The hickory horned devil, scientifically known as Citheronia regalis, is a remarkably large caterpillar with an intimidating appearance. Although this creature might seem threatening, it’s important to note that it is actually harmless to humans. Found commonly feeding on leaves of walnut, hickory, pecan, persimmon, and sweet gum trees, these sizable caterpillars are intriguing subjects worth exploring.
Before growing into regal moths, hickory horned devils go through multiple stages of growth and molt. As gigantic blue-green caterpillars, they come with long, black-tipped spines and curved orange horns, which might lead one to worry about the possibility of poisoning. However, these fascinating insects should not be avoided out of fear; instead, we can appreciate this unique species from a safe distance, observing all it has to offer.
Hickory Horned Devil: General Overview
Identification and Appearance
The hickory horned devil, or Citheronia regalis, is a large and colorful caterpillar often seen in North America. Despite its intimidating appearance, it is harmless. The caterpillar has:
- Turquoise-blue body
- Black spines on each segment
- Horn-like structures on the second and third thoracic segments that are orange with black tips
These distinctive features make it easy to identify the hickory horned devil.
Habitat and Distribution
The hickory horned devil can be found primarily in the eastern United States, ranging from the south up to southern Massachusetts. Its habitat mainly includes:
- Walnut trees
- Hickory trees
- Persimmon trees
- Sycamore trees
- Ash trees
The caterpillar feeds on the leaves of these trees during the summer months. It later transforms into the royal walnut moth, a nocturnal creature rarely seen due to its nighttime habits. The moth mates and lays eggs in these regions, and the larvae grow into the hickory horned devils to continue the life cycle.
Life Cycle and Behavior
From Caterpillar to Moth
The hickory horned devil (Citheronia regalis) starts its life as a tiny caterpillar hatched from an egg laid by a regal moth. Over several weeks, it grows and molts through different instars, eventually reaching a mature size of approximately 5.5 inches (14 cm) long1. Despite its ferocious appearance, the hickory horned devil is harmless, with non-poisonous spines2. When ready to pupate, the caterpillar leaves its host plant and finds a suitable spot in the soil to create an earthen chamber3.
Within this chamber, the caterpillar transforms into a pupa. After a period of around nine months, the regal moth emerges from the pupae, signaling the end of the life cycle4. Adult moths are nocturnal and not commonly seen.
Feeding Habits and Host Plants
Throughout its life as a caterpillar, the hickory horned devil feeds on various tree leaves:
These host plants provide nourishment for the larvae, sustaining them through their growth and development8. The adult moths, on the other hand, do not feed at all9.
.Characteristics of Hickory Horned Devil and Regal Moth
| Hickory Horned Devil (Caterpillar) | Regal Moth (Adult) |
|---|---|
| Non-poisonous, harmless spines2 | Nocturnal, rarely seen10 |
| Feeds on tree leaves8 | Does not feed9 |
| Creates an earthen chamber3 | N/A |
Is the Hickory Horned Devil Poisonous?
Physical Features and Toxicity
The hickory horned devil (Citheronia regalis) is a large caterpillar with a striking appearance. Some of its distinct features include:
- Pea green to blue-green body
- 4 to 5 inches in length
- Two pairs of yellow to orange curved horns
- Paired rows of spines down the back
Despite its fierce appearance, the hickory horned devil is harmless. It doesn’t produce any toxins and is not poisonous. The caterpillar typically feeds on the leaves of hickories, pecans, sweetgums, and sumac in deciduous forests.
Potential Threats to Humans
Although the hickory horned devil caterpillar may appear intimidating, it poses no real threat to humans. Its spines and horns are not venomous or harmful. In fact, the caterpillar is quite rare in the wild, minimizing the chances of human encounters.
Comparison between the harmless hickory horned devil and potentially dangerous caterpillars:
| Feature | Hickory Horned Devil | Potentially Dangerous Caterpillars |
|---|---|---|
| Size | Large (4 to 5 inches) | Varies (usually smaller) |
| Color | Pea green to blue-green | Varies (can overlap with hickory horned devil) |
| Spines/Horns | Yellow to orange curved horns; paired rows of spines | Can have urticating hairs or venomous spines |
| Toxicity | Not toxic or poisonous | Can cause skin irritation, rashes, or even systemic reactions |
In conclusion, the hickory horned devil caterpillar is an interesting and fascinating creature. Its unique appearance may lead many people to think it is dangerous, but in reality, it poses no real threat to humans.
Conservation and Population Status
Decline in Numbers
The hickory horned devil (Citheronia regalis) is a rare and unique creature. Due to factors like habitat loss and decreasing host plants availability, their numbers have been declining. Some specific threats include:
- Loss of hickory-type trees, pecans, buttonbush, filbert, and persimmon leaves
- Introduction of non-native predators
- Human disturbance
Efforts to Protect Hickory Horned Devils
There are various actions we can take to help conserve the hickory horned devil population. Some examples are:
- Protect and conserve their natural habitats, specifically in New England and New Jersey
- Plant more host trees on which they feed and lay their eggs
- Educate the public about these fascinating creatures and their importance in the ecosystem
Comparison Table: Hickory Horned Devil vs. Other Saturniidae Moths
| Feature | Hickory Horned Devil | Other Saturniidae Moths |
|---|---|---|
| Binomial Name | Citheronia regalis | Varies |
| Appearance | Large, green body, yellow markings, horn-like mouthparts | Varies, often vibrant colors and patterns |
| Host Trees | Hickory, pecans, buttonbush, filbert, persimmon | Varies, often specific trees |
| Natural Distribution | New England, New Jersey | Worldwide, depending on species |
Footnotes
- https://vtechworks.lib.vt.edu/bitstream/handle/10919/50295/ENTO-20.pdf ↩
- https://content.ces.ncsu.edu/hickory-horned-devil ↩ ↩2
- https://entnemdept.ufl.edu/creatures/bfly/regal_moth.htm ↩ ↩2
- https://content.ces.ncsu.edu/hickory-horned-devil ↩
- https://ct.gov/CAES/Plant-Pest-Handbook/pphH/Hickory ↩
- https://clemson.edu/what-is-it-wednesday-hickory-horned-devil-caterpillar ↩ ↩2
- https://entnemdept.ufl.edu/creatures/bfly/regal_moth.htm ↩ ↩2
- https://clemson.edu/what-is-it-wednesday-hickory-horned-devil-caterpillar ↩ ↩2
- https://entnemdept.ufl.edu/creatures/bfly/regal_moth.htm ↩ ↩2
- https://ct.gov/CAES/Plant-Pest-Handbook/pphH/Hickory ↩
7 Comments. Leave new
We found a female Royal walnut over 5 inches beautiful in a industrial park on a door we brought home to set free around trees before we could she layed eggs not sure what we should do now appreciate any help. The Browns. Toms river NJ
Place the eggs near a viable food source, preferably walnut or hickory, though BugGuide lists additional acceptable food plants: “Larvae feed on leaves of ash, burning bush, butternut, cotton, gum, hickory, lilac, pecan, persimmon, sumac, sycamore, and walnut.” The eggs should hatch within a week, and you can try transferring the newly hatched caterpillars to a food plant instead of trying to transfer the eggs.
I found one today on the sidewalk near my flower garden – Middle Tennessee; city of Lebanon. I have photos and a few measurements – it is huge!
You may submit images by using the Ask What’s That Bug? link on our site.
I have a Regal Moth right now.. Just found it. It was hanging tight on tiny tomato start plant on my front porch. I brought it in until tonight then I’ll put it out on the hickory tree just outside my front door and let it go.. Don’t want it eaten until it’s found a mate. It’s Gorgeous and HUGE!!
Found a beautiful walnut moth here, in Dayton Virginia, today: 7/2022
Took photos
Momma royal walnut laid eggs last year on my porch. We raised the catapillar and overwintered the pupas. Hatching they flew away. Now i think one came back “home” to lay her eggs. Is it possible that they have memory of where they had plentiful food supply ( we fed them fresh leaves every day! Lots of work) and come back to leave there offspring??
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