch, releasing tiny caterpillars. These larvae immediately begin constructing their own protective bags using materials from their host plants. As they feed and grow, they drag these bags along, enlargening them to accommodate their increasing size.
  • Pupa: By mid-August, having reached about an inch in length, the bagworm enters the pupal stage. The larva attaches its bag to a branch, seals itself inside, and begins its transformation.
  • Adult: By mid-September, the transformation is complete. Male bagworms emerge as black, furry moths with transparent wings that span about an inch. Their primary purpose is to find a female and mate. Interestingly, the female bagworms undergo a different transformation. They evolve into a maggot-like, soft-bodied worm that remains inside the bag, awaiting a male to mate with her through an opening in the bag.
Bagworm Moth

Physical Appearance: Cocoon Bags, Camouflage Techniques, and Adult Forms

Cocoon Bags: The most distinguishing feature of bagworms is their cocoon-like bags. 

These bags, often mistaken for pine cones or other tree debris, are constructed from silk and pieces of the host plant. 

This not only provides protection but also acts as a brilliant camouflage against predators.

Bagworms can be found inside the house as well.

Camouflage Techniques: The art of camouflage is vital for the bagworm’s survival. 

By using materials from their immediate environment, they blend seamlessly, making them hard to spot. 

This is especially true for the younger larvae, whose bags are smaller and even more inconspicuous.

Adult Forms: While the bags of the larvae are often the most noticed, the adult forms are less commonly seen. 

The male moths, with their black furry bodies and transparent wings, are the more mobile of the two sexes, flying in search of females. 

In contrast, the female remains stationary, never leaving the bag she constructed during her larval stage.

Preferred Habitats 

Bagworms are not particularly picky when it comes to their habitat, but they do have preferences. 

Evergreen trees are especially susceptible to bagworm infestations. 

Arborvitae, junipers, and cedars often bear the brunt of their appetite. However, they are also known to infest deciduous trees, expanding their potential habitats and food sources. 

The choice of host plant plays a significant role in the materials the bagworms use for their bags, influencing their appearance and camouflage techniques.

Damage Caused by Bagworms

While they are not directly harmful to humans, bagworms can be a significant menace to various trees and plants. 

Their insatiable appetite, if left unchecked, can lead to severe consequences for the affected vegetation.

Types of Trees and Plants Affected

Bagworms are not particularly selective eaters, but they do have their favorites. They are known to feed on the foliage of over 100 different species. Some of their preferred hosts include:

  • Evergreen trees such as arborvitae, juniper, cedar, and pine.
  • Deciduous trees like maple, oak, sycamore, and poplar.
  • Other plants including spruce, fir, sweetgum, black locust, honey locust, and more.

Detecting an Infestation

Detecting a bagworm infestation early can be the key to managing and mitigating the damage. Some signs to look out for include:

  • Bag-like Cocoons: One of the most evident signs of a bagworm infestation is the presence of their distinctive bags. These can often be seen hanging from the branches of trees and shrubs, resembling small pine cones or other tree debris.
  • Defoliation: As bagworms feed, they strip trees and plants of their foliage. An affected tree might display patchy, uneven defoliation or entirely bare branches.
  • Brown or Dying Branch Tips: Especially in evergreen trees, the tips of branches may turn brown and eventually die due to the feeding activity of bagworms.

Long-term Impact on Trees and Shrubs

The damage caused by bagworms can range from mild to severe, depending on the extent of the infestation.

  • Weakening of Plants: Continuous feeding can weaken trees and shrubs, making them more susceptible to diseases and other pests.
  • Death of Trees: In severe cases, especially with evergreen trees, bagworms can consume so much of the foliage that the tree cannot recover. If they eat more than 70% of an evergreen tree, it can lead to the tree’s death.
  • Aesthetic Damage: Even if the tree or shrub survives, the aesthetic damage can be long-lasting. Trees can appear patchy, and their growth can be stunted.
  • Impact on Deciduous Trees: While deciduous trees can also be affected, they often have a better chance of recovery. Even if defoliated, they can produce new leaves in the following growth season.
Bagworm

What Eats Bagworms? Natural Predators of Bagworms

Nature has its own checks and balances, and when it comes to bagworms, several natural predators play a crucial role in controlling their population. 

These predators not only help in reducing the number of bagworms but also provide an eco-friendly alternative to chemical control methods.

Birds

Several bird species are known to feed on bagworms, playing a significant role in keeping their numbers in check.

  • Sparrows: These common birds are known to be effective predators of bagworms. Making landscapes bird-friendly, especially for sparrows, can help in reducing bagworm populations.
  • Finches: Recognizable by their yellow breasts, finches consume various insects, including bagworms, especially during specific periods of the year.
  • Chickadees: These birds have a varied diet that includes berries, seeds, and insects. They are particularly fond of bagworms and can help control their population.
  • Nuthatches: During winter, nuthatches feed on insect eggs, including those of bagworms. They can be particularly effective in reducing the next generation of bagworms.
  • Titmice: These birds are natural predators of various insects, including bagworms. They feed on insects primarily during the summer months, helping control bagworm populations.

Insects

Certain insects are natural enemies of bagworms and can be effective in controlling their population.

Predatory Wasps: These tiny insects, such as Chirotic thyridopteryx and Itoplectis conquisitor, belong to a group of insects known as predatory wasps. 

They do not sting humans and are known to parasitize other insects, including bagworms. 

Planting members of the aster family can attract these wasps, which lay their eggs inside bagworms, effectively controlling their population.

Assassin Bugs: These bugs have a unique ability to attack bagworms. 

Their long, pointy mouthpart, known as the rostrum, allows them to pierce the protective cocoon of the bagworm and feed on the larva inside.

Bagworm Cocoon

Planting Strategies to Attract Predators

To encourage the presence of these natural predators, certain planting strategies can be adopted.

  • Nectar-producing Plants: Planting a strip of long-blooming, nectar-rich perennials, such as Agastache or Pycnanthemum, can attract beneficial predatory wasps.
  • Mixed Buffers: Incorporating a mix of deciduous trees and broadleaf evergreens in your landscape can provide food and shelter for birds, especially those that nest in June. This encourages predation of bagworm larvae when they are most vulnerable.
  • Bird-friendly Landscapes: Ensuring that your landscape is bird-friendly by providing nesting materials, bird baths, and feeders can attract birds that feed on bagworms.

Alternative Control and Management Methods

While natural predators play a significant role in controlling bagworm populations, there are times when additional intervention may be necessary. 

Here’s a look at some alternative methods for managing and controlling bagworm infestations:

Manual Removal

One of the most straightforward and organic methods to control bagworms is manual removal.

Especially effective for smaller trees and shrubs, this method involves physically removing the bagworm’s bags from the tree and destroying them. 

This approach is most effective from late fall to spring when the bags contain eggs, ensuring the removal of future generations.

Chemical Controls

Chemical interventions can be effective but should be used judiciously to minimize harm to the environment and beneficial insects.

Bt (Bacillus thuringiensis): Bt is a naturally occurring soil bacterium that specifically targets bagworm caterpillars. 

When ingested, it causes the caterpillars to become sick, cease feeding, and eventually die. 

The best time to apply Bt is during the hatching period of young worms, typically in late May or early June. 

Bagworms

Synthetic Pesticides: Chemicals such as acephate (Orthene), cyfluthrin, sevin, and spinosad can be used to control bagworms. 

While they can be effective, they also come with environmental considerations. These chemicals are toxic to bees and other beneficial insects. 

If using synthetic pesticides, it’s essential to apply them on calm, dry days to minimize drift and ensure rapid drying.

Strategies for Prevention

Prevention is always better than cure. Adopting certain strategies can help prevent or reduce bagworm infestations.

Planting Less Susceptible Trees and Shrubs: While bagworms can feed on a wide variety of trees, certain species are less prone to infestation. 

Broadleaf evergreens and deciduous trees, for instance, show much less damage compared to needle evergreens.

Encouraging Bird Activity: Birds are natural predators of bagworms. 

By setting up birdfeeders and creating bird-friendly landscapes, you can attract birds like chickadees, nuthatches, and titmice, which feed on bagworms.

Importance of Monitoring

Regular monitoring is crucial for early detection and effective management of bagworm infestations.

IPM (Integrated Pest Management): IPM is a holistic approach to pest control that combines various strategies and practices to manage pests effectively and in an environmentally friendly manner. 

It emphasizes understanding the life cycle of the pest and its interaction with the environment.

PHC (Plant Health Care) Program: PHC is a proactive approach that focuses on maintaining and improving the health of plants, making them less susceptible to pests and diseases. 

Regular monitoring, proper fertilization, and appropriate watering are some of the components of a PHC program.

In conclusion, while bagworms can be a challenge, a combination of natural predators, manual removal, chemical controls, and preventive strategies can effectively manage and control their populations. 

Regular monitoring and a proactive approach are key to ensuring the health and beauty of your landscape.

Conclusion

Bagworms, while small, can pose a significant threat to the health and aesthetics of our landscapes. 

However, nature itself offers some of the most effective solutions to this challenge. 

Natural predators, such as specific bird species and insects, play a pivotal role in keeping bagworm populations in check. 

Their presence not only reduces the need for chemical interventions but also contributes to a balanced and thriving ecosystem.

Early detection and timely intervention are crucial in managing bagworm infestations. 

By regularly monitoring our plants and being observant of the early signs of infestation, we can take proactive measures before the situation escalates. 

This not only saves our plants but also reduces the need for aggressive control methods.

It’s also important to prioritize environmentally-friendly control methods. 

Whether it’s manual removal, using targeted organic treatments, or fostering habitats for natural predators, these methods ensure that we address the problem without causing undue harm to the environment.

The battle against bagworms is not just about protecting our plants but also about preserving the delicate balance of our ecosystem. 

By leaning on nature’s own mechanisms and adopting sustainable practices, we can ensure a green, healthy, and harmonious landscape for generations to come.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Large Bagworm or Saunder's Case Moth from Australia

 

Stick-shelled beetlepillar Location: Australia (Sydney Basin) April 2, 2011 10:50 pm My daughter found this wandering around my backyard. I’ve seen these before but always assumed they were a cocoon, rather than a sort of shell. This one has been around the backyard for at least a month as I have seen it hanging from trees, then mysteriously vanishing. I also have video of it checking out the camera Signature: Carey
Large Bagworm
Hi Carey, This is a Bagworm in the family Psychidae, and we quickly identified it as a Large Bagworm or Saunder’s Case Moth, Metura elongatus, on the Brisbane Insect Website.  The caterpillar forms a silken case containing plant material from its food plant that it remains in, eventually pupating inside of the case.  The adult female is wingless and she never leaves her case, using pheromones to attract a mate.  The Butterfly House website has images of the entire life cycle. Thanks for that, my daughter was fascinated (so was I) to see photographs of the adult moth. Cheers Carey

Letter 2 – Bagworm Moth lays eggs in Australia

 

unusual bug Location: eastern suburbs Sydney April 9, 2011 2:27 am I came across this bug in my backyard 9/4/11. It’s about 8mm in body length. Second image the next day after being kept under a glass. What looks like thousend of eggs! Signature: Heinz57
Unknown Moth
Dear Heinz57, This is a Moth, though we haven’t been able to come up with a conclusive identification.  We also don’t know if her wings failed to expand after metamorphosis, or if this is a flightless species with vestigial wings.  Many female Tussock Moths are flightless, and the markings on your specimen match those of Oligeria hemicalla pictured on the ButterflyHouse website, but we are unable to locate an image of a female moth.  The Painted Apple Moth is an example of a Tussock Moth in the family Lymantriidae that has a wingless female.  The photos on Wikipedia indicate that it is not your species, though the eggs look quite similar.  Perhaps one of our readers will be able to supply an identification.
Unknown Moth lays eggs
Karl provides an identification Unknown flightless moth lays eggs in Australia Hi Daniel and Heinz57: The looks like a female Australian Bagmoth, Cebysa leucotelus (Psychidae). It is native to southern Australia and has recently shown up in New Zealand. Apparently the larvae feed on lichens growing on tree trunks, rocks, etc. and the lichen fragments get incorporated into the larval cases, or ‘bags’. Only the females are flightless. Regards. Karl

Letter 3 – Bug of the Month: September 2007 – Bagworm

 

a little caterpillar with a traveling cocoon Hi, I’m hoping you can identify this little fellow. He’s been hanging around (literally) ,and under my blue ceramic bird bath. At first I thought he was building a cocoon, but he keeps crawling all over the place with it . Let me know, please, if you can identify him. His cocoon seems to be about 3″ long. I live in Parma, Ohio (a suburb of Cleveland). Thank you. Mary Griffin Hi Mary, This caterpillar is a Bagworm. Bagworms are Moths in the family Psychidae. According to BugGuide: “Larvae (bagworms) construct spindle-shaped bags covered with pieces of twigs, leaves, etc., and remain in them, enlarging them as they grow, till they pupate (also in the bag). Adult females remain in the bag, emitting pheromones which attract adult males to mate with them.”

Letter 4 – Male Evergreen Bagworm Moth

 

Wow, you nailed it!
I saw this weird moth on my garage so I captured it: Went to your site and found it without even looking: Large Tolype I scanned down a bit and found this one too: Chickweed Moth
But I wouldn’t even know where to start with this one:
hank



Hi Hank,
We are happy to hear you find our site user friendly and helpful. No matter how hard you tried, you would not have located your Male Evergreen Bagworm, Thyridopteryx ephemeraeformis, on our site since your photo is the first adult photo we have received. We have a Bagworm page since we get so many requests to identify the caterpillars and cocoons. Only male Bagworm moths are winged. Females never leave the cocoon and mating occurs when the winged male locates a female ready to mate. She then lays her eggs in the bag and dies. Thanks for your wonderful addition to our archives.

Letter 5 – Tiger Beetle and Bagworm from Japan

 

Hi I am an American in Japan and thought you’d be interested in seeing what the tiger beetles here look like. They’re called hanmyou here. I also included photos of a bagworm called a minomushi which means “straw raincoat”. They are a favorite of children here. Melody McFarland Yokosuka, Japan Hi Melody, Thank you for sending us your wonderful images as well as the language lesson. The jaws on that Hanmyou Tiger Beetle are quite formidable.

Letter 6 – Oiketicus Bagworm

 

stick cocoon
Hi!
I found this cocoon on my rose bush in west central Florida on Sept. 17, 2005. I’d never seen one like it before, and being a 4th grade teacher, took it in for my class to see. No one at school seems to know what it is, nor have they ever seen one before. I keep putting fresh rose leaves in the container with a bit of water and the catepillar ventures out occasionally to feed. Attaching a photo. Any idea what it is?
Elane Rogers



Hi Elane,
We were pretty sure this was a Bagworm, but didn’t recognize it. Now we believe it is in the genus Oiketicus. Thank you for the great photo.

Letter 7 – Mystery: Bagworm (we think) from Oman

 

What bug had made this? May 23, 2010 I clicked this picture thinking it was a screw.. Then someone corrected me saying that its probably an insect which makes a cocoon out of twigs. Can you tell what it really is… ‘coz its definitely not a screw that I shot! brinda Muscat, Oman
Bagworm:  Amicta quadrangularis
Hi Brinda, The only conclusion we can draw is that this must be some species of Bagworm, a group of moths in the family Psychidae.  Many North American species are represented on BugGuide.  We decided to search online in an effort to be more specific with your individual.  The closest we found is a Bagworm from Singapore with a bag construction similar to your example, but with an interesting twist.  Some photos are on a Blog about Singapore (scroll about 3/4 way down) and one of the photos is also posted on Flickr.  Bagworms begin constructing a bag when they are young caterpillars, adding to the bag as they grow.  The bag acts as a means of shelter and protection and the caterpillar does not leave the bag, eventually pupating inside.  The bag is constructed from silk and plant material, generally from the plant upon which the caterpillar feeds.  Many female Bagworms are wingless and legless, and they never leave the shelter of the bag.  The male seeks the female out when she is sexually mature and mates either inside the bag or in the entrance to the bag.  Perhaps one of our readers will have better luck identifying the species for us.

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