STEMAcademiaAgriculture & FarmingHumanitiesSocial Sciences

Hickory Horned Devil Caterpillars: Ferocious Looking, but Harmless

Updated on September 12, 2017
Casey White profile image

Although Mike's interest in insects is mainly in photographing them, Dorothy loves sharing with readers her in-depth research on them.

Hickory horned devil caterpillar.  Chickens...be afraid...very afraid.
Hickory horned devil caterpillar. Chickens...be afraid...very afraid. | Source

Nothing to Fear

Wow! Hickory horned devil caterpillars have really got their bluff in on everyone, including chickens that normally eat caterpillars! They are huge and look like they could swallow a mouse for lunch, but although their looks scream "get away...run," they are just some big, old harmless babies that wouldn't hurt a flea. They are usually about 5-6 inches long, so you can see why a chicken might be a little nervous tackling one of them.

This big, ugly sucker, however, will eventually turn into a large, colorful regal (or royal walnut) moth.

Even those scary, long red horns with black tips don't sting; it's all a ruse. These bright green caterpillars are actually pretty easy to handle, so when you see one, go ahead and pick him up, you'll be just fine.

Their large size and fierce look are what keep chickens from eating hickory horned devil caterpillars. Their scary-looking appearance allows them to become beautiful regal moths.
Their large size and fierce look are what keep chickens from eating hickory horned devil caterpillars. Their scary-looking appearance allows them to become beautiful regal moths. | Source

They Burrow Instead of Spin

The hickory horned devil caterpillar differs from most other caterpillars that spin a cocoon. Instead, they actually burrow down into the ground to transform into an adult moth. In fact, you are unlikely to see one of these caterpillars until he climbs down out of a tree looking for a site for pupation. If you do see one of them on the pavement or any other area where burrowing would be difficult, you can help it out by picking it up and moving it to an area where the soil is soft enough for burrowing.

Did We Mention That They Are Large?

As you can see, a hickory horned devil caterpillar is huge, but it also has predators, which include birds (they are the primary food source for many birds), ladybird beetles, yellow jackets and human beings.
As you can see, a hickory horned devil caterpillar is huge, but it also has predators, which include birds (they are the primary food source for many birds), ladybird beetles, yellow jackets and human beings.
But, so is the regal moth with a wingspan of 4-6 inches (and, females are larger than males).  They are common southward but rare northward. It is regarded as a threatened species in some areas.
But, so is the regal moth with a wingspan of 4-6 inches (and, females are larger than males). They are common southward but rare northward. It is regarded as a threatened species in some areas.

Hickory Horned Devils Love Shade Trees

Some of the trees these caterpillars like to hang out in include hickory, ash, persimmon, sweetgum, sycamore and walnut. And, even though a hickory horned devil caterpillar will eat the leaves of shade trees, usually the damage is minimal because their numbers are small.

When regal moths emerge from the soil during the summer, they mate and a female moth will spend most of her remaining life laying eggs, depositing them on leaves in clusters. It takes the eggs about 15-16 days to hatch, starting the four larval stages - embryo, larva, pupa and imago. In the final stages, these caterpillars have voracious appetites.

If you disturb a hickory horned devil caterpillar, it will throw its body from side to side trying to scare you away, but it is all an act and they really are harmless. In late summer to early fall, the caterpillar will burrow into the soil to pupate and overwinter. Most will remain as pupae for a little less than a year, although others take almost two years to turn into moths.

Populations of these caterpillars appear to be declining and they are generally not considered a pest. They can survive a very moderate frost and will continue to feed as it gets warmer, but because there are so few of them, no pest control is recommended.

Calling the hickory horned devil a large caterpillar may be an understatement, as you can see in this photograph, but their appearance makes a human one of their major predators because they don't understand that they are not dangerous.
Calling the hickory horned devil a large caterpillar may be an understatement, as you can see in this photograph, but their appearance makes a human one of their major predators because they don't understand that they are not dangerous.

Taxonomic Rank

In case you wondered about the taxonomic rank of the hickory horned devil caterpillar:

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Subphylum: Atelocerata
  • Class: Hexapoda (including Insecta)
  • Infraclass: Neoptera
  • Subclass: Pterygota
  • Order: Lepidoptera
  • Superfamily: Bombycoidea
  • Family: Saturniidae
  • Subfamily: Ceratocampinae
  • Genus: Citheronia
  • Subject: Citheronia regalis (Fabricius)

© 2017 Mike and Dorothy McKenney

Comments

    0 of 8192 characters used
    Post Comment

    • Casey White profile image
      Author

      Mike and Dorothy McKenney 2 months ago from United States

      You are absolutely right about them, and I agree whole-heartedly with the chickens. I'm going to research the Jerusalem Cricket...might be a story in that (one to tell around campfires late at night) ewwwwwww.

    • profile image

      Tamara Moore 2 months ago

      Ugh! Not your post! Your post is fascinating! I'm talking about this evil looking "thing"! This...caterpillar. It has fangs! And, it's huge! It's disgusting. And it throws its body around, too, like in the Exorcist movie! I hope they don't live near me.

      Have you heard of the Jerusalem Cricket? They scare me so bad and my cat once brought one into the house, and I grabbed my purse, keys, and dog, and left! I am terrified of them. If you ever write an article about these orange and black striped horrors, please get my immediate attention as I will want to read about them!

      Thank you for this article, (and, pictures...ugh!)...great job..LOL. You should categorize this under "Dark Poetry".

      Hugsssssss,

      Tamara

    • Mamerto profile image

      Mamerto I Relativo Jr 2 months ago from Cabuyao

      Fascinating creatures! I mean they remind me of a real life Pokémon, or a miniature alien creature. I wished we have one in our backyard and backwoods.