Polyphemus Moth vs Cecropia: Battle of the Giant Silk Moths

The beautiful and captivating Polyphemus and Cecropia moths are two species of large, silk-producing moths native to North America. Both belonging to the Saturniidae family, these moths display unique and striking features, often leaving observers in awe of their size and eye-catching wing patterns.

Polyphemus moths (Antheraea polyphemus) are known for their buckskin-brown color and large eyespots on their hindwings, which serve to deter predators. These moths can be found on a variety of host plants, including oak, maple, and birch trees. On the other hand, Cecropia moths (Hyalophora cecropia) are dark brown with white crescent-shaped spots near the center of their wings. They can be spotted on trees like apple, plum, cherry, walnut, and maple, among others 1.

Both species are known for their remarkable size, beauty, and nocturnal nature. They play an essential role in the ecosystem, serving as pollinators and a food source for other wildlife. While they share some similarities, such as belonging to the same family and being large silk moths, Polyphemus and Cecropia moths also exhibit distinct differences in appearance, habitat, and behavior, making them fascinating subjects for nature lovers and scientists alike.

Polyphemus Moth

Physical Characteristics

The Polyphemus moth (Antheraea polyphemus) is known for its distinctive appearance. Some key features of this large moth include:

  • Wingspan of 4 to 5 inches1
  • Light green wings with transparent spots1
  • Pink-purple or yellow forewing margins1
  • Hind wings bearing long twisted tails1

A striking characteristic of the Polyphemus moth is its eyespots on the wings, which can startle potential predators1. These moths also have large, feathery antennae that they use for detecting pheromones during the mating process1.

Habitat and Distribution

The Polyphemus moth can be found across North America, particularly in the United States2. It usually inhabits deciduous forests and can be seen around various tree species, such as:

  • Oak2
  • Maple2
  • Willow2
  • Hickory2
  • Walnut2
  • Sycamore2

These moths typically produce one to two generations per year2, with each generation living and reproducing in the same forest habitat.

Comparison Table: Polyphemus Moth vs. Cecropia Moth

Feature Polyphemus Moth Cecropia Moth
Scientific Name Antheraea polyphemus1 Hyalophora cecropia3
Wingspan 4 to 5 inches1 5 to 7 inches3
Wing Coloration Light green with transparent spots1 Dark brown with white crescent-shaped spots3
Eyespots Large and conspicuous1 Smaller and less prominent3
Antennae Large and feathery1 Similar, but less feathery3
Distribution United States2 North America3
Typical Habitat Deciduous forests2 Deciduous forests3

Cecropia Moth

Physical Attributes

The Cecropia moth, Hyalophora cecropia, is the largest moth in North America with a wingspan ranging from five to seven inches. Here are some prominent features:

  • Dark brown coloration
  • Four white crescent-shaped spots near the center of the wings
  • Two black oval-shaped spots on the tips of the forewings

Habitat and Distribution

Cecropia moths are primarily native to the United States and Canada. They prefer habitats with a variety of host plants, including:

  • Cherry
  • Birch
  • Pear
  • Plum
  • Elms
  • Peach
  • Beech

The Cecropia caterpillar goes through five instar stages before pupating. Female moths lay around one hundred eggs, usually in groups of 2 to 6 on both sides of a leaf of one of its host plants. In about two weeks, the eggs hatch into tiny, hungry black caterpillars.

Polyphemus vs Cecropia: Size Comparison

Moth Species Wingspan Range
Polyphemus 4-5 inches
Cecropia 5-7 inches

Life Cycle of Both Moths


Polyphemus moth and Cecropia moth lay their eggs on the leaves of various host plants. While Cecropia moths lay around 100 eggs in groups of 2 to 6 on both sides of a leaf, the exact number of eggs laid by Polyphemus moths is not specified.


  • Polyphemus caterpillar: Green with a few sparse hairs, it becomes larger with every molt, reaching around three inches in length before pupation.
  • Cecropia caterpillar: Starts as a small black caterpillar and grows to about four inches long, changing color and developing tubercles throughout the molts.

They both go through several molts before turning into pupae.


  • Polyphemus pupa: Forms a brown and tough cocoon attached to the leaf.
  • Cecropia pupa: Forms a similar cocoon, but they often overwinter as pupae attached to the twigs of the host trees before emerging as adult moths.

The pupa stage is where both species stay dormant and undergo transformation into adult moths.

Adult Moths

Feature Polyphemus Moth Cecropia Moth
Appearance Varying shades of brown Dark brown with crescent-shaped spots
Wings Eyespots on all four wings Two black oval spots on forewings
Wingspan Up to six inches Five to seven inches

Both the Polyphemus and Cecropia moths are impressive in size, with eye-catching wing patterns. They are important pollinators and a delight to nature enthusiasts.

Diet and Host Plants

Polyphemus Moth Diet

The Polyphemus moth (Antheraea polyphemus) has a larval diet that consists of a variety of leaves. They feed on:

  • Oak
  • Willow
  • Maple

Caterpillars obtain nutrients from these plants’ green foliage, which serves as their primary food source.

Cecropia Moth Diet

On the other hand, the Cecropia moth (Hyalophora cecropia) also consumes leaves during its larval stage. It specifically feeds on:

  • Wild cherry
  • Apple
  • Plum

These host plants provide the necessary nutrients for healthy development.

Polyphemus Moth Diet Cecropia Moth Diet
Host Plants Oak, Willow, Maple Wild cherry, Apple, Plum
Food Source Leaves, green foliage Leaves, green foliage
Key Nutrients Obtained from host plants’ leaves and foliage Acquired from host plants’ leaves

Caterpillars of both moth species obtain key nutrients from their respective host plants, which ultimately supports their growth and metamorphosis.

Reproduction and Mating

Polyphemus Moth Mating

The Polyphemus moth uses pheromones to locate potential mates. The female emits these powerful scents to attract males. Males have larger, more sensitive antennae to detect these pheromones from miles away. Sexual dimorphism is evident in Polyphemus moths, with females being larger with heavier bodies and lighter wing coloration, while males have smaller bodies and darker wings.

Polyphemus moths typically produce one or two broods per year, depending on their geographical location and climate.

Some key features of Polyphemus moth mating are:

  • Pheromone communication
  • Sexual dimorphism
  • One or two broods per year

Cecropia Moth Mating

Cecropia moths also rely on pheromones, with the female releasing them to attract males. Males have larger antennae for detecting these scents. Sexual dimorphism is present in Cecropia moths as well; females are larger and more robust, while males showcase more vibrant color patterns.

Cecropia moths generally produce one brood per year.

Cecropia moth mating characteristics include:

  • Pheromone communication
  • Sexual dimorphism
  • One brood per year

Comparison Table

Feature Polyphemus Moth Cecropia Moth
Mating method Pheromones Pheromones
Sexual dimorphism Yes Yes
Number of broods One or two One

Predators and Threats

Natural Predators

Polyphemus moth and Cecropia moth caterpillars both have their share of natural predators. For the Polyphemus moth, some of its predators include insect parasitoids and generalist predators. In comparison, Cecropia moth caterpillars are targeted by squirrels and the parasitic fly, Compsilura concinnata. Here are some examples of predators for each moth:

  • Polyphemus moth caterpillars:
    • Insect parasitoids
    • Generalist predators
  • Cecropia moth caterpillars:
    • Squirrels
    • Compsilura concinnata (parasitic fly)

Human Impacts

Human activities are known to affect the populations of both Polyphemus and Cecropia moths. One major impact is the unintentional introduction and spread of invasive predators like the gypsy moth. Another issue is the use of outdoor lights, which disorient and attract moths, preventing them from mating and laying eggs.

Pruning trees also affects the survival of these moths, as their caterpillars depend on the leaves for food. Conservation efforts can help protect these species from human-induced threats.

Impact Polyphemus Moth Cecropia Moth
Gypsy Moth Affects population Affects population
Outdoor lights Impairs mating Impairs mating
Pruning Reduces food source Reduces food source
Conservation Helps protect Helps protect

Comparison of Both Moths

The Polyphemus moth (Antheraea polyphemus) and Cecropia moth (Hyalophora cecropia) are both members of the Saturniidae family, also known as giant silk moths. These nocturnal insects are part of the Lepidoptera order, which includes butterflies and moths. The Polyphemus moth is named after the Greek mythological figure Polyphemus, while the Cecropia moth is the largest moth in North America with a wingspan of five to seven inches12.

Polyphemus Moth

  • Wingspan: 4 to 5 inches3
  • Light green wings with transparent spots3
  • Pink-purple or yellow forewing margins3
  • Long twisted tails on hind wings3

Cecropia Moth

  • Wingspan: 5 to 7 inches1
  • Dark brown wings with white crescent-shaped spots1
  • Red body with a white “collar” and white bands on the abdomen4
  • Reddish patch at the base of each forewing4

The table below presents a comparison of several features of the Polyphemus and Cecropia moths:

Feature Polyphemus Moth Cecropia Moth
Wingspan 4-5 inches3 5-7 inches1
Wing Color Light green3 Dark brown1
Wing Pattern Transparent spots3 White crescent-shaped spots1
Body Color Not mentioned Red with white “collar” and white bands on the abdomen4

Although both moths are part of the Saturniidae family, they showcase different characteristics in terms of size, color, and wing patterns. For example, the Polyphemus moth has a smaller wingspan and light green wings with transparent spots3, whereas the Cecropia moth has a larger wingspan and dark brown wings with white crescent-shaped spots1.

In conclusion, the Polyphemus and Cecropia moths are both fascinating examples of giant silk moths, exhibiting unique attributes that set them apart from one another. From their wing patterns to body colors, these two species offer captivating insights into the diverse world of Lepidoptera.

Mimicry and Unique Features

The Polyphemus moth and Cecropia moth are two large and fascinating species of North American moths. They are closely related and share some characteristics. Below are a few of their key mimicry and unique features.

Polyphemus moth:

  • Wingspan: 4 to 5 inches1.
  • Light green wings with transparent spots1.
  • Pink-purple or yellow forewing margins1.
  • Long twisted hind wing tails1.

Cecropia moth:

  • Stout, hairy bodies2.
  • Feathery antennae2.
  • Red body with white collar and white bands on the abdomen2.
  • Dark brown or gray wings with reddish patch2.
  • Crescent-shaped spots near the wing centers2.

As the largest native moth in North America2, the Cecropia has a wider variety of colors than the Polyphemus1. Both species display eye-like markings in their hind wings, called “eyespots”1. These eyespots are believed to deter predators, as they mimic the eyes of larger animals1.

Feature Polyphemus Moth Cecropia Moth
Wingspan 4 to 5 inches1 Larger2
Colors Light green, pink-purple or yellow1 Red, white, dark brown/gray2
Unique markings Transparent spots1 Crescent-shaped spots2

These similarities and differences allow both the Polyphemus and Cecropia moths to thrive in their environment. They use their unique characteristics, from colors to patterns, to deter predators and ensure their survival.


  1. (https://ipm.missouri.edu/MEG/2016/3/Polyphemus_and_Cecropia_Moths/index.cfm) 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

  2. Polyphemus moth – Antheraea polyphemus (Cramer) 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

  3. Polyphemus and Cecropia Moths – University of Missouri 2 3 4 5 6 7 8 9 10 11 12 13 14 15

  4. https://www.nps.gov/articles/species-spotlight-cecropia-moth.htm 2 3

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 – Cecropia Moth


large moth found in new jersey
any idea what kind of moth this is?it was found in new jersey in may sometime.
faith kessner

Hi Faith,
We have gotten many pictures of Cecropia Moths this spring.

Letter 2 – Cecropia Moth


Moth or Butterfly in WI
Hi: This beautiful creature was drying it’s wings (or so I’m guessing) by hanging upside down on our garage door trim this morning. It’s beautiful. I’m unable to find it in my field guide — I’m thinking that it is probably a moth instead of a butterfly because it has such a plump, furry body. I’ve attached several pics that I took this morning. Just would really like to know what it is. Any help you can provide in identifying this beautiful creature would be most appreciated. Thanks!
Ann in WI

Hi Ann,
This is a Cecropia Moth. We have identified so many specimens in the past week, we think it is time to post another photo, and yours is just perfect.

Letter 3 – Cecropia Moth


Can you help identify thsi moth?
This moth was just spotten in Clayton, NJ. Can you help identify it? Thanks,

Hi Ron,
Your moth is a Cecropia Moth, one of the Giant Silk Moths.

Letter 4 – Cecropia Moth


Cecropia Moth
Hello. I found this beauty in Rockne, Texas, just outside of Austin, on Easter Sunday. We were all amazed at the soft fur like feel on the body of the cecropia moth. Thanks for having such a great site, I look all the time but this was the first real good picture I was able to get, and had to share.
Whitney K

Hi Whitney,
Thanks so much for sending your awesome photo. We have gotten images of four different Giant Silk Moths in the past two days and we are struggling to get them all posted online.


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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.

  • 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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