Currently viewing the category: "Hickory Horned Devil"
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Strange caterpillar or what?
Location: Ellicott City, MD
October 20, 2011 9:19 pm
I’ve tried to look through your photos of caterpillars to identify this one. We took this picture this past August while hiking at a local state park, next to the river. I can’t seem to look through very many of your pictures because they creep me out, much like this one did! It is neat at the same time though and I would like to find out what it really is. It was pretty large as you can see, next to my 7 year old’s shoe. We didn’t want to get too close as it was moving across the rock. Thanks for any information you can give me!
Signature: Tracey

Hickory Horned Devil

Dear Tracey,
You had the good fortune to observe the largest caterpillar in North America, the Hickory Horned Devil.  Though your sighting is two months old, we have decided to post it anyways since the last Hickory Horned Devil sightings might still occur, though most of our sightings are in August and September.  We did not receive as many sightings this past year as we have previously.

Hickory Horned Devil

What's That Bug? does not endorse extermination

whats this bug???
Location: odenville,al just n.e. of birmingham,al
September 17, 2011 1:15 pm
This bug was in my yard in odenville,al….
Signature: just wondering paw pawo

Hickory Horned Devil

Dear paw pawo,
The Hickory Horned Devil is North America’s largest caterpillar, and it is also probably the most unforgettable looking.  Despite its large size, frightening appearance, and diabolical name, it is perfectly harmless.

What's That Bug? does not endorse extermination

crazy creature?
Location: ohio, united states
August 12, 2011 9:12 am
can you tell me what kind of creature this is? we found it at work the other day, and maybe what it eats?? thanks.
Signature: christy

Hickory Horned Devil

Hi Christy,
We thought this might be an earlier instar of a Hickory Horned Devil, but according to BugGuide, it is a chocolate brown form of the typically green giant caterpillar.  We still believe your caterpillar will continue to grow and eventually turn green.  BugGuide states:  “Larvae feed on leaves of ash, burning bush, butternut, cotton, gum, hickory, lilac, pecan, persimmon, sumac, sycamore, and walnut.”

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Crazy Caterpillar
Location: Plant City, FL
August 1, 2011 8:49 am
Dear Bugman,
My cousin and I were out touring Dinosaur World when we saw this massive and ornately decorated caterpillar. We thought it was so exotic looking and were wondering what it was called and what kind of butterfly it will eventually turn into?
Signature: Trini & Amii

Hickory Horned Devil

Dear Trini and Amii,
This is a Hickory Horned Devil, and it will metamorphose into a Royal Walnut Moth.

What's That Bug? does not endorse extermination

Could u help me with this bug please?
Location: Bradstown ky
July 29, 2011 11:49 am
My friend found this caterpillar by the creek in our back yard. The closets thing i can find in your section is the Hickory Horned Devil? I am going to try to keep it and watch it transform but need to know what it is and how to take care of it.
Signature: Sue

Pre-Pupal Hickory Horned Devil

Hi Sue,
You are correct.  This is a Hickory Horned Devil, and it is pre-pupal, meaning it is about to pupate.  Hickory Horned Devils pupate underground.  For some reason, this individual did not bury itself.  You can put it in a container with loose earth and lightly bury it.  You will need to keep it from drying out, but the earth should not get soggy.  An adult moth should emerge next June or July.  You should keep it in a sheltered place over the winter that does not get too warm, like an unheated porch or garage.

What's That Bug? does not endorse extermination

LARGE Caterpillar found in Ozark, Missouri
Location: Ozark, MO (southwest Missouri)
July 21, 2011 10:39 pm
Can you identify this large dark/bronze/copper/brown colored caterpillar? We found it in early July in my flower bed, not far from my Walnut tree. It was about 3 inches long. We saw no others before or since. I’ve lived here 12 years and have never seen such a creature! In the photos, you can see the ”horns” and the tufts of ”hair”. It has a black ”band” across it’s head. Also, what Moth or Butterfly will it become?
Signature: ~Susi M.

Hickory Horned Devil

Hi Susi,
Your large caterpillar, a Hickory Horned Devil, will nearly double in size and change color from brown to aqua-green as it progresses through metamorphosis to become the largest North American Caterpillar.  We received our first Hickory Horned Devil sighting of 2011 a few weeks back and we have been getting numerous reports of the adult Royal Walnut Moths this summer, which makes us believe that there will be even more mature caterpillar sightings in August and September.  Folks don’t usually notice the Hickory Horned Devil until the caterpillars have grown to full size and  then climb from the trees to crawl upon the ground in search of a suitable location to dig beneath the surface where pupation occurs.  Walnut and Hickory, which provide the common names for the moth and its caterpillar, are just a few of the trees that serve as a host for the caterpillar.  Others include sumac and persimmon.  The adult Royal Walnut Moth, like other Giant Silk Moths, does not feed as an adult.  Adults live long enough to mate and lay eggs.  BugGuide has a nice series of images of various instars of the Hickory Horned Devil.  The fully grown caterpillar with its bright coloration and striking horns is often likened to a Chinese dragon.

Daniel,
Thank you SO much for replying so QUICKLY!! We found a very large moth last night fluttering against a rock wall here, put it in a jar and by morning it had laid numerous eggs! We think it may be the Royal Walnut Moth from our Hickory Horned Devil Caterpillar you identified! I will take photos and send them to you to be sure. It doesn’t look exactly like the other Royal Walnut Moths I’ve seen photos of at the Bug Guide link you sent me, but it may be one of them. I’ve lived here many years and have never seen these caterpillars near any walnut trees in this area. Where are they normally from? And why would they be appearing here all of a sudden? Thanks again.
~Susi Meredith
Ozark, Missouri

Hi again Susi,
Just because you didn’t notice any Hickory Horned Devils does not mean they were not present.  Even though they are large, they could easily escape notice in a large tree.  Since the adult moths fly, they are capable of increasing their range to places where there is available food.  Perhaps you are part of a natural range expansion.

What's That Bug? does not endorse extermination