Hickory Horned Devil: A Close Encounter with a Giant Caterpillar

The Hickory Horned Devil is a fascinating creature that you should know about. Known as the largest caterpillar in North America, this insect is the larval stage of the Regal Moth, scientifically named Citheronia regalis. Despite their alarming appearance, Hickory Horned Devils are actually harmless creatures.

You’ll most likely find these striking caterpillars feasting upon the leaves of various trees, such as walnut, hickory, pecan, persimmon, and sweet gum trees. They have a unique appearance, with their blue-green color and two pairs of yellow to orange curved horns just behind the head, as well as paired rows of spines down their back.

As the caterpillar matures, it can grow up to 12.5 to 14 cm in length, or about the size of a large hot dog. Their fascinating appearance and biological traits are what make the Hickory Horned Devil an intriguing species to learn about.

Hickory Horned Devil: Origins and Habitat

First Discovery and Classification

The Hickory Horned Devil (Citheronia regalis) was first discovered and classified in 1793. It is known for its impressive size and ferocious appearance. However, despite its intimidating looks, it is a harmless caterpillar.

Geographical Range

The Hickory Horned Devil can be found in various locations across North America such as:

  • Eastern United States
  • Central Florida
  • East Texas
  • Eastern Texas
  • Southeastern United States

The range also extends from Massachusetts and New Jersey down to Florida, reaching as far west as Texas and possibly extending into Mexico.

Habitat: These caterpillars are commonly found in areas where:

  • Hickory trees or walnut trees are present
  • Eastern hardwood forests are dominant.

Notable characteristics:

  • Caterpillars can grow up to 5.5 inches (14 cm) in length
  • They have a blue-green or pea green color
  • Their body has long, curved orange horns with black tips.

Examples of their preferred host trees are various species of hickory and walnut.

Physical Characteristics and Life Cycle

Distinctive Appearance

The hickory horned devil, Citheronia regalis, is a large caterpillar with a vivid appearance. Its color ranges from pea green to blue-green, and its back is adorned with rows of spines and two pairs of yellow or orange horns right behind its head [1]. The adult moth, called a regal moth, has impressive orange wings with narrow yellow bands and can have a wingspan of around 6 inches [2].

Some features include:

  • Pea green to blue-green color
  • Rows of spines and horns on back
  • Large size

Stages of Development

The life cycle of the hickory horned devil starts with eggs [1]. Once hatched, the caterpillar goes through several larval stages, growing and molting before reaching its full size of up to 5 inches long [3]. The larval stage lasts around 4-6 weeks [4].

Next, the caterpillar enters the pupation stage and forms a cocoon underground [4]. Pupation can last from 9 months up to two years, with some delaying emergence as an extra year insurance policy against catastrophes that can affect their generation [4].

Mating and Reproduction

After the pupation period, the adult regal moth emerges with its beautiful wings [2]. The adult stage is brief and primarily focused on mating and reproduction. Regal moths are nocturnal and therefore rarely seen [5].

Once mating has occurred, the female moth lays hundreds of eggs on the leaves of host trees like walnut, hickory, pecan, persimmon, and sweet gum [5]. The cycle then repeats as the eggs hatch into new hickory horned devil caterpillars.

Diet and Host Plants

Preferred Trees for Feeding

The Hickory Horned Devil, a caterpillar that eventually transforms into the Regal Moth, feeds on the leaves of various tree species. These caterpillars have a preference for:

Leaves and Nuts as Food Source

Leaves are the primary food source for Hickory Horned Devil caterpillars. They consume large quantities, enabling them to grow and molt several times before reaching their full size. This diet consists mainly of leaves from the preferred trees mentioned above, such as walnut, hickory, and pecan trees, along with persimmon and sweet gum source. Though nuts can also be found in some of these trees, the caterpillars do not consume them.

Comparison Table: Hickory Horned Devil’s Preferred Trees

Tree Genus Leaves as Food Source Nuts as Food Source
Walnut Juglans Yes No
Hickory Carya Yes No
Pecan Carya Yes No
Persimmon Diospyros Yes No
Sweet gum Liquidambar Yes No

These caterpillars play an essential ecological role by feeding on the leaves of these trees and causing them to shed earlier, which can help with the overall health and growth of the host plants. On the other hand, infestations can lead to defoliation and stress the trees. However, these caterpillars rarely reach population levels high enough to cause significant damage source.

Behavior and Interactions

Defensive Mechanisms and Deceptions

The Hickory Horned Devil (Citheronia regalis) is a unique species of moth native to North America. As the largest caterpillar in East Texas, some people might mistake it for a tiny dragon due to its appearance. Though it might appear ferocious, the hickory horned devil is actually harmless. Its spikes and large size serve as deceptive features to ward off potential predators:

  • Spikes: Present along the caterpillar’s body, these spikes may appear dangerous but are not toxic or poisonous.
  • Size: Its size, often compared to a large hot dog, can intimidate predators such as birds and snakes.
  • Coloration: The caterpillar has yellow spots that stand out against its green body, making it look more threatening.

Role in the Ecosystem

The hickory horned devil plays a crucial role in the ecosystem. As a caterpillar, it feeds on the leaves of walnut, hickory, pecan, persimmon, and sweet gum trees, helping control these plant species’ growth. It also serves as a food source for predators such as birds and snakes, despite its deceptive appearance. When it matures, the horned devil goes through a metamorphosis into the less commonly seen regal moth which is nocturnal. Additionally, since the adult moth has no functional mouthparts, it relies on the energy it stored as a caterpillar to sustain itself as it searches for a mate using pheromones with limited time.

Here’s a comparison between the hickory horned devil caterpillar and regal moth:

Feature Hickory Horned Devil Caterpillar Regal Moth
Size 12.5 to 14 cm Smaller than larvae
Colour Green with yellow spots Orange with yellow bands
Food Tree leaves Doesn’t consume food
Activity pattern Daytime Nocturnal

In short, the hickory horned devil is an important part of the ecosystem, providing a unique role as both a plant regulator and a food source for other species. Its deceptive appearance helps ensure its survival, allowing it to grow into the regal moth and contribute to its overall lifecycle.

Conservation Status and Human Impact

Threats and Challenges

The hickory horned devil, or Citheronia regalis, is a large caterpillar that turns into the regal moth, also known as the royal walnut moth. These insects live in deciduous forests and are drawn to:

  • Walnuts
  • Pecans
  • Buttonbush
  • Filbert
  • Persimmon leaves

They largely feed on leaves and meal from the mentioned plants. Although they are not considered rare, they face a few challenges:

  1. Destruction of their natural habitat
  2. Climate change
  3. Predators, like the cecropia moth

Importance and Protection

The hickory horned devil plays a vital role in their ecosystem. They are important for:

  • Plant pollination
  • Serving as a food source for other species

Protection efforts for these creatures are also important because they help maintain a balanced ecosystem. Regulated hunting and wildlife conservation efforts, such as the North American Model of Wildlife Conservation, focus on long-term management that benefits a wide range of species, including the hickory horned devil.

Preserving their natural habitats and implementing adaptive resource management processes are crucial steps for ensuring their survival. By protecting and conserving these insects, we contribute to the overall health and balance of their ecosystems.

Authors

    by
  • 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.

  • 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.

26 thoughts on “Hickory Horned Devil: A Close Encounter with a Giant Caterpillar”

  1. i just found one of these in my backyard today. got curious and had to show my son, and we did some searching and found out what it was. thought it was poisonous and thank god its not. how do i post a picture of it on here? thanks, robin

    Reply
  2. I found something that looks exactly like the pupae in your picture in my garden a few weeks ago but I live in the northwest corner of Washington. I put it in a plastic container with some soil and plant roots so that I could look it up but I didn’t get around to it. Now, at least three or four weeks later I have a winged insect in the container. It’s furry with clear wings and is mostly black. However, it has white shoulders and a white stripe at it’s mouth. It also has a gray triangle on it’s back, just below the shoulders, lighter gray stripes a little below that, and two white spots at the end of it’s abdomen. It’s eyes look to be a very dark red or black and it has a thick proboscis. If anyone could help me identify it, I’d appreciate it.

    Reply
  3. The weirdest thing happened today. the cat caught a chippie and brought it in to the garage where we were sitting and dropped it on the floor. she cuffed it a few times but it was dead so she walked away and left it. about 5 mins later I got up to get rid of it and there was a black thing about an inch long moving on the floor, I believe it was some sort of pupas. it was alive and I couldn’t figure out where it came from. it was slowly moving away from the chippie. I went into the house for a few minutes and when I came out there was another one on the floor and it was moving too. so I looked at the chippie and there was another one coming out of her birth canal. that is the strangest thing I’ve ever seen. they were not baby chippies they were black and rigged. I looked it up on the internet trying to figure out if those things can grow inside an animal. didn’t come up with much. one site was talking about a ‘host’ for pupas but they really didn’t detail it enough so I could figure out if this happens to animals. maybe the chippie ate something that had pupas eggs and they grew inside of it. don’t know. they were black and more ridges, about 3/4′ to 1′ too.
    they looked like this but were black and more ridges, about that size too. tried to attach a picture but i couldn’t past it into this comment.

    Reply
  4. The weirdest thing happened today. the cat caught a chippie and brought it in to the garage where we were sitting and dropped it on the floor. she cuffed it a few times but it was dead so she walked away and left it. about 5 mins later I got up to get rid of it and there was a black thing about an inch long moving on the floor, I believe it was some sort of pupas. it was alive and I couldn’t figure out where it came from. it was slowly moving away from the chippie. I went into the house for a few minutes and when I came out there was another one on the floor and it was moving too. so I looked at the chippie and there was another one coming out of her birth canal. that is the strangest thing I’ve ever seen. they were not baby chippies they were black and rigged. I looked it up on the internet trying to figure out if those things can grow inside an animal. didn’t come up with much. one site was talking about a ‘host’ for pupas but they really didn’t detail it enough so I could figure out if this happens to animals. maybe the chippie ate something that had pupas eggs and they grew inside of it. don’t know. they were black and more ridges, about 3/4′ to 1′ too.
    they looked like this but were black and more ridges, about that size too. tried to attach a picture but i couldn’t past it into this comment.

    Reply
  5. I LOVE YOUR PICTURES. THEY ARE SO COOL. I’M ELEVEN YEARS OLD AND I GOT TO TOUCH A HICORY HORNED DEVIL IN CLASS. I WAS THE ONLY ONE WHO TOUCHED IT AND WAS WILLING TO TOUCH IT WITHOUT FREAKING OUT. I MADE A WEBSIT WITH THIS TEXT BOX AND MORE AS WELL[FORM] GO TO K&S PRODUCTIONS.HTML

    Reply
  6. found one today in my yard in Mechanicsville Virginia. It is extremely hot today. I have no garden and no idea where he came from. He was HUGE.

    Reply
  7. My husband just found a horn devil today. He was about 6″ long and as big around as a quarter! He is beautiful but bugs just creap me out. Lol. Do we need to worry about him causing problems wirh our trees?

    Reply
  8. Thank You for info…
    do you know how to tell the
    Guy from the girl ?
    He was gone this morning I hope it was because his wings were good to go and not something got him. Yes saying him is better to me then it. I was lucky enough to get pictures ๐Ÿ™‚ but did not know how to post here.
    Anyway I just thought he was very pretty ….But sad to know they go through so much and only live a week after they get their wings and can’t eat. ๐Ÿ™
    OOP running off again with the mouth sorry !
    Thanks for reply Again !

    Reply

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