What Do Imperial Moth Caterpillars Eat? The Ultimate Food Guide for Your Little Critters

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Imperial moth caterpillars are fascinating creatures known for their vibrant colors and large size, growing up to 5.5 inches long. As they search for food, you might be wondering what these caterpillars typically eat.

These caterpillars enjoy munching on a variety of host plants. Some examples include maple, oak, and even some forest and shade trees. This variety in their diet makes them quite adaptable and easy to find in numerous environments.

No matter where you encounter them, imperial moth caterpillars will likely be feasting on the foliage of their preferred plants. Watching their growth and development can be a delightful experience for anyone interested in nature and these unique insects.

The Imperial Moth Caterpillar

Life Cycle

The Imperial Moth Caterpillar, scientifically known as Eacles imperialis, is a fascinating creature. It goes through several stages in its life cycle, including egg, larvae, pupa, and finally, the adult moth1(https://entnemdept.ufl.edu/creatures/bfly/moth2/imperial_moth.htm).

As the caterpillars grow, they undergo a series of molts called instars. At each instar, the caterpillar feeds on the foliage of its host plants, providing nourishment for its continued growth2(https://content.ces.ncsu.edu/imperial-moth).


Imperial Moth Caterpillars can be found in various geographical locations throughout North America. Their range extends from the Atlantic Coast to the Rocky Mountains, and even down into Mexico and Argentina3(https://entnemdept.ufl.edu/creatures/bfly/moth2/imperial_moth.htm). In the United States, they can be found in areas such as the Florida Keys, Maryland, Nebraska, Texas, and even as far north as Martha’s Vineyard.

Below is a comparison table of some regions that are home to the Imperial Moth Caterpillar:

Region Distribution Details
U.S Atlantic Coast to Rocky Mountains, Florida Keys to Martha’s Vineyard
Canada Southern areas
Mexico Southern regions
Argentina Northern provinces

When exploring these regions, you can spot imperial moth caterpillars of varying appearances, from their striking colors to their impressive size^4^.

Overall, the imperial moth caterpillar is a captivating species with a unique life cycle and wide distribution. By shedding light on their development and range, you can better understand and appreciate these remarkable creatures.

Physical Characteristics


Imperial moth caterpillars exhibit a wide variety of colors, ranging from green to brown and even shades of black. Their wings are predominantly yellow, but they can also have spots and speckles of pink, orange, or rusty pale purple12. This diversity in coloration not only makes them visually striking but can also help them blend in with their environment.


Imperial moth caterpillars are known for their large size, often growing up to a substantial 5.5 inches3. Their wingspan as moths can also be quite impressive. Comparing their size to other caterpillars, imperial moth caterpillars are generally larger and more visually stunning.

In summary, imperial moth caterpillars are well-known for their striking appearance and diverse coloration. With predominantly yellow wings, these insects also exhibit spots and speckles of various colors, making them a sight to behold. Their size and overall appearance contribute to their distinct nature among caterpillars and moths.

Habitat and Host Plants

Trees as Host

Imperial moth caterpillars primarily feed on the foliage of various trees. Their preferred host plants include:

  • Oaks (Quercus species)
  • Hickory (Carya species)
  • Maples (Acer species)
  • Pines (Pinus species)
  • Spruce (Picea species)
  • Sweetgum (Liquidambar styraciflua)
  • Sassafras (Sassafras albidum)

These trees provide the necessary nutrients for the caterpillars to grow and develop into adult moths. As the caterpillars grow, their color and appearance may change, but they remain large and easy to spot on the host plants they inhabit 1.


Imperial moth caterpillars can be found in diverse habitats, such as woodlands or forests, where their host plants are abundant. Woodlands provide a sheltered environment that is essential for the caterpillars’ survival and growth. In these areas, the caterpillars find ample foliage to consume and eventually, a suitable location to pupate.

As the caterpillars grow, they develop prolegs which aid in their movement and help them navigate through the branches and leaves of their host plants. This allows the caterpillars to easily access food sources and take full advantage of the diverse habitats where they live 2.

To sum up, the imperial moth caterpillar’s habitat consists mainly of woodlands where their preferred host plants are present, providing them with the necessary resources to grow and thrive.

Behavior and Lifestyle

Feeding Habits

Imperial moth caterpillars are known for their large size, with some individuals growing up to 5.5 inches! These caterpillars primarily feed on the foliage of host plants. You’ll often see these caterpillars feasting on leaves, which provide the nutrients they need for development.

Caterpillar Diet Adult Diet
Foliage of host plants Nectar, not applicable in some cases

Mating Habits

When it comes to mating, adult imperial moths exhibit certain behaviors. Males and females are both attracted to lights at night, although males have more feathery antennae. This could be an adaptation to allow the males to better detect female pheromones, making it easier for them to find mates.

After mating, female imperial moths lay their eggs on the foliage of host plants. The cycle continues as the eggs hatch into caterpillars, which will eventually pupate and metamorphose into adult moths.

Remember that the behavior and lifestyle of imperial moths include both feeding and mating habits, with caterpillars feeding on foliage and adults engaging in nocturnal mating activities. Keep an eye out for these fascinating creatures and their unique habits when observing your natural surroundings.

Survival Tactics

Defense Mechanisms

Imperial moth caterpillars have developed a few tactics to defend themselves from predators and other threats. They can be found in various colors, ranging from light to dark brown, burgundy, or green, which helps them blend into the foliage of their host plants, where they lay their eggs. This camouflage assists them in avoiding detection by predators such as birds and insects. Furthermore, these caterpillars also have the ability to grow up to 5.5 inches in size, which might act as a deterrent to some predators.


Despite their defense mechanisms, imperial moth caterpillars still face predation from various sources. Here are some common predators and threats they encounter:

  • Birds: Many bird species are known to consume caterpillars, including imperial moth caterpillars.
  • Insects: Insects such as parasitoids and predatory insects may prey on imperial moth caterpillars. A parasitoid could lay its eggs inside the caterpillar, which will eventually lead to its death.
  • Pesticides/Insecticides: The use of chemical insecticides and pesticides can pose a threat to these caterpillars, as they are susceptible to these chemicals.

Comparison Table: Predators and Threats

Threat Impact on Imperial Moth Caterpillar Examples
Birds Direct predation
Insects Direct predation, parasitism Parasitoids, predators
Pesticides Indirect threat due to human actions Chemical insecticides

By being aware of these survival tactics, you can better appreciate the fascinating world of imperial moth caterpillars and the challenges they face in their environment.

The Imperial Moth

Imperial moths are large, showy insects that usually fly at night. They belong to the family Saturniidae, which includes some of the largest and most colorful moths and butterflies. There are various subspecies of imperial moths, each adapted to their specific habitats and host plants.

These moths are known for their striking appearance, with wings that are yellow and speckled with spots of pink, orange, or rusty pale purple. Their antennae are distinctive as well – males have more feathery antennae than females. An important part of their life cycle involves laying eggs on the foliage of host plants.

Imperial moth caterpillars are just as impressive as the adult moths. They can grow up to 5.5 inches in length and have various color forms, ranging from light to dark green, tan, or dark brown. These caterpillars have short, stiff hairs on their bodies and large, white spiracles along their sides, which act as breathing holes.

When it comes to their diet, imperial moth caterpillars feed on a variety of trees and shrubs. Some of their preferred host plants include:

  • Maple
  • Oak
  • Hickory
  • Walnut
  • Hemlock

As they feed on these plants, the caterpillars grow and eventually form a cocoon made of silk, which is spun from their mouths. Within the cocoon, they undergo metamorphosis and transform into adult moths, ready to continue the life cycle by finding mates and laying eggs on suitable host plants.


Imperial moth caterpillars are fascinating creatures with their large, vibrant appearance, and they play an essential role in their ecosystems. However, they have been experiencing a decline in recent years. In this section, we’ll discuss some conservation measures that you can take to help protect and preserve these amazing insects.

Firstly, it’s crucial to learn about their natural habitat and food sources. Imperial moth caterpillars typically feed on the foliage of host plants. By planting and preserving the native trees and plants in your area, you’re providing these caterpillars with the resources they need to thrive.

To further promote a healthy environment for the imperial moth caterpillars, consider reducing or eliminating the use of pesticides in your garden. Pesticides can be harmful to beneficial insects like caterpillars and their natural predators. Instead, opt for organic pest control methods that have minimal impact on the caterpillars and other non-target species.

Lastly, spreading awareness about the importance of imperial moth caterpillars and their role in maintaining a balanced ecosystem is essential for their conservation. Share your knowledge with friends and neighbors and encourage them to take part in creating a better environment for these captivating creatures.

By following these simple steps, you’re contributing to the conservation of imperial moth caterpillars and helping to preserve their populations for future generations to admire and appreciate. Together, we can make a positive impact on their well-being and the overall health of our ecosystems.

Scientific Classification

Imperial moth caterpillars, scientifically known as Eacles imperialis, belong to the Animalia kingdom and fall under the Arthropoda phylum. For your convenience, here’s a table showcasing their classification:

Classification Category
Kingdom Animalia
Phylum Arthropoda
Class Insecta
Order Lepidoptera
Family Saturniidae
Subfamily Ceratocampinae
Species Eacles imperialis

Being part of the Lepidoptera order, they belong to a large group of insects that includes moths and butterflies. These caterpillars are considered the larvae stage of the Imperial moth species.

The Imperial moth is positioned within the Saturniidae family, comprised mostly of large, showy moth species. Additionally, the Imperial moth and its caterpillar reside in the subfamily Ceratocampinae, known for its fascinating and diverse moth species.

Notably, Imperial moth caterpillars tend to have substantial size variations, specifically reaching up to 5.5 inches in length. In their natural habitat, they primarily feed on the foliage of host plants, making them an essential part of the ecosystem.

As you explore their fascinating world, remember that understanding the scientific classification of the Imperial moth caterpillar can greatly enhance your knowledge and appreciation of these remarkable creatures.


  1. Imperial Moth | Missouri Department of Conservation 2 3

  2. imperial moth – Eacles imperialis imperialis (Drury, 1773) 2 3

  3. Imperial Moth | NC State Extension Publications 2

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 – Unknown Moth Pupa: Possibly Imperial Moth


What is this pupa?
Location: Indianapolis, IN
November 4, 2010 6:07 pm
I just found this pupa on the ground in our yard, underneath a tree. What on earth is it???? It is black and definitely alive because it keeps wriggling. Its surface is really hard and smooth with clearly defined ringed segments encircling half of it. On the end opposite the rings, there are 2 tear-drop shaped impressions — possibly wings? There is a series of holes down the sides. What is it? And, can we keep it in a jar to watch it come out without killing it?
Signature: Zion, age 6

Moth Pupa

Hi Zion,
We applaud your curiosity.  This is a Moth Pupa, but we are a bit reluctant to attempt a species identification because so many moths that form pupa underground look similar.  Our first guess was perhaps a Regal Moth, but we don’t think the outline of the wing pads (you were correct) seem different.  Our second guess would be an Imperial Moth, and in our attempt to locate an image of its pupa, we stumbled upon this charming YouTube Video called Imperial Moth Caterpillar Goes to Pupate by Andrei Sourakov.  The Pupa was not on screen long enough to compare.  You pupa does seem to resemble the Imperial Moth Pupa,
Eacles imperialis, posted on BugGuide.   The series of holes are the spiracles by which the insect breathes.  We would not recommend a jar for keeping this pupa alive.  We would suggest a cage with potting soil in the bottom.  Do not keep the potting soil to wet or too dry.  Ideal temperature is a protected and unheated area, like perhaps a garage.  Good Luck.

Thanks so much for your response. We have all been wondering what this treasure represents. We will do our best to keep it alive until it emerges. This is an interesting project for my son’s inquisitive mind.

Letter 2 – NOT Imperial Moth Eggs Hatch


Well its only been about 4 hours since I took a photo of them and sent it. But checking on them at lunch time gave us a surprise, they were hatching. So I grabbed 4 or 5 different types of tree leaves to put in the cage. Do they need water?? or is the leaves enough. I really want the little guys to have a chance or turning into those beautiful Imperial moths.
Karen Maier
PS let me know if u want any more photos as they grow or if you have enough of that type. dont want to send any you cant use.

Hi Karen,
These are not Imperial Moth caterpillars. Ed Note:  August 30, 2009.  We do believe they are some Giant Silkmoth. We fear you misidentified your original moth. BugGuide has an image of a newly hatched Imperial Moth, and it does not look at all like your caterpillars. We cannot identify your specimen from this hatchling image. We suspect this is still one of the Giant Silk Moths. If you describe the moth, we may be able to identify it. It would be great if you could take a photo at each stage of development, known as instars. Each time a caterpillar molts, there is a new instar. There are five instars before pupation. You caterpillars will fulfull their water needs through the leaves they eat. Thank you for noting in your photo title that the eggs hatched after four days.

Sad Update
Im sorry to say that all of our babies died. Im not sure why, I gave them the leaves from the tree they came from and a few others too. but they just sat around and didnt seem interested in them. and by today they were all gone. I wish we could of found out just what kind they were.

Letter 3 – Pre-Pupal Imperial Moth Caterpillar


Subject:  Caterpillar ID ?
Geographic location of the bug:  Western NC
Date: 09/11/2017
Time: 01:39 PM EDT
I discovered the caterpillar in the attached photo over the weekend at my home in Western NC – and was wondering what it is ?
any information you could provide would be greatly appreciated
Thank you
How you want your letter signed:  Don Underwood

Imperial Moth Caterpillar

Dear Don,
This impressive caterpillar is an Imperial Moth Caterpillar and its orange color indicates it is pre-pupal.  It has recently come down from the deciduous or coniferous tree upon which it was feeding.  According to BugGuide:  “Larvae feed on leaves of Bald Cypress, basswood, birch, cedar, elm, hickory, Honeylocust, maple, oak, pine, Sassafras (
Sassafras albidum), Sweetgum (Liquidambar styraciflua), sycamore, walnut.  Adults do not feed.”

Letter 4 – Pre-Pupal Imperial Moth Caterpillar


Subject:  Unknown catepillar
Geographic location of the bug:  Pennsylvania
Date: 09/19/2017
Time: 01:22 PM EDT
Can’t figure out what kind of catepillar this is, can you help?
How you want your letter signed:  Sarah

Imperial Moth Caterpillar

Dear Sarah,
This is an Imperial Moth Caterpillar, and the orange color indicates it is pre-pupal.

Letter 5 – Pre-Pupal Imperial Moth Caterpillar


Subject:  Big Green & Fuzzy
Geographic location of the bug:  Orrick, MO
Date: 09/24/2017
Time: 05:09 PM EDT
@In mid-September, my husband accidentally kicked this guy on the ground. He thought it was some sort of “premature pinecone”. Low and behold, it moved. That’s when we realized that is was some sort of large caterpillar. It almost seemed like it had a hard shell, but I didn’t touch him to find out. We left him on the ground and don’t know what happened to him but still curious as to what it was…
How you want your letter signed:  D&C at Shak Creek

Pre-Pupal Imperial Moth Caterpillar

Dear D&C at Shak Creek,
This is a pre-pupal Imperial Moth Caterpillar.  Just prior to pupation, many caterpillars change color and search for an appropriate site to commence metamorphosis.  As pupation time nears, the caterpillars become more sluggish.

Pre-Pupal Imperial Moth Caterpillar

Letter 6 – Pre-Pupal Imperial Moth Caterpillar


Subject:  Catapillar
Geographic location of the bug:  Backyard in Northern Illinois
Date: 08/31/2018
Time: 07:30 PM EDT
Your letter to the bugman:  What is it? I think I’ve seen a green one on my sidewalk 3 yrs ago.
How you want your letter signed:  LikesBugsNot

Imperial Moth Caterpillar

Dear LikesBugsNot,
The orange color on this Imperial Moth Caterpillar indicates it is pre-pupal, and it has left the tree or shrub upon which it was feeding in order to find an appropriate place to pupate.

Letter 7 – Tattered Imperial Moth


Subject: Mad moth disease
Location: Clarksville, tn
July 18, 2014 3:30 pm
Let me tell you about this moth, it was pretty big. A little smaller than a luna moth, I found it while coming home from work. It was smashing itself into the ground over and over and over, and was so loud I thought it was a dog with long claws trotting up the street to me. I made an attempt to catch it, but the damn thing would not stop it’s furious flapping frenzy. Woke up this morning to find it dead on my porch with it’s abdomin busted out like it was possessed by something unholy! I’m mostly just curious, what kind of moth and what do you think did it in? Personally I’m thinking parasite possession!
Signature: Skye

Bedraggled Imperial Moth
Bedraggled Imperial Moth

Dear Skye,
Based on its condition, this Bedraggled Imperial Moth was at the end of its short life, and it appears it encountered considerable trauma, perhaps getting caught in a storm or falling victim to some predator like a domestic cat or dog or possibly a bird.  One cannot appreciate the beauty of this lovely moth in its present condition, and we have numerous images of more pristine Imperial Moths on our site.  Like other members of the family Saturniidae, Imperial Moths do not feed as adults and generally live for less than a week, long enough to mate and lay eggs.

Letter 8 – Unknown Pupae from Australia might be Imperial Jezebel


Subject:  Pupa identification
Geographic location of the bug:  Canberra Australia
Date: 10/06/2018
Time: 05:14 AM EDT
Your letter to the bugman:  Been trying to identify this but coming up with no idea. It looks like a tent caterpillar web but not their pupae…
How you want your letter signed:  Thanks

Possibly Pupae of Imperial Jezebel

We wish your image had more critical detail, especially of the individual pupae.  We do not believe these pupae belong to a caterpillar.  We will continue to research this matter, but in the meanwhile, we are posting your request as Unidentified.

Update:  Thanks to a comment from Richard Stickney, we believe these might be the pupae of the Imperial Jezebel or Imperial White, Delias harpalyce, which is pictured on The Victoria Museum site.


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    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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4 Comments. Leave new

  • Richard Stickney
    October 10, 2018 1:16 pm

    I haven’t seen them personally, but I’ve seen another photo like it. These are pupae of a Jezebel or Imperial White butterfly, Delias sp.

  • Shellabelle Oconnor
    September 3, 2021 10:41 pm

    I have taken a photo in victoria of one just the same but with a white Imperial Jezabel on the web with the Pupae.

  • I have the exact same pupae with webbing in my front garden at the moment. I am in the Yarra Valley, Victoria.
    So far I have two Imperial Jezebel butterflies that have not flow away? Is this normal? They have been there for a few days. I can send pictures if you like.


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