What Do Giant Silk Moths Eat: A Glimpse into Their Diet

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Giant silk moths are fascinating creatures that intrigue many with their striking colors, large size, and unique features. As part of the Saturniidae family, they include some of the largest moths in North America like the Cecropia, Promethea, Polyphemus, and Luna moths, with wingspans ranging from 4 to 6 inches source. You might have wondered, “What do these magnificent insects eat?”

Well, the adult giant silk moths actually live off stored energy since their mouthparts are small or absent, meaning they don’t consume any food during their short lifespan of a few weeks source. However, their caterpillars, which eventually transform into these magnificent moths, have different feeding habits, munching on a variety of host plants like trees and shrubs. This sustenance is vital for their development, so let’s take a closer look at what these caterpillars eat.

Caterpillars of different giant silk moth species have distinct food preferences, feeding on leaves from trees such as cherry, willow, birch, maple, and more source. By focusing on their preferred host plants, these caterpillars can grow and develop, eventually spinning protective cocoons where they will metamorphose into the beautiful moths that capture our attention.

Life Cycle of Giant Silk Moths

Giant silk moths belong to the family Saturniidae, which is known for their large size and striking colors1. Understanding their life cycle starts with the eggs they lay. Female moths lay their eggs on specific host plants, ensuring their offspring have a food source as soon as they hatch2.

When the eggs hatch, the larvae, also known as caterpillars, emerge and begin feeding on their host plants. These caterpillars go through multiple stages, called instars, as they grow3. At each stage, they’ll molt, shedding their old skin to accommodate their increasing size4. They continue to eat and grow until they reach the pupa stage.

The pupa is where the transformation into an adult moth occurs. Giant silk moths typically create a cocoon in which they undergo this metamorphosis5. Cocoon spinning is an important part of their life cycle, as it provides a protective barrier from predators while they develop.

Giant silk moths have two main types of generations: univoltine and bivoltine. Univoltine moths have one generation per year, while bivoltine species have two generations6.


  • One generation per year
  • Longer life cycle


  • Two generations per year
  • Shorter life cycle

It’s fascinating to learn about the life cycle of these striking moths. By understanding how they grow and develop, you can appreciate their amazing existence in our ecosystems even more.

Diet of Giant Silk Moths

Giant silk moths’ diet changes as they go through their life cycle. As caterpillars, they feed on a variety of leaves from host trees. Some common host trees include:

  • Pear
  • Maple
  • Cherry
  • Birch
  • Willow
  • Oak
  • Walnut
  • Plum
  • Sassafras
  • Sweetgum

Caterpillars tend to be voracious eaters. They consume many of these leaves to store energy for their transition into adults. During this stage, they’ll molt several times, growing larger each time.

However, when the caterpillars become adult moths, their diet changes drastically. They no longer consume leaves and often do not eat at all. In fact, adult giant silk moths have no gut and only vestigial mouthparts1. They rely on the energy they stored as caterpillars to survive and focus on reproduction during their short adult lives.

In summary, the diet of giant silk moths depends on their life stage. Caterpillars eat various leaves from host trees, while adult moths do not need to feed due to their stored energy.

Physical Characteristics

Giant silk moths, also known as saturniids, are known for their unique and striking physical features. These moths vary in size and can have a wingspan ranging from medium to large. As you might expect, their color, size, and appearance differ based on the species.

One prominent feature of giant silk moths is their feathery antennae. Males tend to have more feathery antennae than females, with females usually having a thin filament or less feathery antennae. This distinction in antennae can help differentiate the sexes in some species.

Bright colors and patterns are common among these moths, with many species displaying prominent eyespots on their wings. These eyespots serve to deter predators, making the moths appear more intimidating.

Now let’s have a look at a quick comparison table of two popular giant silk moth species:

Species Wingspan Antennae Eyespots Color
Io 2.0-3.5 in Feathery (male) Yes Bright tan, red
Luna 3.0-4.5 in Thread-like No Pale green, white

Overall, the physical characteristics of giant silk moths make them truly remarkable creatures. Their large wingspans, varied colors, and unique antennae provide an intriguing blend of beauty and fascinating adaptations.

Habitat and Distribution

Giant silk moths, belonging to the family Saturniidae, have a widespread presence across North America. Their diverse habitats include forests, fields, and suburban areas, which provide ample space for them to thrive and reproduce.

In Florida, you can find Imperial Moths, a type of giant silk moth. These showy insects usually inhabit foliage of appropriate host plants, which often serve as food sources for their large, colorful caterpillars.

However, it’s important to note that adult giant silk moths typically don’t feed due to their small or nonexistent mouthparts. Consequently, they rely on the energy reserves they accumulated as caterpillars to sustain their few weeks of adult life.

Scientific Classification

Kingdom to Order

Giant silk moths belong to the kingdom Eukaryota, which comprises a wide range of organisms, including animals like them. These moths fall under the phylum Arthropoda and class Insecta. Being insects with scales on their wings, they belong to the order Lepidoptera.

Family to Species

The family Saturniidae, also known as giant silk moths or saturniid moths, includes some of the most impressive and beautiful moth species like Antheraea, Hyalophora cecropia, and Actias luna. They belong to the subfamily Saturniinae.

Binomial Nomenclature

The binomial name system is used in the scientific classification of species. Swedish naturalist Carl Linnaeus introduced this system in his work Systema Naturae. Some examples of binomial names for giant silk moths include Hyalophora cecropia (cecropia moth), Actias luna (luna moth), and Antheraea polyphemus (polyphemus moth).

Specific Species

Here are some noteworthy giant silk moth species:

  • Cecropia moth (Hyalophora cecropia): The largest native North American moth, with a wingspan of up to 6 inches.
  • Luna moth (Actias luna): Recognizable by their lime-green color and long, sweeping tails on each hindwing.
  • Polyphemus moth (Antheraea polyphemus): Named after the cyclops Polyphemus from Greek mythology, due to their large eyespots on their hindwings.
  • Spongy moth (Lymantria dispar): Known for its potential to defoliate large areas of trees.

In conclusion, the scientific classification of giant silk moths helps us understand their place in the animal kingdom and differentiate specific species within the family Saturniidae. Whether it’s the cecropia, luna, or polyphemus moth, each species carries unique characteristics, making them distinct and fascinating creatures.

Behavior and Adaptations

Giant silk moths are fascinating creatures with unique behaviors and adaptations that enable them to survive and reproduce.

One essential aspect of their life cycle is mating. These moths typically mate soon after emerging from their cocoons. Since they have a short adult life, their primary focus is reproducing.

It’s important to recognize that these moths have developed various defense mechanisms to protect themselves from predators. Some moths have prominent eyespots, which can startle or deter the attackers by mimicking large predatory eyes.

You might be interested to know that in captivity, giant silk moth caterpillars are often fed on fresh leaves, such as oak or cherry. However, adult moths don’t feed, as they have only vestigial mouthparts.

Here’s a brief comparison table of some key features:

Feature Giant Silk Moth
Survival Strategy Defense mechanisms, short adult life focused on reproduction
Predators Squirrels, owls, bats, and woodpeckers
Diet Fresh leaves (for caterpillars), no feeding for adults

Interestingly, their adult stage does not include eating. The stored energy gathered during their time as caterpillars sustains them as they search for a mate.

Giant silk moths have fascinating exoskeletons, which not only provide them protection but also contribute to their impressive appearance. NSCoderm}
Moreover, they are known for creating beautiful and large cocoons, wherein they develop into adult moths. This cocoon stage is an essential part of their life cycle and metamorphosis.

In conclusion, understanding the behavior and adaptations of the giant silk moth allows you to appreciate its contributions to the ecosystem and its amazing survival abilities even more. So next time you encounter one, take a moment to marvel at its intriguing features and life cycle.

Conservation and Threats

Natural Predators

Giant silk moths face various threats in their natural habitat. One significant threat comes from their natural predators, such as squirrels and birds. For example, the Screech Owls and bats are known to feed on adult giant silk moths. On the other hand, woodpeckers extract the pupae from their cases.

Parasitism and Diseases

Another challenge to the survival of giant silk moths is parasitism and diseases. The introduced parasitic fly, Compsilura concinnata, has been responsible for a decline in wild silk moth populations, including the Giant Silk Moths. This fly attacks caterpillars, significantly affecting the survival rate of the moths.

In conclusion, ensuring the conservation of giant silk moths requires addressing these threats and maintaining their natural habitats. This can be achieved through conservation efforts and awareness about the significance of these species.

Cultural Significance

In the world of moths, the giant silk moth holds a special place. These magnificent creatures are known for their large size and stunning patterns. Many people find them fascinating, and they have even made their way into various aspects of human culture.

For example, you might be interested to know that the largest moth, the Atlas moth, is named after a figure in Greek mythology. Atlas, a Titan, was condemned to hold up the heavens for all eternity. The moth’s impressive size and beautiful wings are reminiscent of this legendary character.

In addition to their size, giant silk moths are admired for their silk production. While not as strong as spider silk, the silk produced by these moths has inspired artists and been used for various purposes throughout history.

These captivating moths have also found their way into folktales and stories across different cultures. They are often portrayed as gentle giants with mystical qualities, symbolizing grace, transformation, and the ephemeral nature of life.

Even today, these beautiful creatures continue to capture the imagination of people around the world. Whether you’re marveling at their stunning patterns or admiring their cultural significance, giant silk moths are truly a wonder in the world of insects.

References and External Links

In your exploration of giant silk moths and their diet, it’s essential to consider reliable sources. Here are some references and external links to help you expand your knowledge:

  • Elkinton, J. S., and Boettner, G. H., two respected researchers, have studied giant silk moths and their behavior. They offer valuable insight into the lives and feeding habits of these fascinating creatures.

  • The University of Kentucky’s Entomology website provides detailed information about giant silkworm moths, including their life cycle and diet.

  • Missouri Department of Conservation’s field guide on giant silk and royal moths offers information about their feeding habits and other useful facts.

  • The Field Station at the University of Wisconsin-Milwaukee describes the lives and diets of giant silk moths in detail, from their transformation as caterpillars to adult moths.

Remember to keep these resources handy as you continue learning about giant silk moths, their diets, and their ecological roles. Being well-informed ensures that you understand the fascinating world of these beautiful insects. And, as always, approach your research with a friendly and open mind. Happy learning!


  1. Giant Silkworm Moths | Entomology – University of Kentucky 2

  2. Giant Silkworm and Royal Moths – Missouri Department of Conservation

  3. Giant Silk Moths (Family Saturnidae) – Field Station

  4. Giant Silk Moths (Family Saturnidae) – Field Station

  5. The Filippi’s Glands of Giant Silk Moths: To Be or Not to Be?

  6. Giant silk moths: not all moths are tiny, drab creatures – River Reporter

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 – Polyphemus Moth


Need ID of This Beautiful Nocturnal(?) Moth
Hi There Bugman,
Just discovered your funky bug site. I need an ID on this critter that crossed my path (literally flew into my face) one warm evening in August of ’03. I live on Long Island NY and never in my 42 years seen one of these kind of moths flying around. I initially mistook it for a small brown bat! I then figured it for a Luna moth but after seeing one ID’d on your site I have not a clue. Please Advise.

Hi R.P.
Your Polyphemus Moth, Antheraea polyphemus, belongs to the same Family as the Luna Moth. Both are Saturnids or Giant Silkworm Moths. Caterpillars eat leaves from many deciduous trees and adults do not feed, living only a few days to mate and reproduce.

Letter 2 – Polyphemus Moth Caterpillar


Location: Macedonia Ohio
August 1, 2011 6:11 pm
Hi! Found your website and figured you might be able to help! We found what we think is a caterpillar, but I’m not sure. It was a very bright green color, almost neon and had a head that came out of its body, that almost looked like a beetles head! Also reminded me of a gummy worm cause of the consistency. We didn’t bother him much, just took him out of the driveway and put him on a tree. We would really like to know more about this pretty little thing! Ill try to attach a picture of him! Thank you very much!
Signature: Amanda

Polyphemus Moth Caterpillar

Hi Amanda,
We really love the way your Polyphemus Moth Caterpillar appears to be smiling for the camera.

Thank you so much!! And yes.. we joked about when he seen me there, he kinda lifted his head up to say hello! He’s awesome!

Letter 3 – Polyphemus Moth Cocoon


Subject: Nest Glob in Birch Tree?
Location: Moss Beach, CA, USA
January 8, 2016 3:50 pm
Dear Bugman,
I just discovered this thing in our birch tree. I went up a ladder and took a photo. It is about 4″-5″ tall and about 3″-4″ wide. It looks like it was made with leaves and fibers wrapped around something which are now decayed and attached with little stringy bits at the top and to some small branches. I can’t see an entrance anywhere, but it was up high so I couldn’t see the very top. I haven’t seen any activity going in or out. We are about a block and a half from the ocean, if that helps. I don’t want to cut it down in case it is something that is not harmful. But if it IS harmful, I want it off of there before something creepy, bitey and stingy emerges!
Signature: Christine

Polyphemus Moth Cocoon
Polyphemus Moth Cocoon

Dear Christine,
If you had been located in the Eastern portion of the U.S., we would have been in doubt of the identity of your cocoon, but since the Luna Moth is not a western species, by the process of elimination, we believe this is the cocoon of a Polyphemus Moth.  The caterpillar constructs the cocoon by spinning silk around leaves from the food plant, and sometimes the cocoon remains on the tree and sometimes it falls to the ground when the leaves fall.  We were not certain if birch was a food plant for the Polyphemus Moth, but according to the Auburn University Entomology and Plant Pathology site:  “The larva feeds on the foliage of many species of trees, including oak, maple, basswood, beech, butternut, walnut, birch, yellow-poplar, sassafras, ash, willow, elm, and sycamore. ” 

About fifteen minutes ago I sent a photo of a nest in our birch tree.  I think I may have figured it out.  I started searching a different way and found photos of Giant Silk Moth nests which look very like what is in our birch tree.  Some photos show  holes from a woodpecker and I want your opinion on an idea I have.  I would love to see the moth emerge and was thinking of placing a protective netting  cage around it so it still gets moisture and the cold air it needs and then closely monitor it.  It would be sad if a woodpecker found it and ate the yummy moth inside!
Signature: Christine

Hi again Christine,
A protective netting will help keep out large predators, but you will have to remain diligent and check for emergence on a daily basis.  You might be better off letting nature take its course.

Hello Mr. Marlos,
Thank you for responding so quickly.  I am a housewife and am at home most of the time; the birch tree is just 15′ from our front door and I feed the birds out in the garden.  I can keep a close eye on it.  Maybe I can fashion something with a door so if there is a day when I will be gone for a long time, I can keep it open and hope for the best.  I found a website dedicated to raising them and I now have a pretty good idea of how best to keep it safe, but when it hatches, let it go about its mothy business!  I hope I can get some nice photos!
Thank you,

Letter 4 – Polyphemus Moth emerges in New York


Subject: Polyphemus moth?
Location: Spencerport, NY
March 2, 2016 2:51 pm
Hello! We found this lovely caterpillar in the fall and watched it make a chrysalis. Today I found it alive and well and clinging to my Keurig in the warm evening sunshine! We are in Spencerport, NY and it is May 2nd. Rather chilly outside still so we are not putting it outside. We would love to know what to give to it for a food source to help it survive until it is warm enough for it to be outside. My kids are ecstatic watching the wings unfold!! As am I!
Signature: The Trainer Clan

Polyphemus Moth
Polyphemus Moth

Dear Trainer Clan,
While observing the transformations that occur during metamorphosis is a wonderful experience for both children and adults, we are sad that this particular emergence will not result in perpetuation of the species.  The Polyphemus Moth, like other Giant Silkmoths, does not feed as an adult.  Adult Giant Silkmoths only live a few days, long enough to find a mate and reproduce.  The females, and your individual is a female, release pheromones that the males, with their well developed, feathery antennae, can sense from many miles away, enabling them to fly to the females.  Keeping a cocoon or chrysalis indoors interrupts the natural life cycle, and the indoor warmth will cause early emergence.  Unfortunately, your female will die unmated as she will not live long enough for the outdoor weather to warm.

Letter 5 – Polyphemus Moth Caterpillar


polyphemus caterpillar?
I think from your site that this might be a polyphemus caterpillar, but I couldn’t really tell because the pictures of them weren’t quite sharp enough. So here is my picture. The kids found it in the back yard on September 9 near a maple tree, I believe. We live in Portland, Or. Thanks!
Leah Parker

Hi Leah,
You are correct. This is a Polyphemus Moth Caterpillar. Here is BugGuide’s description of the caterpillar: “Larva: body large, bright green, with red and silvery spots below setae, and oblique yellow lines running through spiracles on abdomen; diagonal streak of black and silver on ninth abdominal segment; head and true legs brown; base of primary setae red, subdorsal and lateral setae have silver shading below; end of prolegs with yellow ring, and tipped in black.” Most of the identifying features cannot be viewed from your camera angle. A lateral view is best. While the Polyphemus Moth Caterpillar might be confused with the Luna Moth Caterpillar in the east, there is nothing similar looking in the western U.S.

Letter 6 – Polyphemus Moth Caterpillar


Subject: Big green caterpillar
Location: Appalachian southern Ohio
October 19, 2013 7:06 am
Thank you for this excellent site! I have been looking at hornworms, sphinx moths etc but cannot find this particular species. Over 5 inches when extended, picture is of adult hand. Who is this lovely creature?
Signature: C. Suggs

Polyphemus Caterpillar
Polyphemus Caterpillar

Dear C. Suggs,
You were unable to identify your caterpillar because it is not a Hornworm.  This is a Giant Silkmoth Caterpillar, or more specifically, a Polyphemus Moth Caterpillar.  You may also compare your image to this photo on BugGuide.  This individual is most likely preparing to pupate.

Thank you so much!  I really appreciate your work in helping people to appreciate insects.  I am an unofficial ambassador on behalf of insects as well.
Charlene  Suggs

Letter 7 – Polyphemus Moth


Giant Moth ID?
What kind of a beautiful moth is this? We reside in SE Wisconsin and have never seen such a large, beautiful moth! Is it a member of the Witch moth family? Great website!
Suz and Joe K.

Hi Suz and Joe,
Not a Witch Moth but a Giant Silkworm or Saturnid Moth. More specifically, a Polyphemus Moth.

Letter 8 – Polyphemus Moth


moth identity
Found this beautiful & large moth in my backyard last night, the second one in as many weeks, much to my kids joy. I’m pretty sure it’s a hawk-eyed moth, but would like confirmation. Also any links for more info, such as what the larva is consuming. Cheers!
Okanagan Valley, British Columbia, Canada

Hi Greg,
Your moth is not a Hawkmoth, but a Polyphemus Moth, Antheraea polyphemus, one of the Giant Silkworms in the Family Saturniidae. The large caterpillars eat leaves from alder, basswood, birch, chestnut, elm, hickory, maple, poplar sycamore, and oak as well as other hardwood trees.

Letter 9 – Polyphemus Moth


I live in the Bay Area and saw this moth yesterday on the sidewalk. What type of moth is this? Is this moth rare?

Hi Derek,
This is a Polyphemus Moth, Antheraea polyphemus. It ranges throughout the U.S. and is not rare. Because of their large size, they always create a stir when seen for the first time.

Letter 10 – Polyphemus Moth


Subject: Moth
Location: Florida
February 18, 2014 2:13 pm
Hi there~ this guy was parked by my front door today! Very cool moth! Look at the strange antenae?
Signature: twirlyboggs

Polyphemus Moth
Polyphemus Moth

Dear twirlyboggs,
Your moth is a Polyphemus Moth and the highly developed, feathery antennae indicate that this is a male.  He uses his antennae to locate a female through her pheromones.

Letter 11 – Polyphemus Moth


Subject: Moth
Location: Coatesville, Indiana
August 7, 2014 11:31 pm
I found this moth in Coatesville, Indiana. It was the beginning of August, Midday. It had deformed wings, and you can see the size compared to my fingertips. It had a furry body, deformed wings, and it kept laying eggs or pellets on my fingers. the pellets were beige with a black dot in the middle and an almost tar-like substance on the bottom to attach it. I’m really curious what this little guy is called!!!
Signature: Deena B.

Polyphemus Moth
Polyphemus Moth

Dear Deena,
This Polyphemus Moth either has atrophied wings, or they have not completely expanded after emergence from the pupa.

Letter 12 – Polyphemus Moth


Subject: Huge Moth
Location: South Central Texas
March 27, 2015 6:08 pm
Could you identify this moth for me? I live at the easternmost edge of the Texas Hill Country where cedar and oak trees are prolific. The moth’s wings are about 3 inches in length. It clung to this brick in this position for 3 days. The antennae are very interesting. I believe it is a male. Many thanks!
Signature: Rita K, Schertz, TX

Polyphemus Moth
Polyphemus Moth

Dear Rita,
This beauty is a Polyphemus Moth,
Antheraea polyphemus, and you can tell by the feathery antennae that it is a male.  We hope you were able to see him with his wings opened, because the incredible eyespots on his wings are quite showy.

Letter 13 – Polyphemus Moth


Subject: Large Moth
Location: Austin, Texas
April 8, 2015 3:44 pm
We have a moth that we found on the outside of our house near our light. It leaves every night and returns the next day, and has been for a couple days now. It is quite large relative to the moths we usually see. It is about the size of my fist when the moth is closed like in the picture, maybe even a little bigger. Do you know what kind it is and why it keeps returning to our house?
Signature: Jamie Dawson

Polyphemus Moth
Polyphemus Moth

Dear Jamie,
This Polyphemus Moth is most likely being attracted to your light.  Polyphemus Moths do not feed as adults and only live a few days, long enough to mate, so your nightly visits by this individual will end soon.

Letter 14 – Polyphemus Moth


Subject: Moth or spider or both?
Location: Kansas City, Missouri
May 30, 2015 4:39 pm
Hi Daniel, my niece found this adorable little critter in Kansas City Missouri.
Any idea what it might be?
Thanks a bunch,
Signature: Michele

Polyphemus Moth
Polyphemus Moth

Dear Michele,
Moths do not have wings.  This is a Polyphemus Moth, and if he had opened his wings, you would have been treated to a marvelous sight.  The markings on a Polyphemus Moth are thought to mimic eyes, indicating a much larger and potentially dangerous creature that would frighten away a predatory bird.

Letter 15 – Polyphemus Moth


Subject: Type of Moth?
Location: St. Louis, MO
July 20, 2015 6:50 am
I was out walking the dog this morning (July 20th), at about 8AM, when I saw this poor beauty dying on the sidewalk! They are about 8 inches or so wide, from wing tip to wing tip. I found them by a park (Fox Park) in the southern inner city area of west St. Louis. Help me correctly mark their grave!
Signature: Angela

Polyphemus Moth
Polyphemus Moth

Dear Angela,
This beauty is a Polyphemus Moth, and adults do not eat, only living long enough to mate and reproduce, so while she is not long for this world, your assessment that she is dying might be premature.  Because of the antennae, this appears to be a female Polyphemus Moth, and if she has not yet laid eggs, she is likely heavy with eggs, meaning it takes tremendous energy to fly.  Place her in a sheltered location and she may take flight after dark.  If she has not mated, she will release pheromones to hopefully attract a mate.  If she has mated, she can lay fertilized eggs.  The eggs will hatch in about a week, and you can release the caterpillar on an appropriate food plant.  According to BugGuide, the caterpillars will eat the leaves of:  “birch, grape, hickory, maple, oak, willow, and members of the rose family.”

Letter 16 – Polyphemus Moth


Subject: Injured moth outside a building
Location: Melbourne Florida
March 20, 2016 9:39 am
Hello, a few month back I took a picture of a moth siting on the side of a building. It had an injury on one of its wings. I was hoping you could identify it for me.
Signature: Travis

Polyphemus Moth
Polyphemus Moth

Dear Travis,
The magnificent Polyphemus Moth is found across the continental North America.

Letter 17 – Polyphemus Moth


Subject: Moth ID
Location: Massachusetts
yJune 2, 2016 12:51 pm
What kind of moth is this? Don’t know? Maybe I can name it after myself. . .
This moth was about 4 inches (8 inch wingspan). Acted dead.
Signature: Discoverer

Polyphemus Moth
Polyphemus Moth

Dear Discoverer,
This magnificent moth is a Polyphemus Moth, one of the Giant Silkmoths in the family Saturniidae, that owes its common name Polyphemus Moth to the eyespots on its underwings that are used to frighten potential predators.  Polyphemus is the legendary Cyclops from Greek mythology.

Letter 18 – Polyphemus Moth


Subject: Large moth
Location: Collegeville., PA
June 25, 2016 9:19 am
This was at my sons door in Collegeville, PA this week
Signature: Dave C

Polyphemus Moth
Polyphemus Moth

Dear Dave,
This beauty is a Polyphemus Moth.

Letter 19 – Polyphemus Moth


Subject: What kind of moth is this
Location: Cypress,TX
August 3, 2016 7:23 pm
We found a large moth (5″ across) on the edge of our pool on Aug 2 in Cypress TX. Reddish brown with eyespots, some black on the lower wings. Think it layed eggs on the edge of the pool. Was gone by dark. It was really gorgeous. Can you tell me what kind of moth it was? I can send a picture.
Signature: Cheryl Claybough

Polyphemus Moth
Polyphemus Moth

Dear Cheryl,
This lovely moth is a Polyphemus Moth.

Thanks so much for the quick response.  We just moved to the Houston area and this was the first one I have seen. It stayed for quite awhile without moving right about the waterline of our pool.  Up close you could tell it had many of the same colors as our pool tiles.
Also I really appreciate your website.

The Polyphemus Moth has been reported from all 48 continental United States as well as across Canada.

Letter 20 – Polyphemus Moth


Subject: What is this?
Location: Bronx, NY, 10467
August 10, 2016 7:30 pm
So it was around 9pm, I’m using the bathroom and I hear a PLAT and I look and i see this giant moth, I’ve never seen this before in New York. I didn’t even know we had moths like this. Do you have any idea of what this is?
Signature: Corinthia Ferreiras

Polyphemus Moth
Polyphemus Moth

Dear Corinthia,
This is probably the ghostliest image we have ever received of a Polyphemus Moth.

Letter 21 – Polyphemus Moth


Subject: Unknown Bug on Car
Location: Winter Park, FL
October 15, 2016 8:26 am
This large looking moth was hanging on the side of a car. Hurricane Matthew recently came through, wondered if it could have been disturbed by the storm.
Signature: Maxwell D Osborne

Male Polyphemus Moth
Male Polyphemus Moth

Dear Maxwell,
This male Polyphemus Moth is a local species for you, and we don’t believe Hurricane Matthew had anything to do with its appearance.  The startling eyespot markings are hidden in your image.  Polyphmus Moths are found in all 48 lower United States.

Letter 22 – Polyphemus Moth


Subject: Polyphemus Moth?
Location: Southeastern PA
April 27, 2017 10:40 am
This moth was here most of the day yesterday. (April 26 2017)
We weren’t sure what type it is, then we saw your site. We think it is a Polyphemus moth.
Signature: Lori

Polyphemus Moth

Dear Lori,
You are correct that this is a Polyphemus Moth.  It is resting with the wings folded above the body, a position that is often cited to identify butterflies by distinguishing them from moths, yet it is a resting position frequently used by the Polyphemus Moth, perhaps because it effectively camouflages the Polyphemus Moth among dried leaves.  We hope you were able to witness the spectacular eyespots on the upper surface of the underwings.  When startled, the Polyphemus Moth will “open its eyes” which effectively startles predators like birds into thinking they are about to be eaten by a much larger predator.

Letter 23 – Polyphemus Moth


Subject: What is this?
Location: Ashland va. USA
June 4, 2017 9:23 pm
Saw this on the wall of a business in
Ashland virginia thought it looked strange…
Signature: Curious. …

Polyphemus Moth

Dear Curious,
This beautiful Giant Silkmoth is the Polyphemus Moth, named after the mythical Greek, one-eyed giant Clyclops.  If you disturb the moth, it might flash its large false eyespots that it uses to startle an imminent predator into thinking it is about to be eaten by a much larger creature.  One more image of mating Polyphemus Moths from our archives.

Letter 24 – Polyphemus Moth


Subject: Large Moth in N. Mississippi
Location: Southaven, Mississippi
August 9, 2017 7:56 am
Hi Daniel!
One of your previous bug queen’s of the day here. LoL. I was sent this photo of an extremely large brown moth and wondered if you would be so kind as to identify it. I thought it might be a type of silk moth, but, this is a first for me.
Signature: Stephanie

Polyphemus Moth

Dear Stephanie,
This is a Polyphemus Moth, and it appears to be a female that is full of eggs.

Letter 25 – Polyphemus Moth


Subject:  Large  Moth
Geographic location of the bug:  Arlington TX
Date: 03/31/2019
Time: 11:29 PM EDT
Your letter to the bugman:  Hi! I found a large brown moth with something that looks like eyes on the wings. It been by my front door for over 24 hours. It is very weird with a furry like head and legs like spiders. Is it dangerous and where did it come from? Thanks!
How you want your letter signed:  Minnie Moore

Polyphemus Moth

Dear Minnie Moore,
This is a female Polyphemus Moth, which was named after the one-eyed cyclops of mythology, but we have always pondered why a moth with two large eyespots would be named after a one eyed giant.  Perhaps it is because when the moth is startled and reveals its eyespots to frighten a predator, it begins by only revealing one spot, winking at its attacker in an effort to startle the predator into perceiving that it has awoken a sleeping giant that might in fact “eat” the predator.

Very interesting!
It’s still on the side of the house since Saturday, but moved up some. Is something going on with it? We thought it would have flown away by now. No one wants to disturb “her”.
Thank you so much!

Hi again Minnie,
Giant Silkmoths do not feed as adults, so they do not waste energy by flying unnecessarily.  She may be waiting to attract a mate before she flies off to lay eggs.

Letter 26 – Polyphemus Moth


Subject:  large moth
Geographic location of the bug:  High Point, North Carolina
Date: 04/26/2019
Time: 12:59 PM EDT
Your letter to the bugman:  I’d like to identify this large moth I saw sitting on a piece of lawn furniture outside yesterday
How you want your letter signed:  Weremonkey

Polyphemus Moth

Dear Weremonkey,
Congratulations on your Polyphemus Moth sighting.

Letter 27 – Polyphemus Moth


Subject:  Polyphemus
Geographic location of the bug:  Florida
Date: 10/06/2019
Time: 01:56 PM EDT
Your letter to the bugman:  I found this almost becoming prey to a bird when I came outside. Luckily I scared the bird off but the moth was struggling to get up. I put the dog inside and came back out to find it waddling up the tree to safety. Can you tell if it’s a female, pregnant, or going to be ok? Is there anything I can do?
How you want your letter signed:  Concerned neighbor

Female Polyphemus Moth

Dear Concerned neighborh,
This is indeed a Polyphemus Moth and she is a female moth.  Since all Giant Silkmoths, including the Polyphemus, do not feed as adults, they only have a few days to mate and produce a new generation, so virtually all female Polyphemus Moths are “pregnant”.  You should let nature takes its course, but your kind actions in rescuing this individual from a bird has earned you the Bug Humanitarian Award.

Letter 28 – Polyphemus Moth and Caterpillar


Subject: Beautiful moth
Location: West of St.Louis Missouri
July 15, 2015 6:49 pm
Hi we found this beautiful moth, it actually flew right into me when I was on my deck one evening :), the 2nd picture is a caterpillar my son found, it spun a cocoon so I know it is a moth but not what kind.
Signature: ?

Polyphemus Moth
Polyphemus Moth

Dear ?,
The moth and caterpillar are both the same species.  Thanks for providing such beautiful images of a Polyphemus Moth and a Polyphemus Caterpillar.  If you are able, we would love to include an image of the cocoon in the posting as well.  You can read more about the Polyphemus Moth on BugGuide where it states:  “Larvae feed on leaves of broad-leaved trees and shrubs, including birch, grape, hickory, maple, oak, willow, and members of the rose family.  Adults do not feed.”

Polyphemus Caterpillar
Polyphemus Caterpillar


Letter 29 – Polyphemus Moth Caterpillar


My son found this near our home in Croydon Pa. What is it?

Your son found a Polyphemus Moth, Antheraea polyphemus, caterpillar.

Letter 30 – Polyphemus Moth Caterpillar


Our daughter found this crawling in our backyard in Dripping Springs, Texas (Central Texas). We thought it might be a type of Luna Moth caterpillar…can you identify? Notice the patch of blue (both sides). Thanks,
Chip and Nancy Beebe

Hi Chip and Nancy,
It is easy to confuse the Luna Moth Caterpillar with the Polyphemus Moth Caterpillar. This is actually the Polyphemus Moth Caterpillar.

Letter 31 – Polyphemus Moth Caterpillar


Unknown Caterpillar
My nephew found this caterpillar on November 17, in the top of an oak tree, in Apopka, Fl. Can you tell us what it is?
Patty W.

Hi Patty,
This is a Polyphemus Moth Caterpillar. It is one of the Giant Silk Moths or Saturnid Moths. We have many photos of adult moths.

Letter 32 – Polyphemus Moth Caterpillar


What’s this caterpillar?
A friend gave me your link, and I’ve looked but can’t find this caterpillar. Can you help? We have TONS of Luna Moths, and I’m wondering if this is a caterpillar to a Luna Moth. The first time I saw them, they were about as big around as a pencil and only 2″ long. Now they are over 4″ long and as big around as a magic marker. Please email back and let me know what it is, and if I should be concerned. They sure are going to town eating my Lobelia!! Here is a close up it let me take. Camera was only a couple inches from it, as I wanted to get it’s “face” in the picture. Are those
teeth?? Have a wonderful day!
Pamela Graham

Hi Pamela,
We believe this is a Polyphemus Moth Caterpillar. They do not have teeth.

Letter 33 – Polyphemus Moth Caterpillar


Big Yellow-Green Crawler with mouse teeth
Thu, Oct 30, 2008 at 3:25 PM
I found this crawling down our driveway this morning and the kids and I want to know what it is? We live in North Texas and have some Live Oak trees.
Always Wondering
Dallas, TX area

Polyphemus Caterpillar
Polyphemus Caterpillar

Dear Always,
This is a Polyphemus Moth Caterpillar, Antheraea polyphemus, and you may find information on the caterpillar and moth by visiting BugGuide. Giant Silkworm Caterpillars like this are often noticed when they leave trees and search for places to pupate.

Letter 34 – Polyphemus Moth Caterpillar


”Bubbly” the caterpillar
Location: Portland, OR
September 19, 2011 9:14 pm
Playing at Patton Square City Park in Portland, OR this afternoon, some kids found this really cool caterpillar. Posting a photo on facebook led to many suggestions, including the Polyphemus Moth, Luna Moth, and Tomato worm. Regardless of what he was, or what he will be, he was really, really cool to watch. What do you think?
Signature: ALW

Polyphemus Moth Caterpillar

Dear ALW,
Your first choice was correct.  This is the caterpillar of a Polyphemus Moth.  The Luna Moth is not found that far west, and the Tomato Hornworm does not feed on oak.

Letter 35 – Polyphemus Moth Caterpillar Cocooning


Subject: Believed to be a polyphemus moth caterpillar
Location: Hickory, North Carolina
October 14, 2015 11:32 am
Hey, I found this little beauty on my porch, and I’ve been sitting with him for a few hours. At first he would hide his head, but has seemed to get somewhat comfortable with me. I thought you might like the picture.
Signature: Zeb Sterling Austin

Polyphemus Moth Caterpillar
Polyphemus Moth Caterpillar

Dear Zeb,
We agree that this is a Polphemus Moth Caterpillar and we congratulate you on being able to distinguish it from a Luna Moth Caterpillar.  According to BugGuide:  “Larva: body large, bright green, with red and silvery spots below setae, and oblique yellow lines running through spiracles on abdomen; diagonal streak of black and silver on ninth abdominal segment; head and true legs brown; base of primary setae red, subdorsal and lateral setae have silver shading below; end of prolegs with yellow ring, and tipped in black”  Of the Luna Moth Caterpillar, BugGuide notes:  “Larva lime-green with pink spots and weak subspiracular stripe on abdomen. Yellow lines cross the larva’s back near the back end of each segment (compare Polyphemus moth caterpillars, which have yellow lines crossing at spiracles). Anal proleg edged in yellow.(2) Sparse hairs.”
We suspect your caterpillar might be preparing to pupate.  Put it near some fallen leaves that have not yet dried out and see if it spins a cocoon.

It has already started to spin it’s cocoon on my windowsill, and he’s making some definite progress. I’ll gladly include more pictures if you would like. I was absolutely ecstatic to see both the little guy and that you posted my request. I’ve followed the website since I was around 12, but have never really needed anything identified. I just wanted to make sure I was right. Thank you very much for making my day. (Although my girlfriend would probably like me to shut up about how excited I am.)
Many thanks,

Polyphemus Caterpillar Cocooning
Polyphemus Caterpillar Cocooning

Hey, here’s an update on the little guy’s progress. He did something odd. (It may be normal behavior, I’m no expert) But he dragged strings of silk down nearly the entire length of the windowsill, then returned to work on his cocoon. It’s very interesting to watch him build.

I apologize for the amount of emails, but something a bit funny just happened. The caterpillar was cold and curled up, and I started petting his back. Well he turned and started running his head against my finger like he was showing affection. I’m sure it was just checking out my finger, but it was incredibly adorable.

Polyphemus Caterpillar Cocooning
Polyphemus Caterpillar Cocooning

We believe the caterpillar is ensuring that the cocoon will be well anchored to the window sill.  Providing some leaves would be a nice assistance.

Letter 36 – Polyphemus Moth Caterpillar


Subject: Big bug
Location: Bowling green, Ohii
August 7, 2017 2:33 pm
I have seen these creaturs before but rarely. My friend just sent me your site. This one was almost 2 inches long.
Thanks in advance for your ID help!
Signature: Lynn

Polyphemus Moth Caterpillar

Dear Lynn,
This is the caterpillar of a Polyphemus Moth.  Despite having two prominent eyespots, the Polyphemus Moth was named after the one-eyed Cyclops of Odyssey fame.  Polyphemus Moths are found in all 48 of the continental United States.  Featured Creatures has an excellent posting on the Polyphemus Moth which includes this information:  “Caterpillars are solitary and develop through five instars. Immediately after hatching, caterpillars eat their egg shells (Opler et al. 2012 ). Older instars eat whole leaves and then sever the petioles to drop them to the ground (Tuskes et al. 1996) – possibly to obscure their presence from predators The presence of large larvae on branches overhead may often be detected by the presence of frass (caterpillar droppings) on pavement of driveways or parking lots.”

Letter 37 – Polyphemus Moth Caterpillar


Subject:  Large Catepillar
Geographic location of the bug:  Lynnwood WA Late September
Date: 09/21/2021
Time: 05:58 PM EDT
Your letter to the bugman:  Large Lime Green caterpillar. Large cross of brown located at the Anul area.
How you want your letter signed:  Bill

Polyphemus Moth Caterpillar

Dear Bill,
This is a Polyphemus Moth Caterpillar.  The Polyphemus Moth has the greatest range of all the North American Giant Silk Moths, being reported in all 48 lower states.

Letter 38 – Polyphemus Moth Cocoon


Your site is wonderful. We have just moved from Southern Calif to South Carolina and would like to learn the flora and fauna here in south. I photographed this cocoon and have been watching it closely but if I miss it I would sure like to know what I missed. Thanks,

Hi Kathy,
If you happen to catch the metamorphosis, you will be in for quite a treat. This is a Polyphemus Moth Cocoon. We have images of the moths on our Giant Silkworm or Saturnid Moth page. Sometimes the cocoons are suspended from branches like your photo, and sometimes they are found in leaf litter on the ground.

Letter 39 – Two Luna Moths in Maine


Luna Moth
Location: Freeport Maine
July 24, 2011 10:42 am
I discovered a Luna Moth on my barn door. It stayed with us 3 days before a 2nd one appeared. They stayed an additional day and a half for a total of 4 1/2 days for the first and 1 1/2 days for the 2nd. I understand it is very rare to see one, let alone 2 in the same place at the same time. We live in Maine and this is the first time we have ever seen one before.
Signature: Lisa in Maine

Luna Moth

Hi Lisa,
Luna Moths have a relatively extensive range, and each year we get numerous reports.  While they have a large range, the population does not seem to be distributed evenly.  In areas where conditions are favorable and food plants are available, they can be quite plentiful.  Reports indicate that Maine is a location where populations of Luna Moths can be quite dense.

Luna Moths

Letter 40 – Polyphemus Moth ecloses in dead of winter


Subject: Help – our moth hatched and its snowing outside!
Location: Columbus, Ohio
February 16, 2014 7:28 am
Hi. My kids found a big fat green caterpillar and brought it in the house. The first night we had it, it made a caccoon. This was 18 weeks ago. We thought it was dead – but it hatched last night. We live in Ohio and its snowing with 20 degree temps right now. Do we set it free or keep it inside? What do we feed it?
Thanks for your help!
Shelly Breehl & Family
Signature: The Breehl Family

Polyphemus Moth
Polyphemus Moth

Dear Shelly and the Breehl Family,
This is a Polyphemus Moth, a member of the Giant Silk Moth family Saturniidae.  Setting it free with sub-freezing temperatures will result in instant death.  Keeping the moth indoors will most probably result in a longer life than it would have in the wild where it would have to avoid being eaten by predators.  Giant Silk Moths do not feed as adults, but the caterpillars have a ravenous appetite.  Fat is stored in the body of the caterpillar and this is used to help sustain the adult moth long enough for it to mate and reproduce.  The life span of an adult moth in the wild would rarely be longer than a week.  It is difficult to be certain, but your individual appears to be a female.  The antennae of the males are much more developed and feathery because the male uses his antennae to locate a female, sometimes from miles away, because of the pheromones she releases upon emergence from the cocoon.  When we are asked for advice on keeping caterpillars, we always advise keeping the cocoon or pupa at approximately the same temperature as the outdoors to prevent early eclosion in areas with a harsh winter.  Though this Polyphemus Moth may live as long as two weeks in captivity, it will not be able to mate and reproduce.  Reproduction is the primary goal of the adult moths.  If this is a female, she will most likely lay sterile eggs.

Thank you so much. This helps a lot!

Letter 41 – Polyphemus Moth Eggs Hatching


More Polyphemus Love
April 2, 2010
About 3 1/2 weeks later… 🙂
Houston, Texas

Polyphemus Eggs Hatching

Thanks for the update Matt.  It is great seeing the result of the mating photo you sent.


  • Bugman

    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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  • 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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Tags: Giant Silk Moth

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28 Comments. Leave new

  • I recognize the caterpillar, but I’m not sure what that other thing is in the picture. I vaguely remember seeing these things in the past and I think they have something to do with being able to purchase goods and services but I am not sure…

  • At our vacation home about 30 miles northwest of Portland, Maine, we generally see Luna moths the weekend closest to June 15th and maybe a week or possibly two earlier and later. There is a woods with lots of beech trees behind our house. If we have outdoor lights on after midnight that time of year we may have a half-dozen of them around at one time — so I’ll go along with “Maine is a location where populations of Luna Moths can be quite dense.”

    • Thanks for providing yet another opinion to support our statement which is entirely based on submissions we have received and no formal scientific investigation.

  • Barbara Piesse
    June 9, 2015 5:12 am

    I just found this guy on my patio door this morning. OMG!!! I have a fear of this kinda thing. I captured it in a container shud I let him go or keep him???

  • Sylvia Moritz
    June 26, 2015 8:38 am

    My granddaughter has been feeding her caterpillar for the past 6 or so weeks. It has created a chrysalis. They have placed it outside. How long before it completes its metamorphoses? It is a beautiful moth? Is it related to the cecrophia moth? Thanks in advance for your time.

    Sylvia Moritz

    • The Polyphemus Moth and the Cecropia Moth are both Giant Silk Moths in the family Saturniidae, but the Polyphemus Moth is actually more closely related to the Luna Moth. Since it is so early in the year, we suspect the adult moth may eclose within a few months, enabling multiple generations per year.

  • Looks fat and happy 🙂

  • I’ve only seen one in my life and that was when I was young and it was cought in a spider web I saved it did me proud to know I saved a beautiful creature. I lives in main at the time I saw one

  • Assuming Christine’s measurements are accurate, and based on what I see as more of a spindle shape, I think it’s more likely this is a Cecropia moth cocoon!

  • Oops, missed that it was found in California. Possibly Hyalophora euryalus?

    • Thanks Ben,
      We based the ID on the incorporation of the leaf into the cocoon and the birch food source. Since the cocoon was up a tree a bit, we did not place too much emphasis on the measurements which seem too big to us.

  • Pat McKeever
    June 12, 2016 10:08 am

    Hi Bugman, I was just out walking and came upon one of the polyphemus moths standing in the street so I moved him to the grass so he would not get run over. When I approached him to move him he opened his wings to be flat exposing his full size and the eyes on his wings. I have to assume they are a deterrent against predators? It was mid day and he did not fly away so am I to assume he is close to the end of his life cycle? You mentioned that the adults do not eat, only mate and, I guess, lay eggs but the body on this one was quite large, can I assume that it has not laid its eggs yet?

  • I had one of these in Libby Montana 3 years ago Had no idea what it was but it was big and green

  • How long will they be in cocoon for? I have found one and out it in a container until I could identify and it began to spin it’s cocoon. I want to be able to let it free when it is transformed but the container is not see thru. Thanks!!

    • Probably several weeks at this time of year. They do overwinter as pupa within the cocoon in northern climates.

  • Polyphemus moth Lebanon Oh. Thanks for the help identifying!

  • Mrs samples
    May 19, 2018 2:45 pm

    Is this caterpillar poisonous if touched by a child?

  • I hatched one from a cocoon I found 10 months ago!

  • Dawn Neault
    June 4, 2018 1:29 pm

    Just found one the other day. I wonder if Prince George is their normal range.

  • I just found one. So pretty!

  • Ha!! Do NOT be fooled. He has all sorts of pretty masks, but only rarely will he show his actual, gruesome face. This insect has the most terrifying, hideous countenance you can imagine, tucked tightly away under that smooth round foreskin at the front of his body, and no doubt those cute eyes and smiles painted all over in a morph are the adaptations permitting survival. It’s the stuff of nightmares. Literally. I saw it once, and can’t hold them without an intense shudder of fear flashing quickly through my body, complete with the instinct to remove the little horror from the gene pool.

    Looks like cotton candy. Tastes like poison.


    These little fu…. err, uh… buggers are the psychopaths of the insect world. I kid you not. Don’t mess with them. Unless you have lizards. Then they’re the best food you’ll ever find,


    AMD ONLY if they haven’t been eating their natural diet. You know, nightshades. Cause then they turn into little axe murderers instead of one of the best superfoods you’ll ever find.

  • Ha!! Do NOT be fooled. He has all sorts of pretty masks, but only rarely will he show his actual, gruesome face. This insect has the most terrifying, hideous countenance you can imagine, tucked tightly away under that smooth round foreskin at the front of his body, and no doubt those cute eyes and smiles painted all over in a morph are the adaptations permitting survival. It’s the stuff of nightmares. Literally. I saw it once, and can’t hold them without an intense shudder of fear flashing quickly through my body, complete with the instinct to remove the little horror from the gene pool.

    Looks like cotton candy. Tastes like poison.


    These little fu…. err, uh… buggers are the psychopaths of the insect world. I kid you not. Don’t mess with them. Unless you have lizards. Then they’re the best food you’ll ever find,


    AMD ONLY if they haven’t been eating their natural diet. You know, nightshades. Cause then they turn into little axe murderers instead of one of the best superfoods you’ll ever find.

  • Linda Swehla
    July 5, 2022 5:48 pm

    July 5, 2022 we found a Polyphemus Moth in our back yard. We thought it was dead, touched it gently and it fluttered but didn’t move away. We think it might have been hurt, but checked it later and it had flown away. Beautiful :)!!


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