Saturniid Moth: All You Need to Know in a Nutshell

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Saturniid moths, also known as giant silk moths, belong to the family Saturniidae and are known for their impressive size and striking appearance. With over 2,300 species worldwide, these moths can have a wingspan ranging from 3 to 6 inches and are often adorned with intriguing patterns and eye-catching eyespots (Missouri Department of Conservation).

As you explore the world of Saturniid moths, you’ll discover that these fascinating insects have unique characteristics. Most adults have little or no mouthparts, which means they don’t eat and only live for about a week or two (ENT 425 – General Entomology). Some well-known species you might come across include the cecropia moth, luna moth, and polyphemus moth (Panhandle Outdoors). These enchanting creatures with their vibrant colors and distinct markings are sure to capture your attention and curiosity.

Overview of Saturniid Moths

Saturniid moths belong to the family Saturniidae and are a group of large moths found in the order Lepidoptera. These fascinating creatures fall under the Animalia kingdom and class Insecta. As members of the phylum Arthropoda, they exhibit some exciting features. Let’s delve into the world of Saturniid moths and discover their unique traits.

These moths are known for their striking appearance and large size, boasting impressive wingspans. For example, the Atlas moth is one of the Saturniid moths with the largest wingspans, reaching up to 12 inches.

Here are some key characteristics of Saturniid moths:

  • Large, often brightly colored wings
  • Prominent eyespots on their wings
  • Lush, robust, and fuzzy bodies
  • Males generally have larger, feathery antennae than females

Within the Saturniidae family, there are numerous species of moth, each with its distinct traits. For example, the Luna moth has a pale green color and elongated tails on its hindwings, while the Cecropia moth is North America’s largest native moth, identified by its red-orange body and intricate wing patterns.

Here’s a comparison table highlighting the differences between two well-known Saturniid moths:

Attribute Luna Moth Cecropia Moth
Wingspan 3-4.5 inches 5-7 inches
Body Color Light green Red-orange
Wing Pattern Translucent with creamy-yellow lines Bands of red, white, and gray, with large eyespots
Distribution North America (eastern region) North America (from Canada to Mexico)

Now that you’ve learned about Saturniid moths’ main features and some examples, you should have a solid understanding of these fascinating insects. So, next time you encounter a large, colorful moth, you might be able to identify it as a magnificent Saturniid moth.

Physical Attributes

Popular Species

When discussing the physical attributes of Saturniid moths, it’s essential to take a look at some popular species, such as the Luna Moth, Polyphemus Moth, Emperor Moth, and Io Moth. Each species has unique characteristics that make them stand out.

Wings and Wingspan

Saturniid moths are known for their broad wings, which can vary in color among species. For example, the Luna Moth has a vibrant green color, while the Polyphemus Moth displays a more subtle brown tone. Wingspans can also differ significantly, ranging from 2 inches in the Io Moth to a whopping 12 inches in the Atlas Moth.

Here’s a brief comparison of popular species and their wingspans:

Species Wingspan
Luna Moth 3 – 4.5 inches
Polyphemus Moth 4 – 6 inches
Emperor Moth 3 – 4 inches
Io Moth 2 – 3.5 inches
Atlas Moth 10 – 12 inches

Eyespots and Antennae

A notable feature in Saturniid moths is the presence of eyespots on their wings. These circular markings resemble eyes and help ward off predators. The central eyespot size and pattern can vary among species. Additionally, these moths have feathery antennae that aid them in detecting pheromones and finding mates.

When observing various species, you’ll find that their eyespots and antennae can differ:

  • Luna Moth: Subtle eyespots; long, twisted antennae
  • Polyphemus Moth: Large, transparent eyespots; bushy antennae
  • Emperor Moth: Prominent, colorful eyespots; feathery antennae
  • Io Moth: Bold, contrasting eyespots; hair-like antennae

In conclusion, the physical attributes of Saturniid moths are diverse and unique, with different species showcasing various wing colors, wingspans, eyespots, and antennae. By understanding these characteristics, you can better appreciate the beauty and complexity of these fascinating creatures.

Life Cycle

The life cycle of Saturniid moths is broken down into a few essential stages. We’ll start by discussing each point in brief.

Eggs: The beginning of the Saturniid moth’s journey starts with the tiny eggs laid by the female. These eggs usually hatch within a week or two.

Larvae and Caterpillars: Once the eggs hatch, the larvae emerge as small, hungry caterpillars. These caterpillars go through a process called instars, where they molt and grow. As they grow, they’ll consume leaves, eventually reaching their final stage, the full-grown caterpillar.

Pupae and Cocoons: When the caterpillar has finished growing, it’s time for metamorphosis. The caterpillar spins a silken cocoon around itself and transforms into a pupa.

  • Silken Cocoons: These protective structures house the developing moth pupae. They’re usually created using silk produced by the caterpillar.
  • Diapause: This is a period of dormancy that may occur during the pupa stage. Depending on the species, diapause can be a short or long phase.

Metamorphosis: Within the cocoon, the pupa undergoes an incredible transformation. Its body structure changes, and eventually, a fully formed adult moth emerges, ready to lay eggs and begin the cycle anew.

Distribution and Habitat

Saturniid moths can be found in various regions around the world, including North America, Asia, and Europe. They inhabit subtropical regions where they thrive in diverse habitats, such as forests and meadows.

Host Plants

The larvae of Saturniid moths feed on a variety of host plants. Some common trees and shrubs they prefer include:

  • Maple trees: These trees provide a rich food source for many Saturniid moth species, such as the rosy maple moth and the polyphemus moth.
  • Birch trees: The cecropia moth and the promethea moth are just a couple of examples of Saturniid moths that rely on birch trees as host plants.
  • Hickory trees: Species like the royal walnut moth and the imperial moth find sustenance from hickory trees.
  • Other shrubs and trees: Some Saturniid moths, such as the ailanthus silkmoth, may opt for other varieties of shrubs and trees as host plants.

It is important for the survival and development of these moths that they have access to a diverse range of host plants in their habitats. By understanding their distribution and the types of plants they rely on, you can better appreciate the diverse and fascinating world of Saturniid moths.


Saturniid moths are fascinating creatures with unique behaviors. They are nocturnal, which means they are active during the night and rest during the day. This particular behavior helps them avoid predators and find food more efficiently.

In their search for food and mates, Saturniid moths primarily rely on their senses of smell and touch. One of the most common ways they locate food sources is by detecting the scent of flowers that bloom at night. You’ll often find them around these flowers, gathering nectar and pollinating the plants.

When it comes to finding a mate, male Saturniid moths rely heavily on their strong sense of smell to locate a female. Females produce special pheromones to attract potential partners. Once a male picks up on this scent, he’ll follow the trail to find his mate.

During their brief adult lives, Saturniid moths focus mainly on two objectives: eating and reproducing. These life priorities are very important because the adult moths don’t live for very long. They don’t have functional mouths, so they don’t eat. They survive only on the energy they stored as larvae.

In summary, understanding the behavior of Saturniid moths provides an insight into these beautiful, nocturnal insects’ unique way of life. Their night-time activity, sensory-based methods of finding food, and their reliance on pheromone communication make these creatures truly fascinating.

Interactions with Humans

Impact on Ecosystem

Saturniid moths play a vital role in supporting ecosystems. They are known for their commercial silk production, which benefits humans. Some species like the silkworm moth (Bombyx mori), have been domesticated for this purpose. However, their impact is not limited to silk production.

Their existence in nature is also crucial for predators such as birds and bats, which rely on these moths as a food source. Maintaining a healthy population of Saturniid moths can help balance the ecosystem and secure the survival of various animal species.

As a collector’s item, Saturniid moths are highly sought after for their unique appearances and large sizes. Collecting these moths can contribute to scientific knowledge about their biology and their role in their habitats. However, removing them from their natural habitats might have some negative impact on the local ecosystem as well.

Despite their importance, some Saturniid moth species may become pests, causing damage to trees and plants in forests and gardens. This damage can have a domino effect on other species in the ecosystem that rely on these plants for their survival. To manage these potential risks, it is essential to monitor and manage Saturniid moth populations responsibly.

In summary, Saturniid moths have a complex relationship with humans and their ecosystems. They are vital for silk production, serve as food for predators, and can be collected for scientific research. However, it’s crucial to respect their role in the environment and manage their populations responsibly.


Saturniid moths are fascinating creatures, and their conservation is crucial for maintaining the health of ecosystems. As you explore the world of these moths, you’ll learn about the importance of their contributions to nature.

In some regions, Saturniid moths face threats such as habitat loss and climate change. Due to these factors, it’s vital to take steps to protect their populations. For example, the bog buck moth is listed as endangered under the Endangered Species Act, highlighting the need for conservation efforts.

Conservation plays a key role in preserving Saturniid moths’ habitats, such as forests and wetlands. By supporting initiatives that restore and protect these areas, you can contribute to the moths’ well-being. Additionally, participating in local clean-up events and planting native species in your garden are small actions that can make a big difference.

Another important aspect of conservation is education. By learning more about Saturniid moths and sharing your knowledge, you can raise awareness about these fascinating species and the need for their protection. Attending workshops, joining online forums, and connecting with researchers and enthusiasts are excellent ways to expand your understanding of these captivating creatures.

In summary:

  • Protect their habitats by participating in conservation efforts
  • Support restoration projects to preserve their ecosystems
  • Educate yourself and raise awareness about Saturniid moths and their importance

By following these steps, you’ll be playing your part in ensuring the survival of these striking and essential insects. So, start enjoying the world of Saturniid moths while making a positive impact on their conservation.

Contact Us

If you’d like to know more about the fascinating Saturniid moths, don’t hesitate to get in touch. We’re here to help and provide the information you need.

To discuss your questions, just drop us a message via email, and we’ll get back to you as soon as possible. We understand that your inquiries might be unique, so feel free to reach out anytime.

When you contact us, please make sure to include:

  • Your full name
  • Your preferred contact method
  • Details about your inquiry, to help us respond efficiently

We’re committed to providing a friendly and accessible experience. If you prefer a different communication medium, feel free to connect with us through our social media channels as well.

Lastly, don’t forget to browse our website for informative articles and resources about Saturniid moths. Your next discovery might be just a few clicks away!

Your passion for these fascinating creatures matters to us, so don’t hesitate to contact us with any concerns, inquiries, or feedback. We’re always here to help and engage with you, making your journey into the world of Saturniid moths a delight.

Reader Emails

Over the years, our website, 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 – Saturniid Caterpillar from Chile


Subject: Blue caterpillar
Location: Chiloe, Chile.
February 4, 2016 5:12 pm
Hello! I was trekking in Chiloe national park, in the great island of Chiloe, Chile, and I find this beautiful caterpillar, but no one could tell me it’s species. I hope you could tell me more about it. Cheers!
Signature: Marcos Nijborg

Giant Silkmoth Caterpillar
Giant Silkmoth Caterpillar

Dear Marcos,
We believe your Giant Silkmoth Caterpillar is in the subfamily Hemileucinae, the Buck and Io Moths.  Furthermore, we believe it is in the genus Automeris because of it strong resemblance to the North American Io Moth Caterpillar.  The closest match we could find is the Caterpillar of
Automeris hamata, a species pictured on DeviantArt and found in Argentina.  We will contact Bill Oehlke to see if he can provide any information.

Giant Silkmoth Caterpillar
Giant Silkmoth Caterpillar

Bill Oehlke Responds
Larvae of Chilean Saturniidae are not well known. It is one of the Hemileucinae species, and I suspect of Ormiscodes genus based on spinage. There are probably six different Ormiscodes species from that area.
Bill Oehlke

Here is a link to Healthy Home Garden that contains images of a caterpillar in the genus Ormiscodes.

Letter 2 – Dysdaemonia boreas, a Costa Rican Saturniid


Large Brown Moth
July 17, 2009
What is this? It’s a large brown moth spotted in Uvita, Costa Rica?
Uvita, Costa Rica

Giant Silk Moth
Dysdaemonia boreas

Hi Whitney,
Your moth is one of the Giant Silk Moths in the family Saturniidae.  We quickly identified your moth as Dysdaemonia boreas on the Worlds Largest Saturniidae Site.  Back in August 2008, we received another submission of this lovely moth from Mexico.  We are going to copy Bill Oehlke on our reply as he is compiling complex species distribution data on many large moths.

Letter 3 – Possibly Mendocino Saturnia Moth Caterpillar


Subject:  Caterpillar
Geographic location of the bug:  Siskiyou  county, CA
Date: 07/18/2018
Time: 02:05 PM EDT
Your letter to the bugman:  I found this little guy crawling through the Oak Leaves in my yard. I’ve never seen one like it.
How you want your letter signed:  Donna B

Mendocino Saturnia Moth Caterpillar, we believe

Dear Donna,
If our identification is correct, we believe this is a Mendocino Saturnia Moth Caterpillar,
Saturnia mendocino, a caterpillar not well represented on the internet.  We located a similar image that we cannot link to, and then we located this image on iNaturalist that looks remarkably like your individual.  According to Pacific Northwest Moths:  “The last instar larva is yellow and has scoli or tubercles covered with orange hair tufts and longer white hairs.  It is illustrated by Miller & Hammond (2003).  Miller & Hammond (2007) also illustrate the young larvae that change dramatically in color pattern with each instar.”  According to Butterflies and Moths of North America:  “Caterpillar Hosts: Manzanita (Arctostaphylos) and madrone (Arbutus menziesii), both in the heath family (Ericaceae).”  Do you have those host plants growing nearby?  We will check with Saturniidae expert Bill Oehlke to verify this identity.  He may request permission to post your image to his site.

Letter 4 – Saturnid Moth from Argentina


Rothschildia jacobaeae
My name is Vanesa I live in Buenos Aires. I found 2 days ago what I’ve been told is a Rothschildia jacobaeae female, I thought it was a common buttefly dying. It didn’t move. I took it to my appartment and put it in my balcony, the next day I found there was an other one just identical but smaller. Is it the male? I took both of them to a park five blocks away from my home and set them free yesterday and today I had the little one again in my balcony. 6th floor. What should I do? Is it dangerous? How do I know if it is a male or a female? Can you send me good information? Thank you so much Sincerely yours
Vanesa Mautner

Hi Vanessa,
Rothschildia jacobaeae is one of the Saturnid or Giant Silkmoths. It ranges from Brazil to Argentina. Adult females Saturnids have larger bodies and males have more feathery antennae. The female moth releases pheromones that the male senses with his antennae, allowing him to locate a female that is ready to mate. That is how the original male found the female on your balcony. When you removed the pair, the pheromones remained behind and attracted another male the next day. These moths and other members in the family do not feed as adults. They live to mate and die shortly afterwards. Thanks for sending your lovely photo to us.

Letter 5 – Saturnid Moth from Botswana: Genus Pseudobunaea


Botswana Moth
I was traveling in Botswana recently and took this picture but have not been able to identify the moth. It is sort of like the Emperor Moth of Australia.
Gerry Byrnes

Hi Gerry,
We are happy to once again have access to Kirby Wolfe’s awesome Saturnid Website, where we beleive we have correctly identified your moth as Pseudobunaea irius. We have tried contacting Kirby Wolfe directly to get verification.

Dear Daniel,
I’ve seen your website over the years. You do a great service to the bug-curious community. Regarding the Pseudobunaea, I believe that it is not irius. However, African species are not my forte, and I am presently spending the winter in Costa Rica where I do not have access to my diagnostic collection or reference library, so I am not qualified to give you the last word. I don’t know if you have access to Bill Oehlke’s site, but it’s likely that you could find a photo of your species there. Sorry to not be of more help. Regards,

After getting the reply from Kirby, we located another German website with other members of the genus Pseudobunaea.

Update: (03/21/2008)
The Pseudobunaea from Botswana might be irius, but I think it is more likely pallens.
Bill Oehlke

Letter 6 – Saturnid Moth Pupa


large pupa Cicada?
This is a picture taken by Missouri Department Of Conservation, we are having trouble IDing this guy. Is it a cicada pupa? Or some type of beetle. Any information you can give will be very helpful. Thank you
Shelly Cox

Hi Shelly,
This is the pupa of one of the large Saturnid Moths, often called Giant Silk Moths. It can be distinguished from the Sphinx Moth Pupa, also found underground, due to its robust girth and lack of future mouthparts, the Proboscis. Most Saturnid Moths build some type of cocoon, which eliminates many possible species. We are surmising that perhaps this is a Regal Moth, but your best course of action is to wait for the adult to emerge.

Letter 7 – Saturniid Caterpillar from Brazil


Subject:  Saturniid butterfly in Brazil
Geographic location of the bug:  Brazil, Santa Catarina, Benedito Novo
Date: 01/07/2018
Time: 11:43 AM EDT
Hello, I found this caterpillar and I have no clue what it is. At first it seemed like an Automeris, then a Pseudautomeris, then a Molippa… Now I don’t know what it is.
How you want your letter signed:  Oscar Neto

Saturniid Caterpillar

Dear Oscar,
Though they both belong to the same insect order Lepidoptera, most English speaking countries differentiate between butterflies which are primarily diurnal, and moths which are primarily, but not exclusively nocturnal.  There are also structural differences between them that is clarified in the taxonomic process.  We agree that this caterpillar belongs to the moth family Saturniidae, and it also appears to be an earlier instar caterpillar.  Many online images are of more mature caterpillars that sometimes differ in appearance from earlier stages.  Our initial guess would also be the genus
Automeris, and our second guess would be Leucanella, and both genera are well represented in Brazil.  We will attempt to get Bill Oehlke, an expert in Saturniids, to attempt to provide you with a species identification.  By chance, was if found feeding on a plant?  Often knowing the food plant is a great assistance in the identification process.

Letter 8 – Saturniid Caterpillar from Panama: Pseudautomeris salmonea


Subject: Spiny Caterpillar in Panama
Location: Panama, Central America
January 7, 2014 4:43 am
Hi Bugman! Any ideas about this caterpillar in Panama? Found in Panama City, Panama in January 2014 (the dry “summer” season here) in the early evening. It fell on my hand at one point as I was moving a leaf to take its picture, and it left a brief nettle rash on my hand, so I’m pretty sure those spines are poisonous. Thanks for any help!
Signature: Megan

Saturniid Caterpillar:  Pseudautomeris salmonea
Saturniid Caterpillar: Pseudautomeris salmonea

4:23 AM
to Whats
I think I found it!  Pretty sure it’s a Saturniid moth caterpillar.  Saturniidae family, Hemileucinae subfamily, scientific name “Pseudautomeris salmonea”.  Looks like it’s normally found in Panama, Colombia, Venezuela, French Guiana, and Brazil.  Very cool!

Saturniid Caterpillar:  Pseudautomeris salmonea
Saturniid Caterpillar: Pseudautomeris salmonea

Hi Megan,
We would have guessed the genus
Automeris, and if our knowledge of ancient languages that is frequently used for taxonomic names is correct, the identification you provided would be a “false” AutomerisAutomeris Caterpillars and closely related species do possess stinging spines.  We found an image of Pseudautomeris salmonea on a page called Preimaginal instars of Saturniidae (all species reared by Bernhard Wenczel) and it looks like a match to your caterpillar.  Merriam-Webster Dictionary defines “preimaginal” as:  “of, relating to, occurring in, or constituting a stage in insect development that immediately precedes the imago,” but that would include all eggs, caterpillars and pupae.  We did locate another photo of Pseudautomeris salmonea on Saturniidae World, but that individual has much shorter spines.  We are guessing that your caterpillar might be of different instar as that individual, because caterpillars change morphologically after each of the five molts they undergo prior to pupation.  The image on the Kirby Wolfe Collection on Bizland also looks very similar to your caterpillar.  We also located a matching image on a site with great caterpillar photos that we have never visited before called Chenilles-Guyane.  The photo we found on Project Noah, also from Panama, appears to be eating the same type of leaf as your caterpillar.  Thanks so much for writing in with a name.

That’s fantastic, thank you so much!  What a cool caterpillar.  So glad I stumbled upon him and got to my camera in time.  Thank you for the lightning fast response, confirmation of the ID, and additional resources.  That Chenilles-Guyane site does indeed have some great shots.  Thanks again to you and all your staff for what you do!  It’s such a cool resource.  ~Megan

Letter 9 – Saturniid Moth from Costa Rica: female Eacles imperialis decoris


Large Yellow Moth
July 18, 2009
I need help with identification of another moth. This one is a large yellow moth and was found in Uvita, Costa Rica also.
Uvita, Costa Rica

Saturniid from Costa Rica:  Eacles species
Saturniid from Costa Rica: Eacles imperialis decoris

Hi again Whitney,
We believe this is a female Eacles species, possibly Eacles masoni, based on some images on the World’s Greatest Saturniidae Site.  There is a U.S. species known as the Imperial Moth and there are several subspecies of the Imperial Moth, Eacles imperialis found in Costa Rica as well.  Again, we will be copying Bill Oehlke on this response so that he may catalog the sighting, and perhaps he will be able to clarify exactly what species this is.  Your close winged view is not one found on the WGSS website.

Correction from Bill Oehlke
It is Eacles imperialis decoris female, based on thin slightly scalloped pm line.
Bill Oehlke

Letter 10 – Saturniid Moth from South Africa: Imbrasia wahlbergi


Hawk Moth, but what kind?
A friend of mine sent a picture of a moth from Durban, South Africa. She said it was a hawk moth, but do you know what type of hawk moth it is please?

Hi JJ,
This is not a Hawk Moth, it is a Giant Silkmoth. We identified it as Imbrasia wahlbergi on Kirby Wolfe’s spectacular Saturniidae site.

Letter 11 – Unknown Chinese Saturnid Moth identified as Caligula Moth


what kind of bug
I found this moth on our boat on the Yanstze River in China. What kind of moth is it?

Hi Dave,
In a general sense, this is a Saturnid Moth, but sadly, we cannot tell you the species. We tried web searching, but need more time to get you an exact identification. It really is a gorgeous moth.

Update: (08/06/2006)
Hi Guys,
Hope this note finds you both well. The Chinese Saturnid on the Yangtze riverboat is Caligula simla. I found it on Kirby Wolfe’s absolutely impressive site.
David Gracer

Letter 12 – Unknown Saturnid Moth from South Africa identified as Southern Marbled Emperor


Ed. Note: (05/24/2008) It took us a bit of coaxing to get information from Selwyn, so we are posting this letter two days after it originally arrived.
(05/22/2008) HI
HI Please tell me what kind of moth this is many thanks

where was it photographed?

Plettenberg Bay

And where is Plettenberg Bay?

Ahaa you are not in South Africa. Sorry I took that for granted. Plettenberg bay is in South Africa

Thanks for that information Selwyn,
We scoured Kirby Wolfe’s excellent website to no avail. We can tell you this is a Giant Silk Moth or Emperor Moth in the family Saturniidae. We are contacting Kirby Wolfe to see if he can provide the species.

Update: (05/25/2008) ID for the South African Saturniid
I have contacted you before. Regarding that Saturniid from Plettenberg Bay, South Africa it appears to be Heniocha apollonia.

Hi Ryan,
Thank you for this valuable information. We managed to locate one website with two images of mounted specimens of Heniocha apollonia online, and it appears you are correct. Thanks again and have a wonderful day.

Update: (05/26/2008)
Hi Daniel,
The moth is Heniocha apollonia, the Southern Marbled Emperor, my favorite African moth. The one time I had eggs, the resulting larvae died for unknown reasons.


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. 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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  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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