Cecropia Moth Caterpillar Poisonous: Essential Facts Revealed

The cecropia moth caterpillar is a fascinating creature with a sizeable larva known for being the largest in Iowa and often found in late summer throughout the state. Interestingly, these caterpillars mature into the cecropia moth, which is the largest moth in North America, and are part of the giant silkworm moths family due to their large, silk-spinning caterpillars and cocoons. They can be found feeding on trees and shrubs or wandering across lawns, sidewalks, and driveways.

Although cecropia moth caterpillars are visually striking, it is essential to know if they pose any risks, such as being poisonous or harmful to humans. While some caterpillars have been known to cause severe pain with their poisonous spines, such as the puss caterpillar or the buck moth caterpillar, the cecropia moth caterpillar does not belong to this category.

Instead, the cecropia moth caterpillar is not considered poisonous or venomous, making them safer to observe and handle compared to other harmful caterpillars. However, caterpillars, in general, should be handled with care to avoid any potential allergic reactions or irritation in sensitive individuals.

Cecropia Moth Caterpillar Basics

Physical Characteristics

The Cecropia moth caterpillar, scientifically known as Hyalophora cecropia, belongs to the Lepidoptera order. It is the larval stage of the Cecropia moth, the largest North American moth. The caterpillar has a distinct appearance, with a greenish color and bright-colored tubercles or warts on its body, making it easily recognizable 1.

Feature Description
Color Greenish body with bright tubercles or warts
Size Large, up to 4.5 inches
Hair Sparse hairs on tubercles

Some notable characteristics of the Cecropia moth caterpillar include:

  • Soft, plump body
  • Greenish body color
  • Vividly colored tubercles or warts on the body
  • Can grow very large, up to 4.5 inches

Range and Habitat

Cecropia moth caterpillars can be found throughout North America, spanning from the Rocky Mountains to the east coast. Their habitat primarily consists of deciduous forests where their food sources, such as various fruit trees and shrubs, are abundant. Some examples of host plants for these caterpillars include cherry, plum, maple, and birch trees. Cecropia moth caterpillars have a wide range of predators, such as birds, small mammals, and parasitic wasps 2.

In summary, Cecropia moth caterpillar habitats include:

  • Deciduous forests
  • Areas with host plants like fruit trees and shrubs
  • Found throughout North America, from the Rocky Mountains to the east coast

The Life Cycle of Cecropia Moth Caterpillar

Egg Stage

The life cycle of the cecropia moth (Hyalophora cecropia) begins with the female moth laying eggs, often on foliage, ready to hatch into larvae:

  • Single or closely placed small clusters
  • Yellowish-white color
  • Approximately 2 weeks till hatching

Larva and Instar Stages

Upon hatching, the larvae go through several instar stages, each marked by significant growth and distinct physical changes:

  1. First instar:

    • Black-headed and lightly bristled
    • Start consuming leaves
  2. Second instar:

    • Develop red-orange spikes
    • More noticeable bristles
  3. Third to fifth instars:

    • Yellow, blue, and red body coloration with tubercles
    • Feast on a variety of host plants

During these stages, the caterpillars must avoid predators such as spiders.

Pupa and Chrysalis Stage

Once the caterpillars have completed the larval stages, they will spin a tough, brown cocoon made of silk to enter the pupa, or chrysalis, stage:

  • Attached to twigs on host trees
  • Overwintering period (several months)
  • Inside, the caterpillar transforms into an adult moth

Adult Moth Stage

The cecropia moth finally emerges from the cocoon as an adult, featuring a large wingspan and characteristic coloration:

  • Wingspan: up to 6 inches
  • Stout, hairy bodies
  • Reddish patch on each forewing
  • Feathery antennae

At this stage, the adult moths do not feed but will only focus on mating and laying eggs, completing their one-year life cycle.

Host Plants and Diet

Common Trees and Shrubs

Cecropia moth caterpillars feed on a variety of trees and shrubs. Some of the most common host plants include:

  • Maple (Acer species)
  • Elm (Ulmus species)
  • Birch (Betula species)
  • Willow (Salix species)
  • Ash (Fraxinus species)
  • Lilac (Syringa species)
  • Poplar (Populus species)
  • Alder (Alnus species)
  • Wild cherry (Prunus species)
  • Plum (Prunus species)
  • Walnut (Juglans species)
  • Box elder (Acer negundo)
  • Crabapple (Malus species)
  • Beech (Fagus species)
  • Dogwood (Cornus species)
  • Oak (Quercus species)
  • Grape (Vitis species)
  • Button bush (Cephalanthus occidentalis)

Food Source During Different Life Stages

Cecropia moth caterpillars’ diet changes as they grow. The table below illustrates their food source preferences during different life stages:

Life Stage Preferred Food Source
Eggs Attached to the undersides of leaves on host plants
Young caterpillars Tender leaves of host plants, initially focusing on one leaf
Mature caterpillars Entire leaves and sometimes small branches of host plants

The caterpillars have tubercles, which are fleshy protuberances, that help them to grip the leaves and branches of their host plants effectively. As they grow, they actively feed on the leaves of various trees and shrubs to reach their full potential before entering the pupal stage.

Interaction with Humans and Nature

Cecropia Moths and Pest Control Services

Cecropia moths, as part of the Saturniidae family, have limited impact on pest control services. Their caterpillars mostly feed on the leaves of hardwood trees, such as oaks, cherry, beech, and apple trees, in hardwood forests.
However, they rarely cause significant defoliation or damage.

Cecropia Moths and Conservation

Cecropia moth populations contribute to the overall biodiversity and ecological balance within their native habitats. These moths serve as pollinators, and their caterpillars act as a food source for various natural predators such as birds and small mammals.

Events in Nature Involving Cecropia Moths

Cecropia moths go through a fascinating life cycle in nature. Female moths lay around 100 eggs on their host plants and in about 2 weeks, the eggs hatch into black caterpillars. These caterpillars feed and grow, eventually shedding their skins multiple times until they reach full size. They then form cocoons and overwinter as pupae, emerging as adults the following spring.

Caterpillar Care:

  • Provide fresh leaves from host plants
  • Keep the environment clean and well-ventilated
  • Monitor for signs of illness or parasites

Here is a comparison table outlining some key features of Cecropia moth caterpillars:

Feature Description
Size Large, up to 4-5 inches as full-grown caterpillars
Color Bright green with bristly spines
Diet Leaves of hardwood trees
Defense Visual appearance may deter predators

Cecropia moth caterpillars have some intriguing characteristics:

  • They spin tough, brown silk cocoons
  • They can be found in North America, especially in hardwood forests
  • They have a passive defense through their bright green appearance and bristly spines

In conclusion, while Cecropia moths and their caterpillars have minimal influence on pest control services, they play a vital role in maintaining the balance and biodiversity of their ecosystems. They also provide us with a fascinating glimpse into the intricacies of the natural world.

The Mating and Reproduction Process

A Meticulous Courtship Dance

Cecropia moth’s mating process involves an elegant dance that helps them find suitable partners. Adult moths perform this dance during the summer months when they are most active. The dance consists of delicate movements, signaling their readiness to mate.

Attracting Mates with Pheromones

  • Pheromones: Chemical substances released by female moths
  • Purpose: Attract nearby male moths for mating

Female cecropia moths release pheromones to attract potential mates. These chemical signals can travel great distances, increasing the chances of locating a suitable partner. Once a male moth detects the scent, it follows the pheromone trail to locate the female.

Characteristics of Cecropia Moths Importance in Mating Process
Large size Easier for potential mates to spot them
Colorful wings Attracts attention and displays good genetics
Feathery antennae Helps detect pheromones and locate mates

After successful mating, the female moth lays her fertilized eggs on trees, which provide food and shelter for the emerging larvae. The eggs hatch into caterpillars, which feed on the tree leaves for sustenance. Despite the size and color of cecropia moths, they often escape predation by birds, as their caterpillars are not poisonous and have no major defensive mechanisms.

Cecropia Moth Caterpillar and Protection

Defense Mechanisms

The Cecropia moth caterpillar (Hyalophora cecropia) is equipped with various features to protect itself from predators, such as:

  • Vibrant colors
  • Tubercles or warts

These caterpillars have a greenish body with bright colored tubercles (warts) that serve as a deterrent to potential predators1. Unlike Io moth caterpillars, they do not have venomous spines that can cause irritation2.

Polyphemus moth caterpillars display similar defense mechanisms, with eye-like spots to confuse predators3.

Natural Enemies

Cecropia moth caterpillars face various natural enemies, including:

  • Insects
  • Spiders
  • Birds

For example, bolas spiders are known to prey on large moths and their caterpillars4. These cunning predators use a unique method, throwing a sticky “bolas” to catch their prey mid-flight5.

Comparison Table: Defense Mechanisms of Different Moth Caterpillars

Caterpillar Defense Mechanism
Cecropia Vibrant colors, warts
Io Venomous spines
Polyphemus Eye-like spots

In conclusion, the Cecropia moth caterpillar has developed unique visual defense mechanisms to protect itself from predators, utilizing bright colors and warts to deter potential threats. While facing various predators like insects, spiders, and birds, it differs from other moth caterpillars, such as the Io and Polyphemus moths, in its specific defensive adaptations.

Rearing Cecropia Moth Caterpillars

Creating a Suitable Environment

To raise healthy cecropia moth caterpillars, you should first provide an appropriate rearing container. The container should:

  • Be spacious, clean, and well-ventilated
  • Have a secure cage or wire to prevent escape
  • Allow for easy access to add fresh foliage and clean up waste

For example, you can use a large plastic container or a mesh enclosure as a suitable space for the caterpillars.

Feeding and Caring for Larvae

Cecropia caterpillars feed on a variety of food plants, such as:

  • Oak
  • Cherry
  • Beech
  • Apple
  • Button bush

Provide fresh foliage regularly to avoid digestive issues. Monitor their growth closely, as cecropia caterpillars can become large (over four inches in length) during late summer, as mentioned by Iowa State University.

Remember to clean the container, as larvae can produce waste, and replace old food with fresh foliage to prevent mold growth.

Transition to Adult Moths

Cecropia caterpillars undergo a pupa stage before becoming adult moths. To ensure a smooth transition:

  • Allow caterpillars to overwinter in their cocoons
  • Follow expert instructions for properly maintaining the rearing environment

Cecropia moths are not known to be poisonous; thus, they pose no threat to humans or pets like cats. However, always practice good hygiene when handling any insects or their rearing containers.

Pros of rearing cecropia moth caterpillars:

  • Witnessing the fascinating life cycle of North America’s largest moth species
  • Contributing positively to the ecosystem by fostering native pollinators

Cons of rearing cecropia moth caterpillars:

  • Requires regular maintenance for both the container and the caterpillars
  • Caterpillars can damage host plants due to their voracious feeding habits

Comparison table between cecropia moth caterpillar rearing and other methods:

Aspect Cecropia Moth Caterpillar Rearing Other Methods
Level of difficulty Moderate Variable
Impact on native ecosystems Generally positive Varies
Poisonous/toxic Not poisonous Varies according to species
Suitable for human or pet interaction Yes (with proper hygiene) Varies according to species

Unique Facts and Curiosities

The Largest Moths in North America

The Cecropia moth, also known as Hyalophora cecropia, is the largest moth in North America1. A distinct characteristic of these moths is their impressive wingspan, which can reach up to 6 inches2. They are mostly active in the summer months and can be commonly found in states like Iowa3.

Cecropia moth caterpillars have an appetite for a variety of plants, including ornamentals, and feed on different species of trees4. Some examples of their favorite plants are:

  • Willow
  • Maple
  • Apple
  • Cherry

Cecropia Moths in Popular Culture

These large, colorful moths have inspired people’s fascination and found their way into popular culture. An example is the Pokemon “Venomoth,” which bears some resemblance to the Cecropia moth.

Cecropia moths are not poisonous, hence making them harmless to humans and animals5. However, their vibrant appearance often sparks curiosity and admiration.

Footnotes

  1. Cecropia Moth – Cornell Cooperative Extension 2 3

  2. cecropia moth – Hyalophora cecropia Linnaeus 2 3

  3. Polyphemus Moth 2

  4. Bolas Spiders 2

  5. Bolas Spider Hunting Technique 2

Reader Emails

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

Letter 1 – Cecropia Moth Cocoon

 

Subject: cocoon
Location: Lakefield Ontario Canada
February 3, 2013 11:07 am
Found a cocoon this morn attached to a cherry tree. It is quite large about 4 in. long and about 3 in. girth.It is brown in colour. I took it off the tree took some photos and then put it in a more secure location. I am most interested to know if it will survive our Canadian Winter and what it might be?
Signature: Delphine C. Patzel

Cecropia Moth Cocoon

Dear Delphine,
This looks to us to be the cocoon of a Cecropia Moth, Hyalophora cecropia, or perhaps the closely related Columbia Silkmoth.  Bill Oehlke’s Silkmoth website gives a nice comparison of the cocoons on the Columbia Moth page, which would indicate your cocoon is that of a Cecropia Moth.  The Cecropia Moth page of Oehlke’s Silkmoth website is a nice place for information.  Removing the cocoon from the cherry tree might have damaged the pupa inside.  Only time will tell.  Cecropia Moths have adapted to areas with harsh winters and the silken cocoon helps to shelter the pupa through the cold season.

Thank you so much for the ident. I took the cocoon off very carefully so hope it survives. I put it back in a secure spot so that it doesn’t blow away. I’d be thrilled to see the actual moth appear. It is very beautiful.
Thanks again   Including a few photos.

Letter 2 – Cecropia Moth Caterpillar

 

I found a weird bug today in my dads car
Hello Bugman,
My name is Jimmy, today I found this wierd type of caterpillar my dad thought it was a tomato bug. We didn’t know. We researched your website but we couldn’t find it at all. Can you please help me. I don’t know if it was poisonous or not so i used a kleenex to pic it up and there was this slik like substance behind it when it walked. Can you tell me which is his head and which is his butt?
Thank You
Jimmy Brickner
Strongsville, Ohio

Hi Jimmy,
The reason you could not find your caterpillar on our website is because we only post photos that readers send in. You are the first person to send in a photo of a Cecropia Moth Caterpillar, Samia Cecropia. This is the largest North American Moth, and its wingspan reaches six inches across. It is a member of the Giant Silkworm family Saturnidae, and as adults, the moths do not feed. Your caterpillar looks nearly mature. They eat leaves from cherry , maple, willow and other trees. Try keeping the caterpillar in a well ventilated box with fresh leaves. I am guessing that since it was in your dad’s car, it was looking for a place to pupate. The cocoon is usually spun on a branch. It will overwinter as a cocoon and emerge as a grown moth in the spring. Thank you for the photo. They are not poisonour. The head end has the orange tubercles. In your photo, it is on the left.

Letter 3 – Cecropia Moth Cocoon

 

Mystery Egg Sac(?) in Minnesota
Hello Bugman,
I live in Minneapolis, MN. A couple weeks ago I noticed an egg sac (I think that is what it is) on a shrub branch (I think its an ornamental Ribes/currant shrub) in our front yard landscaping (see attached photo). I looked through your website and it looks as if it may be a praying mantis egg sac? I’d be curious what you think…thanks for any light you can shed on our front yard mystery critters. If it is a good critter, we want to watch it hatch. If it is a bad (e.g., invasive) critter, we may want to destroy or at least contain the hatchlings. Also, do you reply to e-mails, or do we need to visit WTB website (and look where for your response). Thanks!
Doug, Griffin & Eva

Hi Doug, Griffin and Eva,
We believe this is the Cocoon of a Cecropia Moth, but it is also possibly the cocoon of the closely related Columbia Silk Moth. Since we are only able to post a fraction of the letters we receive, we often send short responses first. We don’t even have the time to answer personally every letter we receive, but we try to answer as many as possible. Some questions are so vague, or images so blurry, that we just ignore them. When we post an answer, there is generally a more detailed response, and we email that to the querant, but sometimes we forget. In your case, you got a short answer originally, and now that we are posting letters from May 3, yours included, you are getting a second more detailed answer.

Letter 4 – Cecropia Moth Cocoon

 

What was that bug?
Hi Bugman !
I was recently visiting my folks in Maine, this cocoon(?) was in a maple tree in the yard. It is probably about 5 inches long. What do you think? Pondering in Portland,
Jim

Hi Jim,
This is a Cecropia Moth Cocoon. The small hole in the second photograph indicates that it may have been parasitized since it seems to small for the adult moth to have emerged.

Letter 5 – Cecropia Moth Caterpillar

 

Bugman
Can you help me identifie this worm? It and another one were found in a apple tree in Michigan. Thank you so much for any help.
John Warren

Hi John,
Your Cecropia Moth Caterpillar will become a large gorgeous Saturnid Moth.

Letter 6 – Cecropia Moth Caterpillar

 

found in georgian bay becomes large moth what is name?

This is a Cecropia Moth Caterpillar.

Letter 7 – Cecropia Moth Cocoon

 

picture of a chrysalis
here is a chrysalis I found in my back yard……does it contain a good or bad moth? Thanks for any reply
Roy

Hi Roy,
This is a Cecropia Moth Cocoon, a big beautiful Giant Silk Moth.

Letter 8 – Cecropia Moth Caterpillar

 

What kind of bug is this
I’m from Ontario, Canada. My son was walking along the grass when he found this caterpillar. We have no idea what kind it is. Wondering if anyone can put a name on it for us. Thank you
Erin & Graham

Hi Eric and Graham,
This is a Cecropia Moth Caterpillar, one of the Giant Silk Moths or Saturnid Moths.

Letter 9 – Cecropia Moth Caterpillar

 

whats this caterpillar?
Found this one eating dogwood tree leaves in our yard (in Maryland). What would it change into?
Wayne Hebert

Hi Wayne,
We love the forced perspective on your Cecropia Moth Caterpillar. We have photos of the adult Cecropia Moth on our Saturnid or Giant Silkmoth pages.

Letter 10 – Cecropia Moth Caterpillar

 

Cecropia Moth Caterpillar
Dear Bug Man,
My kids went out to ride their bikes and found this caterpillar crawling across the dirveway. I’ve been researching this for a bit and came across your site which let us know what this caterpillar was….or so we hope. It’s @ 4 inches long and @ 1 inch in diameter.
Here are some pics we took, June 2007.
Darryl, Ashton and Savanah McNabb
Brenham, TX

Hi Darryl, Ashton and Savanah,
Congratulations on your Cecropia Caterpillar sighting and its proper identification.

Letter 11 – Cecropia Moth Caterpillar

 

Caterpillar – large, green
July 28, 2009
Hi,
We spotted this fella eating away on our skip laurel bushes. It’s the end of July and we are in middle Tennessee. He/she is almost 4 inches long. Can you identify? Also, strange question but- could the critter’s waste possibly look like brown, segregated pellets? Those things are on several leaves beneath him and on the ground below. Thanks,
Thanks for your help, Karen
Middle Tennessee

Cecropia Moth Caterpillar
Cecropia Moth Caterpillar

Hi Karen,
Your caterpillar is a Cecropia Moth Caterpillar, one of the Giant Silk Moths.

Letter 12 – Cecropia Moth Caterpillar

 

CECROPIA MOTH CATERPILLAR
June 29, 2010
At the end of July, while at the park, we came across this HUGE catepillar on a weeping willow tree. We were all so amazed at it’s size as well as all of the brilliant, differents colors and patterns. We took a lot of pictures and came home and looked in our “Fun with Nature, Take-Along Guide” and we were amazed that we were able to identifiy it. It was soooo exciting for the children as well as their dad and I. We found out that it was a Cecropia Moth Caterpillar. Thought you might like to see some pictures. I must admit, I was a little frightened by the size of it, I did put my hand next to it to try to show the size, but I was afraid to go any closer!!!!
Always looking at nature, GSO, NC
In Greensboro, NC on a weeping willow tree

Cecropia Moth Caterpillar

Dear nature fans,
Thanks for taking the time to submit your photo of a Cecropia Moth Caterpillar.  It is the first we received this year.

Letter 13 – Cecropia Moth Caterpillar

 

A spiny caterpillar – possibly a species of silk moth?
July 3, 2010
Hiya,
I found two of these guys happily munching away on a single beach plum (prunus maritima) in my front yard in Newbury, MA. They are approximately 2 inches long at the moment. I’m thinking they are some sort of silk moth instar, but I can’t find anything quite like them in my books. So naturally – I turned to you folks. Ideas?
Michele
Newbury, Massachusetts

Cecropia Moth Caterpillar

Hi Michele,
Your caterpillar is most definitely one of the Giant Silkmoths.  It is the Cecropia Moth Caterpillar,
Hyalophora cecropia, and we find it hard to believe that it is not pictured in your identification guides.

Letter 14 – Cecropia Moth Caterpillar

 

Subject: Tomato worm?
Location: Eastlake ohio
July 26, 2013 6:32 pm
What are these? I’m thinking maybe a tomato worm
Signature: Kristy

Cecropia Moth Caterpillar
Cecropia Moth Caterpillar

Hi Kristi,
Tomato Hornworms would be found feeding on the leaves of tomatoes and related plants.  This Cecropia Moth Caterpillar is feeding on the leaves of a tree, possibly wild cherry, which is a listed food plant on BugGuide.

Letter 15 – Cecropia Moth ecloses in dead of winter!!!

 

Subject: what is this bug
Location: Port Huron MI
February 3, 2014 7:19 pm
Please help me identify this bug that came out of it’s cocoon today in Michigan, 2/3/14
Signature: Jennifer Beltramo

Cecropia Moth Eclosion
Cecropia Moth Eclosion

Dear Jennifer,
This is a Cecropia Moth.  Since it has just emerged or eclosed, the wings have not yet expanded to the full size.  You did not provide much information, so we are speculating that you found the cocoon in the fall and kept it to see what would emerge.  While we applaud your enthusiasm about the natural world, cocoons should not be kept indoors overwinter as the moths will most likely emerge too early to be released, and they will die without mating.  The Cecropia Moth is one of the Giant Silkmoths, and they only live a few days.  They do not eat as adults.

Thank you for the reply.  I actually took that picture from a friends facebook post.  They were quite shocked to see something living emerge from the cocoon and they actually just picked the cocoon up over the weekend covered in snow.  I can assure you, she won’t allow her children to do that ever again…scared the daylights out of her 🙂  She let her 5 year old take it in for show and tell they day I sent you the picture and when they came home from school, she just had it sitting on her kitchen counter, came back into the kitchen to see something wiggling its way out.
Thanks again for the quick reply!  We were just curious what it was.

Letter 16 – Cecropia Moth Cocoon

 

Subject: some kind of big egg sac or coccoon
Location: Perrysburg, Ohio
May 24, 2015 10:07 pm
Do you know what this is? It is about 5 inches in length. I found it under a railing on my deck. Should I be scared of it? It is right where my family sits and relaxes. I do not like to kill anything but I am very scared of spiders. I doubt it is a spider sac because of the texture of it.
Signature: FreddieAnitaBell

Cecropia Moth Cocoon
Cecropia Moth Cocoon

Dear FreddieAnitaBell,
This is the cocoon of a Cecropia Moth, and it passed the entire winter unnoticed on your deck railing.  Now that warm weather has arrived, the adult moth should emerge soon, and if you are vigilant and lucky, you may get to witness the Cecropia Moth that emerges.

Letter 17 – Cecropia Moth Caterpillar

 

Subject: Caterpillars
Location: Minnesota
August 9, 2015 8:42 pm
Found this on our Apple tree her in Minnesota. He was munching on a leaf. It was a little fatter than my thumb and about 3 inches long.
Signature: Cindy

Cecropia Caterpillar
Cecropia Caterpillar

Hi Cindy,
This is a Cecropia Moth Caterpillar, and according to BugGuide:  “Larvae feed on leaves of various trees and shrubs including alder, apple, ash, beech, birch, box-elder, cherry, dogwood, elm, gooseberry, maple, plum, poplar, white oak, willow.  may also feed on lilac and tamarack.”  The adult Cecropia Moth is a magnificent creature.

Letter 18 – Cecropia Moth Caterpillar

 

Subject: Catapillar
Location: South central New York state
August 14, 2015 8:19 am
Found crawling up th side of a house. 5 inches long and 1 inch wide. Beautiful yellow and blue spikes.
Signature: Bart

Cecropia Moth Caterpillar
Cecropia Moth Caterpillar

Dear Bart,
This beauty is a Cecropia Moth Caterpillar, and many folks would argue that the adult Cecropia Moth is even lovelier.

Letter 19 – Cecropia Moth Caterpillar

 

Subject: what is this?
Location: Putnam, CT 06260
August 26, 2015 1:20 pm
We found 2 of these caterpillars today (August 26,2015) in Putnam, CT while we were trimming bushes. The crew is very curious what they are as none of us had ever seen anything like it before. Each one was about 5 inches long and they were eating a vine-like weed growing inside a forsythia bush. We found them between 11:00 AM and 1:00PM.
Everyone also wanted to know if they were poisonous. It looks like there are barbs or stingers on the body, guessing for protection?
Thank you do your help! Hope to hear back from you.
Signature:  Steve Gallant and The Crew at Eclipse Landscaping

Cecropia Moth Caterpillar
Cecropia Moth Caterpillar

Dear Steve and Crew,
Your impressive caterpillars are Cecropia Moth Caterpillars, and the fleshy protuberances are not barbs or stingers.  Cecropia Moth Caterpillars pose no threat to humans.  Your large individuals have probably attained maximum growth and they will soon spin a cocoon and molt into a pupa that will overwinter, with the adult Cecropia Moth emerging next spring.  We are very curious what vine they were feeding upon, because according to BugGuide:  “Larvae feed on leaves of various trees and shrubs including alder, apple, ash, beech, birch, box-elder, cherry, dogwood, elm, gooseberry, maple, plum, poplar, white oak, willow. may also feed on lilac and tamarack.”

Cecropia Moth Caterpillar
Cecropia Moth Caterpillar

 

Letter 20 – Cecropia Moth Cocoon

 

Subject: Large Cocoon
Location: Delaware Ontario Canada
October 16, 2015 5:29 am
We found this large cocoon attached to our wood fence on Oct. 15th 2015. It appeared almost overnight. We are thinking it is some kind of moth, but would like to know more. We did have a hummingbird hawk moth in the garden this summer (picture 2) Any idea what this cocoon might be?
Signature: Lori L.

Cecropia Moth Cocoon
Cecropia Moth Cocoon

Dear Lori,
Hawkmoths do not spin a cocoon and they pupate underground.  This is the cocoon of a Cecropia Moth, and if you are lucky, you will see the emergence of the adult Cecropia Moth next spring.

Letter 21 – Cecropia Moth Caterpillar

 

Subject: Cecropia Caterpillar
Location: Middlebury, VT
May 3, 2017 2:19 pm
My grandson found this on our maple tree a few years ago and I thought you’d like to have the picture.
Signature: BrendaB

Cecropia Moth Caterpillar

Dear BrendaB,
We thought this was very early for a Cecropia Caterpillar sighting, especially in Vermont, and then we noticed your digital file is dated 2012.  We would expect to see Cecropia Moth Caterpillar late in the summer.

Oh yes!  I did say it was a few years ago.  I just think the picture is great, so I wanted to share.

And we agree that it is an awesome image, which is why we posted it.
We did not mean to seem dismissive.  We just wanted to inform our readers when to expect to see Cecropia Moth Caterpillars.

Thank you!  I am happy to know when to look for them as I haven’t seen one since 2012.  They seriously look like a Fisher Price toy.  Put a string on the front of it and it could be a pull toy.  J

 

Letter 22 – Cecropia Moth Caterpillar

 

Subject: Caterpillar?
Location: Buffalo, NY
August 20, 2017 10:47 am
Can you tell me what this is and is it harmful?
Thank you
Signature: Sue

Cecropia Moth Caterpillar

Dear Sue,
This impressive caterpillar is a Cecropia Moth Caterpillar.  It is perfectly harmless unless a morbid and irrational fear of the unknown causes a person who encounters one to flee, and run in front of a car.  Even the most benign creatures can be a contributing factor in the harming of a human being.   The caterpillar will eventually metamorphose into a gorgeous, and very large Cecropia Moth.

Letter 23 – Cecropia Moth Caterpillar

 

Subject:  Caterpillar
Geographic location of the bug:  Williamston, MI
Date: 07/21/2018
Time: 08:58 PM EDT
Your letter to the bugman:  Wanted to submit a photo for the Cecropia moth caterpillar
How you want your letter signed:  Steve W.

Cecropia Moth Caterpillar

Dear Steve,
Your image of a Cecropia Moth Caterpillar nicely illustrates many of the features that ensure correct species identification, and it is a great addition to our archives.

Letter 24 – Cecropia Moth Caterpillar

 

Subject:  Rainbow Spike Slug
Geographic location of the bug:  Heuvelton, NY
Your letter to the bugman:  WHAT IS THIS BUG?
How you want your letter signed:  Jo

Cecropia Moth Caterpillar

Dear Jo,
This is a Cecropia Moth Caterpillar.  It will spin a cocoon and eventually emerge as an adult Cecropia Moth, one of the largest North American moths.

THANK YOU SO MUCH!
Thank you oh so very much, and I hope this message makes you smile!
Jo

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 Cocoon

 

Subject: cocoon
Location: Lakefield Ontario Canada
February 3, 2013 11:07 am
Found a cocoon this morn attached to a cherry tree. It is quite large about 4 in. long and about 3 in. girth.It is brown in colour. I took it off the tree took some photos and then put it in a more secure location. I am most interested to know if it will survive our Canadian Winter and what it might be?
Signature: Delphine C. Patzel

Cecropia Moth Cocoon

Dear Delphine,
This looks to us to be the cocoon of a Cecropia Moth, Hyalophora cecropia, or perhaps the closely related Columbia Silkmoth.  Bill Oehlke’s Silkmoth website gives a nice comparison of the cocoons on the Columbia Moth page, which would indicate your cocoon is that of a Cecropia Moth.  The Cecropia Moth page of Oehlke’s Silkmoth website is a nice place for information.  Removing the cocoon from the cherry tree might have damaged the pupa inside.  Only time will tell.  Cecropia Moths have adapted to areas with harsh winters and the silken cocoon helps to shelter the pupa through the cold season.

Thank you so much for the ident. I took the cocoon off very carefully so hope it survives. I put it back in a secure spot so that it doesn’t blow away. I’d be thrilled to see the actual moth appear. It is very beautiful.
Thanks again   Including a few photos.

Letter 2 – Cecropia Moth Caterpillar

 

I found a weird bug today in my dads car
Hello Bugman,
My name is Jimmy, today I found this wierd type of caterpillar my dad thought it was a tomato bug. We didn’t know. We researched your website but we couldn’t find it at all. Can you please help me. I don’t know if it was poisonous or not so i used a kleenex to pic it up and there was this slik like substance behind it when it walked. Can you tell me which is his head and which is his butt?
Thank You
Jimmy Brickner
Strongsville, Ohio

Hi Jimmy,
The reason you could not find your caterpillar on our website is because we only post photos that readers send in. You are the first person to send in a photo of a Cecropia Moth Caterpillar, Samia Cecropia. This is the largest North American Moth, and its wingspan reaches six inches across. It is a member of the Giant Silkworm family Saturnidae, and as adults, the moths do not feed. Your caterpillar looks nearly mature. They eat leaves from cherry , maple, willow and other trees. Try keeping the caterpillar in a well ventilated box with fresh leaves. I am guessing that since it was in your dad’s car, it was looking for a place to pupate. The cocoon is usually spun on a branch. It will overwinter as a cocoon and emerge as a grown moth in the spring. Thank you for the photo. They are not poisonour. The head end has the orange tubercles. In your photo, it is on the left.

Letter 3 – Cecropia Moth Cocoon

 

Mystery Egg Sac(?) in Minnesota
Hello Bugman,
I live in Minneapolis, MN. A couple weeks ago I noticed an egg sac (I think that is what it is) on a shrub branch (I think its an ornamental Ribes/currant shrub) in our front yard landscaping (see attached photo). I looked through your website and it looks as if it may be a praying mantis egg sac? I’d be curious what you think…thanks for any light you can shed on our front yard mystery critters. If it is a good critter, we want to watch it hatch. If it is a bad (e.g., invasive) critter, we may want to destroy or at least contain the hatchlings. Also, do you reply to e-mails, or do we need to visit WTB website (and look where for your response). Thanks!
Doug, Griffin & Eva

Hi Doug, Griffin and Eva,
We believe this is the Cocoon of a Cecropia Moth, but it is also possibly the cocoon of the closely related Columbia Silk Moth. Since we are only able to post a fraction of the letters we receive, we often send short responses first. We don’t even have the time to answer personally every letter we receive, but we try to answer as many as possible. Some questions are so vague, or images so blurry, that we just ignore them. When we post an answer, there is generally a more detailed response, and we email that to the querant, but sometimes we forget. In your case, you got a short answer originally, and now that we are posting letters from May 3, yours included, you are getting a second more detailed answer.

Letter 4 – Cecropia Moth Cocoon

 

What was that bug?
Hi Bugman !
I was recently visiting my folks in Maine, this cocoon(?) was in a maple tree in the yard. It is probably about 5 inches long. What do you think? Pondering in Portland,
Jim

Hi Jim,
This is a Cecropia Moth Cocoon. The small hole in the second photograph indicates that it may have been parasitized since it seems to small for the adult moth to have emerged.

Letter 5 – Cecropia Moth Caterpillar

 

Bugman
Can you help me identifie this worm? It and another one were found in a apple tree in Michigan. Thank you so much for any help.
John Warren

Hi John,
Your Cecropia Moth Caterpillar will become a large gorgeous Saturnid Moth.

Letter 6 – Cecropia Moth Caterpillar

 

found in georgian bay becomes large moth what is name?

This is a Cecropia Moth Caterpillar.

Letter 7 – Cecropia Moth Cocoon

 

picture of a chrysalis
here is a chrysalis I found in my back yard……does it contain a good or bad moth? Thanks for any reply
Roy

Hi Roy,
This is a Cecropia Moth Cocoon, a big beautiful Giant Silk Moth.

Letter 8 – Cecropia Moth Caterpillar

 

What kind of bug is this
I’m from Ontario, Canada. My son was walking along the grass when he found this caterpillar. We have no idea what kind it is. Wondering if anyone can put a name on it for us. Thank you
Erin & Graham

Hi Eric and Graham,
This is a Cecropia Moth Caterpillar, one of the Giant Silk Moths or Saturnid Moths.

Letter 9 – Cecropia Moth Caterpillar

 

whats this caterpillar?
Found this one eating dogwood tree leaves in our yard (in Maryland). What would it change into?
Wayne Hebert

Hi Wayne,
We love the forced perspective on your Cecropia Moth Caterpillar. We have photos of the adult Cecropia Moth on our Saturnid or Giant Silkmoth pages.

Letter 10 – Cecropia Moth Caterpillar

 

Cecropia Moth Caterpillar
Dear Bug Man,
My kids went out to ride their bikes and found this caterpillar crawling across the dirveway. I’ve been researching this for a bit and came across your site which let us know what this caterpillar was….or so we hope. It’s @ 4 inches long and @ 1 inch in diameter.
Here are some pics we took, June 2007.
Darryl, Ashton and Savanah McNabb
Brenham, TX

Hi Darryl, Ashton and Savanah,
Congratulations on your Cecropia Caterpillar sighting and its proper identification.

Letter 11 – Cecropia Moth Caterpillar

 

Caterpillar – large, green
July 28, 2009
Hi,
We spotted this fella eating away on our skip laurel bushes. It’s the end of July and we are in middle Tennessee. He/she is almost 4 inches long. Can you identify? Also, strange question but- could the critter’s waste possibly look like brown, segregated pellets? Those things are on several leaves beneath him and on the ground below. Thanks,
Thanks for your help, Karen
Middle Tennessee

Cecropia Moth Caterpillar
Cecropia Moth Caterpillar

Hi Karen,
Your caterpillar is a Cecropia Moth Caterpillar, one of the Giant Silk Moths.

Letter 12 – Cecropia Moth Caterpillar

 

CECROPIA MOTH CATERPILLAR
June 29, 2010
At the end of July, while at the park, we came across this HUGE catepillar on a weeping willow tree. We were all so amazed at it’s size as well as all of the brilliant, differents colors and patterns. We took a lot of pictures and came home and looked in our “Fun with Nature, Take-Along Guide” and we were amazed that we were able to identifiy it. It was soooo exciting for the children as well as their dad and I. We found out that it was a Cecropia Moth Caterpillar. Thought you might like to see some pictures. I must admit, I was a little frightened by the size of it, I did put my hand next to it to try to show the size, but I was afraid to go any closer!!!!
Always looking at nature, GSO, NC
In Greensboro, NC on a weeping willow tree

Cecropia Moth Caterpillar

Dear nature fans,
Thanks for taking the time to submit your photo of a Cecropia Moth Caterpillar.  It is the first we received this year.

Letter 13 – Cecropia Moth Caterpillar

 

A spiny caterpillar – possibly a species of silk moth?
July 3, 2010
Hiya,
I found two of these guys happily munching away on a single beach plum (prunus maritima) in my front yard in Newbury, MA. They are approximately 2 inches long at the moment. I’m thinking they are some sort of silk moth instar, but I can’t find anything quite like them in my books. So naturally – I turned to you folks. Ideas?
Michele
Newbury, Massachusetts

Cecropia Moth Caterpillar

Hi Michele,
Your caterpillar is most definitely one of the Giant Silkmoths.  It is the Cecropia Moth Caterpillar,
Hyalophora cecropia, and we find it hard to believe that it is not pictured in your identification guides.

Letter 14 – Cecropia Moth Caterpillar

 

Subject: Tomato worm?
Location: Eastlake ohio
July 26, 2013 6:32 pm
What are these? I’m thinking maybe a tomato worm
Signature: Kristy

Cecropia Moth Caterpillar
Cecropia Moth Caterpillar

Hi Kristi,
Tomato Hornworms would be found feeding on the leaves of tomatoes and related plants.  This Cecropia Moth Caterpillar is feeding on the leaves of a tree, possibly wild cherry, which is a listed food plant on BugGuide.

Letter 15 – Cecropia Moth ecloses in dead of winter!!!

 

Subject: what is this bug
Location: Port Huron MI
February 3, 2014 7:19 pm
Please help me identify this bug that came out of it’s cocoon today in Michigan, 2/3/14
Signature: Jennifer Beltramo

Cecropia Moth Eclosion
Cecropia Moth Eclosion

Dear Jennifer,
This is a Cecropia Moth.  Since it has just emerged or eclosed, the wings have not yet expanded to the full size.  You did not provide much information, so we are speculating that you found the cocoon in the fall and kept it to see what would emerge.  While we applaud your enthusiasm about the natural world, cocoons should not be kept indoors overwinter as the moths will most likely emerge too early to be released, and they will die without mating.  The Cecropia Moth is one of the Giant Silkmoths, and they only live a few days.  They do not eat as adults.

Thank you for the reply.  I actually took that picture from a friends facebook post.  They were quite shocked to see something living emerge from the cocoon and they actually just picked the cocoon up over the weekend covered in snow.  I can assure you, she won’t allow her children to do that ever again…scared the daylights out of her 🙂  She let her 5 year old take it in for show and tell they day I sent you the picture and when they came home from school, she just had it sitting on her kitchen counter, came back into the kitchen to see something wiggling its way out.
Thanks again for the quick reply!  We were just curious what it was.

Letter 16 – Cecropia Moth Cocoon

 

Subject: some kind of big egg sac or coccoon
Location: Perrysburg, Ohio
May 24, 2015 10:07 pm
Do you know what this is? It is about 5 inches in length. I found it under a railing on my deck. Should I be scared of it? It is right where my family sits and relaxes. I do not like to kill anything but I am very scared of spiders. I doubt it is a spider sac because of the texture of it.
Signature: FreddieAnitaBell

Cecropia Moth Cocoon
Cecropia Moth Cocoon

Dear FreddieAnitaBell,
This is the cocoon of a Cecropia Moth, and it passed the entire winter unnoticed on your deck railing.  Now that warm weather has arrived, the adult moth should emerge soon, and if you are vigilant and lucky, you may get to witness the Cecropia Moth that emerges.

Letter 17 – Cecropia Moth Caterpillar

 

Subject: Caterpillars
Location: Minnesota
August 9, 2015 8:42 pm
Found this on our Apple tree her in Minnesota. He was munching on a leaf. It was a little fatter than my thumb and about 3 inches long.
Signature: Cindy

Cecropia Caterpillar
Cecropia Caterpillar

Hi Cindy,
This is a Cecropia Moth Caterpillar, and according to BugGuide:  “Larvae feed on leaves of various trees and shrubs including alder, apple, ash, beech, birch, box-elder, cherry, dogwood, elm, gooseberry, maple, plum, poplar, white oak, willow.  may also feed on lilac and tamarack.”  The adult Cecropia Moth is a magnificent creature.

Letter 18 – Cecropia Moth Caterpillar

 

Subject: Catapillar
Location: South central New York state
August 14, 2015 8:19 am
Found crawling up th side of a house. 5 inches long and 1 inch wide. Beautiful yellow and blue spikes.
Signature: Bart

Cecropia Moth Caterpillar
Cecropia Moth Caterpillar

Dear Bart,
This beauty is a Cecropia Moth Caterpillar, and many folks would argue that the adult Cecropia Moth is even lovelier.

Letter 19 – Cecropia Moth Caterpillar

 

Subject: what is this?
Location: Putnam, CT 06260
August 26, 2015 1:20 pm
We found 2 of these caterpillars today (August 26,2015) in Putnam, CT while we were trimming bushes. The crew is very curious what they are as none of us had ever seen anything like it before. Each one was about 5 inches long and they were eating a vine-like weed growing inside a forsythia bush. We found them between 11:00 AM and 1:00PM.
Everyone also wanted to know if they were poisonous. It looks like there are barbs or stingers on the body, guessing for protection?
Thank you do your help! Hope to hear back from you.
Signature:  Steve Gallant and The Crew at Eclipse Landscaping

Cecropia Moth Caterpillar
Cecropia Moth Caterpillar

Dear Steve and Crew,
Your impressive caterpillars are Cecropia Moth Caterpillars, and the fleshy protuberances are not barbs or stingers.  Cecropia Moth Caterpillars pose no threat to humans.  Your large individuals have probably attained maximum growth and they will soon spin a cocoon and molt into a pupa that will overwinter, with the adult Cecropia Moth emerging next spring.  We are very curious what vine they were feeding upon, because according to BugGuide:  “Larvae feed on leaves of various trees and shrubs including alder, apple, ash, beech, birch, box-elder, cherry, dogwood, elm, gooseberry, maple, plum, poplar, white oak, willow. may also feed on lilac and tamarack.”

Cecropia Moth Caterpillar
Cecropia Moth Caterpillar

 

Letter 20 – Cecropia Moth Cocoon

 

Subject: Large Cocoon
Location: Delaware Ontario Canada
October 16, 2015 5:29 am
We found this large cocoon attached to our wood fence on Oct. 15th 2015. It appeared almost overnight. We are thinking it is some kind of moth, but would like to know more. We did have a hummingbird hawk moth in the garden this summer (picture 2) Any idea what this cocoon might be?
Signature: Lori L.

Cecropia Moth Cocoon
Cecropia Moth Cocoon

Dear Lori,
Hawkmoths do not spin a cocoon and they pupate underground.  This is the cocoon of a Cecropia Moth, and if you are lucky, you will see the emergence of the adult Cecropia Moth next spring.

Letter 21 – Cecropia Moth Caterpillar

 

Subject: Cecropia Caterpillar
Location: Middlebury, VT
May 3, 2017 2:19 pm
My grandson found this on our maple tree a few years ago and I thought you’d like to have the picture.
Signature: BrendaB

Cecropia Moth Caterpillar

Dear BrendaB,
We thought this was very early for a Cecropia Caterpillar sighting, especially in Vermont, and then we noticed your digital file is dated 2012.  We would expect to see Cecropia Moth Caterpillar late in the summer.

Oh yes!  I did say it was a few years ago.  I just think the picture is great, so I wanted to share.

And we agree that it is an awesome image, which is why we posted it.
We did not mean to seem dismissive.  We just wanted to inform our readers when to expect to see Cecropia Moth Caterpillars.

Thank you!  I am happy to know when to look for them as I haven’t seen one since 2012.  They seriously look like a Fisher Price toy.  Put a string on the front of it and it could be a pull toy.  J

 

Letter 22 – Cecropia Moth Caterpillar

 

Subject: Caterpillar?
Location: Buffalo, NY
August 20, 2017 10:47 am
Can you tell me what this is and is it harmful?
Thank you
Signature: Sue

Cecropia Moth Caterpillar

Dear Sue,
This impressive caterpillar is a Cecropia Moth Caterpillar.  It is perfectly harmless unless a morbid and irrational fear of the unknown causes a person who encounters one to flee, and run in front of a car.  Even the most benign creatures can be a contributing factor in the harming of a human being.   The caterpillar will eventually metamorphose into a gorgeous, and very large Cecropia Moth.

Letter 23 – Cecropia Moth Caterpillar

 

Subject:  Caterpillar
Geographic location of the bug:  Williamston, MI
Date: 07/21/2018
Time: 08:58 PM EDT
Your letter to the bugman:  Wanted to submit a photo for the Cecropia moth caterpillar
How you want your letter signed:  Steve W.

Cecropia Moth Caterpillar

Dear Steve,
Your image of a Cecropia Moth Caterpillar nicely illustrates many of the features that ensure correct species identification, and it is a great addition to our archives.

Letter 24 – Cecropia Moth Caterpillar

 

Subject:  Rainbow Spike Slug
Geographic location of the bug:  Heuvelton, NY
Your letter to the bugman:  WHAT IS THIS BUG?
How you want your letter signed:  Jo

Cecropia Moth Caterpillar

Dear Jo,
This is a Cecropia Moth Caterpillar.  It will spin a cocoon and eventually emerge as an adult Cecropia Moth, one of the largest North American moths.

THANK YOU SO MUCH!
Thank you oh so very much, and I hope this message makes you smile!
Jo

Authors

  • Daniel Marlos

    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.

4 thoughts on “Cecropia Moth Caterpillar Poisonous: Essential Facts Revealed”

  1. I found one under my apple tree in the fall. I put it in an aquarium where it made a cocoon and stayed the whole winter. On a breezy April day it emerged and I knew it was time to let him (or her) take flight. I was surprised at how much strength were in those wings as it took off up and over some large oak trees, not a single look back!

    Reply

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