Hickory Horned Devil
Entomologist Dr. Art Evans and VPM radio producer Steve Clark discuss the remarkable hickory horned devil, a caterpillar that develops into the regal moth, one of North America’s largest insects.
Dr. Arthur V. Evans teams up with VPM Radio producer Steve Clark for a weekly feature, “What’s Bugging You?,” which airs during NPR’s Morning Edition. The program takes its name from another of Evans’ books “What’s Bugging You – A Fond Look at the Animals We Love to Hate.”
Tune in each Tuesday at 8:45 a.m. or at 5:44 p.m. on VPM News
Steve Clark: I'm Steve Clark with Dr. Art Evans, entomologist, and this is What’s Bugging You.
Art Evans: So what's the largest caterpillar you've ever seen?
Clark: I think it was probably a tobacco horn worm.
Evans: Oh sure, yeah, they’re about three inches long, maybe as big around as your finger or my finger. This is great radio. We're looking at fingers right now, with a horn on the end. But nope, that one pales in comparison to the one that my neighbor, Jean Hollings, found the other day.
Clark: What did she find?
Evans: The hickory horned devil.
Clark: [laughing] That's an intimidating sound.
Evans: Oh, the name of it alone should tell you something is up. But this caterpillar is five inches long. It is the size of a hot dog, and it's bright green and it has orange horns behind its head. [laughing]
Clark: I've seen a picture. I didn't have any idea of the scale.
Evans: Oh they're, they’re amazing. I, I've seen a couple over the years, and I remember the first time that I saw one. I know they can't hurt you. With those spines it looks like they can sting. They sort of look like these orange dreadlocks, and they start thrashing their fore bodies around, whipping their heads around and, and just looking very menacing. And even though I knew that I can't get hurt, they don't bite, they don't sting, I kept jumping every time [laughing] it would, it would thrash about. But she took a lovely photograph of one, and I was so enamored with it that it inspired me to talk about it today and post it on my Facebook page.
Clark: So did you get to see the live worm?
Evans: I did not. I did not. They were on a day trip, and it was away, but you find them throughout Virginia. They feed on a wide variety of trees, including hickory, walnut and sweet gum.
Clark: So apparently from the name they really like hickory, and they have a horn, and they. . .
Evans: [laughing] They look like the devil.
Clark: And they look like the devil, yeah.
Evans: And the moths are spectacular. They're one of the largest, if not the largest moth in North America in terms of wingspan. They’re sort of a beautiful gray with fine orange stripes running through them and patches of yellow, very heavy-bodied. And they're often attracted to lights at night during the summer.
Clark: I think I have a video of one of those.
Evans: Oh, they’re, they're real eye-catching.
Clark: Eye popping, yes.
Evans: But this is a moth that's widespread through eastern North America, and it's something to keep an eye out for.
Clark: Is there something special about their life cycle?
Evans: Well, one of the things that I learned about them is they don't spin a cocoon like many other giant silk moths that the caterpillars wrap themselves up in a silken cocoon before they pupate inside. This one produces a pupa that's naked. There's no cocoon at all, and they bury themselves. The caterpillar digs a chamber in the soil before it pupates out of sight, and that's how they spend the winter. And then that moth will emerge in late-May or early-June. The caterpillars we're seeing in late summer are the second generation, and they will pupate in the ground, and that's where they'll spend the winter. We won't see them again until the following spring as adult moths.
Clark: Now I’d like to see a time lapse.
Evans: Mmmhmm, right.
Clark: Dr. Art Evans is a research associate at the Virginia Museum of Natural History. You’ll find photos, audio, and links to the museum and Art’s Facebook page at vpm.org/bugs.